Pixel driving circuit and display panel

Abstract

The present application belongs to the field of display, and specifically relates to a pixel driving circuit and a display panel. The pixel driving circuit includes a first transistor, a first capacitor, a second transistor, a voltage acquisition unit, and a voltage amplification unit. The first end of the first transistor is connected to the first power supply end through a first node, the second end of the first transistor is connected to the second power supply end through a display light-emitting unit, the voltage of the first power supply end is greater than the voltage of the second power supply end, the first capacitor is connected to the control end of the first transistor and the first node, the control end of the second transistor is connected to a scan line, and the first end of the second transistor is connected to a data line. The voltage acquisition unit is used to acquire the voltage of the first capacitor, and the voltage amplification unit is connected to the second node, the voltage acquisition unit, and the first node. During part of the charging period, the output voltage of the voltage amplification unit is greater than the voltage of the first capacitor. The charging voltage is amplified by the voltage amplification unit, thereby increasing the charging speed and facilitating an increase in the refresh rate of the display panel.

Description

Technical Field

[0001] The present application belongs to the field of display, and specifically relates to a pixel driving circuit and a display panel. Background Art

[0002] OLED (Organic Light-Emitting Diode) display panels have many advantages such as self-luminescence, flexibility, thin thickness, high brightness, low power consumption, fast response, and wide color gamut. They are widely used in electronic products such as televisions, mobile phones, and laptops.

[0003] Organic light-emitting diodes (OLEDs) are driven by current. The pixel drive circuit includes a switching transistor and a driver transistor. The degree to which the driver transistor is switched on determines the current flowing through the OLED, and thus the OLED's brightness. Due to the limitations of transistor manufacturing processes, the threshold voltage differences between adjacent transistors are small, but the threshold voltages of transistors spaced farther apart can vary significantly. To eliminate display unevenness caused by these threshold voltage differences, the pixel drive circuit must compensate for these differences.

[0004] The pixel driver circuit includes a storage capacitor. During the charging phase, the data voltage and threshold voltage are written to the storage capacitor to compensate for the threshold voltage. During the light-emitting phase, the brightness of the organic light-emitting diode is determined by the data voltage or current, and is not affected by the threshold voltage. However, when charging low-grayscale light in existing pixel driver circuits, the charging current is very low and the charging time is too long, which is not conducive to improving the refresh rate of the display panel. Summary of the Invention

[0005] The purpose of the present application is to provide a pixel driving circuit and a display panel to increase the charging speed of the storage capacitor of the pixel driving circuit.

[0006] To achieve the above-mentioned objectives, the present application provides a pixel driving circuit, including a first transistor and a first capacitor, wherein a first terminal of the first transistor is connected to a first power supply terminal via a first node, a second terminal of the first transistor is connected to a second power supply terminal via a display light-emitting unit, a voltage of the first power supply terminal is greater than a voltage of the second power supply terminal, and the first capacitor is connected to a control terminal of the first transistor and the first node. The pixel driving circuit further includes:

[0007] a second transistor, wherein a control terminal of the second transistor is connected to the scan line, and a first terminal of the second transistor is connected to the data line;

[0008] a voltage acquisition unit, wherein an input terminal of the voltage acquisition unit is connected to the second terminal of the first transistor via a second node, and the voltage acquisition unit is used to acquire the voltage of the first capacitor;

[0009] a voltage amplifying unit, wherein a first input terminal of the voltage amplifying unit is connected to the second node, a second input terminal of the voltage amplifying unit is connected to the output terminal of the voltage acquiring unit, and an output terminal of the voltage amplifying unit is connected to the first node; at the end of charging, a voltage at the output terminal of the voltage amplifying unit is equal to the voltage of the first capacitor; and during a portion of the charging period, a voltage at the output terminal of the voltage amplifying unit is greater than the voltage of the first capacitor.

[0010] Optionally, the voltage acquisition unit includes a third transistor and a second capacitor, the first end of the third transistor is connected to the second node, the second end of the third transistor is connected to the second power supply end, the first end of the second capacitor is connected to the second node, the second end of the second capacitor is connected to the control end of the third transistor and the second power supply end, and the first end of the third transistor and the first end of the second capacitor are input ends of the voltage acquisition unit.

[0011] Optionally, the voltage acquisition unit further includes a third capacitor, a first end of the third capacitor is connected to the second end of the third transistor, and a second end of the third capacitor is an output end of the voltage acquisition unit;

[0012] The voltage amplification unit includes a voltage amplifier and a first resistor, the first input end of the voltage amplifier is connected to the second node, the second input end of the voltage amplifier is connected to the output end of the voltage acquisition unit, the output end of the voltage amplification unit is connected to the first node, and the first resistor is connected to the output end of the voltage acquisition unit and the first node.

[0013] Optionally, the voltage amplifier includes a fourth transistor, a fifth transistor and a sixth transistor, the control end of the fourth transistor is connected to the output end of the voltage acquisition unit, the first end of the fourth transistor is connected to the first current source, the second end of the fourth transistor is connected to the second current source, the control end of the fifth transistor is connected to the second node, the first end of the fifth transistor is connected to the first current source, the second end of the fifth transistor is connected to the second current source through a third node, the control end of the sixth transistor is connected to the third node, the first end of the sixth transistor is connected to the third current source and the first node, and the second end of the sixth transistor is connected to the second power supply end.

[0014] Optionally, the capacitance of the second capacitor is smaller than the capacitance of the first capacitor.

[0015] Optionally, the threshold voltage of the third transistor is equal to the threshold voltage of the first transistor.

[0016] Optionally, the voltage acquisition unit further includes a second resistor, and the second resistor is connected to the second end of the third transistor and the second power supply end.

[0017] Optionally, the pixel driving circuit further includes a seventh transistor, a control end of the seventh transistor being connected to the scan line, a first end of the seventh transistor being connected to the output end of the voltage amplifying unit, and a second end of the seventh transistor being connected to the first node.

[0018] Optionally, the pixel driving circuit further includes an eighth transistor, the control end of the eighth transistor is connected to the light emitting control line, the first end of the eighth transistor is connected to the first power supply end, and the second end of the eighth transistor is connected to the first node.

[0019] The present application also provides a display panel, comprising:

[0020] the pixel driving circuit;

[0021] A display light-emitting unit is connected to the first transistor.

[0022] The pixel driving circuit and display panel disclosed in this application have the following beneficial effects:

[0023] In the present application, a pixel driving circuit includes a first transistor, a first capacitor, a second transistor, a voltage acquisition unit, and a voltage amplification unit. The first end of the first transistor is connected to the first power supply terminal via a first node, the second end of the first transistor is connected to the second power supply terminal via a display light-emitting unit, the first capacitor is connected to the control end of the first transistor and the first node, the control end of the second transistor is connected to a scan line, the first end of the second transistor is connected to a data line, the second end of the second transistor is connected to the input end of the voltage acquisition unit via a second node, the voltage acquisition unit is used to acquire the voltage of the first capacitor, and the voltage amplification unit is connected to the second node, the voltage acquisition unit, and the first node. During part of the charging period, the output voltage of the voltage amplification unit is greater than the voltage of the first capacitor. The charging voltage is amplified by the voltage amplification unit, thereby increasing the charging speed and facilitating an increase in the refresh rate of the display panel.

[0024] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by practice of the present application.

[0025] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0027] Figure 1 This is a structural block diagram of the pixel driving circuit in Example 1 of the present application.

[0028] Figure 2 It is a structural diagram of the pixel driving circuit in Example 1 of the present application.

[0029] Figure 3 This is a schematic diagram of the charging voltage change in Example 1 of the present application.

[0030] Figure 4 It is a structural diagram of the display panel in the second embodiment of the present application.

[0031] Description of reference numerals:

[0032] 110, first transistor; 120, first capacitor; 200, second transistor;

[0033] 300, voltage acquisition unit; 310, third transistor; 320, second capacitor; 330, third capacitor; 340, second resistor;

[0034] 400, voltage amplifying unit; 410, first resistor; 420, fourth transistor; 430, fifth transistor; 440, sixth transistor;

[0035] 510, a seventh transistor; 520, an eighth transistor;

[0036] 901, first power supply terminal; 902, second power supply terminal; 903, scan line; 904, data line; 905, first current source; 906, second current source; 907, third current source; 908, light-emitting control line;

[0037] 10. Pixel driving circuit; 20. Display light-emitting unit. DETAILED DESCRIPTION

[0038] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0039] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0040] The present application is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0041] Example 1

[0042] See also Figure 1 and Figure 2 As shown, in this embodiment, the pixel driving circuit 10 includes a first transistor 110 and a first capacitor 120. The first transistor 110 is a driving transistor. The first end of the first transistor 110 is connected to the first power supply terminal 901 through the first node A, and the second end of the first transistor 110 is connected to the second power supply terminal 902 through the display light-emitting unit 20. The voltage of the first power supply terminal 901 (VDD) is greater than the voltage of the second power supply terminal 902. The second power supply terminal 902 can be a ground terminal, and the voltage of the second power supply terminal 902 can be 0. The first capacitor 120 is connected to the control terminal of the first transistor 110 and the first node A. The display light-emitting unit 20 includes an organic light-emitting diode (OLED), a light-emitting diode (LED), and a mini light-emitting diode (Mini / Micro LED).

[0043] The pixel driving circuit 10 may further include a second transistor 200, a voltage acquisition unit 300, and a voltage amplification unit 400. The control terminal of the second transistor 200 is connected to the scan line 903, the first terminal of the second transistor 200 is connected to the data line 904, and the second terminal of the second transistor 200 is connected to the input terminal of the voltage acquisition unit 300 via the second node B. The voltage acquisition unit 300 is used to acquire the voltage V1 of the first capacitor 120. The first input terminal of the voltage amplification unit 400 is connected to the second node B, the second input terminal of the voltage amplification unit 400 is connected to the output terminal of the voltage acquisition unit 300, and the output terminal of the voltage amplification unit 400 is connected to the first node A.

[0044] The output voltage Vout of the voltage amplifying unit 400 represents the charging voltage of the first capacitor 120. At the end of charging, the output voltage Vout of the voltage amplifying unit 400 is equal to the voltage V1 of the first capacitor 120, ensuring that the charging voltage is not distorted, which would otherwise cause the charging voltage to fail to reflect the magnitude of the data voltage or data current. During portions of the charging process, the output voltage Vout of the voltage amplifying unit 400 is greater than the voltage V1 of the first capacitor 120. Specifically, the output voltage Vout of the voltage amplifying unit 400 first increases to a value greater than the voltage V1 of the first capacitor 120 and then decreases to a value equal to the voltage V1 of the first capacitor 120. This high-voltage charging process accelerates charging.

[0045] The first transistor 110 and the second transistor 200 may both be P-channel transistors, the control end of the first transistor 110 and the control end of the second transistor 200 being gates, the first end of the first transistor 110 and the first end of the second transistor 200 being sources, and the second end of the first transistor 110 and the second end of the second transistor 200 being drains.

[0046] In some technical solutions, the second end of the second transistor 200 is directly connected to the first node A, and the data voltage or data current of the data line 904 directly charges the first capacitor 120. When charging low grayscale light, the charging current is very small and the charging time is too long, which is not conducive to improving the refresh rate of the display panel.

[0047] In this embodiment, the pixel driving circuit 10 includes a first transistor 110, a first capacitor 120, a second transistor 200, a voltage acquisition unit 300, and a voltage amplification unit 400. The first end of the first transistor 110 is connected to the first power supply terminal 901 via a first node A, and the second end of the first transistor 110 is connected to the second power supply terminal 902 via the display light-emitting unit 20. The first capacitor 120 is connected to the control end of the first transistor 110 and the first node A. The control end of the second transistor 200 is connected to the scan line 903, the first end of the second transistor 200 is connected to the data line 904, and the second end of the second transistor 200 is connected to the input end of the voltage acquisition unit 300 via a second node B. The voltage acquisition unit 300 is used to acquire the voltage V1 of the first capacitor 120. The voltage amplification unit 400 is connected to the second node B, the voltage acquisition unit 300, and the first node A. During part of the charging period, the output voltage Vout of the voltage amplification unit 400 is greater than the voltage V1 of the first capacitor 120. The charging voltage is amplified by the voltage amplification unit 400, thereby improving the charging speed and facilitating an increase in the refresh rate of the display panel.

[0048] In addition, at the end of charging, the output voltage Vout of the voltage amplifying unit 400 is equal to the voltage V1 of the first capacitor 120 , which ensures that the charging voltage will not be distorted, resulting in the charging voltage not being able to reflect the data voltage or data current.

[0049] In some embodiments, the voltage acquisition unit 300 includes a third transistor 310 and a second capacitor 320. A first terminal of the third transistor 310 is connected to the second node B, and a second terminal of the third transistor 310 is connected to the second power supply terminal 902. A first terminal of the second capacitor 320 is connected to the second node B, and a second terminal of the second capacitor 320 is connected to the control terminal of the third transistor 310 and the second power supply terminal 902. The first terminal of the third transistor 310 and the first terminal of the second capacitor 320 serve as input terminals of the voltage acquisition unit 300.

[0050] The third transistor 310 can be a P-channel transistor, with the control terminal of the third transistor 310 being its gate, the first terminal of the third transistor 310 being its source, and the second terminal of the third transistor 310 being its drain. The third transistor 310 and the second capacitor 320 can be viewed as mirror images of the first transistor 110 and the first capacitor 120, and the voltage V2 of the second capacitor 320 is equal to the voltage V1 of the first capacitor 120.

[0051] The voltage acquisition unit 300 includes a third transistor 310 and a second capacitor 320. The third transistor 310 and the second capacitor 320 serve as mirror images of the first transistor 110 and the first capacitor 120. The voltage acquisition unit 300 acquires the voltage V2 of the second capacitor 320. The voltage V2 of the second capacitor 320 is equal to the voltage V1 of the first capacitor 120. That is, the voltage acquisition unit 300 can acquire the voltage V1 of the first capacitor 120. When the data line 904 signal is a current signal, it is not convenient to directly amplify the current signal. The voltage acquisition unit 300 acquires the voltage V2 of the second capacitor 320. The voltage V2 of the second capacitor 320 can reflect the data line 904 signal. The voltage amplification unit 400 can amplify the voltage to quickly charge the first capacitor 120.

[0052] In some embodiments, the threshold voltage of the third transistor 310 is equal to the threshold voltage of the first transistor 110. Since the third transistor 310 and the first transistor 110 are designed in the same pixel driving circuit 10, the third transistor 310 and the first transistor 110 are adjacent to each other on the display panel, and the threshold voltages of the third transistor 310 and the first transistor 110 are equal or have a small difference.

[0053] The threshold voltage of the third transistor 310 is equal to the threshold voltage of the first transistor 110 , and the voltage V2 of the second capacitor 320 is equal to the voltage V1 of the first capacitor 120 . The voltage V1 of the first capacitor 120 does not need to be corrected and can directly reflect the data voltage or data current.

[0054] In some embodiments, the voltage acquisition unit 300 further includes a third capacitor 330, the first end of the third capacitor 330 is connected to the second end of the third transistor 310, the second end of the third capacitor 330 is the output end of the voltage acquisition unit 300, and the voltage of the output end of the voltage acquisition unit 300 is V-.

[0055] The voltage amplifying unit 400 includes a voltage amplifier and a first resistor 410. The first input terminal of the voltage amplifier is connected to the second node B, the second input terminal of the voltage amplifier is connected to the output terminal of the voltage acquisition unit 300, the output terminal of the voltage amplifying unit 400 is connected to the first node A, and the first resistor 410 is connected between the output terminal of the voltage acquisition unit 300 and the first node A. The first input terminal, second input terminal, and output terminal of the voltage amplifier serve as the first input terminal, second input terminal, and output terminal of the voltage amplifying unit 400, respectively.

[0056] The voltage amplifier can amplify the voltage V2 of the second capacitor 320, so that the output voltage Vout of the voltage amplifying unit 400 is greater than the voltage V1 of the first capacitor 120 during part of the charging period. The voltage V- at the output of the voltage acquisition unit 300 can pull down the output voltage Vout of the voltage amplifying unit 400, so that the output voltage Vout of the voltage amplifying unit 400 is equal to the voltage V1 of the first capacitor 120 at the end of charging.

[0057] For details, see Figure 2 As shown, the voltage amplifier includes a fourth transistor 420, a fifth transistor 430, and a sixth transistor 440. The control terminal of the fourth transistor 420 is connected to the output terminal of the voltage acquisition unit 300, the first terminal of the fourth transistor 420 is connected to the first current source 905, and the second terminal of the fourth transistor 420 is connected to the second current source 906. The control terminal of the fifth transistor 430 is connected to the second node B, the first terminal of the fifth transistor 430 is connected to the first current source 905, and the second terminal of the fifth transistor 430 is connected to the second current source 906 via the third node C. The control terminal of the sixth transistor 440 is connected to the third node C, the first terminal of the sixth transistor 440 is connected to the third current source 907 and the first node A, and the second terminal of the sixth transistor 440 is connected to the second power supply terminal 902.

[0058] The fourth transistor 420 and the sixth transistor 440 may be P-channel transistors, the control end of the fourth transistor 420 and the control end of the fifth transistor 430 may be their gates, the first end of the fourth transistor 420 and the first end of the fifth transistor 430 may be their sources, the second end of the fourth transistor 420 and the second end of the fifth transistor 430 may be their drains, the sixth transistor 440 may be an N-channel transistor, the control end of the fourth transistor 420 may be its gate, the first end of the fourth transistor 420 may be its drain, and the second end of the fourth transistor 420 may be its source.

[0059] The control terminal of the fifth transistor 430 is the first input terminal of the voltage amplifier, the control terminal of the fourth transistor 420 is the second input terminal of the voltage amplifier, and the first terminal of the sixth transistor 440 is the output terminal of the voltage amplifier. The voltage V+ at the control terminal of the fifth transistor 430 is equal to the voltage V2 of the second capacitor 320, and the voltage V- at the control terminal of the fourth transistor 420 is V-.

[0060] The output voltage Vout of the voltage amplifying unit 400 is equal to K(V+-V-), where K is a constant. When the control voltage V- of the fourth transistor 420 is lower than the control voltage V+ of the fifth transistor 430, since Vout = K(V+-V-), the output voltage Vout of the voltage amplifying unit 400 increases, and the control voltage V- of the fourth transistor 420 increases along with the output voltage Vout of the voltage amplifying unit 400. When the control voltage V- of the fourth transistor 420 is higher than the control voltage V+ of the fifth transistor 430, since Vout = K(V+-V-), the output voltage Vout of the voltage amplifying unit 400 decreases, and the control voltage V- of the fourth transistor 420 decreases along with the output voltage Vout of the voltage amplifying unit 400.

[0061] Because first resistor 410 connects first node A and the control terminal of fourth transistor 420, and because first resistor 410 is a small resistor and the internal resistance of the transistor is much greater than the resistance of first resistor 410, voltage V- at the control terminal of fourth transistor 420 can be considered equal to voltage Vout at the output terminal of voltage amplification unit 400, i.e., V- = Vout, thus forming a negative feedback loop. Based on Vout = K(V+ - V-) and V- = Vout, we can deduce that V+ = V-(1+1 / K). Since K is very large, V+ can be considered = V-, which is a virtual short.

[0062] See also Figure 3As shown, the second end of the second transistor 200 is directly connected to the first node A. When the data voltage or data current of the data line 904 directly charges the first capacitor 120, the charging voltage of the first capacitor 120 gradually increases, as shown in the charging voltage curve L1. In this embodiment, because the third capacitor 330 needs to be charged, when the data line 904 begins to charge the second capacitor 320, the control terminal voltage V- of the fourth transistor 420 does not immediately follow the output terminal voltage Vout of the voltage amplifying unit 400, but lags behind for a period of time. Since this hysteresis does not hold, the output terminal voltage Vout of the voltage amplifying unit 400 increases to a value greater than the control terminal voltage V+ of the fifth transistor 430. When the third capacitor 330 is completely charged, the control terminal voltage V- of the fourth transistor 420, the control terminal voltage V+ of the fifth transistor 430, and the output terminal voltage Vout of the voltage amplifying unit 400 are equal, as shown in the charging voltage curve L2. The voltage acquisition unit 300 and the voltage amplification unit 400 can amplify the charging voltage and improve the charging speed, while ensuring that the charging voltage is not distorted, resulting in the charging voltage not being able to reflect the data voltage or data current.

[0063] In some embodiments, the capacitance of the second capacitor 320 is smaller than the capacitance of the first capacitor 120 .

[0064] The capacitance of the second capacitor 320 is smaller than that of the first capacitor 120 . The second capacitor 320 is charged faster, and accordingly, the first capacitor 120 is also charged faster.

[0065] It should be understood that, since the output terminal voltage Vout of the voltage amplifying unit 400 is greater than the control terminal voltage V+ of the fifth transistor 430 during part of the charging period, high-voltage charging is used to accelerate the charging speed of the first capacitor 120. Even if the capacitance of the second capacitor 320 is equal to or greater than the capacitance of the first capacitor 120, the charging speed of the first capacitor 120 will be faster than the technical solution in which the second end of the second transistor 200 is directly connected to the first node A and the data voltage or data current of the data line 904 directly charges the first capacitor 120.

[0066] In some embodiments, the voltage acquisition unit 300 further includes a second resistor 340, which is connected between the second terminal of the third transistor 310 and the second power supply terminal 902. The resistance value of the second resistor 340 is equal to the internal resistance of the display light-emitting unit 20. The second terminal of the second capacitor 320 is connected to the second power supply terminal 902 through the third resistor 340.

[0067] The second resistor 340 is connected to the second terminal of the third transistor 310 and the second power supply terminal 902. The second resistor 340 can reduce the current of the third transistor 310. At the same time, the resistance value of the second resistor 340 is equal to the internal resistance of the display light-emitting unit 20, which can reduce the impact of the current of the third transistor 310 on the voltage V2 of the second capacitor 320.

[0068] In some embodiments, the pixel driving circuit 10 further includes a seventh transistor 510, wherein a control terminal of the seventh transistor 510 is connected to the scan line 903, a first terminal of the seventh transistor 510 is connected to the output terminal of the voltage amplifying unit 400, and a second terminal of the seventh transistor 510 is connected to the first node A. The seventh transistor 510 may be a P-channel transistor, wherein the control terminal of the seventh transistor 510 is a gate, the first terminal of the seventh transistor 510 is a source, and the second terminal of the seventh transistor 510 is a drain.

[0069] In the charging stage, the seventh transistor 510 and the second transistor 200 are turned on simultaneously. In the light-emitting stage, the seventh transistor 510 and the second transistor 200 are turned off simultaneously to prevent leakage of the first capacitor 120 from affecting the light-emitting unit 20 .

[0070] In some embodiments, the pixel driving circuit 10 further includes an eighth transistor 520, wherein the control terminal of the eighth transistor 520 is connected to the light emission control line 908, the first terminal of the eighth transistor 520 is connected to the first power supply terminal 901, and the second terminal of the eighth transistor 520 is connected to the first node A. The eighth transistor 520 may be a P-channel transistor, wherein the control terminal of the eighth transistor 520 is its gate, the first terminal of the eighth transistor 520 is its source, and the second terminal of the eighth transistor 520 is its drain.

[0071] It should be understood that the first transistor 110, the second transistor 200, the third transistor 310, the fourth transistor 420, the fifth transistor 430, the seventh transistor 510 and the eighth transistor 520 may all be P-channel transistors, and the sixth transistor 440 may be an N-channel transistor, but is not limited to this. By adjusting the control signal, each of the first transistor 110, the second transistor 200, the third transistor 310, the fourth transistor 420, the fifth transistor 430, the sixth transistor 440, the seventh transistor 510 and the eighth transistor 520 may be between an N-channel transistor and a P-channel transistor.

[0072] In the charging stage, the eighth transistor 520 is turned off, and in the light-emitting stage, the eighth transistor 520 is turned on, and current flows through the first power supply terminal 901, the eighth transistor 520, the first transistor 110, the display light-emitting unit 20 and the second power supply terminal 902. The display light-emitting unit 20 is controlled to emit light through the eighth transistor 520, thereby avoiding current flowing through the display light-emitting unit 20 in the charging stage.

[0073] In this embodiment, when the pixel driving circuit 10 works:

[0074] During the charging phase, the second transistor 200 and the seventh transistor 510 are turned on, and the eighth transistor 520 is turned off. The data voltage or data current of the data line 904 charges the second capacitor 320. Since the capacitance of the second capacitor 320 is smaller than that of the first capacitor 120, the second capacitor 320 can be quickly charged. During the charging process, the voltage V2 of the second capacitor 320 is amplified by the voltage amplification unit 400, quickly charging the first capacitor 120.

[0075] During the light-emitting stage, the second transistor 200 and the seventh transistor 510 are turned off, and the eighth transistor 520 is turned on. Since the capacitance of the second capacitor 320 is smaller than the capacitance of the first capacitor 120, the first capacitor 120 with a larger capacitance maintains the current of the first transistor 110, which can make the current of the first transistor 110 more stable, thereby improving the display effect of the light-emitting unit 20.

[0076] Example 2

[0077] See also Figure 4 As shown, in this embodiment, the display panel includes a pixel driving circuit 10, a display light-emitting unit 20, a scan line 903 and a data line 904, the pixel driving circuit 10 includes the pixel driving circuit 10 disclosed in Example 1, the display light-emitting unit 20 is connected to the second end of the first transistor 110, the scan line 903 is connected to the control end of the second transistor 200, and the data line 904 is connected to the first end of the second transistor 200.

[0078] In this embodiment, the display panel includes a pixel driving circuit 10, which includes a first transistor 110, a first capacitor 120, a second transistor 200, a voltage acquisition unit 300 and a voltage amplification unit 400. The first end of the first transistor 110 is connected to the first power supply end 901 through the first node A, and the second end of the first transistor 110 is connected to the second power supply end 902 through the display light-emitting unit 20. The first capacitor 120 is connected to the control end of the first transistor 110 and the first node A, the control end of the second transistor 200 is connected to the scan line 903, the first end of the second transistor 200 is connected to the data line 904, the second end of the second transistor 200 is connected to the input end of the voltage acquisition unit 300 through the second node B, the voltage acquisition unit 300 is used to obtain the voltage V1 of the first capacitor 120, and the voltage amplification unit 400 is connected to the second node B, the voltage acquisition unit 300 and the first node A. During part of the charging period, the output voltage Vout of the voltage amplifying unit 400 is greater than the voltage V1 of the first capacitor 120 . The charging voltage is amplified by the voltage amplifying unit 400 , thereby increasing the charging speed and facilitating the improvement of the refresh rate of the display panel.

[0079] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0080] In this application, unless otherwise specified or limited, terms such as "assembly" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0081] In the description of this specification, the reference terms "some embodiments", "exemplarily", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0082] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent application.

Claims

1. A pixel driving circuit, comprising a first transistor and a first capacitor, wherein a first terminal of the first transistor is connected to a first power terminal via a first node, a second terminal of the first transistor is connected to a second power terminal via a display light-emitting unit, a voltage at the first power terminal is greater than a voltage at the second power terminal, and the first capacitor is connected between a control terminal of the first transistor and the first node, characterized in that: The pixel driving circuit further includes: a second transistor, wherein a control terminal of the second transistor is connected to the scan line, and a first terminal of the second transistor is connected to the data line; a voltage acquisition unit, wherein an input terminal of the voltage acquisition unit is connected to the second terminal of the second transistor via a second node, and the voltage acquisition unit is used to acquire the voltage of the first capacitor; a voltage amplifying unit, wherein a first input terminal of the voltage amplifying unit is connected to the second node, a second input terminal of the voltage amplifying unit is connected to the output terminal of the voltage acquiring unit, and an output terminal of the voltage amplifying unit is connected to the first node, a voltage at the output terminal of the voltage amplifying unit is equal to the voltage of the first capacitor at the end of charging, and a voltage at the output terminal of the voltage amplifying unit is greater than the voltage of the first capacitor during a portion of the charging period; The voltage acquisition unit includes a third transistor and a second capacitor, the first end of the third transistor is connected to the second node, the second end of the third transistor is connected to the second power supply end, the first end of the second capacitor is connected to the second node, the second end of the second capacitor is connected to the control end of the third transistor and the second power supply end, and the first end of the third transistor and the first end of the second capacitor are input ends of the voltage acquisition unit.

2. The pixel driving circuit according to claim 1, wherein: The voltage acquisition unit further includes a third capacitor, a first end of the third capacitor is connected to the second end of the third transistor, and a second end of the third capacitor is an output end of the voltage acquisition unit; The voltage amplification unit includes a voltage amplifier and a first resistor, the first input end of the voltage amplifier is connected to the second node, the second input end of the voltage amplifier is connected to the output end of the voltage acquisition unit, the output end of the voltage amplification unit is connected to the first node, and the first resistor is connected to the output end of the voltage acquisition unit and the first node.

3. The pixel driving circuit according to claim 2, wherein: The voltage amplifier includes a fourth transistor, a fifth transistor and a sixth transistor, the control end of the fourth transistor is connected to the output end of the voltage acquisition unit, the first end of the fourth transistor is connected to the first current source, the second end of the fourth transistor is connected to the second current source, the control end of the fifth transistor is connected to the second node, the first end of the fifth transistor is connected to the first current source, the second end of the fifth transistor is connected to the second current source through a third node, the control end of the sixth transistor is connected to the third node, the first end of the sixth transistor is connected to the third current source and the first node, and the second end of the sixth transistor is connected to the second power supply end.

4. The pixel driving circuit according to claim 1, wherein: The capacitance of the second capacitor is smaller than the capacitance of the first capacitor.

5. The pixel driving circuit according to claim 1, wherein: A threshold voltage of the third transistor is equal to a threshold voltage of the first transistor.

6. The pixel driving circuit according to claim 1, wherein: The voltage acquisition unit further includes a second resistor connected to the second end of the third transistor and the second power supply end.

7. The pixel driving circuit according to claim 1, wherein: The pixel driving circuit further includes a seventh transistor, a control end of the seventh transistor is connected to the scan line, a first end of the seventh transistor is connected to the output end of the voltage amplifying unit, and a second end of the seventh transistor is connected to the first node.

8. The pixel driving circuit according to claim 1, wherein: The pixel driving circuit further includes an eighth transistor, a control end of the eighth transistor is connected to the light emitting control line, a first end of the eighth transistor is connected to the first power supply end, and a second end of the eighth transistor is connected to the first node.

9. A display panel, characterized in that: include: The pixel driving circuit according to any one of claims 1 to 8; A display light-emitting unit is connected to the first transistor.

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