Pixel driving circuit, display panel and display device

Abstract

The embodiment of the invention relates to a pixel driving circuit, a display panel and a display device. The circuit comprises a first switch unit, a second switch unit, a third switch unit, a data line, a scanning line, an energy storage capacitor and a light emitting unit. The control end of the first switch unit is connected with a scanning line, the signal input end is connected with a data line, and the signal output end is connected with the control end of the third switch unit; the control end of the second switch unit is connected with the data line, the signal input end is connected with the scanning line, and the signal output end is connected with the signal input end of the third switch unit; the signal output end of the third switch unit is connected with the light-emitting unit; one end of the energy storage capacitor is connected with the scanning line, and the other end is connected with the control end of the third switch unit. According to the embodiment of the invention, the energy storage capacitor drives the light-emitting diode to emit light, so that the problem that the light-emitting brightness is reduced line by line due to the fact that the power supply voltage drives multiple lines of light-emitting units is avoided, the light-emitting stability of the light-emitting units is improved, and the circuit structure is simplified.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a pixel driving circuit, a display panel and a display device. Background Art

[0002] In the existing light-emitting diode display array, the scan line corresponding to each row usually drives the row to receive the input data signal, and the data line corresponding to each column drives each light-emitting unit in a row to emit light of corresponding intensity. Assuming that the equivalent resistance value generated by the power supply line at each row of the scan line is the same, when scanning the first row, the power supply voltage is VDD at this time. When scanning to the second row, the power supply voltage changes from VDD of the previous row to VDD', VDD'=VDD-I*R, I is the current flowing into the light-emitting unit. It can be seen that when the screen size is larger and the number of scan rows is more, the power supply voltage of each row will decrease row by row, so that the driving current provided to the light-emitting unit will decrease row by row, which will affect the brightness of the entire screen display and cause uneven screen brightness. Summary of the invention

[0003] In view of this, in order to solve some or all of the above technical problems, the embodiments of the present application provide a pixel driving circuit, a display panel and a display device.

[0004] In a first aspect, an embodiment of the present application provides a pixel driving circuit, which includes: a first switch unit, a second switch unit, a third switch unit, a data line, a scan line, an energy storage capacitor and a light-emitting unit; the control end of the first switch unit is connected to the scan line, the signal input end of the first switch unit is connected to the data line, and the signal output end of the first switch unit is connected to the control end of the third switch unit; the control end of the second switch unit is connected to the data line, the signal input end of the second switch unit is connected to the scan line, and the signal output end of the second switch unit is connected to the signal input end of the third switch unit; the signal output end of the third switch unit is connected to the light-emitting unit; one end of the energy storage capacitor is connected to the scan line, and the other end is connected to the control end of the third switch unit.

[0005] In one possible embodiment, a scanning cycle of the scanning line includes a charging phase and a discharging phase. In the charging phase, the voltage difference between the scanning line and the data line drives the first switch unit to turn on and drives the second switch unit and the third switch unit to turn off; in the discharging phase, the voltage difference between the scanning line and the data line drives the first switch unit to turn off and drives the second switch unit and the third switch unit to turn on.

[0006] In a possible implementation manner, the turn-on voltages of the first switch unit and the second switch unit are the first voltage, the turn-on voltage of the third switch unit is the second voltage, and the polarities of the first voltage and the second voltage are opposite.

[0007] In a possible implementation manner, the first switch unit and the second switch unit are N-type field effect transistors, and the third switch unit is a P-type field effect transistor.

[0008] In one possible implementation, the voltage on the scan line is greater than the voltage on the data line, the first switch unit is turned on, and the second and third switch units are turned off; in the discharge phase, the voltage on the scan line is less than the voltage on the data line, the first switch unit is turned off, and the second and third switch units are turned on.

[0009] In a possible implementation manner, the first switch unit and the second switch unit are P-type field effect transistors, and the third switch unit is an N-type field effect transistor.

[0010] In one possible implementation, in the charging stage, the voltage on the scan line is lower than the voltage on the data line, the first switch unit is turned on, and the second and third switch units are turned off; in the discharging stage, the voltage on the scan line is higher than the voltage on the data line, the first switch unit is turned off, and the second and third switch units are turned on.

[0011] In a possible implementation, the light emitting unit is an organic light emitting diode, an anode of the organic light emitting diode is connected to the signal output end of the third switch unit, and a cathode of the organic light emitting diode is connected to the common voltage end.

[0012] In a second aspect, an embodiment of the present application provides a display panel, which includes: a scan driving module, a data driving module, a first preset number of scan lines, a second preset number of data lines and a pixel array; the scan driving module is connected to the first preset number of scan lines, and the data driving module is connected to the second preset number of data lines; each pixel in the pixel array is connected to the corresponding scan line and data line, and each pixel includes a first switch unit, a second switch unit and a third switch unit, an energy storage capacitor and a light-emitting unit, and constitutes the above-mentioned pixel driving circuit with the corresponding scan line and data line.

[0013] In a third aspect, an embodiment of the present application provides a display device, comprising: a display panel, a panel frame, a power module and a data receiving module as described in the second aspect above; the display panel is installed on the panel frame, the power supply end of the display panel is connected to the power module, and the signal receiving end of the display panel is connected to the data receiving module.

[0014] The pixel driving circuit, display panel and display device provided by the embodiment of the present application are provided with a first switch unit, a second switch unit and a third switch unit, an energy storage capacitor and a light emitting unit in a single pixel, wherein the control end of the first switch unit is connected to the scan line, the signal input end of the first switch unit is connected to the data line, and the signal output end of the first switch unit is connected to the control end of the third switch unit; the control end of the second switch unit is connected to the data line, the signal input end of the second switch unit is connected to the scan line, and the signal output end of the second switch unit is connected to the signal input end of the third switch unit; the signal output end of the third switch unit is connected to the light emitting unit; one end of the energy storage capacitor is connected to the scan line, and the other end is connected to the control end of the third switch unit; according to the voltage difference between the scan line and the data line, the first switch unit, the second switch unit and the third switch unit can be respectively controlled to be turned on and off; the voltage at both ends of the energy storage capacitor is related to the voltage on the scan line and the data line, and has nothing to do with the power supply voltage; the energy storage capacitor drives the light emitting diode to emit light, thereby avoiding the problem of the light emitting brightness decreasing row by row due to driving multiple rows of light emitting units by a unified power supply voltage, and improving the light emitting stability of the light emitting unit. In addition, there is no need to provide a separate power supply and wiring, which simplifies the circuit structure. . BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 A schematic diagram of the structure of a pixel driving circuit provided in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of the structure of another pixel driving circuit provided in an embodiment of the present application;

[0020] Figure 3 An exemplary schematic diagram of a voltage signal and a switch state provided in an embodiment of the present application;

[0021] Figure 4A schematic diagram of the structure of another pixel driving circuit provided in an embodiment of the present application;

[0022] Figure 5 An exemplary schematic diagram of another voltage signal and switch state provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of the structure of a display panel provided in an embodiment of the present application;

[0024] Figure 7 A schematic diagram of the structure of a display device provided in an embodiment of the present application.

[0025] Reference numerals:

[0026] 100-pixel driving circuit; 101-first switch unit; 102-second switch unit; 103-third switch unit; 104-data line; 105-scan line; 106-energy storage capacitor; light-emitting unit-107; 600-display panel; 601-scanning drive module; 602-data drive module; 603-a first preset number of scan lines; 604-a second preset number of data lines; 605-pixel array; 700-display device; 701-panel frame; 702-power module; 703-data receiving module. DETAILED DESCRIPTION

[0027] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the numerical expressions and the numerical values ​​described in these embodiments do not limit the scope of the present application.

[0028] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present application are only used to distinguish between different steps, devices, modules and other objects, and do not represent any specific technical meanings, nor do they indicate the logical order between them.

[0029] It should also be understood that in this embodiment, “plurality” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0030] It should also be understood that any component, data or structure mentioned in the embodiments of the present application can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0031] In addition, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0032] It should also be understood that the description of the various embodiments in this application focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced to each other, and for the sake of brevity, they will not be described one by one.

[0033] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0034] Technologies, circuits, and devices known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the above-mentioned technologies, circuits, and devices should be considered as part of the specification.

[0035] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. To facilitate the understanding of the embodiments of the present application, the present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] The existing scheme of using light-emitting diodes to form a pixel array usually includes two transistors T1 and T2 and a capacitor C. Among them, T1 is an addressing transistor (taking PMOS as an example). When the scanning signal (Sel) is at a low level L, T1 is turned on, and the data signal (Data) charges the capacitor C through T1; when sel is at a high level H, T1 is turned off. Since C has no discharge path, the capacitor C will retain the charge until the next time T1 is turned on. The charge stored in the capacitor C is directly connected across the gate source of the T2 driving transistor (taking PMOS as an example), which determines the current flowing through the source and drain of T2, and then determines the brightness of the light-emitting unit. Taking the OLED screen as an example, the driving current value is Wherein, μ is the mobility of the active layer, Cox is the capacitance between the gate and the active layer, W is the channel width of the light emitting diode, L is the channel length of the light emitting diode, Vdata is the data signal voltage, and VDD is the power supply voltage.

[0038] If R represents the equivalent resistance of the VDD power supply line at the scanning line, it is assumed that the equivalent resistance generated by the power supply line at each scanning line is the same. When scanning the first line, the power supply voltage is VDD at this time. When scanning to the second line, the power supply voltage changes from VDD of the previous line to VDD', VDD'=VDD-I oled *R. It can be seen that when the screen size is larger and the number of scanning lines is more, the power supply voltage of each line will decrease line by line, so that the driving current provided to the OLED will decrease line by line, which will in turn affect the brightness of the image displayed on the entire OLED screen.

[0039] In order to solve the problem that the driving current of the light-emitting unit decreases row by row due to the equivalent impedance of the power line, Figure 1 As shown, the embodiment of the present application provides a pixel driving circuit 100, which is generally applied to each pixel in a display panel. The circuit specifically includes: a first switch unit 101, a second switch unit 102, a third switch unit 103, a data line 104 (Data), a scan line 105 (Sel), an energy storage capacitor 106 and a light emitting unit 107.

[0040] The scan line 105 is used to control the on or off of the light emitting unit 107 in the circuit. The data line 104 is used to output a data signal voltage corresponding to a pixel in the current display image to the light emitting unit 107, and the voltage drives the light emitting unit 107 to emit light of corresponding brightness.

[0041] In this embodiment, the control end of the first switch unit 101 is connected to the scan line 105 , the signal input end of the first switch unit 101 is connected to the data line 104 , and the signal output end of the first switch unit 101 is connected to the control end of the third switch unit 103 .

[0042] The control end of the second switch unit 102 is connected to the data line 104 , the signal input end of the second switch unit 102 is connected to the scan line 105 , and the signal output end of the second switch unit 102 is connected to the signal input end of the third switch unit 103 .

[0043] The signal output terminal of the third switch unit 103 is connected to the light emitting unit 107 .

[0044] One end of the energy storage capacitor 106 is connected to the scan line 105 , and the other end is connected to the control end of the third switch unit 103 .

[0045] The first switch unit 101, the second switch unit 102, and the third switch unit 103 may be various types of controlled switch units, such as field effect transistors, triodes, etc. The voltage difference output by the scan line 105 and the data line 104 may control the on or off state of the first switch unit 101 and the second switch unit 102.

[0046] The energy storage capacitor 106 is used to charge the energy storage capacitor 106 by using the voltage difference between the scan line 105 and the data line 104 when the first switch unit 101 is adjusted to the on state and the second switch unit 102 and the third switch unit 103 are adjusted to the off state in one scanning cycle. Then, when the first switch unit 101 is adjusted to the off state and the second switch unit 102 is adjusted to the on state, the voltage across the energy storage capacitor 106 turns on the third switch unit 103, thereby discharging the energy storage capacitor 106 to drive the light emitting unit 107 to emit light.

[0047] Optionally, the light-emitting unit 107 is an organic light-emitting diode, the anode of the organic light-emitting diode is connected to the signal output end of the third switch unit 103, and the cathode of the organic light-emitting diode is connected to the common voltage end, so as to drive the pixels composed of the organic light-emitting diode and improve the display stability of the organic light-emitting diode.

[0048] The pixel driving circuit provided by the embodiment of the present application is provided with a first switch unit, a second switch unit and a third switch unit, an energy storage capacitor and a light-emitting unit in a single pixel, wherein the control end of the first switch unit is connected to the scan line, the signal input end of the first switch unit is connected to the data line, and the signal output end of the first switch unit is connected to the control end of the third switch unit; the control end of the second switch unit is connected to the data line, the signal input end of the second switch unit is connected to the scan line, and the signal output end of the second switch unit is connected to the signal input end of the third switch unit; the signal output end of the third switch unit is connected to the light-emitting unit; one end of the energy storage capacitor is connected to the scan line, and the other end is connected to the control end of the third switch unit; according to the voltage difference between the scan line and the data line, the conduction and cutoff of the first switch unit, the second switch unit and the third switch unit can be controlled respectively; the voltage at both ends of the energy storage capacitor is related to the voltage on the scan line and the data line, and has nothing to do with the power supply voltage; the light-emitting diode is driven by the energy storage capacitor to emit light, thereby avoiding the problem of the light brightness decreasing row by row due to driving multiple rows of light-emitting units by a unified power supply voltage, and improving the light-emitting stability of the light-emitting unit. And there is no need to provide a separate power supply and wiring, which simplifies the circuit structure. 。

[0049] In some optional implementations of the present embodiment, a scanning cycle of the scanning line 105 includes a charging phase and a discharging phase. In the charging phase, the voltage difference between the scanning line 105 and the data line 104 drives the first switch unit 101 to turn on, and drives the second switch unit 102 and the third switch unit 103 to turn off; in the discharging phase, the voltage difference between the scanning line 105 and the data line 104 drives the first switch unit 101 to turn off, and drives the second switch unit 102 and the third switch unit 103 to turn on.

[0050] Specifically, in the charging stage, the first switch unit 101 is turned on, the second switch unit 102 is turned off, the two ends of the energy storage capacitor 106 are connected to the scan line 105 and the data line 104, and the energy storage capacitor 106 is charged. The signal input end of the third switch unit 103 is in a high impedance state, so the third switch unit 103 is also turned off, and the light-emitting unit 107 has no current input and does not emit light.

[0051] In the discharge stage, the first switch unit 101 is turned off, the second switch unit 102 is turned on, and at the same time, the voltage across the energy storage capacitor 106 drives the third switch unit 103 to turn on, and the energy storage capacitor 106 discharges to the light emitting unit 107, driving the light emitting unit 107 to emit light.

[0052] This embodiment controls the on or off state of the first switch unit, the second switch unit and the third switch unit by changing the voltage difference between the scan line and the data line within a scan cycle, thereby achieving the light-emitting unit driven by the data line to emit light, avoiding the reduction of the current input to the light-emitting unit due to the equivalent resistance of the power supply.

[0053] In some optional implementations of this embodiment, the on-state voltage of the first switch unit 101 and the second switch unit 102 is a first voltage, the on-state voltage of the third switch unit 103 is a second voltage, and the polarities of the first voltage and the second voltage are opposite.

[0054] The first voltage is a voltage threshold for turning on the first switch unit 101 and the second switch unit 102, and the second voltage is a voltage threshold for turning on the third switch unit 103. For example, the first switch unit 101 and the second switch unit 102 are field effect transistors of the same type, and the polarity of their turn-on voltage Vth is the same, for example, Vth>0; the third switch unit 103 is a field effect transistor of another type, and the polarity of its turn-on voltage Vth is opposite to that of the first switch unit 101 and the second switch unit 102, for example, Vth<0.

[0055] In the charging stage, since the control terminals of the first switch unit 101 and the second switch unit 102 are connected to different voltage terminals, the control voltage polarities of the first switch unit 101 and the second switch unit 102 are opposite. For example, if the control voltage Vgs1 of the first switch unit 101 is greater than 0, the control voltage Vgs2 of the second switch unit 102 is less than 0, so the first switch unit 101 is turned on and the second switch unit 102 is turned off. The energy storage capacitor 106 is charged, and at the same time, the signal input terminal of the third switch unit 103 is in a high impedance state, and the third switch unit 103 is turned off.

[0056] In the discharge phase, the voltage outputted by the scanning line 105 changes, making the control voltage Vgs1 of the first switch unit 101 less than 0, and the control voltage Vgs2 of the second switch unit 102 greater than 0, so the first switch unit 101 is turned off and the second switch unit 102 is turned on. Due to the existence of the energy storage capacitor 106, the voltage difference across the energy storage capacitor 106 makes the control voltage Vgs3 of the third switch unit 103 less than 0. Since the on-state voltage of the third switch unit 103 is opposite to the on-state voltage polarity of the other two switch units, the third switch unit 103 is also turned on, the energy storage capacitor 106 is discharged, and the light-emitting unit 107 is driven to emit light.

[0057] In this embodiment, by setting the first switch unit 101 and the second switch unit 102 to have the same polarity of on-state voltage and the third switch unit 103 to have the opposite polarity of on-state voltage, the third switch unit 103 is cut off during the charging phase and is turned on during the discharging phase, thereby accurately controlling the on and off of the light-emitting unit 107.

[0058] In some optional implementations of this embodiment, the first switch unit 101 and the second switch unit 102 are N-type field effect transistors, and the third switch unit 103 is a P-type field effect transistor.

[0059] like Figure 2 As shown, T1, T2, and T3 are respectively the first switch unit 101, the second switch unit 102, and the third switch unit 103. The gate (i.e., the control end) of T1 is connected to the scan line 105, the source (i.e., the signal input end) is connected to the data line 104, and the drain (i.e., the signal output end) is connected to the gate of T3. The gate of T2 is connected to the data line 104, the source is connected to the scan line 105, and the drain is connected to the source of T3. The drain of T3 is connected to the light-emitting unit 107. T1 and T2 are both N-type field effect transistors, and their on-state voltage Vth>0. T3 is a P-type field effect transistor, and its on-state voltage Vth<0.

[0060] This embodiment provides a selection method for the first switch unit 101, the second switch unit 102 and the third switch unit 103, and can accurately control the state of the light-emitting unit 107 in the charging stage and the discharging stage, so that the light-emitting unit 107 can emit light stably.

[0061] In some optional implementations of this embodiment, according to Figure 2 In the circuit shown, in the charging stage, the voltage on the scan line 105 is greater than the voltage on the data line 104, the first switch unit 101 is turned on, and the second switch unit 102 and the third switch unit 103 are turned off; in the discharging stage, the voltage on the scan line 105 is less than the voltage on the data line 104, the first switch unit 101 is turned off, and the second switch unit 102 and the third switch unit 103 are turned on.

[0062] like Figure 3 As shown, it shows the voltage signal changes on the scan line 105 and the data line 104, and the state changes of the first switch unit 101, the second switch unit 102, and the third switch unit 103. Figure 3 and Figure 2 The circuit shown corresponds to the above. In the charging stage, the voltage on the scan line 105 is 15V, and the voltage on the data line 104 is 10V. Then the control voltage Vgs1 of T1 is 15V-10V=5V>Vth, T1 is turned on (the number "1" indicates that it is turned on), and the control voltage Vgs2 of T2 is 10V-15V=-5V<Vth, and T2 is turned off (the number "0" indicates that it is turned off). The source of T3 is in a high-resistance state, T3 is also turned off, and the light-emitting unit 107 does not emit light. The voltage difference δ across the energy storage capacitor 106 is 15V-10V=5V.

[0063] In the discharge phase, the voltage on the scan line 105 drops to 8V, and the voltage on the data line 104 remains at 10V. Since the voltage across the energy storage capacitor 106 cannot change suddenly, it is still δ=5V. Therefore, the drain voltage of T1 and the gate voltage of T3 are: Vd1=Vg3=8V-δ=3V, the gate voltage of T1 Vg1=8V, and the source voltage is still the voltage on the data line 104, that is, Vs1=10V. Therefore, the control voltage of T1 Vgs1=8V-10V=-2V<0, and T1 is cut off. The control voltage of T2 Vgs2>Vth, and T2 is turned on. The gate voltage of T3 Vg3=3V, and the source voltage is the voltage on the scan line 105, that is, Vs3=8V. Therefore, the control voltage of T3 Vgs3=3V-8V=-5V<0. Since T3 is a P-type field effect transistor, T3 is turned on. Finally, the energy storage capacitor 106 discharges to the light emitting unit 107 through T3, and the light emitting unit 107 emits light.

[0064] In this embodiment, when the first switch unit 101 and the second switch unit 102 are N-type field effect transistors and the third switch unit 103 is a P-type field effect transistor, the voltage on the scan line 105 in the charging stage is greater than the voltage on the data line 104, and the voltage on the scan line 105 in the discharging stage is less than the voltage on the data line 104. This achieves accurate control of the on and off state of the light-emitting unit 107 within one scanning cycle, thereby improving the stability of the light-emitting unit 107.

[0065] In some optional implementations of this embodiment, the first switch unit 101 and the second switch unit 102 are P-type field effect transistors, and the third switch unit 103 is an N-type field effect transistor.

[0066] like Figure 4 As shown, the gate of T1 is connected to the scan line 105, the source is connected to the data line 104, and the drain is connected to the gate of T3. The gate of T2 is connected to the data line 104, the source is connected to the scan line 105, and the drain is connected to the source of T3. The drain of T3 is connected to the light-emitting unit 107. Both T1 and T2 are P-type field effect transistors, and their on-state voltage Vth is less than 0. T3 is an N-type field effect transistor, and its on-state voltage Vth is greater than 0.

[0067] This embodiment enriches the implementation method of the circuit by providing another selection method of the first switch unit 101, the second switch unit 102 and the third switch unit 103. In the charging stage and the discharging stage, the state of the light-emitting unit 107 can be accurately controlled to make the light-emitting unit 107 emit light stably.

[0068] In some optional implementations of the present embodiment, in the charging stage, the voltage on the scan line 105 is less than the voltage on the data line 104, the first switch unit 101 is turned on, and the second switch unit 102 and the third switch unit 103 are turned off; in the discharging stage, the voltage on the scan line 105 is greater than the voltage on the data line 104, the first switch unit 101 is turned off, and the second switch unit 102 and the third switch unit 103 are turned on.

[0069] like Figure 5 As shown, it shows the voltage signal changes on the scan line 105 and the data line 104, and the state changes of the first switch unit 101, the second switch unit 102, and the third switch unit 103. Figure 5 and Figure 4The circuit shown in the figure corresponds to the above. In the charging stage, the voltage on the scan line 105 is 3V, and the voltage on the data line 104 is 8V. Then the control voltage Vgs1 of T1 is 3V-8V=-5V, T1 is turned on, and the control voltage Vgs2 of T2 is 8V-3V=5V, T2 is turned off. The source of T3 is in a high-resistance state, T3 is also turned off, and the light-emitting unit 107 does not emit light. The voltage difference δ across the energy storage capacitor 106 is 3V-8V=-5V.

[0070] In the discharge phase, the voltage on the scan line 105 increases to 10V, and the voltage on the data line 104 remains at 8V. Since the voltage across the energy storage capacitor 106 cannot change suddenly and is still δ=-5V, the drain voltage of T1 and the gate voltage of T3 are: Vd1=Vg3=10V-δ=15V, the gate voltage of T1 is Vg1=10V, and the source voltage is still the voltage on the data line 104, that is, Vs1=8V, therefore, the control voltage of T1 is Vgs1=10V-8V=2V>0, and T1 is cut off. The control voltage of T2 is Vgs2=8V–10V=-2V, and T2 is turned on. The gate voltage of T3 is Vg3=15V, and the source voltage is the voltage on the scan line 105, that is, Vs3=10V, therefore, the control voltage of T3 is Vgs3=15V-10V=5V, and since T3 is an N-type field effect transistor, T3 is turned on. Finally, the energy storage capacitor 106 discharges to the light emitting unit 107 through T3, and the light emitting unit 107 emits light.

[0071] In this embodiment, when the first switch unit 101 and the second switch unit 102 are P-type field effect transistors and the third switch unit 103 is an N-type field effect transistor, the voltage on the scan line 105 in the charging stage is smaller than the voltage on the data line 104, and the voltage on the scan line 105 in the discharging stage is larger than the voltage on the data line 104. This achieves accurate control of the on and off state of the light-emitting unit 107 within one scanning cycle, thereby improving the stability of the light-emitting unit 107.

[0072] Figure 6 A schematic diagram of the structure of a display panel 600 provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the display panel specifically includes: a scan driving module 601, a data driving module 602, a first preset number of scan lines 603 (Sel_1-Sel_N), a second preset number of data lines 604 (Data_1-Data_M) and a pixel array 605. Each scan line corresponds to a row of the pixel array, and each data line corresponds to a column of the pixel array.

[0073] The scanning driving module 601 is connected to the first preset number of scanning lines 603, and the data driving module 602 is connected to the second preset number of data lines 604. The scanning driving module 601 is used to output scanning signals to the first preset number of scanning lines 603 respectively according to the input timing signal. In each scanning cycle, the light-emitting unit of each pixel can be controlled to turn on and off by charging and discharging the energy storage capacitor in each pixel unit in the pixel array 605. The data driving module 602 is used to convert the input image data and the pixel value of each column in the image into a voltage signal, and output it to each column of pixels through the second preset number of data lines 604.

[0074] Each pixel in the pixel array 605 is connected to the corresponding scan line and data line. Each pixel includes a first switch unit, a second switch unit, a third switch unit, a storage capacitor and a light-emitting unit, and together with the corresponding scan line and data line constitutes the pixel driving circuit described in the above embodiments. Figure 6 The types of the first switch unit, the second switch unit, and the third switch unit shown are only examples, and the present embodiment does not limit the types of the first switch unit, the second switch unit, and the third switch unit.

[0075] In addition, the display panel may also include components such as a timing control module and a power management module to provide the pixel array 605 with scanning timing, image data, various level signals and the like.

[0076] The display panel provided in the embodiment of the present application, by applying the above-mentioned pixel driving circuit, achieves the effect of avoiding the gradual decrease in the brightness of each row of pixels caused by the same column of pixels sharing the same power supply when displaying an image, thereby making the display panel more uniform in brightness when displaying an image and improving the picture display quality.

[0077] Figure 7 A schematic diagram of the structure of a display device 700 provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, the display device includes:

[0078] Display panel 600, panel frame 701, power module 702 and data receiving module 703;

[0079] The display panel 600 may be Figure 6 The display panel 600 is shown. The display panel 600 is mounted on a panel frame 701.

[0080] The power supply end of the display panel 600 is connected to the power module 702 , and the signal receiving end of the display panel 600 is connected to the data receiving module 703 .

[0081] The power module 702 can provide the display panel 600 with the power required for operation, the data receiving module 703 can receive input data, and the display panel 600 drives the corresponding pixels to display the corresponding colors according to the received data.

[0082] In addition, the display device Figure 7 In addition to the parts shown, it may also include a memory for storing data and programs, a processor for running application programs, a data transmission bus, various data interfaces (such as a network interface, a user interface), etc.

[0083] The display device provided in the embodiment of the present application, by applying the above-mentioned display panel, achieves the goal of avoiding the gradual decrease in brightness of each row of pixels caused by pixels in the same column sharing the same power supply when displaying an image, thereby making the display panel more uniform in brightness when displaying an image and improving the picture display quality.

[0084] The professionals should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different circuits to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0085] The steps of the circuits or algorithms described in conjunction with the embodiments disclosed herein may be implemented using hardware, software modules executed by a processor, or a combination of the two. The software modules may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0086] It should be understood that the terms used in the text are only for the purpose of describing specific example embodiments, and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used in the text may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The steps, processes, and operations described in the text are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0087] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A pixel driving circuit, characterized in that: The circuit comprises: a first switch unit, a second switch unit, a third switch unit, a data line, a scan line, an energy storage capacitor and a light emitting unit; The control end of the first switch unit is connected to the scan line, the signal input end of the first switch unit is connected to the data line, and the signal output end of the first switch unit is connected to the control end of the third switch unit; The control end of the second switch unit is connected to the data line, the signal input end of the second switch unit is connected to the scan line, and the signal output end of the second switch unit is connected to the signal input end of the third switch unit; The signal output end of the third switch unit is connected to the light emitting unit; One end of the energy storage capacitor is connected to the scan line, and the other end is connected to the control end of the third switch unit.

2. The circuit according to claim 1, characterized in that A scanning cycle of the scanning line includes a charging phase and a discharging phase. In the charging phase, the voltage difference between the scanning line and the data line drives the first switch unit to be turned on and drives the second switch unit and the third switch unit to be turned off; in the discharging phase, the voltage difference between the scanning line and the data line drives the first switch unit to be turned off and drives the second switch unit and the third switch unit to be turned on.

3. The circuit according to claim 2, characterized in that The on-state voltages of the first switch unit and the second switch unit are first voltages, the on-state voltage of the third switch unit is second voltage, and the first voltage and the second voltage have opposite polarities.

4. The circuit according to claim 3, characterized in that The first switch unit and the second switch unit are N-type field effect transistors, and the third switch unit is a P-type field effect transistor.

5. The circuit according to claim 4, characterized in that In the charging stage, the voltage on the scan line is greater than the voltage on the data line, the first switch unit is turned on, and the second switch unit and the third switch unit are turned off; in the discharging stage, the voltage on the scan line is less than the voltage on the data line, the first switch unit is turned off, and the second switch unit and the third switch unit are turned on.

6. The circuit according to claim 3, characterized in that The first switch unit and the second switch unit are P-type field effect transistors, and the third switch unit is an N-type field effect transistor.

7. The circuit according to claim 6, characterized in that In the charging stage, the voltage on the scan line is lower than the voltage on the data line, the first switch unit is turned on, and the second switch unit and the third switch unit are turned off; in the discharging stage, the voltage on the scan line is higher than the voltage on the data line, the first switch unit is turned off, and the second switch unit and the third switch unit are turned on.

8. The circuit according to any one of claims 1 to 7, characterized in that: The light emitting unit is an organic light emitting diode, an anode of the organic light emitting diode is connected to the signal output end of the third switch unit, and a cathode of the organic light emitting diode is connected to a common voltage end.

9. A display panel, characterized in that: include: A scan driving module, a data driving module, a first preset number of scan lines, a second preset number of data lines and a pixel array; The scan driving module is connected to the first preset number of scan lines, and the data driving module is connected to the second preset number of data lines; Each pixel in the pixel array is connected to a corresponding scan line and a data line. Each pixel includes a first switch unit, a second switch unit, a third switch unit, a storage capacitor and a light-emitting unit, and together with the corresponding scan line and data line constitutes a pixel driving circuit as described in any one of claims 1 to 8.

10. A display device, characterized in that: include: The display panel, panel frame, power module and data receiving module as claimed in claim 9; The display panel is mounted on the panel frame, a power supply end of the display panel is connected to the power module, and a signal receiving end of the display panel is connected to the data receiving module.

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