Pixel driving circuit, display panel and its manufacturing method and display device

Abstract

This application provides a pixel driving circuit, a display panel, a method for fabricating the same, and a display device. The pixel driving circuit includes a driving circuit for driving light-emitting units to emit light. The driving circuit includes a first driving circuit and a second driving circuit, which are connected in parallel with the first driving circuit at a first node and a second node. The resistance value of the second driving circuit is greater than that of the first driving circuit. In a first grayscale state, under the control of a control signal terminal, the driving current of the first driving circuit is greater than that of the second driving circuit. In a second grayscale state, under the control of the control signal terminal, the driving current of the first driving circuit is less than that of the second driving circuit. The technical solution of this application can improve the brightness control capability of the display panel in low grayscale states without affecting the mobility and stability of the devices on the driving circuit.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a pixel driving circuit, a display panel, a method for manufacturing the same, and a display device. Background Technology

[0002] In related technologies, oxide transistors, when used as driving transistors in organic light-emitting diode (OLED) display panels, suffer from a small subthreshold swing (Ss), resulting in poor brightness control of OLED display panels at low grayscale levels. Summary of the Invention

[0003] This application provides a pixel driving circuit, a display panel, a method for manufacturing the same, and a display device to solve or alleviate one or more technical problems in the prior art.

[0004] As a first aspect of the embodiments of this application, this application provides a pixel driving circuit, including: a driving circuit for driving a light-emitting unit to emit light, the driving circuit including a first driving circuit and a second driving circuit, the second driving circuit being connected in parallel with the first driving circuit at a first node and a second node, the resistance value of the second driving circuit being greater than the resistance value of the first driving circuit; wherein, in a first grayscale state, under the control of a control signal terminal, the driving current of the first driving circuit is greater than the driving current of the second driving circuit; in a second grayscale state, under the control of a control signal terminal, the driving current of the first driving circuit is less than the driving current of the second driving circuit.

[0005] In one embodiment, the first driving circuit includes a first driving transistor, the first terminal of which is connected to a first node, and the second terminal of which is connected to a second node; the second driving circuit includes a second driving transistor, the first terminal and / or the second terminal of which are connected in series with at least one resistor, and the control terminal of which is connected to the first control terminal of which is the first driving transistor.

[0006] In one embodiment, at least one resistor includes a first resistor and a second resistor, one end of the first resistor is connected to the first electrode of the second driving transistor, and the other end of the first resistor is connected to the first node; one end of the second resistor is connected to the second electrode of the second driving transistor, and the other end of the second resistor is connected to the second node.

[0007] In one implementation, the resistivity of each resistor is greater than 1 Ω·cm.

[0008] In one embodiment, the first driving transistor further has a second control electrode connected to the control signal terminal. The second control electrode is used to adjust the threshold voltage of the first driving transistor in response to the signal at the control signal terminal, so as to adjust the driving current of the first driving circuit.

[0009] In one embodiment, the second driving transistor further includes an active layer having a channel region and a first region and a second region located at both ends of the channel region, the channel region being disposed opposite to a control electrode, the first electrode being connected to the first region and the second electrode being connected to the second region; wherein at least a portion of the first region and / or the second region is a non-conductive region to form at least one resistor.

[0010] In one embodiment, the pixel driving circuit further includes: a data writing circuit connected to the first node and the data signal terminal, used to transmit the signal from the data signal terminal to the first node in response to a first control signal; a compensation circuit connected to the second node and the driving circuit, used to connect the second node and the driving circuit in response to a second control signal; a light emission control circuit connected to the first node, the second node, the first power supply terminal, the light emission unit, and the enable signal terminal, used to connect the first power supply terminal and the first node in response to the signal from the enable signal terminal, and to connect the light emission unit and the second node; a storage circuit connected between the first power supply terminal and the driving circuit; and a reset circuit connected to the driving circuit, the reset signal terminal, and the initial signal terminal, used to connect the driving circuit and the initial signal terminal in response to the signal from the reset signal terminal.

[0011] In one embodiment, the data writing circuit includes a writing transistor, the first terminal of which is connected to a first node, and the second terminal of which is connected to a data signal terminal; and / or the compensation circuit includes a compensation transistor, the first terminal of which is connected to a second node, and the second terminal of which is connected to a driving circuit; and / or the light-emitting control circuit includes a first control transistor and a second control transistor, the first terminal of which is connected to the first node, and the second terminal of which is connected to a first power supply terminal; the first terminal of which is connected to a light-emitting unit, and the second terminal of which is connected to a second node, and the control terminals of both the second and first control transistors are connected to an enable signal terminal; and / or the storage circuit includes a storage capacitor, the first terminal of which is connected to the first power supply terminal, and the second terminal of which is connected to a driving circuit; and / or the reset circuit includes a first reset transistor and a second reset transistor, the first terminal of which is connected to an initial signal terminal, and the second terminal of which is connected to a driving circuit; the first terminal of which is connected to the initial signal terminal, and the second terminal of which is connected to a light-emitting unit, and the control terminals of both the first and second reset transistors are connected to a reset signal terminal.

[0012] As a second aspect of the present application, the present application provides a display panel including the pixel driving circuit of any of the above embodiments.

[0013] As a third aspect of the present application, the present application provides a method for fabricating a display panel, the display panel being the display panel of the second aspect described above. The fabrication method includes: providing a substrate; forming an active layer on one side of the substrate, the active layer including an active layer of a first driving transistor and an active layer of a second driving transistor, each active layer having a channel region and a first region and a second region located at both ends of the channel region; forming a first control electrode of the first driving transistor and a control electrode of the second driving transistor on the side of the active layer away from the substrate; forming a photoresist for blocking ion implantation on the side of the active layer of the second driving transistor away from the substrate; performing a conductorization treatment on the active layer using an ion implantation process, such that the first region and the second region of the active layer of the first driving transistor are conductorized regions, and at least a portion of the first region and the second region of the active layer of the second driving transistor are non-conductive regions; and stripping the photoresist.

[0014] As a fourth aspect of the present application, the present application provides a method for fabricating a display panel, the display panel being the display panel of the second aspect described above. The fabrication method includes: providing a substrate; forming an active layer on one side of the substrate, the active layer including an active layer of a first driving transistor and an active layer of a second driving transistor, each active layer having a channel region and a first region and a second region located at both ends of the channel region; forming a first control electrode of the first driving transistor, a control electrode of the second driving transistor, a first shielding portion and a second shielding portion on the side of the active layer away from the substrate, the first shielding portion and the second shielding portion being used to shield ion implantation; and performing a conductor treatment on the active layer, such that the first region and the second region of the active layer of the first driving transistor are conductor regions, and at least a portion of the first region and the second region of the active layer of the second driving transistor are non-conductive regions.

[0015] As a fifth aspect of the present application, the present application provides a display device including a display panel of any of the above embodiments.

[0016] The embodiments of this application employ the above-described technical solution to improve the brightness control capability of the display panel in low grayscale states without affecting the mobility and stability of the devices on the driving circuit.

[0017] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0019] Figure 1 A schematic diagram of a pixel driving circuit according to an embodiment of this application is shown;

[0020] Figure 2 This diagram illustrates the structure of a display panel according to an embodiment of the present application.

[0021] Figure 3 A partial structural layout of a display panel according to an embodiment of this application is shown;

[0022] Figure 4 A schematic diagram of the structure of a display panel according to another embodiment of this application is shown;

[0023] Figure 5 A schematic diagram of a pixel driving circuit according to another embodiment of this application is shown;

[0024] Figure 6 A schematic flowchart illustrating a method for manufacturing a display panel according to an embodiment of this application is shown.

[0025] Figure 7 A schematic flowchart illustrating a method for manufacturing a display panel according to another embodiment of this application is shown.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10: Pixel driving circuit; 100: Driving circuit; 110: First driving circuit; 120: Second driving circuit; 130: Active layer; 131: Channel region; 132: First region; 133: Second region;

[0028] 20: Display panel; 201: Substrate; 202: First buffer layer; 203: First gate metal layer; 204: Second buffer layer; 205: Gate insulating layer; 206: Second gate metal layer; 2061: Control electrode; 2062: First shielding portion; 2063: Second shielding portion; 2064: First control electrode; 2065: Second control electrode; 207: First interlayer insulating layer; 208: Third gate metal layer; 209: Second interlayer insulating layer; 210: Planarization layer; 211: Anode; 212: Pixel defining layer; 213: Total active layer; 214: Source / drain metal layer. Detailed Implementation

[0029] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0030] In related technologies, oxide transistors (OTTs) used as driving transistors in OLED display panels suffer from a small subthreshold swing, resulting in poor brightness control at low grayscale levels. The subthreshold swing is determined by defects in the active layer film of the OTT. More defects in the active layer film lead to a larger subthreshold swing. Therefore, increasing the number of defects in the active layer film is commonly used to improve the subthreshold swing of the OTT. However, this approach reduces the mobility and stability of the OTT to some extent.

[0031] To address the aforementioned problems, the first aspect of this application provides a pixel driving circuit. The pixel driving circuit can be applied to a display panel. In the following description, the application of the pixel driving circuit to a display panel will be used as an example.

[0032] Figure 1 A schematic diagram of a pixel driving circuit 10 according to an embodiment of this application is shown. Figure 1 As shown, the pixel circuit includes a driving circuit 100. The driving circuit 100 is used to drive the light-emitting unit OLED to emit light. The driving circuit 100 includes a first driving circuit 110 and a second driving circuit 120. The second driving circuit 120 is connected in parallel with the first driving circuit 110 at the first node N1 and the second node N2. The resistance value of the second driving circuit 120 is greater than the resistance value of the first driving circuit 110.

[0033] It should be noted that "the resistance value of the second driving circuit 120" refers to the overall resistance value of the second driving circuit 120, which may include, for example, the total resistance value of the components and connecting lines on the second driving circuit 120. Similarly, "the resistance value of the first driving circuit 110" refers to the overall resistance value of the first driving circuit 110, which may include, for example, the total resistance value of the components and connecting lines on the first driving circuit 110.

[0034] For example, the total driving current of the driving circuit 100 for driving the OLED to emit light is the parallel current of the first driving circuit 110 and the second driving circuit 120. The first node N1 can be connected to the first power supply terminal, and the second node N2 can be connected to the first electrode of the OLED. The second electrode of the OLED can be connected to the second power supply terminal. The voltage levels of the first and second power supplies are opposite. For example, the first power supply terminal can be a high-level terminal VDD and a low-level terminal VSS; or, the first power supply terminal can be a high-level terminal VDD and the second power supply terminal can be a low-level terminal VSS. For example, the voltage of the high-level terminal VDD can be positive, and the voltage of the low-level terminal VSS can be ground voltage or a negative value. Optionally, the first electrode of the OLED can be the anode of the OLED, and the second electrode of the OLED can be the cathode of the OLED.

[0035] The first driving circuit 110 and / or the second driving circuit 120 are used to connect to the control signal terminal Vmode. That is, only the first driving circuit 110 can be used to connect to the control signal terminal Vmode; or only the second driving circuit 120 can be used to connect to the control signal terminal Vmode; or both the first driving circuit 110 and the second driving circuit 120 can be used to connect to the control signal terminal Vmode.

[0036] In the first grayscale state, under the control of the control signal terminal Vmode, the driving current of the first driving circuit 110 is greater than the driving current of the second driving circuit 120; in the second grayscale state, under the control of the control signal terminal Vmode, the driving current of the first driving circuit 110 is less than the driving current of the second driving circuit 120.

[0037] For example, the first grayscale state can be a high grayscale state, and the second grayscale state can be a low grayscale state, with the first grayscale being greater than the second grayscale. In the first grayscale state, the driving current of the first driving circuit 110 is greater than the driving current of the second driving circuit 120. At this time, the parallel current of the first driving circuit 110 and the second driving circuit 120 is mainly determined by the first driving circuit 110, and the first driving circuit 110 contributes more to the current of the light-emitting unit OLED. In the second grayscale state, the driving current of the first driving circuit 110 is less than the driving current of the second driving circuit 120. The parallel current of the first driving circuit 110 and the second driving circuit 120 is mainly determined by the second driving circuit 120, and the second driving circuit 120 contributes more to the current of the light-emitting unit OLED. Optionally, in the second grayscale state, the driving current of the first driving circuit 110 can be zero, and at this time, the light-emitting unit OLED is driven to emit light by the driving current on the second driving circuit 120. In the second grayscale state, due to the larger resistance value of the second driving circuit 120, the devices (such as driving transistors) on the second driving circuit 120 have a stronger ability to control the current. This eliminates the need to increase the number of defects in the active layer thin film of the devices on the driving circuit 100, thereby ensuring that the devices have high mobility and stability.

[0038] According to the pixel driving circuit 10 of the present application embodiment, by making the resistance value of the second driving circuit 120 greater than the resistance value of the first driving circuit 110, and in the second grayscale state, the driving current of the first driving circuit 110 is less than the driving current of the second driving circuit 120, the brightness control capability of the display panel 20 in the low grayscale state can be improved without affecting the mobility and stability of the devices on the driving circuit 100.

[0039] In one implementation, such as Figure 1 As shown, the first driving circuit 110 includes a first driving transistor T1, the first terminal of which is connected to a first node N1, and the second terminal of which is connected to a second node N2. The second driving circuit 120 includes a second driving transistor T2, the first terminal and / or the second terminal of which are connected in series with at least one resistor R, and the control terminal of the second driving transistor T2 is connected to the first control terminal of the first driving transistor T1.

[0040] For example, the first driving transistor T1 and the second driving transistor T2 can be N-type oxide transistors. When the first driving transistor T1 and the second driving transistor T2 are N-type oxide transistors and the first driving circuit 110 is used to connect to the control signal terminal Vmode, in the first grayscale state, such as the high grayscale state, the absolute value of the voltage at the control signal terminal Vmode is low (e.g., 0V), preventing a large deviation in the threshold voltage of the first driving transistor T1. Under the operating voltage of the driving circuit 100, the first driving transistor T1 can be normally turned on. Because the resistance value of the first driving circuit 110 is small, the driving current of the first driving circuit 110 is greater than the driving current of the second driving circuit 120, and the first driving circuit 110 contributes more to the current of the light-emitting unit OLED. In the second grayscale state, such as the low grayscale state, the voltage at the control signal terminal Vmode can be a higher negative voltage, causing the threshold voltage of the first driving transistor T1 to be significantly positively biased, greater than the operating voltage of the driving circuit 100. Under the operating voltage of the driving circuit 100, the first driving transistor T1 is in the off state, at which time the second driving circuit 120 contributes more to the current of the light-emitting unit OLED. Because at least one resistor R is connected in series between the first and / or second terminals of the second driving transistor T2, the second driving transistor T2 has a stronger ability to control the current.

[0041] In this embodiment, by connecting at least one resistor R in series with the first and / or second terminals of the second driving transistor T2, the resistance value of the second driving circuit 120 can be greater than the resistance value of the first driving circuit 110. This improves the brightness control capability of the display panel 20 in low grayscale conditions without affecting the mobility and stability of the first driving transistor T1 and the second driving transistor T2.

[0042] In one implementation, reference Figure 1 The aforementioned at least one resistor R includes a first resistor R and a second resistor R. One end of the first resistor R is connected to the first terminal of the second driving transistor T2, and the other end of the first resistor R is connected to the first node N1. One end of the second resistor R is connected to the second terminal of the second driving transistor T2, and the other end of the second resistor R is connected to the second node N2. Optionally, the resistivity of each resistor R is greater than 1 Ω·cm, that is, the resistivity of the first resistor R and the resistivity of the second resistor R can both be greater than 1 Ω·cm.

[0043] In this embodiment, the first and second terminals of the second driving transistor T2 can both be connected in series with a resistor R, ensuring that the overall resistance value of the second driving circuit 120 is greater than the overall resistance value of the first driving circuit 110. This ensures that the second driving transistor T2 has a strong ability to control the current in the low grayscale state in the second grayscale state, thereby improving the brightness control capability of the display panel 20 in the low grayscale state.

[0044] Figure 1 The image shows two resistors R, namely the first resistor R and the second resistor R, for illustrative purposes. However, after reading the technical solution of this application, a person skilled in the art will obviously understand that the solution can be applied to other solutions with a number of resistors R, which would also fall within the scope of protection of the application.

[0045] In one embodiment, the first driving transistor T1 further has a second control electrode connected to the control signal terminal Vmode. The second control electrode is used to adjust the threshold voltage of the first driving transistor T1 in response to the signal from the control signal terminal Vmode, thereby adjusting the driving current of the first driving circuit 110. For example, the first control electrode of the first driving transistor T1 can be the top gate of the first driving transistor T1, and the second control electrode of the first driving transistor T1 can be the bottom gate of the first driving transistor T1.

[0046] In this embodiment, by giving the first driving transistor T1 a second control electrode connected to the control signal terminal Vmode, the threshold voltage of the first driving transistor T1 can be adjusted through the second control electrode to control whether the first driving transistor T1 is turned on under the working voltage, thereby enabling the second driving circuit 120 to drive the light-emitting unit OLED to emit light in the second grayscale state, ensuring that the display panel 20 has a strong brightness control capability in the low grayscale state.

[0047] Figure 2 This diagram illustrates the structure of the display panel 20 according to an embodiment of this application. Figure 3 A partial structural layout of a display panel 20 according to an embodiment of this application is shown. In one embodiment, such as Figures 1-3 As shown, the second driving transistor T2 further includes an active layer 130, which has a channel region 131 and a first region 132 and a second region 133 located at both ends of the channel region 131. The channel region 131 is disposed opposite to the control electrode 2061. The first electrode is connected to the first region 132 and the second electrode is connected to the second region 133. At least a portion of the first region 132 and / or the second region 133 is a non-conductive region to form at least one resistor.

[0048] For example, combined Figure 2 and Figure 3The display panel 20 may include a substrate 201, a first buffer layer 202, a first gate metal layer 203, a second buffer layer 204, a total active layer 213, a gate insulating layer 205, a second gate metal layer 206, a first interlayer insulating layer 207, a third gate metal layer 208, a second interlayer insulating layer 209, a source / drain metal layer 214, a planarization layer 210, an anode 211, and a pixel defining layer 212. The first buffer layer 202 is disposed on one side of the substrate 201. The first gate metal layer 203 is disposed on the side of the first buffer layer 202 opposite to the substrate 201. The second buffer layer 204 is disposed on the side of the first buffer layer 202 opposite to the substrate 201 and covers the first gate metal layer 203. The total active layer 213 is disposed on the side of the second buffer layer 204 opposite to the substrate 201. The gate insulating layer 205 is disposed on the side of the second buffer layer 204 opposite to the substrate 201 and covers the total active layer 213. The second gate metal layer 206 is disposed on the side of the gate insulating layer 205 facing away from the substrate 201. The first interlayer insulating layer 207 is disposed on the side of the gate insulating layer 205 facing away from the substrate 201 and covers the second gate metal layer 206. The third gate metal layer 208 is disposed on the side of the first interlayer insulating layer 207 facing away from the substrate 201. The second interlayer insulating layer 209 is disposed on the side of the first interlayer insulating layer 207 facing away from the substrate 201 and covers the third gate metal layer 208. The source / drain metal layer 214 is disposed on the side of the second interlayer insulating layer 209 facing away from the substrate 201 and passes through the second interlayer insulating layer 209, the first interlayer insulating layer 207, and the gate insulating layer 205, and is connected to the total active layer 213. The planarization layer 210 is disposed on the side of the source / drain metal layer 214 facing away from the substrate 201. The anode 211 is disposed on the side of the planarization layer 210 facing away from the substrate 201 and is connected to the source / drain metal layer 214. A pixel defining layer 212 is disposed on the side of the anode 211 away from the substrate 201, and a plurality of pixel openings are formed on the pixel defining layer 212, through which the anode 211 is exposed.

[0049] The first gate metal layer 203 includes the second control electrode 2065 of the first driving transistor T1. The total active layer 213 includes the active layer of the first driving transistor T1 and the active layer 130 of the second driving transistor T2. The second gate metal layer 206 includes the control electrode 2061 of the second driving transistor T2 and the first control electrode 2064 of the first driving transistor T1. The source-drain metal layer 214 includes the first and second electrodes of the first driving transistor T1 and the second driving transistor T2.

[0050] During fabrication, before the conductor formation process following the second gate metal layer 206, the first region 132 and the second region 133 of the active layer 130 of the second driving transistor T2 can be protected with photoresist, preventing the first region 132 and the second region 133 from becoming conductors and presenting a high-resistance state, thus forming the first resistor and the second resistor. After the conductor formation process, the photoresist can be stripped off.

[0051] Figure 4 This diagram shows a partial structural layout of a display panel 20 according to an embodiment of this application. Figure 2 The difference lies in that the second gate metal layer 206 of the display panel 20 further includes a first shielding portion 2062 and a second shielding portion 2063, both of which are spaced apart from the control electrode 2061 of the second driving transistor T2. During the fabrication process, when patterning the second gate metal layer 206, the first shielding portion 2062 can protect a portion of the first region 132, and the second shielding portion 2063 can protect a portion of the second region 133, so that the portions of the first region 132 and the second region 133 are not conductive, exhibiting a high-resistivity state, forming a first resistor and a second resistor.

[0052] Figure 5 A schematic diagram of a pixel driving circuit 10 according to another embodiment of this application is shown. Figure 5 As shown, the pixel driving circuit 10 further includes a data writing circuit, a compensation circuit, a light-emitting control circuit, a storage circuit, and a reset circuit. Specifically, the data writing circuit is connected to the first node N1 and the data signal terminal Vdata, and is used to transmit the signal of the data signal terminal Vdata to the first node N1 in response to the first control signal. The compensation circuit is connected to the second node N2 and the driving circuit 100, and is used to connect the second node N2 and the driving circuit 100 in response to the second control signal. The light-emitting control circuit is connected to the first node N1, the second node N2, the first power supply terminal, the light-emitting unit OLED, and the enable signal terminal EM, and is used to connect the first power supply terminal and the first node N1 in response to the signal of the enable signal terminal EM, and to connect the light-emitting unit OLED and the second node N2. The storage circuit is connected between the first power supply terminal and the driving circuit 100. The reset circuit is connected to the driving circuit 100, the reset signal terminal Reset, and the initial signal terminal Vinit, and is used to connect the driving circuit 100 and the initial signal terminal Vinit in response to the signal of the reset signal terminal Reset.

[0053] In this embodiment, during the reset phase, an initial signal can be input to the driving circuit 100 and the light-emitting unit OLED through the initial signal terminal Vinit. During the compensation phase, the compensation circuit can be used to turn on the first control electrode and the first node N1 of the first driving transistor T1 and the control electrode and the first node N1 of the second driving transistor T2. At the same time, the data writing circuit is used to write a data signal to the first node N1, thereby writing a voltage Vd+Vth to the first control electrode of the first driving transistor T1 and the control electrode of the second driving transistor T2, and storing it in the storage circuit. Here, Vd is the voltage of the data signal terminal Vdata, and Vth is the threshold voltage of the first driving transistor T1 and the second driving transistor T2. During the light-emitting phase, the light-emitting control circuit is used to connect the first power supply terminal and the first node N1, and to connect the light-emitting unit OLED and the second node N2. In the first grayscale state, the first driving transistor T1 and the second driving transistor T2 output driving current to the light-emitting unit OLED under the action of the charge of the corresponding control electrode. In the second grayscale state, the second driving transistor T2 outputs driving current to the light-emitting unit OLED under the action of the charge of the corresponding control electrode.

[0054] In one embodiment, the data writing circuit may include a writing transistor T3, with its first terminal connected to a first node N1 and its second terminal connected to a data signal terminal Vdata. The compensation circuit may include a compensation transistor T4, with its first terminal connected to a second node N2 and its second terminal connected to the driving circuit 100. For example, the second terminal of the compensation transistor T4 may be connected to the first control terminal of the first driving transistor T1 and the control terminal of the second driving transistor T2.

[0055] The light-emitting control circuit may include a first control transistor T5 and a second control transistor T6. The first electrode of the first control transistor T5 is connected to the first node N1, and the second electrode of the first control transistor T5 is connected to the first power supply terminal. The first electrode of the second control transistor T6 is connected to the light-emitting unit OLED, and the second electrode of the second control transistor T6 is connected to the second node N2. The control electrodes of the second control transistor T6 and the first control transistor T5 are both connected to the enable signal terminal EM.

[0056] The storage circuit includes a storage capacitor Cst. The first terminal of the storage capacitor Cst is connected to the first power supply terminal, and the second terminal of the storage capacitor Cst is connected to the driving circuit 100. For example, the second terminal of the storage capacitor Cst can be connected to the first control terminal of the first driving transistor T1 and the control terminal of the second driving transistor T2. The reset circuit includes a first reset transistor T7 and a second reset transistor T8. The first terminal of the first reset transistor T7 is connected to the initial signal terminal Vinit, and the second terminal of the first reset transistor T7 is connected to the driving circuit 100. The first terminal of the second reset transistor T8 is connected to the initial signal terminal Vinit, and the second terminal of the second reset transistor T8 is connected to the light-emitting unit OLED. The control terminals of both the first reset transistor T7 and the second reset transistor T8 are connected to the reset signal terminal Reset.

[0057] The display panel 20 according to the second aspect of the present application includes the pixel driving circuit 10 according to any embodiment of the first aspect of the present application.

[0058] According to the embodiments of this application, the display panel 20, by employing the pixel driving circuit 10 described above, can improve the brightness control capability of the display panel 20 in a low grayscale state without affecting the mobility and stability of the devices on the driving circuit 100.

[0059] Figure 6 A schematic flowchart illustrating a method for manufacturing a display panel according to an embodiment of this application is shown. Figure 1 , Figure 2 and Figure 6 As shown, according to the third aspect embodiment of this application, the display panel is the display panel 20 according to the second aspect embodiment of this application, and the manufacturing method includes:

[0060] Step S601: Provide a substrate 201;

[0061] Step S602: A total active layer 213 is formed on one side of the substrate 201. The total active layer 213 includes the active layer of the first driving transistor T1 and the active layer 130 of the second driving transistor T2. Each active layer has a channel region 131 and a first region 132 and a second region 133 located at both ends of the channel region 131.

[0062] Step S603: Form the first control electrode 2061 of the first driving transistor T1 and the control electrode 2061 of the second driving transistor T2 on the side of the total active layer 213 away from the substrate 201;

[0063] Step S604: A photoresist for blocking ion implantation is formed on the side of the active 130 of the second driving transistor T2 away from the substrate 201.

[0064] Step S605: The total active layer 213 is made conductive by ion implantation, so that the first region and the second region of the active layer of the first driving transistor T1 are conductive regions, and at least a portion of the first region 132 and the second region 133 of the active layer 130 of the second driving transistor T2 are non-conductive regions.

[0065] Step S606: Strip the photoresist.

[0066] Therefore, the first region 132 and the second region 133 of the active layer 130 of the second driving transistor T2 can be protected by photoresist, so that the first region 132 and the second region 133 are not conductive and present a high-resistance state, forming the first resistor and the second resistor.

[0067] Figure 7 A schematic flowchart illustrating a method for manufacturing a display panel according to another embodiment of this application is shown. Figure 1 , Figure 4 and Figure 7 As shown, the method for manufacturing a display panel according to the fourth aspect embodiment of this application, wherein the display panel is the display panel 20 according to the second aspect embodiment of this application described above, includes:

[0068] Step S701: Provide a substrate 201;

[0069] Step S702: A total active layer 213 is formed on one side of the substrate 201. The total active layer 213 includes the active layer of the first driving transistor TI and the active layer 130 of the second driving transistor. Each active layer has a channel region 131 and a first region 132 and a second region 133 located at both ends of the channel region 131.

[0070] Step S703: A first control electrode 2061 of the first driving transistor T1, a control electrode 2061 of the second driving transistor T2, a first shielding portion 2062 and a second shielding portion 2063 are formed on the side of the total active layer 213 away from the substrate 201. The first shielding portion 2062 and the second shielding portion 2063 are used to shield ion implantation.

[0071] Step S704: Conduct the total active layer 213 to make the first region and the second region of the active layer of the first driving transistor T1 conductive regions, and at least a portion of the first region 132 and the second region 133 of the active layer 130 of the second driving transistor T2 non-conductive regions.

[0072] Thus, the first shielding part 2062 and the second shielding part 2063 can protect the first region 132 and the second region 133 respectively, so that a portion of the first region 132 and a portion of the second region 133 are not conductive and present a high-resistivity state, and thus a first resistor and a second resistor can be formed.

[0073] The display device according to an embodiment of the fifth aspect of this application includes a display panel 20 according to any embodiment of the second aspect of this application. Exemplarily, the display device can be any product or component with display functionality, such as an e-reader, mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0074] The display device according to the embodiments of this application, by employing the above-described display panel 20, has a strong brightness control capability in a low grayscale state, thereby improving the display effect of the display device.

[0075] The pixel driving circuit 10, display panel 20 and other components of the display device in the above embodiments can adopt various technical solutions that are now and will be known to those skilled in the art, and will not be described in detail here.

[0076] In the description of this specification, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0077] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0078] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0079] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0080] The foregoing disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A pixel driving circuit, characterized in that, include: A driving circuit is used to drive the light-emitting unit to emit light. The driving circuit includes a first driving circuit and a second driving circuit. The second driving circuit is connected in parallel with the first driving circuit at the first node and the second node. The overall resistance value of the second driving circuit is greater than the overall resistance value of the first driving circuit. In the first grayscale state, under the control of the control signal terminal, the driving current of the first driving circuit is greater than the driving current of the second driving circuit; in the second grayscale state, under the control of the control signal terminal, the driving current of the first driving circuit is less than the driving current of the second driving circuit. The first driving circuit includes a first driving transistor, the first terminal of the first driving transistor is connected to the first node, and the second terminal of the first driving transistor is connected to the second node; The second driving circuit includes a second driving transistor, wherein at least one resistor is connected in series between the first terminal and / or the second terminal of the second driving transistor, and the control terminal of the second driving transistor is connected to the first control terminal of the first driving transistor. The first driving transistor also has a second control electrode connected to the control signal terminal. The second control electrode is used to adjust the threshold voltage of the first driving transistor in response to the signal at the control signal terminal, so as to adjust the driving current of the first driving circuit.

2. The pixel driving circuit according to claim 1, characterized in that, The at least one resistor includes a first resistor and a second resistor, one end of the first resistor is connected to the first electrode of the second driving transistor, and the other end of the first resistor is connected to the first node; One end of the second resistor is connected to the second terminal of the second driving transistor, and the other end of the second resistor is connected to the second node.

3. The pixel driving circuit according to claim 1, characterized in that, The resistivity of each of the resistors is greater than 1 Ω·cm.

4. The pixel driving circuit according to claim 1, characterized in that, The second driving transistor further includes an active layer having a channel region and a first region and a second region located at both ends of the channel region. The channel region is disposed opposite to the control electrode. The first electrode is connected to the first region, and the second electrode is connected to the second region. At least a portion of the first region and / or the second region is a non-conductive region to form the at least one resistor.

5. The pixel driving circuit according to claim 1, characterized in that, Also includes: A data writing circuit is connected to the first node and the data signal terminal, and is used to transmit the signal from the data signal terminal to the first node in response to the first control signal. A compensation circuit, connected to the second node and the driving circuit, is used to connect the second node and the driving circuit in response to a second control signal. A light-emitting control circuit is connected to the first node, the second node, the first power supply terminal, the light-emitting unit, and the enable signal terminal. It is used to connect the first power supply terminal and the first node in response to the signal from the enable signal terminal, and to connect the light-emitting unit and the second node. A storage circuit is connected between the first power supply terminal and the driving circuit; A reset circuit, connected to the drive circuit, the reset signal terminal, and the initial signal terminal, is used to connect the drive circuit and the initial signal terminal in response to the signal from the reset signal terminal.

6. The pixel driving circuit according to claim 5, characterized in that, The data writing circuit includes a writing transistor, the first terminal of which is connected to the first node, and the second terminal of which is connected to the data signal terminal; and / or The compensation circuit includes a compensation transistor, the first terminal of which is connected to the second node, and the second terminal of which is connected to the driving circuit. and / or The light-emitting control circuit includes a first control transistor and a second control transistor. The first terminal of the first control transistor is connected to the first node, and the second terminal of the first control transistor is connected to the first power supply terminal. The first electrode of the second control transistor is connected to the light-emitting unit, the second electrode of the second control transistor is connected to the second node, and the control electrodes of both the second control transistor and the first control transistor are connected to the enable signal terminal. and / or The storage circuit includes a storage capacitor, the first terminal of which is connected to the first power supply terminal, and the second terminal of which is connected to the driving circuit. and / or The reset circuit includes a first reset transistor and a second reset transistor. The first terminal of the first reset transistor is connected to the initial signal terminal, the second terminal of the first reset transistor is connected to the driving circuit, the first terminal of the second reset transistor is connected to the initial signal terminal, the second terminal of the second reset transistor is connected to the light-emitting unit, and the control terminals of both the first reset transistor and the second reset transistor are connected to the reset signal terminal.

7. A display panel, characterized in that, Includes the pixel driving circuit according to any one of claims 1-6.

8. A method for manufacturing a display panel, wherein the display panel is the display panel according to claim 7, the method comprising: Provide a substrate; An active layer is formed on one side of the substrate. The active layer includes an active layer of a first driving transistor and an active layer of a second driving transistor. Each active layer has a channel region and a first region and a second region located at both ends of the channel region. A first control electrode of a first driving transistor and a control electrode of a second driving transistor are formed on the side of the total active layer away from the substrate. A photoresist for blocking ion implantation is formed on the side of the active layer of the second driving transistor away from the substrate; The active layer is made conductive by ion implantation, so that the first and second regions of the active layer of the first driving transistor are conductive regions, and at least a portion of the first and second regions of the active layer of the second driving transistor are non-conductive regions. The photoresist is peeled off.

9. A method for manufacturing a display panel, wherein the display panel is the display panel according to claim 7, the method comprising: Provide a substrate; An active layer is formed on one side of the substrate. The active layer includes an active layer of a first driving transistor and an active layer of a second driving transistor. Each active layer has a channel region and a first region and a second region located at both ends of the channel region. A first control electrode of a first driving transistor, a control electrode of a second driving transistor, a first shielding portion, and a second shielding portion are formed on the side of the total active layer away from the substrate. The first shielding portion and the second shielding portion are used to shield ion implantation. The active layer is subjected to a conductor-enhancing process, such that the first and second regions of the active layer of the first driving transistor are conductor-enhanced regions, and at least a portion of the first and second regions of the active layer of the second driving transistor are non-conductor-enhanced regions.

10. A display device, characterized in that, Includes the display panel according to claim 7.

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