Pixel driving circuit, display device and electronic equipment

Abstract

The invention discloses a pixel driving circuit, a display device and electronic equipment, and belongs to the technical field of display. The pixel driving circuit is used for being connected with a light-emitting element so as to drive the light-emitting element to emit light. The pixel driving circuit comprises a driving unit and a capacitance adjusting unit. The driving unit is connected with an anode of a light-emitting element, the driving unit is used for receiving a lightening signal, and the lightening signal is used for indicating the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element; the capacitance adjusting unit is at least connected with one of an anode or a cathode of the light-emitting element, the capacitance adjusting unit is used for adjusting a capacitance value between a first end and a common grounding end of the pixel driving circuit, and the first end is an output end, connected with the anode of the light-emitting element, of the driving unit.

Description

Technical Field

[0001] This application belongs to the field of display technology, and particularly relates to a pixel driving circuit, a display device, and an electronic device. Background Art

[0002] Active Matrix Organic Light Emitting Diode (AMOLED) display technology has been widely used in electronic devices such as smart phones and smart watches due to its characteristics of high contrast ratio, fast response speed, wide viewing angle, and wide color gamut.

[0003] Currently, the Organic Light-Emitting Diode (OLED) of each pixel in the AMOLED display panel is connected to its corresponding pixel driving circuit. The pixel driving circuit is used to transmit a light-emitting current to the OLED under multiple refresh cycles to drive the OLED to emit light.

[0004] Among them, the OLED has a parasitic capacitance. After receiving the light-emitting current, the OLED needs to first complete the charging of the parasitic capacitance and then light up. However, since the sizes of the parasitic capacitances of the OLEDs emitting different colors of light are different. Therefore, the charging durations of the parasitic capacitances of the OLEDs emitting different colors of light are not equal, which results in different lighting speeds of the OLEDs emitting different colors of light, causing a smear phenomenon when the display panel is refreshed due to the different lighting speeds of the OLEDs. Summary of the Invention

[0005] The purpose of the embodiments of this application is to provide a pixel driving circuit, a display device, and an electronic device, which can solve the problem of smear phenomenon existing when the current display panel is refreshed due to different lighting speeds of the OLEDs.

[0006] In a first aspect, the embodiments of this application provide a pixel driving circuit, which is used to be connected to a light-emitting element to drive the light-emitting element to emit light; the pixel driving circuit includes: a driving unit and a capacitance adjusting unit;

[0007] The driving unit is connected to the anode of the light-emitting element, and the driving unit is used to receive a lighting signal, and the lighting signal is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element;

[0008] The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element, and the capacitance adjusting unit is used to adjust the capacitance value between the first end and the common ground terminal.

[0009] In a second aspect, an embodiment of the present application provides a display device, which includes a light-emitting unit and a pixel driving circuit. The light-emitting unit includes at least two light-emitting sub-units, each light-emitting sub-unit is connected to one pixel driving circuit, and the pixel driving circuit connected to the target light-emitting sub-unit is any one of the pixel driving circuits in the first aspect, and the target light-emitting sub-unit is at least one light-emitting sub-unit among the at least two light-emitting sub-units.

[0010] In a third aspect, an embodiment of the present application provides an electronic device, which includes a device body and the display device described in the second aspect.

[0011] In the embodiment of the present application, the pixel driving circuit includes a driving unit and a capacitance adjusting unit. The driving unit is connected to the anode of the light-emitting element and is used to receive a lighting signal, and this lighting signal is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjusting unit is used to adjust the capacitance value between the first end and the common grounding end of the pixel driving circuit, and this first end is the output end where the driving unit is connected to the anode of the light-emitting element. It is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjusting unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approach the same, thereby improving the ghosting phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0012] For example, in the light-emitting unit of the display panel, there are light-emitting elements that emit red light, light-emitting elements that emit green light, and light-emitting elements that emit blue light. The pixel driving circuit can be used to reduce the lighting speed of the light-emitting elements that emit red light, and / or increase the lighting speed of the light-emitting elements that emit green light, thereby eliminating the difference in the lighting speeds of light-emitting elements of different colors to a certain extent, making the red component, green component, and blue component in the light emitted by the light-emitting unit achieve balanced ratio, and improving the phenomenon of red ghosting that exists when the display panel is refreshed. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of a pixel driving circuit provided by the related art;

[0014] Figure 2 is a schematic timing diagram of a pixel driving circuit provided by the related art;

[0015] Figure 3It is a schematic structural diagram of a pixel driving circuit provided by an embodiment of the present application;

[0016] Figure 4 It is a schematic structural diagram of another pixel driving circuit provided by an embodiment of the present application;

[0017] Figure 5 It is a timing schematic diagram of yet another pixel driving circuit provided by an embodiment of the present application;

[0018] Figure 6 It is a timing schematic diagram of still another pixel driving circuit provided by an embodiment of the present application;

[0019] Figure 7 It is a timing schematic diagram of a pixel driving circuit provided by an embodiment of the present application;

[0020] Figure 8 It is a block diagram of an electronic device provided by an embodiment of the present application;

[0021] Figure 9 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Specific Embodiments

[0022] Next, the technical solutions in the embodiments of the present application will be clearly described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application belong to the scope of protection of the present application.

[0023] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. generally belong to the same category, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the related objects before and after.

[0024] Next, with reference to the accompanying drawings, the problem of uneven brightness of the panel provided by the embodiments of the present application will be described in detail through specific embodiments and their application scenarios.

[0025] Active Matrix Organic Light Emitting Diode (AMOLED) display technology is widely used in electronic devices such as smartphones and smart watches due to its high contrast ratio, fast response speed, wide viewing angle, and wide color gamut.

[0026] Currently, the Organic Light-Emitting Diode (OLED) of each pixel in the AMOLED display panel is connected to its corresponding pixel driving circuit. The pixel driving circuit is used to transmit the light-emitting current to the OLED under multiple refresh cycles to drive the OLED to emit light.

[0027] Exemplarily, please refer to Figure 1 , which shows a schematic diagram of a pixel driving circuit provided by the related art. As Figure 1 shown, the pixel driving circuit is a 7T1C pixel driving circuit, specifically including: a power supply voltage terminal ELVDD, a common ground terminal ELVSS, a first input voltage terminal VINT1, a second input voltage terminal VINT2, a data writing terminal DATA, an nth row scanning line terminal Scan[n], an (n - 1)th row scanning line terminal Scan[n - 1], an nth row scanning enable terminal EM[n], a fourth transistor T4 to a tenth transistor T10, and a capacitor Cst. Among them, the fourth transistor T4 to the tenth transistor T10 are all Thin Film Transistors (TFTs). The power supply voltage terminal ELVDD is used to provide a constant positive voltage. The common ground terminal ELVSS, also known as the common ground terminal, is used to provide an adjustable negative voltage.

[0028] Among them, the fourth transistor T4 serves as a driving transistor, which is used to control the magnitude of the conduction current through the gate voltage. The fifth transistor T5 to the tenth transistor T10 serve as switching transistors, which are used to control the on / off of the circuit. Specifically, the control terminal of the fourth transistor T4 is connected to the third node O3, the input terminal is connected to the fourth node O4, and the output terminal is connected to the fifth node O5. The control terminal of the fifth transistor T5 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the data writing terminal DATA, and the output terminal is connected to the fourth node O4. The control terminal of the sixth transistor T6 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the fifth node O5, the output terminal is connected to the sixth node O6, and the sixth node O6 is connected to the third node O3. The control terminal of the seventh transistor T7 is connected to the (n - 1)th row scan line terminal Scan[n - 1], the input terminal is connected to the first input voltage terminal VINT1, and the output terminal is connected to the sixth node O6. The control terminal of the eighth transistor T8 is connected to the scan enable terminal EM, the input terminal is connected to the power supply voltage terminal ELVDD, and the output terminal is connected to the fourth node O4. The control terminal of the ninth transistor T9 is connected to the scan enable terminal EM, the input terminal is connected to the fifth node O5, and the output terminal is connected to the anode of the OLED. The cathode of the OLED is connected to the common ground terminal ELVSS. The control terminal of the tenth transistor T10 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the second input voltage terminal VINT2, and the output terminal is connected to the anode of the OLED.

[0029] It should be noted that the third node O3 is the electrical connection intersection point between the capacitor Cst and the control terminal of the fourth transistor T4. The fourth node O4 is the electrical connection intersection point between the input terminal of the fourth transistor T4, the output terminal of the fifth transistor T5, and the output terminal of the eighth transistor T8. The fifth node O5 is the electrical connection intersection point between the output terminal of the fourth transistor T4, the input terminal of the sixth transistor T6, and the input terminal of the ninth transistor T9. The sixth node O6 is the electrical connection intersection point between the output terminal of the sixth transistor T6, the input terminal of the seventh transistor T7, and the third node O3. In the case where the transistor is an N-type transistor, the control terminal of the transistor refers to the gate, the input terminal refers to the drain, and the output terminal refers to the source. In the case where the transistor is a P-type transistor, the control terminal of the transistor refers to the gate, the input terminal refers to the source, and the output terminal refers to the drain.

[0030] As Figure 2 shown, the driving principle of the 7T1C pixel driving circuit is as follows: within the refresh period T for displaying one frame of an image, the entire driving timing process includes an initial restoration stage t1, a compensation stage t2, and a light-emitting stage t3, a total of 3 stages.

[0031] Initial reduction stage t1: The Scan[n - 1] terminal of the (n - 1)-th row scan line is connected to a low-level signal, and the Scan[n] terminal of the n-th row scan line and the EM[n] terminal of the n-th row scan enable are connected to high-level signals.

[0032] The seventh transistor T7 is turned on, and the negative voltage provided by the first input voltage terminal VINT1 is written to the gate of the fourth transistor T4 through the turned-on seventh transistor T7 and stored on the capacitor Cst for holding. At this time, the fifth transistor T5, the sixth transistor T6, and the eighth to tenth transistors T8 to T10 are turned off.

[0033] Compensation stage t2: The Scan[n] terminal of the n-th row scan line is connected to a low-level signal, the Scan[n - 1] terminal of the (n - 1)-th row scan line is connected to a low-level signal, and the EM[n] terminal of the n-th row scan enable is connected to a high-level signal.

[0034] The fifth transistor T5, the sixth transistor T6, and the tenth transistor are turned on. At the same time, the fourth transistor T4 remains turned on under the voltage held by the capacitor Cst in the previous stage. The frame voltage data signal input at the DATA input terminal is stored on the capacitor Cst through the fifth transistor T5, the fourth transistor T4, and the sixth transistor T6. At this time, the voltage Vg at the gate of the fourth transistor T4 is Vdata - Vth. Vdata is the voltage value of the frame voltage data signal. Vth is the threshold voltage of the fourth transistor T4. In this way, the threshold voltage Vth of the fourth transistor T4 is extracted, providing a prerequisite for the subsequent optimization of the threshold voltage Vth of the fourth transistor T4.

[0035] Moreover, the seventh transistor T7 is turned on, and the negative voltage provided by the second input voltage terminal VINT2 is written to the anode of the OLED to reset the OLED to release the residual charge accumulated in the OLED. In practical applications, the voltage provided by the second input voltage terminal VINT2T will change accordingly with different emission brightnesses.

[0036] Emission stage t3: The EM[n] terminal of the n-th row scan enable is connected to a low-level signal. The Scan[n - 1] terminal of the (n - 1)-th row scan line and the Scan[n] terminal of the n-th row scan line input high-level signals.

[0037] The eighth transistor T8 and the ninth transistor T9 are turned on. At the same time, the fourth transistor T4 remains continuously turned on under the holding of the voltage Vdata-Vth stored in the capacitor Cst. The fifth transistor T5 to the seventh transistor T7 and the tenth transistor T10 are turned off. The light-emitting current provided by the power supply voltage terminal ELVDD flows through the eighth transistor T8, the fourth transistor T4, and the ninth transistor T9 to the OLED, and then flows to the common ground terminal ELVSS to drive the OLED to emit light. Among them, the pixel driving circuit can sequentially refresh and display the first sub-frame t31, the second sub-frame t32, the third sub-frame t33, etc. in the light-emitting stage t3.

[0038] Among them, the OLED has a parasitic capacitance. After receiving the light-emitting current, the OLED needs to first complete the charging of the parasitic capacitance and then light up. However, due to the different sizes of the parasitic capacitances of the OLEDs emitting different colors of light. Therefore, the charging durations of the parasitic capacitances of the OLEDs emitting different colors of light are not equal, which results in different lighting-up speeds of the OLEDs emitting different colors of light, causing a smearing phenomenon when the display panel is refreshed due to the different lighting-up speeds of the OLEDs.

[0039] For example, usually, the light-emitting units of the display panel include red pixels (R pixels), green pixels (G pixels), and blue pixels (B pixels). The red pixels include OLEDs that emit red light. The green pixels include OLEDs that emit green light. The blue pixels include OLEDs that emit blue light.

[0040] Among them, the OLED that emits green light has the largest parasitic capacitance, the OLED that emits blue light has the second largest parasitic capacitance, and the OLED that emits red light has the smallest parasitic capacitance. And the smaller the parasitic capacitance, the faster the charging of the parasitic capacitance and the shorter the charging duration. Therefore, when the display panel is refreshed, usually the OLED that emits red light lights up first, then the OLED that emits blue light lights up, and the OLED that emits green light lights up last. In this way, due to the difference in the lighting-up speeds of the OLEDs of different colors, the ratio of the red light component, the green light component, and the blue light component in the light emitted by the light-emitting unit is unbalanced, and the red component accounts for a relatively large proportion. Therefore, when the display panel is refreshed, it will initially show an overall red color, with a smearing and redness phenomenon. In particular, when the display panel refreshes and displays a black-and-white image, the overall redness situation will be more obvious, and the smearing and redness phenomenon is serious.

[0041] Please refer to Figure 3 , which shows a schematic structural diagram of a pixel driving circuit provided by an embodiment of the present application. The pixel driving circuit can solve the above problems to a certain extent. As Figure 3 shown, the pixel driving circuit is used to be connected to the light-emitting element 1 to drive the light-emitting element 1 to emit light. Among them, the pixel driving circuit may include: a driving unit 301 and a capacitance adjusting unit 302.

[0042] The driving unit 301 is connected to the anode of the light-emitting element 1. The driving unit 301 is configured to receive a lighting signal. The lighting signal is used to instruct the driving unit 301 to transmit a light-emitting current I to the light-emitting element 1. OLED The light-emitting current I OLED is used to drive the light-emitting element 1 to emit light.

[0043] The capacitance adjusting unit 302 is connected to at least one of the anode or the cathode of the light-emitting element 1. The capacitance adjusting unit 302 is configured to adjust the capacitance value between the first terminal O1 and the common ground terminal ELVSS of the pixel driving circuit, where the first terminal O1 is the output terminal where the driving unit 301 is connected to the anode of the light-emitting element 1.

[0044] In the embodiment of the present application, when the capacitance value between the first terminal O1 and the common ground terminal ELVSS of the pixel driving circuit increases, it is equivalent to increasing the capacitance value of the parasitic capacitance of the light-emitting element 1. Thus, the light-emitting current transmitted by the driving unit 301 to the light-emitting element 1 first needs to satisfy the capacitance charging requirement of the parasitic capacitance of the light-emitting element 1, and then is used to drive the light-emitting element 1 to emit light. Therefore, under the same condition of the light-emitting current I OLED the charging speed of the light-emitting element 1 can be reduced, the charging duration of the light-emitting element 1 can be increased, and thus the lighting speed of the light-emitting element 1 can be slowed down. Similarly, when the capacitance value between the first terminal O1 and the common ground terminal ELVSS of the pixel driving circuit decreases, it is equivalent to reducing the parasitic capacitance of the light-emitting element 1. Therefore, under the same condition of the light-emitting current I OLED the charging speed of the light-emitting element 1 can be increased, the charging duration of the light-emitting element 1 can be reduced, and thus the lighting speed of the light-emitting element 1 can be accelerated. Based on this, by adjusting the capacitance value between the first terminal O1 and the common ground terminal ELVSS in the pixel driving circuit through the capacitance adjusting unit 302, the lighting speed of the light-emitting element 1 can be effectively adjusted.

[0045] In the embodiment of the present application, the pixel driving circuit includes a driving unit and a capacitance adjusting unit. The driving unit is connected to the anode of the light-emitting element and is configured to receive a lighting signal, which is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjusting unit is used for the capacitance value between the first end and the common ground terminal of the pixel driving circuit, and the first end is the output terminal where the driving unit is connected to the anode of the light-emitting element. This is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjusting unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve a consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approach the same, thereby improving the ghosting phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0046] For example, the light-emitting units of the display panel include a light-emitting element that emits red light, a light-emitting element that emits green light, and a light-emitting element that emits blue light. The pixel driving circuit can be used to reduce the lighting speed of the light-emitting element that emits red light, and / or increase the lighting speed of the light-emitting element that emits green light, so as to eliminate the difference in the lighting speeds of light-emitting elements of different colors to a certain extent, so that the red light component, green light component, and blue light component in the light emitted by the light-emitting unit are balanced in proportion, so as to avoid a large proportion of the red component, and further avoid the phenomenon of red ghosting when the display panel is refreshed.

[0047] In an optional case, the capacitance adjusting unit 302 is used to increase the capacitance value between the first end O1 and the common ground terminal ELVSS of the pixel driving circuit. As Figure 4 shown, the capacitance adjusting unit 302 includes: a first switching element 3021 and a first capacitor C1. The first switching element 302 is connected to the anode of the light-emitting element 1 and one end of the first capacitor C1. The other end of the first capacitor C1 is connected to the cathode of the light-emitting element 1.

[0048] The first switching element 3021 is used to control the connection or disconnection between the anode of the light-emitting element 1 and the first capacitor C1.

[0049] Among them, the cathode of the light-emitting element 1 is connected to the common ground terminal ELVSS of the pixel driving circuit. When the anode of the light-emitting element 1 is connected to the first capacitor C1, the first capacitor C1 is connected in parallel with the parasitic capacitance of the light-emitting element 1. In Figure 4Among them, the capacitance value between the first terminal O1 and the common ground terminal ELVSS increases, which is equivalent to increasing the capacitance value of the parasitic capacitance of the light-emitting element 1. Among them, the first terminal O1 is the electrical connection intersection point of the driving unit 301 and the anode of the light-emitting element 1.

[0050] At this time, the light-emitting current transmitted by the driving unit 301 to the light-emitting element 1 first needs to meet the capacitance charging requirement between the first terminal O1 and the common ground terminal ELVSS, and then is used to drive the light-emitting element 1 to emit light. Therefore, when the first switching element 3021 controls the anode of the light-emitting element 1 to be connected to the first capacitor C1, the lighting speed of the light-emitting element 1 can be reduced.

[0051] Optionally, the first switching element 3021 can be used to control the anode of the light-emitting element 1 to be connected to the first capacitor C1 during the light-emitting stage of the light-emitting element 1. Specifically, for example, the first switching element 3021 can be used to control the anode of the light-emitting element 1 to be connected to the first capacitor C1 in the first sub-frame of the light-emitting stage of the light-emitting element 1; and control the anode of the light-emitting element 1 to be disconnected from the first capacitor C1 in other stages of the light-emitting element 1. Other stages refer to other moments except the first sub-frame of the light-emitting stage in the refresh cycle of a single-frame image.

[0052] Since the charging process of the parasitic capacitance of the light-emitting element 1 usually occurs in the first sub-frame of the light-emitting stage. Therefore, only controlling the first switching element 3021 to connect the anode of the light-emitting element 1 and the first capacitor C1 in the first sub-frame of the light-emitting stage to increase the capacitance value between the first terminal O1 and the common ground terminal ELVSS and reduce the lighting speed of the light-emitting element 1 can achieve precise control of the adjustment timing of the capacitance value between the first terminal O1 and the common ground terminal ELVSS, and effectively avoid the influence of the adjusted capacitance between the first terminal O1 and the common ground terminal ELVSS on other timings of the pixel driving circuit.

[0053] Exemplarily, the first switching element 3021 can be used to connect or disconnect the anode of the light-emitting element 1 and the first capacitor C1 under the control of a first control signal. Among them, the first control signal controls the first switching element 3021 to connect the anode of the light-emitting element 1 and the first capacitor C1 in the first sub-frame of the light-emitting stage of the light-emitting element 1. The first control signal controls the first switching element 3021 to disconnect the anode of the light-emitting element 1 and the first capacitor C1 in other stages of the light-emitting element 1.

[0054] In some embodiments of the present application, please continue to refer to Figure 4 Among them, the first switching element 3021 includes: a first transistor T1. The control terminal of the first transistor T1 is used to receive the first control signal, the input terminal of the first transistor T1 is connected to the anode of the light-emitting element 1, and the output terminal of the first transistor T1 is connected to one end of the first capacitor C1. The first transistor T1 is used to conduct or turn off under the control of the first control signal.

[0055] Optionally, the first transistor T1 is configured to receive a first control signal at an effective level during the light-emitting stage of the light-emitting element 1 and conduct under the control of the first control signal at the effective level. Further optionally, the first transistor T1 is configured to receive a first control signal at an effective level in the first sub-frame of the light-emitting stage of the light-emitting element 1 and conduct under the control of the first control signal at the effective level. The first transistor T1 is further configured to receive a first control signal at an ineffective level during other stages of the light-emitting element 1 and turn off under the control of the first control signal at the ineffective level.

[0056] Exemplarily, the first transistor T1 may be an N-type TFT. Correspondingly, the control terminal of the first transistor T1 refers to the gate, the input terminal refers to the drain, and the output terminal refers to the source. And the effective level of the first control signal refers to a high level, and the ineffective level refers to a low level. In another example, the first transistor T1 may be a P-type TFT. Correspondingly, the control terminal of the first transistor T1 refers to the gate, the input terminal refers to the source, and the output terminal refers to the drain. And the effective level of the first control signal refers to a low level, and the ineffective level refers to a high level.

[0057] In an optional case, the capacitance adjustment unit 302 is configured to reduce the capacitance value between the first terminal O1 and the common ground terminal ELVSS of the pixel driving circuit. As Figure 5 shown, the capacitance adjustment unit 302 includes: a second switching element 3022 and a second capacitor C2. The second switching element 3022 is connected to the cathode of the light-emitting element 1, the second capacitor C2, and the common ground terminal ELVSS of the pixel driving circuit. The second switching element 3022 is configured to control the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS through the second capacitor C2, or to control the cathode of the light-emitting element 1 to be directly connected to the common ground terminal ELVSS.

[0058] Wherein, when the cathode of the light-emitting element 1 is connected to the common ground terminal ELVSS through the second capacitor C2, the second capacitor C2 is connected in series with the parasitic capacitance of the light-emitting element 1. In Figure 5 this case, the capacitance value between the first terminal O1 and the common ground terminal ELVSS is reduced, which is equivalent to reducing the capacitance value of the parasitic capacitance of the light-emitting element 1.

[0059] At this time, the light-emitting current transmitted by the driving unit 301 to the light-emitting element 1 first needs to satisfy the charging requirement of the capacitance between the first terminal O1 and the common ground terminal ELVSS, and then is used to drive the light-emitting element 1 to emit light. Therefore, when the second switching element 3022 controls the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS through the second capacitor C2, the lighting speed of the light-emitting element 1 can be increased.

[0060] Optionally, the second switching element 3022 is configured to control the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS through the second capacitor C2 during the light-emitting stage of the light-emitting element 1. Specifically, for example, the second switching element 3022 may be configured to control the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS through the second capacitor C2 in the first sub-frame of the light-emitting stage of the light-emitting element 1; and control the cathode of the light-emitting element 1 to be directly connected to the common ground terminal ELVSS in other stages of the light-emitting element 1.

[0061] Since the charging process of the parasitic capacitance of the light-emitting element 1 usually occurs in the first sub-frame of the light-emitting stage. Therefore, only in the first sub-frame of the light-emitting stage, the second switching element 3022 is controlled to connect the first terminal O1 to the common ground terminal ELVSS through the second capacitor C2, so as to reduce the capacitance value between the first terminal O1 and the common ground terminal ELVSS, reduce the lighting speed of the light-emitting element 1, and can achieve precise control of the adjustment timing of the capacitance value between the first terminal O1 and the common ground terminal ELVSS, effectively avoiding the influence of the adjusted capacitance between the first terminal O1 and the common ground terminal ELVSS on other timings of the pixel driving circuit.

[0062] Exemplarily, the second switching element 3022 may be configured to control the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS through the second capacitor C2 or control the cathode of the light-emitting element 1 to be directly connected to the common ground terminal ELVSS under the control of the second control signal. Wherein, the second control signal controls the second switching element 3022 to connect the first terminal O1 to the common ground terminal ELVSS through the second capacitor C2 in the first sub-frame of the light-emitting stage of the light-emitting element 1. The second control signal controls the second switching element 3022 to directly connect the first terminal O1 to the common ground terminal ELVSS in other stages of the light-emitting element 1.

[0063] In some embodiments of the present application, please continue to refer to Figure 5 , the second switching element 3022 includes: a first switching device 30221 and a second switching device 30222. The first switching device 30221 is connected to the cathode of the light-emitting element 1 and one end of the second capacitor C2. The first switching device 30221 is configured to control the connection or disconnection between the cathode of the light-emitting element 1 and the second capacitor C2. The second switching device 30222 is connected to the cathode of the light-emitting element 1 and the common ground terminal ELVSS. The second switching device 30222 is configured to control the connection or disconnection between the cathode of the light-emitting element 1 and the common ground terminal ELVSS.

[0064] Wherein, when the first switching device 30221 controls the cathode of the light-emitting element 1 to be connected to the second capacitor C2, the second switching device 30222 controls the cathode of the light-emitting element 1 to be disconnected from the common ground terminal ELVSS. When the first switching device 30221 controls the cathode of the light-emitting element 1 to be disconnected from the second capacitor C2, the second switching device 30222 controls the cathode of the light-emitting element 1 to be connected to the common ground terminal ELVSS.

[0065] In an alternative case, the first switching device 30221 is configured to connect or disconnect the cathode of the light-emitting element 1 from the second capacitor C2 under the control of a second control signal. The second switching device 30222 is configured to connect or disconnect the cathode of the light-emitting element 1 from the common ground terminal ELVSS under the control of the second control signal. Wherein, the second control signal is configured to control the second switching device 30222 to be disconnected when controlling the first switching device 30221 to be connected, and to control the second switching device 30222 to be turned on when controlling the first switching device 30221 to be disconnected.

[0066] Exemplarily, please continue to refer to Figure 5 , the first switching device 30221 includes a second transistor T2. The second switching device 30222 includes a third transistor T3. The input terminal of the second transistor T2 is connected to the cathode of the light-emitting element 1, the output terminal of the second transistor T2 is connected to one end of the second capacitor C2, and the control terminal of the second transistor T2 is configured to receive the second control signal.

[0067] The input terminal of the third transistor T3 is connected to the cathode of the light-emitting element 1, the output terminal of the third transistor T3 is connected to the common ground terminal ELVSS, and the control terminal of the third transistor T3 is configured to receive the second control signal. Wherein, the second transistor T2 and the third transistor T3 are configured to be turned on or off under the control of the second control signal. And, the second control signal is configured to control the third transistor T3 to be turned off when controlling the second transistor T2 to be turned on, and to control the third transistor T3 to be turned on when controlling the second transistor T2 to be turned off.

[0068] Further alternatively, the second transistor T2 is configured to receive a second control signal at an effective level during the light-emitting stage of the light-emitting element 1 and to be turned on under the control of the second control signal at the effective level. The third transistor T3 is configured to receive a second control signal at an effective level during the light-emitting stage of the light-emitting element 1 and to be turned off under the control of the second control signal at the effective level.

[0069] Further optionally, the second transistor T2 is configured to receive a second control signal at an effective level during a first sub-frame of the light-emitting stage of the light-emitting element 1, and is turned on under the control of the second control signal at the effective level. The second transistor T2 is further configured to receive a second control signal at an ineffective level during other stages of the light-emitting element 1, and is turned off under the control of the second control signal at the ineffective level.

[0070] The third transistor T3 is configured to receive a second control signal at an effective level during a first sub-frame of the light-emitting stage of the light-emitting element 1, and is turned off under the control of the second control signal at the effective level. The third transistor T3 is configured to receive a second control signal at an ineffective level during other stages of the light-emitting element 1, and is turned on under the control of the second control signal at the ineffective level.

[0071] Exemplarily, the second transistor T2 is an N-type TFT. Accordingly, the control terminal of the second transistor T2 refers to the gate, the input terminal refers to the drain, and the output terminal refers to the source. The third transistor T3 is a P-type TFT. Accordingly, the control terminal of the third transistor T3 refers to the gate, the input terminal refers to the source, and the output terminal refers to the drain. And, the effective level of the second control signal refers to a high level, and the ineffective level refers to a low level.

[0072] In another example, the second transistor T2 is a P-type TFT. Accordingly, the control terminal of the second transistor T2 refers to the gate, the input terminal refers to the source, and the output terminal refers to the drain. The third transistor T3 is an N-type TFT. Accordingly, the control terminal of the third transistor T3 refers to the gate, the input terminal refers to the drain, and the output terminal refers to the source. And, the effective level of the second control signal refers to a low level, and the ineffective level refers to a high level.

[0073] In another alternative case, the first switching device 30221 is configured to connect or disconnect the cathode of the light-emitting element 1 and the second capacitor C2 under the control of the third control signal. The second switching device 30222 is configured to connect or disconnect the cathode of the light-emitting element 1 and the common ground terminal ELVSS under the control of the fourth control signal. Wherein, when the third control signal controls the first switching device 30221 to connect, the fourth control signal controls the second switching device 30222 to disconnect. When the third control signal controls the first switching device 30221 to disconnect, the fourth control signal controls the second switching device 30222 to turn on.

[0074] Exemplarily, the first switching device 30221 includes a second transistor T2. The second switching device 30222 includes a third transistor T3. The input terminal of the second transistor T2 is connected to the cathode of the light-emitting element 1. The output terminal of the second transistor T2 is connected to one end of the second capacitor C2. The control terminal of the second transistor T2 is used to receive a third control signal. The second transistor T2 is used to conduct or turn off under the control of the third control signal.

[0075] The input terminal of the third transistor T3 is connected to the cathode of the light-emitting element 1. The output terminal of the third transistor T3 is connected to the common ground terminal ELVSS. The control terminal of the third transistor T3 is used to receive a fourth control signal. The third transistor T3 is used to conduct or turn off under the control of the fourth control signal.

[0076] Further optionally, the second transistor T2 is used to receive a third control signal with an effective level during the light-emitting stage of the light-emitting element 1 and conduct under the control of the third control signal with the effective level. The third transistor T3 is used to receive a fourth control signal with an invalid level during the light-emitting stage of the light-emitting element 1 and turn off under the control of the fourth control signal with the invalid level.

[0077] Still further optionally, the second transistor T2 is used to receive a third control signal with an effective level in the first sub-frame of the light-emitting stage of the light-emitting element 1 and conduct under the control of the third control signal with the effective level. The second transistor T2 is also used to receive a third control signal with an invalid level in other stages of the light-emitting element 1 and turn off under the control of the third control signal with the invalid level.

[0078] The third transistor T3 is used to receive a fourth control signal with an invalid level in the first sub-frame of the light-emitting stage of the light-emitting element 1 and turn off under the control of the fourth control signal with the invalid level. The third transistor T3 is used to receive a fourth control signal with an effective level in other stages of the light-emitting element 1 and conduct under the control of the fourth control signal with the effective level.

[0079] In some embodiments of the present application, the capacitance adjustment unit 302 is used to reduce the capacitance value between the first terminal O1 and the common ground terminal ELVSS of the pixel driving circuit. As Figure 6 shown, the capacitance adjustment unit 302 includes: a third switching device 3023 and a third capacitor C3. The third switching device 3023 is connected to the driving unit 301, the anode of the light-emitting element 1, and the third capacitor C3. The third switching device 3023 is used to control the driving unit 301 to communicate with the anode of the light-emitting element 1 through the third capacitor C3, or to control the driving unit 301 to directly communicate with the anode of the light-emitting element 1.

[0080] Among them, the cathode of the light-emitting element 1 is connected to the common ground terminal ELVSS. When the anode of the light-emitting element 1 is connected to the driving unit 301 through the third capacitor C3, the third capacitor C3 is connected in series with the parasitic capacitance of the light-emitting element 1. In Figure 6 the capacitance value between the first terminal O1 and the common ground terminal ELVSS decreases, which is equivalent to reducing the capacitance value of the parasitic capacitance of the light-emitting element 1.

[0081] At this time, the light-emitting current transmitted by the driving unit 301 to the light-emitting element 1 first needs to satisfy the capacitance charging requirement between the first terminal O1 and the common ground terminal ELVSS, and then is used to drive the light-emitting element 1 to emit light. Therefore, when the third switching element 3023 controls the driving unit 301 to be connected to the anode of the light-emitting element 1 through the third capacitor C3, the lighting speed of the light-emitting element 1 can be increased.

[0082] Optionally, the third switching element 3023 is used to control the driving unit 301 to be connected to the anode of the light-emitting element 1 through the third capacitor C3 during the light-emitting stage of the light-emitting element 1. Specifically, for example, the third switching element 3023 can be used to control the driving unit 301 to be connected to the anode of the light-emitting element 1 through the third capacitor C3 in the first sub-frame of the light-emitting stage of the light-emitting element 1; in other stages of the light-emitting element 1, the driving unit 301 is directly connected to the anode of the light-emitting element 1.

[0083] Since the charging process of the parasitic capacitance of the light-emitting element 1 usually occurs in the first sub-frame of the light-emitting stage. Therefore, only in the first sub-frame of the light-emitting stage, the third switching element 3023 is controlled to connect the first terminal O1 and the common ground terminal ELVSS through the third capacitor C3 to reduce the capacitance value between the first terminal O1 and the common ground terminal ELVSS and reduce the lighting speed of the light-emitting element 1, so as to achieve precise control of the adjustment timing of the capacitance value between the first terminal O1 and the common ground terminal ELVSS, and effectively avoid the influence of the adjusted capacitance between the first terminal O1 and the common ground terminal ELVSS on other timings of the pixel driving circuit.

[0084] Exemplarily, the third switching element 3023 can be used to control the driving unit 301 to be connected to the anode of the light-emitting element 1 through the third capacitor C3 under the control of the fifth control signal, or control the driving unit 301 to be directly connected to the anode of the light-emitting element 1. Among them, the fifth control signal controls the third switching element 3023 to connect the first terminal O1 and the common ground terminal ELVSS through the third capacitor C3 in the first sub-frame of the light-emitting stage of the light-emitting element 1. The fifth control signal controls the third switching element 3023 to directly connect the first terminal O1 and the common ground terminal ELVSS in other stages of the light-emitting element 1.

[0085] In some embodiments of the present application, please continue to refer to Figure 6, the third switching element 3023 includes: a third switching device 30231 and a fourth switching device 30232.

[0086] The third switching device 30231 is respectively connected to the driving unit 301 and one end of the third capacitor C3, and the other end of the third capacitor C3 is connected to the anode of the light-emitting element 1. The third switching device 30231 is used to control the connection or disconnection between the driving unit 301 and the third capacitor C3. The fourth switching device 30232 is respectively connected to the driving unit 301 and the anode of the light-emitting element 1. The fourth switching device 30232 is used to control the connection or disconnection between the driving unit 301 and the anode of the light-emitting element 1.

[0087] Wherein, when the third switching device 30231 controls the connection between the driving unit 301 and the third capacitor C3, the fourth switching device 30232 controls the disconnection between the driving unit 301 and the anode of the light-emitting element 1, so as to realize the connection between the driving unit 301 and the anode of the light-emitting element 1 through the third capacitor C3. When the third switching device 30231 controls the disconnection between the driving unit 301 and the third capacitor C3, the fourth switching device 30232 controls the connection between the driving unit 301 and the anode of the light-emitting element 1, so as to realize the direct connection between the driving unit 301 and the anode of the light-emitting element 1.

[0088] Exemplarily, please continue to refer to Figure 6 , the third switching device 30231 includes an eleventh transistor. The fourth switching device 30232 includes a twelfth transistor.

[0089] The input end of the eleventh transistor is connected to the driving unit 301, the output end of the eleventh transistor is connected to one end of the third capacitor C3, the other end of the third capacitor C3 is connected to the anode of the light-emitting element 1, and the cathode of the light-emitting element 1 is connected to the common ground terminal ELVSS. The control end of the eleventh transistor is used to receive a fifth control signal.

[0090] The input end of the twelfth transistor is connected to the light-emitting element 1, the output end of the twelfth transistor is connected to the anode of the light-emitting element 1, and the control end of the twelfth transistor is used to receive a fifth control signal. Wherein, the eleventh transistor and the twelfth transistor are used to conduct or turn off under the control of the fifth control signal. And the fifth control signal is used to control the twelfth transistor to turn off when controlling the eleventh transistor to conduct, and control the twelfth transistor to conduct when controlling the eleventh transistor to turn off.

[0091] In some embodiments of the present application, such as Figure 4 and Figure 5As shown, the pixel driving circuit further includes: a light-emitting control unit 303 and a reset unit 304. The light-emitting control unit 303 is connected to the driving unit 301 and the light-emitting element 1, and the reset unit 304 is connected to the driving unit 301 and the light-emitting element 1. The first terminal O1 is the electrical connection intersection point among the light-emitting control unit 303, the reset unit 304, and the light-emitting element 1.

[0092] Among them, the reset unit 304 is used to reset the light-emitting element 1. The light-emitting control unit 303 is used to receive a light-emitting current and transmit the light-emitting current to the light-emitting element 1 through the driving unit 301.

[0093] Optionally, the light-emitting control unit 303 includes an eighth transistor T8 and a ninth transistor T9. The control terminal of the eighth transistor T8 is used to receive an enable signal, the input terminal of the eighth transistor T8 is used to receive a light-emitting current, and the output terminal of the eighth transistor T8 is connected to the driving unit 303. The control terminal of the ninth transistor T9 is used to receive an enable signal, the input terminal of the ninth transistor T9 is connected to the driving unit 303, and the output terminal of the ninth transistor T9 is connected to the anode of the light-emitting element 1. The eighth transistor T8 and the ninth transistor T9 are used to conduct or disconnect under the control of the enable signal. Specifically optionally, the eighth transistor T8 and the ninth transistor T9 are used to conduct under the control of the valid enable signal received during the light-emitting stage of the light-emitting element 1 and turn off under the control of the invalid enable signal received during other stages except the light-emitting stage.

[0094] Further optionally, the reset unit 304 includes a tenth transistor T10. The control terminal of the tenth transistor T10 is used to receive a first scan signal, the input terminal of the tenth transistor T10 is used to receive a second voltage, and the output terminal of the tenth transistor T10 is connected to the anode of the light-emitting element 1. The tenth transistor T10 is used to conduct or disconnect under the control of the first scan signal, and transmit the second voltage to the light-emitting element 1 to reset the light-emitting element 1 when conducting. The first terminal O1 is the electrical connection intersection point among the output terminal of the ninth transistor T9, the output terminal of the tenth transistor T10, and the anode of the light-emitting element 1.

[0095] In some embodiments of the present application, as Figure 4 and Figure 5 shown, the pixel driving circuit further includes: a writing unit 305, a compensation unit 306, an initialization unit 307, and a storage unit 308. The writing unit 305 is connected to the driving unit 301, and the driving unit 301 is further connected to the storage unit 308 through the compensation unit 306. The initialization unit 307 is respectively connected to the driving unit 301 and the storage unit 308.

[0096] Among them, the writing unit 305 is used to receive the frame voltage data signal and output the frame voltage data signal to the driving unit 301. The driving unit 301 is used to store the frame voltage data signal in the storage unit 308 through the compensation unit 306. The initialization unit 307 is used to provide a first voltage to the driving unit 301 and the storage unit 308 for storage in the storage unit 308 and for the driving unit 301 to connect the writing unit 305 and the compensation unit 306.

[0097] Optionally, the storage unit 308 includes a capacitor Cst. The driving unit 301 includes a fourth transistor T4. The writing unit 305 includes a fifth transistor T5. The compensation unit 306 includes a sixth transistor T6. The initialization unit 307 includes a seventh transistor T7.

[0098] The control terminal of the fourth transistor T4 is connected to the capacitor Cs. The input terminals of the fourth transistor T4 are respectively connected to the light-emitting control unit 303 and the output terminal of the fifth transistor T5. The output terminals of the fourth transistor T4 are respectively connected to the sixth transistor T6 and the light-emitting control unit 303.

[0099] The control terminal of the fifth transistor T5 is used to receive the first scan signal. The input terminal of the fifth transistor T5 is used to receive the frame voltage data signal. The output terminal of the fifth transistor T6 is connected to the input terminal of the fourth transistor T4. The fifth transistor T5 is used to conduct or turn off under the control of the first scan signal.

[0100] The control terminal of the sixth transistor T6 is used to receive the first scan signal. The input terminal of the sixth transistor T6 is connected to the output terminal of the fourth transistor T4. The output terminal of the sixth transistor T6 is connected to the capacitor Cs. The sixth transistor T6 is used to conduct or turn off under the control of the first scan signal.

[0101] The control terminal of the seventh transistor T7 is used to receive the second scan signal. The input terminal of the seventh transistor T7 is used to receive the first voltage. The output terminals of the seventh transistor T7 are respectively connected to the control terminal of the fourth transistor T4 and the capacitor Cs. The seventh transistor T7 is used to conduct or turn off under the control of the second scan signal.

[0102] For the convenience of further understanding the technical solution of the present application, the following uses two examples to illustrate the pixel driving circuit provided by the embodiments of the present application.

[0103] Exemplarily, the capacitance adjusting unit 302 is used to increase the capacitance value between the first terminal O1 and the common ground terminal ELVSS. Assume that the light-emitting element is an OLED. As Figure 4As shown, the pixel driving circuit is an 8T2C pixel driving circuit, which further includes: a power supply voltage terminal ELVDD, a common ground terminal ELVSS, a first input voltage terminal VINT1, a second input voltage terminal VINT2, a data writing terminal DATA, an nth row scanning line terminal Scan[n], an (n-1)th row scanning line terminal Scan[n-1], an nth row scanning enable terminal EM[n], a control terminal C, a first transistor T1, fourth transistors T4 to tenth transistors T10, a capacitor Cst, and a first capacitor C1.

[0104] Among them, the power supply voltage terminal ELVDD is used to provide a constant positive voltage and a light-emitting current. The first input voltage terminal VINT1 is used to provide a first voltage. The second input voltage terminal VINT2 is used to provide a second voltage. The data writing terminal DATA is used to provide a frame voltage data signal. The nth row scanning line terminal Scan[n] is used to provide a first scanning signal. The (n-1)th row scanning line terminal Scan[n-1] is used to provide a second scanning signal. The nth row scanning enable terminal EM[n] is used to enable a signal. The control terminal C is used to provide a first control signal. The first transistor T1, fifth transistors T5, sixth transistors T6, seventh transistors T7, and tenth transistors T10 are P-type TFTs. The fourth transistors T4, eighth transistors T8, and ninth transistors T9 are N-type TFTs.

[0105] Among them, the fourth transistor T4 serves as a driving transistor and is used to control the magnitude of the conduction current through the gate voltage. The first transistor T1, fifth transistors T5 to tenth transistors T10 serve as switching transistors and are used to control the on / off of the circuit. Specifically, the control terminal of the first transistor T1 is connected to C, the input terminal is connected to the first terminal O1, the output terminal is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to the common ground terminal ELVSS.

[0106] The control terminal of the fourth transistor T4 is connected to the third node O3, the input terminal is connected to the fourth node O4, and the output terminal is connected to the fifth node O5. The control terminal of the fifth transistor T5 is connected to the n-th row scan line terminal Scan[n], the input terminal is connected to the data write terminal DATA, and the output terminal is connected to the fourth node O4. The control terminal of the sixth transistor T6 is connected to the n-th row scan line terminal Scan[n], the input terminal is connected to the fifth node O5, and the output terminal is connected to the sixth node O6, and the sixth node O6 is connected to the third node O3. The control terminal of the seventh transistor T7 is connected to the (n - 1)-th row scan line terminal Scan[n - 1], the input terminal is connected to the first input voltage terminal VINT1, and the output terminal is connected to the sixth node O6. The control terminal of the eighth transistor T8 is connected to the scan enable terminal EM, the input terminal is connected to the power supply voltage terminal ELVDD, and the output terminal is connected to the fourth node O4. The control terminal of the ninth transistor T9 is connected to the scan enable terminal EM, the input terminal is connected to the fifth node O5, and the output terminal is connected to the anode of the OLED. The cathode of the OLED is connected to the common ground terminal ELVSS. The control terminal of the tenth transistor T10 is connected to the n-th row scan line terminal Scan[n], the input terminal is connected to the second input voltage terminal VINT2, and the output terminal is connected to the anode of the OLED.

[0107] It should be noted that the first terminal O1 is the electrical connection intersection point among the input terminal of the first transistor T1, the output terminal of the ninth transistor T9, the output terminal of the tenth transistor T10, and the anode of the OLED. The common ground terminal ELVSS is the electrical connection intersection point between the other end of the first capacitor C1 and the cathode of the light-emitting element 1. The third node O3 is the electrical connection intersection point between the capacitor Cst and the control terminal of the fourth transistor T4. The fourth node O4 is the electrical connection intersection point among the input terminal of the fourth transistor T4, the output terminal of the fifth transistor T5, and the output terminal of the eighth transistor T8. The fifth node O5 is the electrical connection intersection point among the output terminal of the fourth transistor T4, the input terminal of the sixth transistor T6, and the input terminal of the ninth transistor T9. The sixth node O6 is the electrical connection intersection point among the output terminal of the sixth transistor T6, the input terminal of the seventh transistor T7, and the third node O3. In the case where the transistor is an N-type transistor, the control terminal of the transistor refers to the gate, the input terminal refers to the drain, and the output terminal refers to the source. In the case where the transistor is a P-type transistor, the control terminal of the transistor refers to the gate, the input terminal refers to the source, and the output terminal refers to the drain.

[0108] As Figure 7 shown, Figure 4The driving principle of the pixel driving circuit shown is as follows: within the refresh period T for displaying one frame of an image, the entire driving timing process includes an initial restoration stage t1, a compensation stage t2, and a light-emitting stage t3, a total of 3 stages. Among them, the light-emitting stage t3 includes y sub-frames t3y such as the first sub-frame t31, the second sub-frame t32, and the third sub-frame t33. It should be noted that the number of sub-frames that the light-emitting stage t3 can include can be determined according to the actual situation.

[0109] Initial restoration stage t1: The n - 1th row scan line terminal Scan[n - 1] is connected to a low-level signal, and the nth row scan line terminal Scan[n], the nth row scan enable terminal EM[n], and the control terminal C are all connected to high-level signals.

[0110] The seventh transistor T7 is turned on, and the negative voltage provided by the first input voltage terminal VINT1 is written to the gate of the fourth transistor T4 through the turned-on seventh transistor T7 and stored on the capacitor Cst for holding. At this time, the first transistor T1, the fifth transistor T5, the sixth transistor T6, and the eighth to tenth transistors T8 - T10 are turned off.

[0111] Compensation stage t2: The nth row scan line terminal Scan[n] is connected to a low-level signal, the n - 1th row scan line terminal Scan[n - 1] is connected to a low-level signal, and the nth row scan enable terminal EM[n] and the control terminal C are all connected to high-level signals.

[0112] The fifth transistor T5, the sixth transistor T6, and the tenth transistor are turned on. At the same time, the fourth transistor T4 remains in the on state under the voltage stored on the capacitor Cst in the previous stage. The frame voltage data signal input at the data input terminal DATA is stored on the capacitor Cst through the fifth transistor T5, the fourth transistor T4, and the sixth transistor T6. And, the seventh transistor T7 is turned on, and the negative voltage provided by the second input voltage terminal VINT2 is written to the anode of the OLED to reset the OLED.

[0113] The first sub-frame t31 of the light-emitting stage t3: The nth row scan enable terminal EM[n] and the control terminal C are both connected to low-level signals. The n - 1th row scan line terminal Scan[n - 1] is connected to a high-level signal.

[0114] The first transistor T1, the eighth transistor T8, and the ninth transistor T9 are turned on. At the same time, the fourth transistor T4 remains turned on while the voltage Vdata - Vth is stored in the capacitor Cst. The fifth transistor T5 to the seventh transistor T7 and the tenth transistor T10 are turned off. The light-emitting current provided by the power supply voltage terminal ELVDD flows through the eighth transistor T8, the fourth transistor T4, and the ninth transistor T9 to the first terminal O1. The current passing through the first terminal O1 is divided into two paths and flows to the common ground terminal ELVSS. One path flows through the first transistor T1 and the first capacitor C1 to the common ground terminal ELVSS. The other path flows through the OLED to the common ground terminal ELVSS, driving the OLED to emit light.

[0115] For the second sub-frame t32 to the y-th sub-frame t3y of the light-emitting stage t3: A low-level signal is applied to the n-th row scan enable terminal EM[n]. High-level signals are input to the (n - 1)-th row scan line terminal Scan[n - 1], the n-th row scan line terminal Scan[n], and the control terminal C.

[0116] The eighth transistor T8, the ninth transistor T9, and the fourth transistor T4 are turned on. The first transistor T1, the fifth transistor T5 to the seventh transistor T7, and the tenth transistor T10 are turned off. The light-emitting current provided by the power supply voltage terminal ELVDD flows through the eighth transistor T8, the fourth transistor T4, and the ninth transistor T9 to the first terminal O1, and then flows through the first terminal O1 and the OLED to the common ground terminal ELVSS, driving the OLED to emit light.

[0117] As another example, the capacitance adjustment unit 302 is used to reduce the capacitance value between the first terminal O1 and the common ground terminal ELVSS. Assume that the light-emitting element is an OLED. As Figure 5 shown, the pixel driving circuit is a 9T2C pixel driving circuit, which further includes: a power supply voltage terminal ELVDD, a common ground terminal ELVSS, a first input voltage terminal VINT1, a second input voltage terminal VINT2, a data writing terminal DATA, an n-th row scan line terminal Scan[n], an (n - 1)-th row scan line terminal Scan[n - 1], an n-th row scan enable terminal EM[n], a control terminal C, a second transistor T2 to a tenth transistor T10, a capacitor Cst, and a second capacitor C2.

[0118] Different from the example shown in Figure 4 is that the control terminal C is used to provide a second control signal. The second transistor T2, the fifth transistor T5, the sixth transistor T6, the seventh transistor T7, and the tenth transistor T10 are P-type TFTs. The third transistor T3, the fourth transistor T4, the eighth transistor T8, and the ninth transistor T9 are N-type TFTs.

[0119] Among them, the fourth transistor T4 serves as a driving transistor, and the second transistor T2, the third transistor T3, and the fifth transistor T5 to the tenth transistor T10 serve as switching transistors. Specifically,

[0120] The control terminal of the second transistor T2 is connected to the control terminal C, the input terminal is connected to the cathode of the OLED, the output terminal is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the common ground terminal ELVSS. The control terminal of the third transistor T3 is connected to the control terminal C, the input terminal is connected to the cathode of the OLED, and the output terminal is directly connected to the common ground terminal ELVSS.

[0121] The control terminal of the third transistor T3 is connected to the control terminal C, the input terminal is connected to the cathode of the OLED, the output terminal is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the common ground terminal ELVSS. The control terminal of the fourth transistor T4 is connected to the third node O3, the input terminal is connected to the fourth node O4, and the output terminal is connected to the fifth node O5. The control terminal of the fifth transistor T5 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the data write terminal DATA, and the output terminal is connected to the fourth node O4. The control terminal of the sixth transistor T6 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the fifth node O5, the output terminal is connected to the sixth node O6, and the sixth node O6 is connected to the third node O3. The control terminal of the seventh transistor T7 is connected to the (n - 1)th row scan line terminal Scan[n - 1], the input terminal is connected to the first input voltage terminal VINT1, and the output terminal is connected to the sixth node O6. The control terminal of the eighth transistor T8 is connected to the scan enable terminal EM, the input terminal is connected to the power supply voltage terminal ELVDD, and the output terminal is connected to the fourth node O4. The control terminal of the ninth transistor T9 is connected to the scan enable terminal EM, the input terminal is connected to the fifth node O5, and the output terminal is connected to the anode of the OLED. The cathode of the OLED is connected to the common ground terminal ELVSS. The control terminal of the tenth transistor T10 is connected to the nth row scan line terminal Scan[n], the input terminal is connected to the second input voltage terminal VINT2, and the output terminal is connected to the anode of the OLED.

[0122] It should be noted that the first terminal O1 is the electrical connection intersection point among the output terminals of the ninth transistor T9, the output terminal of the tenth transistor T10, and the anode of the OLED.

[0123] Figure 5 The driving timing of the pixel driving circuit shown is the same as that of Figure 4 the pixel driving circuit shown. Please continue to refer to Figure 7 as shown in Figure 5The driving principle of the pixel driving circuit shown is as follows: within the refresh period T for displaying one frame of an image, the entire driving timing process includes an initial restoration stage t1, a compensation stage t2, and a light-emitting stage t3, a total of 3 stages. Among them, the light-emitting stage t3 includes y sub-frames t3y such as a first sub-frame t31, a second sub-frame t32, and a third sub-frame t33. It should be noted that the number of sub-frames that the light-emitting stage t3 can include can be determined according to the actual situation.

[0124] Initial restoration stage t1: The n - 1th row scan line terminal Scan[n - 1] is connected to a low-level signal, and the nth row scan line terminal Scan[n], the nth row scan enable terminal EM[n], and the control terminal C are all connected to high-level signals.

[0125] The seventh transistor T7 is turned on, and the negative voltage provided by the first input voltage terminal VINT1 is written to the gate of the fourth transistor T4 through the turned-on seventh transistor T7 and stored on the capacitor Cst for holding. At this time, the first transistor T1, the fifth transistor T5, the sixth transistor T6, and the eighth to tenth transistors T8 - T10 are turned off.

[0126] Compensation stage t2: The nth row scan line terminal Scan[n] is connected to a low-level signal, the n - 1th row scan line terminal Scan[n - 1] is connected to a low-level signal, and the nth row scan enable terminal EM[n] and the control terminal C are all connected to high-level signals.

[0127] The fifth transistor T5, the sixth transistor T6, and the tenth transistor are turned on. At the same time, the fourth transistor T4 remains continuously turned on under the voltage stored on the capacitor Cst in the previous stage. The frame voltage data signal input at the data input terminal DATA is stored on the capacitor Cst through the fifth transistor T5, the fourth transistor T4, and the sixth transistor T6. Moreover, the seventh transistor T7 is turned on, and the negative voltage provided by the second input voltage terminal VINT2 is written to the anode of the OLED to reset the OLED.

[0128] First sub-frame t31 of the light-emitting stage t3: The nth row scan enable terminal EM[n] and the control terminal C are both connected to low-level signals. The n - 1th row scan line terminal Scan[n - 1] is connected to a high-level signal.

[0129] The second transistor T2, the eighth transistor T8, and the ninth transistor T9 are turned on. At the same time, the fourth transistor T4 remains in the on state while the voltage Vdata - Vth is stored in the capacitor Cst. The third transistor T3, the fifth transistor T5 to the seventh transistor T7, and the tenth transistor T10 are turned off. The light-emitting current provided by the power supply voltage terminal ELVDD flows through the eighth transistor T8, the fourth transistor T4, and the ninth transistor T9 to the first terminal O1. The current passing through the first terminal O1 flows through the second transistor T2 and the second capacitor C2 to the common ground terminal ELVSS, driving the OLED to emit light.

[0130] For the second sub-frame t32 to the y-th sub-frame t3y of the light-emitting stage t3: The low-level signal is applied to the n-th row scan enable terminal EM[n]. The high-level signals are input to the (n - 1)-th row scan line terminal Scan[n - 1], the n-th row scan line terminal Scan[n], and the control terminal C.

[0131] The third transistor T3, the eighth transistor T8, the ninth transistor T9, and the fourth transistor T4 are turned on. The second transistor T2, the fifth transistor T5 to the seventh transistor T7, and the tenth transistor T10 are turned off. The light-emitting current provided by the power supply voltage terminal ELVDD flows through the eighth transistor T8, the fourth transistor T4, and the ninth transistor T9 to the first terminal O1, and the current passing through the first terminal O1 flows through the third transistor T3 to the common ground terminal ELVSS, driving the OLED to emit light.

[0132] It should be noted that the above two examples with Figure 4 and Figure 5 as references are both illustrated by taking the pixel driving circuit of an AMOLED display device with a low-temperature poly-silicon (LTPS) pixel driving circuit as an example. Of course, the pixel driving circuit provided in the embodiments of the present application can also be illustrated by taking the pixel driving circuit of an AMOLED display device with a low-temperature polycrystalline oxide (LTPO) as an example. The difference between the LTPO pixel driving circuit and the LTPS pixel driving circuit lies in that: in the LTPS pixel driving circuit, the sixth transistor T6 and the seventh transistor T7 are P-type TFTs. While in the LTPO pixel driving circuit, the sixth transistor T6 and the seventh transistor T7 are N-type TFTs.

[0133] In summary, the pixel driving circuit provided in the embodiment of the present application includes a driving unit and a capacitance adjusting unit. The driving unit is connected to the anode of the light-emitting element and is configured to receive a lighting signal, which is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjusting unit is configured to adjust the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit, and the first terminal is the output terminal where the driving unit is connected to the anode of the light-emitting element. This is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjusting unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approximately the same, thereby improving the smear phenomenon that occurs when the display panel is refreshed because multiple light-emitting elements have different lighting speeds.

[0134] For example, in the light-emitting unit of the display panel, there are a light-emitting element that emits red light, a light-emitting element that emits green light, and a light-emitting element that emits blue light. The pixel driving circuit can be used to reduce the lighting speed of the light-emitting element that emits red light and / or increase the lighting speed of the light-emitting element that emits green light, thereby eliminating to a certain extent the difference in the lighting speeds of light-emitting elements of different colors, making the red component, green component, and blue component in the light emitted by the light-emitting unit achieve a balanced ratio, and improving the smear and redness phenomenon that exists when the display panel is refreshed.

[0135] A display device provided in an embodiment of the present application includes a light-emitting unit and a pixel driving circuit. The light-emitting unit includes at least two light-emitting sub-units. Each light-emitting sub-unit is connected to a pixel driving circuit, and the pixel driving circuit connected to the target light-emitting sub-unit is the pixel driving circuit provided in the embodiment of the present application, and the introduction of this pixel driving circuit can refer to the foregoing description.

[0136] Among them, the target light-emitting sub-unit is at least one light-emitting sub-unit among at least two light-emitting sub-units. That is to say, at least some of the light-emitting sub-units in the light-emitting unit are connected to the pixel driving circuit provided in the embodiment of the present application, so that the pixel driving circuit can adjust the lighting speed of the light-emitting elements in the light-emitting sub-units through the capacitance adjusting unit, so that the lighting speeds of the light-emitting elements in each light-emitting sub-unit in the light-emitting unit are close to the same. Optionally, in the pixel driving circuit connected to the target light-emitting sub-unit, the capacitance adjusting unit is used to adjust the capacitance value between the first end and the common ground end of the pixel driving circuit during the light-emitting stage of the light-emitting element. Further optionally, in the pixel driving circuit connected to the target light-emitting sub-unit, the capacitance adjusting unit is used to adjust the capacitance value between the first end and the common ground end of the pixel driving circuit in the first frame of the light-emitting stage of the light-emitting element.

[0137] In an optional implementation manner, the at least two light-emitting sub-units are arranged in the order of decreasing parasitic capacitance of the included light-emitting elements. The capacitance adjusting unit is used to increase the capacitance value between the first end and the common ground end of the pixel driving circuit.

[0138] Among them, the target light-emitting sub-unit is the last x1 light-emitting sub-units among at least two light-emitting sub-units. x1 is a positive integer less than N, and N is the total number of light-emitting sub-units in the light-emitting unit. In this way, in the light-emitting unit, for the light-emitting sub-units with relatively small parasitic capacitance of the light-emitting elements, the pixel driving circuit connected thereto can increase the capacitance value between the first end and the common ground end of the pixel driving circuit through the capacitance adjusting unit to accelerate the lighting speed of the light-emitting elements.

[0139] Exemplarily, the light-emitting unit includes: a red light-emitting sub-unit R, a green light-emitting sub-unit G, and a blue light-emitting sub-unit B. Among them, the red light-emitting sub-unit R, also known as the red sub-pixel, includes a light-emitting element that emits red light. The green light-emitting sub-unit G, also known as the green sub-pixel, includes a light-emitting element that emits green light and red light. The blue light-emitting sub-unit B, also known as the blue sub-pixel, includes a light-emitting element that emits blue light. Among them, the light-emitting element that emits green light has the largest parasitic capacitance, the light-emitting element that emits blue light has the second largest parasitic capacitance, and the light-emitting element that emits red light has the smallest parasitic capacitance.

[0140] In an exemplary case, the red light-emitting subunit R is the target subunit, which is connected to the pixel driving circuit provided in the embodiment of the present application, so that through the capacitance adjusting unit, the lighting speed of the light-emitting element in the red light-emitting subunit R is increased. Among them, the capacitance adjusting unit can increase the lighting speed of the light-emitting element in the red light-emitting subunit R to the first speed. The first speed is the lighting speed of the light-emitting element in the blue light-emitting subunit B (or the green light-emitting subunit G), so that the lighting speeds of the three different light-emitting elements in the light-emitting unit are close to the same, thereby to a certain extent improving the smear phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0141] In another exemplary case, both the red light-emitting subunit R and the blue light-emitting subunit B are target subunits, which are connected to the pixel driving circuit provided in the embodiment of the present application, so that through the capacitance adjusting unit, the lighting speed of the light-emitting element in the light-emitting subunit is increased to the first speed. The first speed is the lighting speed of the light-emitting element in the green light-emitting subunit G, so that the lighting speeds of the three different light-emitting elements in the light-emitting unit are the same, avoiding the smear phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0142] In an optional implementation manner, at least two light-emitting subunits are arranged in the order of the parasitic capacitance of the included light-emitting elements from large to small. The capacitance adjusting unit is used to reduce the capacitance value between the first end and the common ground end of the pixel driving circuit.

[0143] Among them, the target light-emitting subunit is the first x2 light-emitting subunits among at least two light-emitting subunits. x2 is a positive integer less than N. In this way, in the light-emitting unit, for the light-emitting subunit with a relatively large parasitic capacitance of the light-emitting element, the pixel driving circuit connected thereto can reduce the capacitance value between the first end and the common ground end of the pixel driving circuit through the capacitance adjusting unit to reduce the lighting speed of the light-emitting element.

[0144] Exemplarily, the light-emitting unit includes: a red light-emitting subunit R, a green light-emitting subunit G, and a blue light-emitting subunit B. In an exemplary case, the green light-emitting subunit G is the target subunit, which is connected to the pixel driving circuit provided in the embodiment of the present application, so that through the capacitance adjusting unit, the lighting speed of the light-emitting element in the green light-emitting subunit G is reduced. Among them, the capacitance adjusting unit can reduce the lighting speed of the light-emitting element in the green light-emitting subunit G to the second speed. The second speed is the lighting speed of the light-emitting element in the blue light-emitting subunit B (or the red light-emitting subunit R), so that the lighting speeds of the three different light-emitting elements in the light-emitting unit are close to the same, thereby to a certain extent improving the smear phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0145] In another exemplary case, both the green light-emitting subunit G and the blue light-emitting subunit B are target units, which are connected to the pixel driving circuit provided in the embodiment of the present application, so that the lighting speed of the light-emitting element in the light-emitting subunit is reduced to a first speed through the capacitance adjusting unit. The first speed is the lighting speed of the light-emitting element in the red light-emitting subunit R, so that the lighting speeds of the three different light-emitting elements in the light-emitting unit are the same, avoiding the phenomenon of ghosting when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0146] In an optional implementation manner, at least two light-emitting subunits are arranged in the order of decreasing parasitic capacitance of the included light-emitting elements. The target light-emitting subunit includes a first unit and a second unit.

[0147] Among them, the first unit is the first x3 light-emitting subunits among at least two light-emitting subunits, and in the pixel driving circuit connected to the first unit, the capacitance adjusting unit is used to reduce the capacitance value between the first end and the common ground end of the pixel driving circuit. The second unit is the last x4 light-emitting subunits among at least two light-emitting subunits, and in the pixel driving circuit connected to the second unit, the capacitance adjusting unit is used to increase the capacitance value between the first end and the common ground end of the pixel driving circuit. Both x3 and x4 are positive integers less than N / 2. In this way, in the light-emitting unit, for the light-emitting subunit with a relatively large parasitic capacitance of the light-emitting element, the pixel driving circuit connected to it can reduce the capacitance value between the first end and the common ground end of the pixel driving circuit through the capacitance adjusting unit to reduce the lighting speed of the light-emitting element. At the same time, for the light-emitting subunit with a relatively small parasitic capacitance of the light-emitting element, the pixel driving circuit connected to it can increase the capacitance value between the first end and the common ground end of the pixel driving circuit through the capacitance adjusting unit to increase the lighting speed of the light-emitting element.

[0148] Exemplarily, the light-emitting unit includes: a red light-emitting subunit R, a green light-emitting subunit G, and a blue light-emitting subunit B.

[0149] The green light-emitting subunit G is the first unit, which is connected to the pixel driving circuit provided in the embodiment of the present application, so that through the capacitance adjusting unit, the lighting speed of the light-emitting element in the green light-emitting subunit G is reduced to a third speed. At the same time, the red light-emitting subunit R is the second unit, which is connected to the pixel driving circuit provided in the embodiment of the present application, so that through the capacitance adjusting unit, the lighting speed of the light-emitting element in the red light-emitting subunit R is increased to the third speed. The third speed is the lighting speed of the light-emitting element in the blue light-emitting subunit B, so that the lighting speeds of the three different light-emitting elements in the light-emitting unit are the same, thereby avoiding the phenomenon of ghosting when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0150] In summary, for the display device provided in the embodiment of the present application, the pixel driving circuit includes a driving unit and a capacitance adjusting unit. The driving unit is connected to the anode of the light-emitting element and is configured to receive a lighting signal, which is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjusting unit is configured to adjust the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit, and the first terminal is the output terminal where the driving unit is connected to the anode of the light-emitting element. This is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjusting unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approach the same, thereby improving the blurring phenomenon that occurs when the display panel is refreshed because multiple light-emitting elements have different lighting speeds.

[0151] For example, the light-emitting units of the display panel include a light-emitting element that emits red light, a light-emitting element that emits green light, and a light-emitting element that emits blue light. The pixel driving circuit can be used to reduce the lighting speed of the light-emitting element that emits red light, and / or increase the lighting speed of the light-emitting element that emits green light, thereby eliminating the difference in the lighting speeds of light-emitting elements of different colors to a certain extent, so that the red component, green component, and blue component in the light emitted by the light-emitting unit are balanced in proportion, and improving the red blurring phenomenon that exists when the display panel is refreshed.

[0152] A driving method for a pixel driving circuit provided in an embodiment of the present application. The driving method of the pixel driving circuit can be applied to any pixel driving circuit provided in the embodiment of the present application. Alternatively, the driving method of the pixel driving circuit is applied to any display device provided in the embodiment of the present application. The following is illustrated by taking the driving method of the pixel driving circuit being executed by the display driving IC as an example.

[0153] Among them, the pixel driving circuit is configured to drive the light-emitting element to emit light in multiple refresh cycles. The refresh cycle includes an initial restoration stage, a compensation stage, and a light-emitting stage. The light-emitting stage t3 includes y sub-frames such as a first sub-frame, a second sub-frame, and a third sub-frame. The driving method of the pixel driving circuit includes:

[0154] In the pixel driving circuit connected to the target light-emitting unit by the display driving IC, the capacitance adjusting unit is sent a first control signal with an effective level to cause the capacitance adjusting unit to increase the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit, or a second control signal with an effective level is sent to the capacitance adjusting unit in the pixel driving circuit connected to the target light-emitting unit to cause the capacitance adjusting unit to decrease the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit.

[0155] Optionally, the display driving IC sends a first control signal with an effective level to the capacitance adjusting unit connected to the target light-emitting unit during the light-emitting stage of the light-emitting element to cause the capacitance adjusting unit to increase the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit;

[0156] Or, the display driving IC sends a second control signal with an effective level to the capacitance adjusting unit connected to the target light-emitting unit during the light-emitting stage of the light-emitting element to cause the capacitance adjusting unit to decrease the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit.

[0157] Further optionally, in the first frame of the light-emitting stage of the light-emitting element, the display driving IC sends a first control signal with an effective level to the capacitance adjusting unit connected to the target light-emitting unit to cause the capacitance adjusting unit to increase the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit;

[0158] Or, in the first frame of the light-emitting stage of the light-emitting element, the display driving IC sends a second control signal with an effective level to the capacitance adjusting unit connected to the target light-emitting unit to cause the capacitance adjusting unit to decrease the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit.

[0159] In some embodiments of the present application, the target light-emitting unit includes a first unit and a second unit. The display driving IC sends a first control signal with an effective level to the capacitance adjusting unit connected to the first unit and a second control signal with an effective level to the capacitance adjusting unit connected to the second unit.

[0160] Optionally, during the light-emitting stage of the light-emitting element, the display driving IC sends a first control signal with an effective level to the capacitance adjusting unit connected to the first unit and a second control signal with an effective level to the capacitance adjusting unit connected to the second unit.

[0161] Further optionally, in the first frame of the light-emitting stage of the light-emitting element, the display driving IC sends a first control signal with an effective level to the capacitance adjusting unit connected to the first unit and a second control signal with an effective level to the capacitance adjusting unit connected to the second unit.

[0162] In the embodiment of the present application, the pixel driving circuit includes a driving unit and a capacitance adjusting unit. The driving unit is connected to the anode of the light-emitting element and is configured to receive a lighting signal, which is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjusting unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjusting unit is configured to adjust the capacitance value between the first terminal and the common ground terminal of the pixel driving circuit, and the first terminal is the output terminal where the driving unit is connected to the anode of the light-emitting element. This is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjusting unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approach the same, thereby improving the blurring phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0163] The embodiment of the present application further provides a display panel, which includes the pixel driving circuit provided by the embodiment of the present application. Since the display panel includes the pixel driving circuit provided by the embodiment of the present application, it has the same technical effects that the pixel driving circuit can achieve. To avoid repetition, it will not be described here again.

[0164] The embodiment of the present application further provides an electronic device, which includes the pixel driving circuit provided by the embodiment of the present application. Or, it includes the display panel provided by the embodiment of the present application. Or, it includes the display device provided by the embodiment of the present application. Since the electronic device includes the pixel driving circuit provided by the embodiment of the present application, it has the same technical effects that the pixel driving circuit can achieve. To avoid repetition, it will not be described here again.

[0165] The embodiment of the present application further provides a driving device for a pixel driving circuit, which is configured to execute the driving method of the pixel driving circuit provided by the embodiment of the present application. The driving device of the pixel driving circuit may be a component in an electronic device, such as an integrated circuit or a chip. The electronic device may be a terminal or other devices other than terminals. Exemplarily, the electronic device may be a mobile phone, a tablet computer, a laptop computer, a palmtop computer, a vehicle-mounted electronic device, a Mobile Internet Device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc. It may also be a server, a Network Attached Storage (NAS), a personal computer (PC), a television (TV), a teller machine, or a self-service machine, etc. The embodiment of the present application does not make specific limitations.

[0166] The driving device of the pixel driving circuit in the embodiment of the present application may be a device with an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems. The embodiment of the present application does not make specific limitations.

[0167] The driving device of the pixel driving circuit provided by the embodiment of the present application can implement each process implemented by the method embodiment of the present application. To avoid repetition, it will not be elaborated here.

[0168] Optionally, as Figure 8 shown, the embodiment of the present application further provides an electronic device 800, including a processor 801 and a memory 802. A program or instruction that can run on the processor 801 is stored on the memory 802. When the program or instruction is executed by the processor 801, it implements each step of the driving method embodiment of the above pixel driving circuit and can achieve the same technical effect. To avoid repetition, it will not be elaborated here. It should be noted that the electronic device in the embodiment of the present application includes the above-mentioned mobile electronic devices and non-mobile electronic devices.

[0169] Figure 9Schematic diagram of the hardware structure of an electronic device according to an embodiment of the present application. The electronic device 900 includes, but is not limited to: a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909, a processor 910, and other components. In addition, the electronic device further includes a pixel driving circuit provided in the embodiment of the present application. Or, it includes a display panel provided in the embodiment of the present application. Or, it includes a display device provided in the embodiment of the present application.

[0170] Those skilled in the art can understand that the electronic device 900 may further include a power source (such as a battery) for supplying power to each component. The power source can be logically connected to the processor 910 through a power management system, so as to implement functions such as management of charging, discharging, and power consumption management through the power management system. Figure 9 The structure of the electronic device shown does not limit the electronic device. The electronic device may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0171] Among them, the processor 910 is configured to send a first control signal with an effective level to a capacitance adjustment unit in a pixel driving circuit connected to a target light-emitting unit, so that the capacitance adjustment unit increases the capacitance value between the first end and the common ground terminal of the pixel driving circuit, or send a second control signal with an effective level to the capacitance adjustment unit in the pixel driving circuit connected to the target light-emitting unit, so that the capacitance adjustment unit decreases the capacitance value between the first end and the common ground terminal of the pixel driving circuit.

[0172] Optionally, the processor 910 is configured to send a first control signal with an effective level to a capacitance adjustment unit connected to a target light-emitting unit during the light-emitting stage of the light-emitting element, so that the capacitance adjustment unit increases the capacitance value between the first end and the common ground terminal of the pixel driving circuit;

[0173] Or, it is configured to send a second control signal with an effective level to a capacitance adjustment unit connected to a target light-emitting unit during the light-emitting stage of the light-emitting element, so that the capacitance adjustment unit decreases the capacitance value between the first end and the common ground terminal of the pixel driving circuit.

[0174] Optionally, the processor 910 is configured to send a first control signal with an effective level to a capacitance adjustment unit connected to a target light-emitting unit in the first frame of the light-emitting stage of the light-emitting element, so that the capacitance adjustment unit increases the capacitance value between the first end and the common ground terminal of the pixel driving circuit;

[0175] Alternatively, in the first frame of the light-emitting stage of the light-emitting element, a second control signal of an effective level is sent to the capacitance adjustment unit connected to the target light-emitting unit, so that the capacitance adjustment unit reduces the capacitance value between the first end and the common ground end of the pixel driving circuit.

[0176] Optionally, the target light-emitting unit includes a first unit and a second unit. The processor 910 is configured to send a first control signal of an effective level to the capacitance adjustment unit connected to the first unit, and send a second control signal of an effective level to the capacitance adjustment unit connected to the second unit.

[0177] Optionally, the processor 910 is configured to send a first control signal of an effective level to the capacitance adjustment unit connected to the first unit, and send a second control signal of an effective level to the capacitance adjustment unit connected to the second unit during the light-emitting stage of the light-emitting element.

[0178] Optionally, the processor 910 is configured to send a first control signal of an effective level to the capacitance adjustment unit connected to the first unit, and send a second control signal of an effective level to the capacitance adjustment unit connected to the second unit in the first frame of the light-emitting stage of the light-emitting element.

[0179] In the embodiment of the present application, the pixel driving circuit includes a driving unit and a capacitance adjustment unit. The driving unit is connected to the anode of the light-emitting element and is configured to receive a lighting signal, which is used to instruct the driving unit to transmit a light-emitting current for driving the light-emitting element to emit light to the light-emitting element. The capacitance adjustment unit is connected to at least one of the anode or the cathode of the light-emitting element. The capacitance adjustment unit is configured to adjust the capacitance value between the first end and the common ground end of the pixel driving circuit, and the first end is the output end where the driving unit is connected to the anode of the light-emitting element. This is equivalent to adjusting the magnitude of the parasitic capacitance of the light-emitting element. By adjusting the magnitude of the parasitic capacitance of the light-emitting element, the charging speed of the light-emitting element can be adjusted, and further the lighting speed of the light-emitting element can be adjusted. Since the capacitance adjustment unit in the pixel driving circuit can indirectly adjust the lighting speed of the light-emitting element. Therefore, the pixel driving circuit can be used to achieve consistent adjustment of the lighting speeds between different light-emitting elements, so that the lighting speeds of different light-emitting elements are the same or approach the same, thereby improving the smear phenomenon that occurs when the display panel is refreshed due to different lighting speeds of multiple light-emitting elements.

[0180] It should be understood that in the embodiments of the present application, the input unit 904 may include a Graphics Processing Unit (GPU) 9041 and a microphone 9042. The GPU 9041 processes the image data of static pictures or videos obtained by an image capturing device (such as a camera) in a video capturing mode or an image capturing mode. The display unit 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 907 includes at least one of a touch panel 9071 and other input devices 9072. The touch panel 9071 is also referred to as a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. The other input devices 9072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, power on / off keys, etc.), a trackball, a mouse, and a joystick, which will not be elaborated here.

[0181] The memory 909 can be used to store software programs and various data. The memory 909 mainly includes a first storage area for storing programs or instructions and a second storage area for storing data. Among them, the first storage area can store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). In addition, the memory 909 may include a volatile memory or a non-volatile memory, or the memory 909 may include both a volatile memory and a non-volatile memory. Among them, the non-volatile memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. The volatile memory may be a Random Access Memory (RAM), a Static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), a Double Data Rate SDRAM (DDR SDRAM), an Enhanced SDRAM (ESDRAM), a Synch link DRAM (SLDRAM), and a Direct Rambus RAM (DRRAM). The memory 909 in the embodiments of the present application includes, but is not limited to, these and any other suitable types of memories.

[0182] The processor 910 may include one or more processing units; optionally, the processor 910 integrates an application processor and a modem processor. Among them, the application processor mainly processes operations related to the operating system, user interface, application programs, etc., and the modem processor mainly processes wireless communication signals, such as a baseband processor. It can be understood that the above-mentioned modem processor may not be integrated into the processor 910 either.

[0183] The embodiment of the present application further provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, it implements each process of the driving embodiment of the above-mentioned pixel driving circuit and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0184] Among them, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk, or an optical disc, etc.

[0185] The embodiment of the present application further provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run a program or instruction to implement each process of the driving method embodiment of the above-mentioned pixel driving circuit and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0186] It should be understood that the chip mentioned in the embodiment of the present application may also be referred to as a system-on-chip, a system chip, a chip system, or a system-on-chip, etc.

[0187] The embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement each process of the driving method embodiment of the above-mentioned pixel driving circuit and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0188] It should be noted that, in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0189] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0190] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

Claims

1. A pixel driving circuit, characterized in that: The pixel driving circuit is used to be connected to the light emitting element to drive the light emitting element to emit light; The pixel driving circuit comprises: a driving unit and a capacitance adjustment unit; The driving unit is connected to the anode of the light-emitting element, and the driving unit is used to receive a lighting signal, and the lighting signal is used to instruct the driving unit to transmit a light-emitting current to the light-emitting element for driving the light-emitting element to emit light; The capacitance adjustment unit is connected to at least one of the anode or cathode of the light-emitting element, and is used to adjust the capacitance value between the first end and the common ground end of the pixel driving circuit, wherein the first end is the output end of the driving unit connected to the anode of the light-emitting element.

2. The pixel driving circuit according to claim 1, characterized in that: The capacitance adjustment unit includes: a first switch element and a first capacitor; The first switch is connected to the anode of the light emitting element and one end of the first capacitor, and the other end of the first capacitor is connected to the cathode of the light emitting element. The first switch is used to control the connection or disconnection between the anode of the light emitting element and the first capacitor.

3. The pixel driving circuit according to claim 2, characterized in that: The first switch element includes: a first transistor; The control end of the first transistor is used to receive a first control signal, the input end of the first transistor is connected to the anode of the light-emitting element, the output end of the first transistor is connected to one end of the first capacitor, and the first transistor is used to be turned on or off under the control of the first control signal.

4. The pixel driving circuit according to claim 1, characterized in that: The capacitance adjustment unit includes: a second switch element and a second capacitor; The second switch is connected to the cathode of the light-emitting element, the second capacitor and the common ground terminal, and is used to control the cathode of the light-emitting element to be connected to the common ground terminal through the second capacitor, or to control the cathode of the light-emitting element to be directly connected to the common ground terminal.

5. The pixel driving circuit according to claim 4, characterized in that: The second switch device includes: a first switch device and a second switch device; The first switch device is connected to the cathode of the light emitting element and one end of the second capacitor, and is used to control the connection or disconnection between the cathode of the light emitting element and the second capacitor; The second switch device is connected to the cathode of the light emitting element and the common ground terminal, and is used to control the connection or disconnection between the cathode of the light emitting element and the common ground terminal.

6. The pixel driving circuit according to claim 5, characterized in that: The first switching device includes a second transistor; the second switching device includes a third transistor; The input end of the second transistor is connected to the cathode of the light emitting element, the output end of the second transistor is connected to one end of the second capacitor, and the control end of the second transistor is used to receive a second control signal; The input end of the third transistor is connected to the cathode of the light-emitting element, the output end of the third transistor is connected to the common ground end, the control end of the third transistor is used to receive the second control signal, the second transistor and the third transistor are used to be turned on or off under the control of the second control signal, wherein the second control signal is used to control the third transistor to be turned off when the second transistor is turned on, and to control the third transistor to be turned on when the second transistor is turned off.

7. The pixel driving circuit according to claim 1, characterized in that: The capacitance adjustment unit includes: a third switch element and a third capacitor; The third switch is connected to the drive unit, the anode of the light-emitting element and the third capacitor, and is used to control the drive unit to be connected to the anode of the light-emitting element through the third capacitor, or to control the drive unit to be directly connected to the anode of the light-emitting element.

8. The pixel driving circuit according to claim 1, characterized in that: The pixel driving circuit further includes: a light emitting control unit and a reset unit; The light emitting control unit is connected to the driving unit and the anode of the light emitting element, and the reset unit is connected to the driving unit and the anode of the light emitting element; The reset unit is used to reset the light emitting element; The light emitting control unit is used to receive the lighting signal and transmit the lighting signal to the driving unit.

9. A display device, characterized in that: The display device includes a light-emitting unit and a pixel driving circuit, the light-emitting unit includes at least two light-emitting sub-units, each of the light-emitting sub-units is connected to one of the pixel driving circuits, and the pixel driving circuit to which the target light-emitting sub-unit is connected is the pixel driving circuit according to any one of claims 1 to 8, and the target light-emitting sub-unit is at least one of the at least two light-emitting sub-units.

10. The display device according to claim 9, characterized in that: The at least two light-emitting sub-units are arranged in descending order according to the parasitic capacitance of the light-emitting elements included therein, and the capacitance adjustment unit is used to increase the capacitance value between the first end and the common ground end; The target light-emitting sub-unit is the last x1 light-emitting sub-units of the at least two light-emitting sub-units, where x1 is a positive integer less than N, and N is the total number of the light-emitting sub-units in the light-emitting unit.

11. The display device according to claim 9, characterized in that: The at least two light-emitting sub-units are arranged in descending order according to the parasitic capacitance of the light-emitting elements included therein, and the capacitance adjustment unit is used to reduce the capacitance value between the first end and the common ground end; The target light-emitting sub-unit is the first x2 light-emitting sub-units among the at least two light-emitting sub-units, where x2 is a positive integer less than N.

12. The display device according to claim 9, characterized in that: The at least two light-emitting sub-units are arranged in descending order according to the parasitic capacitance of the light-emitting elements included therein; the target light-emitting sub-unit includes a first unit and a second unit; The first unit is the first x3 light-emitting sub-units of the at least two light-emitting sub-units, and in the pixel driving circuit to which the first unit is connected, the capacitance adjustment unit is used to reduce the capacitance value between the first end and the common ground end; The second unit is the last x4 light-emitting sub-units of the at least two light-emitting sub-units, and in the pixel driving circuit to which the second unit is connected, the capacitance adjustment unit is used to increase the capacitance value between the first end and the common ground end, and x3 and x4 are both positive integers less than N / 2.

13. The display device according to claim 9, characterized in that: The at least two light-emitting subunits include a red light-emitting subunit, a green light-emitting subunit and a blue light-emitting subunit; The target light-emitting subunit is the red light-emitting subunit, and in the pixel driving circuit connected to the target light-emitting subunit, the capacitance adjustment unit is used to increase the capacitance value between the first end and the common ground end; Alternatively, the target light-emitting subunit is the green light-emitting subunit, and in the pixel driving circuit connected to the target light-emitting subunit, the capacitance adjustment unit is used to reduce the capacitance value between the first end and the common ground end; Alternatively, the target light emitting subunit includes the red light emitting subunit and the green light emitting subunit.

14. An electronic device, characterized in that: The electronic device comprises a device body and the display device according to any one of claims 9 to 13.

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