Pixel structure, pixel driving circuit, driving method and display device

Abstract

The present application provides a pixel structure, a pixel driving circuit, a driving method and a display device, wherein the pixel structure includes: a driving substrate; a first pixel definition layer, a pixel anode and a second pixel definition layer distributed in sequence on the driving substrate; a first metal structure arranged on the first pixel definition layer and a second metal structure arranged on the second pixel definition layer, and the pixel anode extends in the second pixel definition layer to a corresponding position below the second metal structure; a first insulating structure arranged on the first metal structure and a second insulating structure arranged on the second metal structure; an electroluminescent layer covering a portion of the first pixel definition layer, a portion of the pixel anode and a portion of the second pixel definition layer; a pixel cathode covering the electroluminescent layer, with both ends of the pixel cathode connected to the first metal structure and the second metal structure respectively; the manufacturing cost is reduced, the spatial position of the circuit layout is reduced, the area of ​​the light-emitting area is increased, and the aperture ratio of the pixel structure is improved.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to a pixel structure, a pixel driving circuit, a driving method and a display device. Background Art

[0002] Currently, the pixel structure of an organic light emitting diode (OLED) is manufactured using a high-precision metal mask (FMM) evaporation method. The mask is expensive and costly. The area bridged by the openings of the high-precision metal mask limits the effective area of ​​the pixel light-emitting area and reduces the aperture ratio of the pixel structure. Therefore, the aperture ratio of the pixel structure cannot meet user needs, and the pixel drive circuit layout occupies a relatively large space.

[0003] The existing technology has the problem that the aperture ratio of the pixel structure cannot meet the needs of users, and the pixel driving circuit layout occupies a relatively large space. Summary of the Invention

[0004] The embodiments of the present application provide a pixel structure, a pixel driving circuit, a driving method and a display device, which can solve the problem that the aperture ratio of the pixel structure cannot meet the needs of users and the space occupied by the pixel driving circuit layout is relatively large.

[0005] In a first aspect, an embodiment of the present application provides a pixel structure, including:

[0006] Driver substrate;

[0007] A first pixel definition layer, a pixel anode, and a second pixel definition layer are sequentially distributed on the driving substrate, wherein the first pixel definition layer is not in contact with the second pixel definition layer;

[0008] a first metal structure disposed on the first pixel definition layer and a second metal structure disposed on the second pixel definition layer, wherein the pixel anode extends in the second pixel definition layer to a corresponding position below the second metal structure;

[0009] a first insulating structure provided on the first metal structure and a second insulating structure provided on the second metal structure, wherein the first metal structure and the first insulating structure, and the second metal structure and the second insulating structure all form an eaves structure;

[0010] an electroluminescent layer covering a portion of the first pixel definition layer, a portion of the pixel anode, and a portion of the second pixel definition layer, wherein the electroluminescent layer is located between the first metal structure and the second metal structure;

[0011] A pixel cathode covering the electroluminescent layer, wherein two ends of the pixel cathode are respectively connected to the first metal structure and the second metal structure.

[0012] In one embodiment, the thickness of the first pixel definition layer and the thickness of the second pixel definition layer are both greater than the thickness of the pixel anode;

[0013] The thickness of the first metal structure or the thickness of the second metal structure is greater than the thickness of the first insulating structure; the thickness of the first metal structure or the thickness of the second metal structure is greater than the thickness of the second insulating structure;

[0014] The thickness of the pixel anode is greater than the thickness of the pixel cathode.

[0015] In one embodiment, the pixel anode and the pixel cathode form a first patch capacitor, and the pixel anode and the second metal structure form a second patch capacitor.

[0016] In a second aspect, an embodiment of the present application provides a pixel driving circuit, which is provided on the driving substrate as described in the first aspect, and the pixel driving circuit includes:

[0017] a first driving module, wherein a control end of the first driving module is used to receive a dimming signal, an input end of the first driving module is connected to a working power line for receiving a working voltage, and an output end of the first driving module is respectively connected to first ends of a plurality of pixel circuits for transmitting the working voltage to the first ends of the respective pixel circuits;

[0018] a second driving module, wherein a control end of the second driving module is used to receive an initial signal, an input end of the second driving module is connected to an initial power line for receiving an initial voltage, and an output end of the second driving module is respectively connected to the first end of each pixel circuit for sending the initial voltage to the first end of each pixel circuit;

[0019] a scan line, the scan line being connected to the second end of each pixel circuit, and being used to send a scan signal to the second end of each pixel circuit;

[0020] a data line corresponding to each pixel circuit, wherein any of the data lines is connected to a third terminal of the pixel circuit corresponding to the data line, and is used to send a reference voltage or a data voltage to the third terminal of the corresponding pixel circuit;

[0021] a common ground line, the common ground line being connected to the fourth end of each pixel circuit, for grounding the fourth end of each pixel circuit;

[0022] Wherein, any of the pixel circuits includes:

[0023] a third driving module, wherein a control end of the third driving module is connected to the scan line, an input end of the third driving module is connected to the corresponding data line, and an output end of the third driving module is connected to the first node;

[0024] a fourth driving module, wherein a control end of the fourth driving module is connected to the first node, an input end of the fourth driving module is connected to a second node, the second node is connected to an output end of the first driving module and an output end of the second driving module, and an output end of the fourth driving module is connected to a third node;

[0025] a light-emitting device, wherein an anode of the light-emitting device is connected to the third node, and a cathode of the light-emitting device is connected to the common ground line;

[0026] a first storage unit, wherein a first end of the first storage unit is connected to the first node, and a second end of the first storage unit is connected to the third node and the first end of the second storage unit;

[0027] The second end of the second storage unit is connected to the cathode of the light emitting device and the common ground line.

[0028] In one embodiment, the pixel driving circuit further includes:

[0029] a fifth driving module, wherein a control end of the fifth driving module is used to receive the dimming signal, an input end of the fifth driving module is connected to the working power line for receiving the working voltage, and an output end of the fifth driving module is respectively connected to the first end of a preset number of the pixel circuits for sending the working voltage to the first end of each of the pixel circuits;

[0030] a sixth driving module, wherein a control end of the sixth driving module is used to receive the initial signal, an input end of the sixth driving module is used to be connected to the initial power line for receiving an initial voltage, and an output end of the sixth driving module is respectively connected to the first end of each of the pixel circuits for sending the initial voltage to the first end of each of the pixel circuits;

[0031] a scan line, the scan line being connected to the second end of each pixel circuit, and being used to send the scan signal to the second end of each pixel circuit;

[0032] a data line corresponding to each pixel circuit, wherein any one of the data lines is connected to a third terminal of the pixel circuit corresponding to the data line, and is configured to send the reference voltage or the data voltage to the third terminal of the corresponding pixel circuit;

[0033] A common ground line is connected to the fourth end of each pixel circuit and is used to ground the fourth end of each pixel circuit.

[0034] In one embodiment, the first driving module, the second driving module, the third driving module, the fourth driving module, the fifth driving module and the sixth driving module are all thin film transistors;

[0035] The first storage unit and the second storage unit are both capacitors.

[0036] In a third aspect, an embodiment of the present application provides a driving method for driving the pixel driving circuit as described in any one of the second aspects, including:

[0037] In the reset phase, the low-level dimming signal provided by the dimming signal controls the first driving module to turn off, the high-level initial signal provided by the initial signal controls the second driving module to turn on, the scan line stops sending the high-level scan signal, the first node retains the data line of the previous frame to provide the data voltage, the data voltage of the first node controls the fourth driving module to turn on, the initial voltage is written to the third node, the light-emitting device is reset, and the light-emitting device does not emit light;

[0038] In the compensation phase, the initial signal provides a low-level initial signal to control the second driving module to be turned off, the dimming signal provides a high-level dimming signal to control the first driving module to be turned on, the working voltage provided by the working power line is written to the second node, the high-level scan signal provided by the scan line controls the third driving module to be turned on, the reference voltage provided by the data line is written to the first node, the reference voltage controls the fourth driving module to be turned on, the working voltage charges the third node until the voltage of the third node rises to a preset interval voltage, the fourth driving module is turned off, and the light-emitting device does not emit light;

[0039] In the writing phase, the low-level dimming signal provided by the dimming signal controls the first driving module to be turned off, the high-level scanning signal provided by the scanning line controls the third driving module to be turned on, the data voltage provided by the data line is written to the first node, the voltage of the third node is the coupling voltage, the driving voltage of the fourth driving module is the coupling driving voltage, and the light-emitting device does not emit light;

[0040] In the light-emitting stage, the high-level dimming signal provided by the dimming signal controls the first driving module to be turned on, and the fourth driving module generates a driving current driven by the coupled driving voltage, and the driving current drives the light-emitting device to emit light;

[0041] Wherein, the data voltage and the reference voltage of the previous frame are both greater than or equal to the initial voltage.

[0042] In one embodiment, the coupling voltage is calculated as follows:

[0043] V_N3=Vref-Vth+α×(Vdata-Vref);

[0044] The calculation formula of the coupling driving voltage is:

[0045] VGS=(1-α)×(Vdata-Vref)+Vth;

[0046] Wherein, V_N3 is the coupling voltage, VGS is the coupling driving voltage, Vref is the reference voltage, Vth is the threshold voltage of the fourth driving module, Vdata is the data voltage, α is the capacitance coefficient, and α=C1 / (C1+C2).

[0047] In one embodiment, the preset interval voltage has a value range of: Vinterval≧Vref-Vth;

[0048] Wherein, Vinterval is the preset interval voltage, Vref is the reference voltage, and Vth is the threshold voltage of the fourth driving module.

[0049] In a fourth aspect, an embodiment of the present application provides a display device comprising a pixel driving circuit as described in any one of the contents of the second aspect.

[0050] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0051] A pixel structure provided by the present application, compared with the prior art in which the area of ​​the high-precision metal mask opening bridge limits the effective area of ​​the pixel light-emitting area and the mask cost is high, limits the film-forming area of ​​the electroluminescent layer and the pixel cathode through the first metal structure and the first insulating structure and the second metal structure and the second insulating structure, so that the electroluminescent layer and the pixel cathode can be produced without a mask, thereby reducing the production cost of the pixel structure. At the same time, since the pixel anode extends to the corresponding position below the second metal structure in the second pixel definition layer, the pixel anode can form a capacitor structure with the pixel cathode and the second metal structure respectively, so that some capacitors do not need to occupy space when the pixel driving circuit is laid out, thereby reducing the space position of the pixel driving circuit layout, further increasing the area of ​​the light-emitting area in the pixel structure, and improving the aperture ratio of the pixel structure.

[0052] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 is a cross-sectional schematic diagram of a pixel structure provided by an embodiment of the present application;

[0055] Figure 2 This is a structural diagram of a 4T2C pixel driving circuit provided by the prior art;

[0056] Figure 3 This is a driving timing diagram of a 4T2C pixel driving circuit provided by the prior art;

[0057] Figure 4 1 is a schematic structural diagram of a pixel driving circuit provided in one embodiment of the present application;

[0058] Figure 5 This is a schematic structural diagram of a pixel driving circuit provided in a specific embodiment of the present application;

[0059] Figure 6 is a structural diagram of a pixel driving circuit provided by another embodiment of the present application;

[0060] Figure 7 is a structural diagram of a pixel driving circuit provided by another specific embodiment of the present application;

[0061] Figure 8 1 is a driving timing diagram of a pixel driving circuit provided in an embodiment of the present application;

[0062] Figure 9 1 is a schematic diagram of a driving phase of a driving method provided in an embodiment of the present application;

[0063] Figure 10 1 is a flow chart of a method for manufacturing a pixel structure provided in one embodiment of the present application.

[0064] Reference numerals:

[0065] 1. Drive substrate; 2. First pixel definition layer; 3. Pixel anode; 4. Second pixel definition layer; 5. First metal structure; 6. Second metal structure; 7. First insulating structure; 8. Second insulating structure; 9. Electroluminescent layer; 10. Pixel cathode;

[0066] 210, working power line; 220, initial power line; 230, scanning line; 240, data line; 250, common ground line;

[0067] 110, first driving module; 120, second driving module; 130, pixel circuit; 131, third driving module; 132, fourth driving module; 133, light-emitting device; 134, first storage unit; 135, second storage unit; 140, fifth driving module; 150, sixth driving module;

[0068] N1, first node; N2, second node; N3, third node;

[0069] Td1, first thin film transistor; Ti1, second thin film transistor; T1, third thin film transistor; DT, fourth thin film transistor; Td2, fifth thin film transistor; Ti2, sixth thin film transistor; OLED, organic light emitting diode; C1, first capacitor; C2, second capacitor. DETAILED DESCRIPTION

[0070] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0071] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0072] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0073] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0074] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0075] The technical solution of this application is described below through specific embodiments.

[0076] First, as Figure 1 As shown, an embodiment of the present application provides a pixel structure, including a driving substrate 1; a first pixel definition layer 2, a pixel anode 3 and a second pixel definition layer 4 sequentially distributed on the driving substrate 1, the first pixel definition layer 2 and the second pixel definition layer 4 not in contact; a first metal structure 5 provided on the first pixel definition layer 2 and a second metal structure 6 provided on the second pixel definition layer 4, and the pixel anode 3 extends in the second pixel definition layer 4 to a corresponding position below the second metal structure 6; a first insulating structure 7 provided on the first metal structure 5 and a second insulating structure 8 provided on the second metal structure 6, the first metal structure 5 and the first insulating structure 7, the second metal structure 6 and the second insulating structure 8 all forming an eaves structure; an electroluminescent layer 9 covering part of the first pixel definition layer 2, covering part of the pixel anode 3 and covering part of the second pixel definition layer 4, and the electroluminescent layer 9 is between the first metal structure 5 and the second metal structure 6; an image covering the electroluminescent layer 9 The pixel cathode 10 and the two ends of the pixel cathode 10 are respectively connected to the first metal structure 5 and the second metal structure 6; compared with the area of ​​the high-precision metal mask opening bridge in the prior art, which limits the effective area of ​​the pixel light-emitting area and the high cost of the mask, the first metal structure 5 and the first insulating structure 7 and the second metal structure 6 and the second insulating structure 8 are used to limit the film forming area of ​​the electroluminescent layer 9 and the pixel cathode 10, so that the electroluminescent layer 9 and the pixel cathode 10 can be produced without a mask, thereby reducing the production cost of the pixel structure. At the same time, since the pixel anode 3 extends to the corresponding position below the second metal structure 6 in the second pixel definition layer 4, the pixel anode 3 can form a capacitor structure with the pixel cathode 10 and the second metal structure 6 respectively, so that part of the capacitor does not need to occupy space when the pixel driving circuit is laid out, thereby reducing the space position of the pixel driving circuit layout, further increasing the area of ​​the light-emitting area in the pixel structure, and improving the aperture ratio of the pixel structure.

[0077] It should be noted that the first insulating structure 7 and the second insulating structure 8 serve as the roof, and the first metal structure 5 and the second metal structure 6 serve as the main body. The first metal structure 5 and the first insulating structure 7, and the second metal structure 6 and the second insulating structure 8, all form an eaves structure. Specifically, the projection of the first insulating structure 7 or the second insulating structure 8 on the driving substrate 1 is greater than or equal to the projection of the first metal structure 5 or the second metal structure 6 on the driving substrate 1. In one embodiment, to increase the aperture ratio of the pixel structure, the projection of the first insulating structure 7 or the second insulating structure 8 on the driving substrate 1 is equal to the projection of the first metal structure 5 or the second metal structure 6 on the driving substrate 1.

[0078] In one embodiment, the thickness of the first pixel definition layer 2 and the second pixel definition layer 4 are both greater than the thickness of the pixel anode 3; the pixel definition layer comprises an inorganic material, so that the pixel definition layer isolates the pixel anode 3 from the metal structure, preventing contact between the pixel anode 3 and the metal structure. The thickness of the first metal structure 5 or the second metal structure 6 is greater than the thickness of the first insulating structure 7, and the thickness of the first metal structure 5 or the second metal structure 6 is greater than the thickness of the second insulating structure 8. This facilitates the connection between the first metal structure 5 and the second metal structure 6 and the pixel cathode 10, thereby forming a full-surface metal network with the pixel cathode 10, reducing the voltage drop generated by the pixel cathode 10 signal line itself. The thickness of the pixel anode 3 is greater than the thickness of the pixel cathode 10. The materials of the first metal structure 5 and the second metal structure 6 include, but are not limited to, Mo, Al, Ti, Cu, etc. The materials of the first insulating structure 7 and the second insulating structure 8 include, but are not limited to, silicon nitride, silicon oxide, etc.

[0079] In one embodiment, the pixel anode 3 and the pixel cathode 10 form a first chip capacitor, the pixel anode 3 and the second metal structure 6 form a second chip capacitor, and the first chip capacitor and the second chip capacitor together form a capacitor in parallel with the light-emitting device 133; thus, when the pixel driving circuit is laid out, the capacitor in parallel with the light-emitting device 133 does not need to occupy a spatial position, thereby reducing the spatial position of the pixel driving circuit layout, further increasing the area of ​​the light-emitting area in the pixel structure, and improving the aperture ratio of the pixel structure.

[0080] In one embodiment, the driver substrate 1 includes, in addition to the pixel structure, a pixel driving circuit. For example, the driver substrate 1 also includes a pixel driving circuit that drives the light-emitting device 133 to emit light. The pixel driving circuit can be arranged in an array, so the driver substrate 1 is also called an array substrate. The pixel driving circuit includes components such as thin-film transistors and capacitors. The driver substrate 1 also includes signal lines such as scan lines 230 and data lines 240.

[0081] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0082] A pixel structure provided by the present application, compared with the prior art in which the area of ​​the high-precision metal mask opening bridge limits the effective area of ​​the pixel light-emitting area and the mask cost is high, limits the film-forming area of ​​the electroluminescent layer and the pixel cathode through the first metal structure and the first insulating structure and the second metal structure and the second insulating structure, so that the electroluminescent layer and the pixel cathode can be produced without a mask, thereby reducing the production cost of the pixel structure. At the same time, since the pixel anode extends to the corresponding position below the second metal structure in the second pixel definition layer, the pixel anode can form a capacitor structure with the pixel cathode and the second metal structure respectively, so that some capacitors do not need to occupy space when the pixel driving circuit is laid out, thereby reducing the space position of the pixel driving circuit layout, further increasing the area of ​​the light-emitting area in the pixel structure, and improving the aperture ratio of the pixel structure.

[0083] Furthermore, in conventional organic light-emitting diode (OLED) display panels, the thin-film transistors (TFTs) in each pixel structure gradually age over time, causing a change in threshold voltage (Vth). Furthermore, each TFT has a different threshold voltage (Vth) due to differences in manufacturing processes. OLED display panels are current-driven, and the driving current is primarily affected by the threshold voltage (Vth). As the size of display panels increases, the refresh rate of the display panels increases, for example, from 60 Hz to 120 Hz. The compensation effect of the pixel driving circuit is relatively poor, resulting in uneven brightness in the OLED display panel. Furthermore, the resolution of the display panel is related to the size of a single pixel structure. To improve the resolution, the area of ​​a single pixel structure needs to be reduced, and therefore, the number of thin-film transistors in the pixel driving circuit of each pixel structure needs to be reduced.

[0084] like Figure 2 As shown, Figure 2 FIG. 1 is a structural diagram of a 4T2C (i.e., 4 thin film transistors and 2 capacitors) pixel driving circuit in the prior art, as shown in FIG. Figure 3 As shown, Figure 3 Schematic diagram of the driving timing corresponding to the 4T2C pixel driving circuit.

[0085] Second, as Figure 4As shown, the embodiment of the present application provides a pixel driving circuit, which is arranged on a driving substrate 1 of a pixel structure, and the pixel driving circuit includes a first driving module 110, a second driving module 120, a scanning line 230, a data line 240 corresponding to each pixel circuit 130, a common ground line 250 and a pixel circuit 130; wherein the control end of the first driving module 110 is used to receive a dimming signal, the input end of the first driving module 110 is connected to the working power line 210 for receiving a working voltage, and the output end of the first driving module 110 is respectively connected to the first end of a plurality of pixel circuits 130 for sending a working voltage to the first end of each pixel circuit 130; the control end of the second driving module 120 is used to receive an initial signal, and the output end of the second driving module 120 is used to receive a dimming signal. The input end is connected to the initial power line 220 for receiving the initial voltage, and the output end of the second driving module 120 is respectively connected to the first end of each pixel circuit 130 for sending the initial voltage to the first end of each pixel circuit 130; the scanning line 230 is respectively connected to the second end of each pixel circuit 130 for sending the scanning signal to the second end of each pixel circuit 130; the data line 240 corresponding to each pixel circuit 130, any data line 240 is connected to the third end of the pixel circuit 130 corresponding to the data line 240, for sending the reference voltage or data voltage to the third end of the corresponding pixel circuit 130; the common ground line 250, the common ground line 250 is respectively connected to the fourth end of each pixel circuit 130, for grounding the fourth end of each pixel circuit 130. Each pixel circuit 130 includes a third driving module 131, a fourth driving module 132, a light-emitting device 133, a first storage unit 134, and a second storage unit 135. A control end of the third driving module 131 is connected to the scan line 230, an input end of the third driving module 131 is connected to the corresponding data line 240, and an output end of the third driving module 131 is connected to a first node N1. A control end of the fourth driving module 132 is connected to the first node N1, an input end of the fourth driving module 132 is connected to a second node N2, the second node N2 is connected to the output end of the first driving module 110 and the output end of the second driving module 120, and an output end of the fourth driving module 132 is connected to a third node N3. An anode of the light-emitting device 133 is connected to the third node N3, and a cathode of the light-emitting device 133 is connected to a common ground line 250. A first end of the first storage unit 134 is connected to the first node N1, a second end of the first storage unit 134 is connected to the third node N3 and a first end of the second storage unit 135, and a second end of the second storage unit 135 is connected to the cathode of the light-emitting device 133 and the common ground line 250.

[0086] The pixel driving circuit of this embodiment has a simple structure. By allowing multiple pixel circuits 130 in an entire row to share a first driving module 110 that provides an operating voltage and a second driving module 120 that provides an initial voltage, and by combining the activation timing of each driving module to compensate for the fourth driving module 132, this reduces threshold voltage drift of the fourth driving module 132 due to long-term aging or threshold voltage differences caused by process factors of the display panel. This reduces display brightness differences caused by inconsistent light-emitting currents of organic light-emitting diodes, and improves the brightness uniformity of the display panel. No additional signals are required to control voltage changes during compensation, thereby reducing the number of thin-film transistors in each pixel circuit 130 from four to two. That is, each pixel circuit 130 is converted from a 4T2C circuit to a 2T2C circuit, significantly reducing the area occupied by each pixel circuit 130, improving the pixel density of the display panel, and further increasing the aperture ratio.

[0087] In one embodiment, the first driving module 110, the second driving module 120, the third driving module 131, and the fourth driving module 132 are all thin film transistors, that is, the first driving module 110 is a first thin film transistor Td1, the second driving module 120 is a second thin film transistor Ti1, the third driving module 131 is a third thin film transistor T1, and the fourth driving module 132 is a fourth thin film transistor DT. The first storage unit 134 and the second storage unit 135 are both capacitors, that is, the first storage unit 134 is a first capacitor C1, and the second storage unit 135 is a second capacitor C2.

[0088] It should be noted that the light emitting device 133 includes Figure 1 The pixel anode 3, the electroluminescent layer 9 and the pixel cathode 10, the pixel anode 3 is the anode of the light emitting device 133, the pixel cathode 10 is the cathode of the light emitting device 133, and the light emitting device 133 is an organic light emitting diode; the second capacitor C2 includes a first patch capacitor and a second patch capacitor, that is, the second capacitor C2 includes Figure 1 The first patch capacitor formed by the pixel anode 3 and the pixel cathode 10 and the second patch capacitor formed by the pixel anode 3 and the second metal structure 6 are formed by extending the pixel anode 3 to the corresponding position below the second metal structure 6, thereby forming the second capacitor C2 in the pixel circuit 130, further reducing the occupied area of ​​the pixel circuit 130 in the pixel, improving the pixel density of the display panel, and further improving the aperture ratio.

[0089] In one embodiment, Figure 5As shown, the pixel driving circuit includes a first thin film transistor Td1, a second thin film transistor Ti1, a scan line 230, a data line 240 corresponding to each pixel circuit 130, a common ground line 250 and a pixel circuit 130; wherein, the control end of the first thin film transistor Td1 is used to receive a dimming signal, the input end of the first thin film transistor Td1 is connected to the working power line 210 for receiving a working voltage, the output end of the first thin film transistor Td1 is respectively connected to the first end of a plurality of pixel circuits 130 for sending a working voltage to the first end of each pixel circuit 130; the control end of the second thin film transistor Ti1 is used to receive an initial signal, and the input end of the second thin film transistor Ti1 is connected to the initial power line 220 , used to receive the initial voltage, the output end of the second thin film transistor Ti1 is respectively connected to the first end of each pixel circuit 130, used to send the initial voltage to the first end of each pixel circuit 130; the scan line 230 is respectively connected to the second end of each pixel circuit 130, used to send a scan signal to the second end of each pixel circuit 130; the data line 240 corresponding to each pixel circuit 130, any data line 240 is connected to the third end of the pixel circuit 130 corresponding to the data line 240, used to send a reference voltage or a data voltage to the third end of the corresponding pixel circuit 130; the common ground line 250, the common ground line 250 is respectively connected to the fourth end of each pixel circuit 130, used to ground the fourth end of each pixel circuit 130. Each pixel circuit 130 includes a third thin-film transistor T1, a fourth thin-film transistor DT, an organic light-emitting diode OLED, a first storage unit 134, and a second storage unit 135. A control terminal of the third thin-film transistor T1 is connected to the scan line 230, an input terminal of the third thin-film transistor T1 is connected to the corresponding data line 240, and an output terminal of the third thin-film transistor T1 is connected to the first node N1. A control terminal of the fourth thin-film transistor DT is connected to the first node N1, an input terminal of the fourth thin-film transistor DT is connected to the second node N2, the second node N2 is connected to the output terminal of the first driving module 110 and the output terminal of the second driving module 120, and an output terminal of the fourth thin-film transistor DT is connected to the third node N3. An anode of the organic light-emitting diode OLED is connected to the third node N3, and a cathode of the light-emitting device is connected to the common ground line 250. A first terminal of the first capacitor C1 is connected to the first node N1, a second terminal of the first capacitor C1 is connected to the third node N3 and a first terminal of the second capacitor C2. A second terminal of the second capacitor C2 is connected to the cathode of the light-emitting device and the common ground line 250.

[0090] In another embodiment, Figure 6As shown, the pixel driving circuit further includes a fifth driving module 140, a sixth driving module 150, a scan line 230, a data line 240 corresponding to each pixel circuit 130, a common ground line 250 and the pixel circuit 130; wherein the control end of the fifth driving module 140 is used to receive a dimming signal, the input end of the fifth driving module 140 is connected to the working power line 210 for receiving a working voltage, the output end of the fifth driving module 140 is respectively connected to the first end of a preset number of pixel circuits 130 for sending a working voltage to the first end of each pixel circuit 130; the control end of the sixth driving module 150 is used to receive an initial signal, and the output end of the sixth driving module 150 is used to receive an initial signal. The input end is used to connect to the initial power line 220 for receiving the initial voltage. The output end of the sixth driving module 150 is respectively connected to the first end of each pixel circuit 130 for sending the initial voltage to the first end of each pixel circuit 130; the scan line 230 is respectively connected to the second end of each pixel circuit 130 for sending a scan signal to the second end of each pixel circuit 130; any data line 240 is connected to the third end of the pixel circuit 130 corresponding to the data line 240 for sending a reference voltage or a data voltage to the third end of the corresponding pixel circuit 130; the common ground line 250 is respectively connected to the fourth end of each pixel circuit 130 for grounding the fourth end of each pixel circuit 130.

[0091] In another embodiment, the fifth driving module 140 and the sixth driving module 150 are both thin film transistors, that is, the fifth driving module 140 is a fifth thin film transistor Td2 , and the sixth driving module 150 is a sixth thin film transistor Ti2 .

[0092] In another embodiment, Figure 7As shown, the pixel driving circuit further includes a fifth thin film transistor Td2, a sixth thin film transistor Ti2, a scan line 230, a data line 240 corresponding to each pixel circuit 130, a common ground line 250 and the pixel circuit 130; wherein the control end of the fifth thin film transistor Td2 is used to receive a dimming signal, the input end of the fifth thin film transistor Td2 is connected to the working power line 210 for receiving a working voltage, and the output end of the fifth thin film transistor Td2 is respectively connected to the first end of a preset number of pixel circuits 130 for sending a working voltage to the first end of each pixel circuit 130; the control end of the sixth thin film transistor Ti2 is used to receive an initial signal, and the sixth thin film transistor Ti The input end of the sixth thin-film transistor Ti2 is used to connect to the initial power line 220 for receiving the initial voltage. The output end of the sixth thin-film transistor Ti2 is respectively connected to the first end of each pixel circuit 130 for sending the initial voltage to the first end of each pixel circuit 130; the scan line 230 is respectively connected to the second end of each pixel circuit 130 for sending the scan signal to the second end of each pixel circuit 130; any data line 240 is connected to the third end of the pixel circuit 130 corresponding to the data line 240 for sending the reference voltage or the data voltage to the third end of the corresponding pixel circuit 130; the common ground line 250 is respectively connected to the fourth end of each pixel circuit 130 for grounding the fourth end of each pixel circuit 130.

[0093] The pixel driving circuit of this embodiment has a simple structure. By allowing a predetermined number of pixel circuits in each row to share a first driving module that provides an operating voltage, and allowing the entire row of pixel circuits to share a second driving module that provides an initial voltage, and by combining the activation timings of the various driving modules to compensate for the fourth driving module, threshold voltage drift caused by long-term aging of the fourth driving module or differences in threshold voltage due to process factors in the display panel is reduced. This reduces display brightness variations caused by inconsistent light-emitting currents of organic light-emitting diodes, thereby improving the brightness uniformity of the display panel. No additional signals are required to control voltage changes during compensation. Consequently, the number of thin-film transistors in each pixel circuit is reduced from four to two, meaning that each pixel circuit is converted from a 4T2C circuit to a 2T2C circuit. This significantly reduces the area occupied by each pixel circuit, increases the pixel density of the display panel, and further improves the aperture ratio. Furthermore, because the predetermined number of pixel circuits in each row share the first driving module for the operating voltage, voltage drops caused by signal lines in pixel circuits farther away from the first driving module are avoided, thereby improving the consistency of the predetermined number of pixel circuits and further improving the brightness uniformity of the display panel.

[0094] Thirdly, as Figure 8 、 Figure 9As shown, the embodiment of the present application provides a driving method for driving the pixel driving circuit as described in any one of the second aspects, the driving method includes a reset phase, a compensation phase, a writing phase, and a light emitting phase. The specific driving process is as follows:

[0095] In the reset stage, the low-level dimming signal provided by the dimming signal controls the first driving module 110 to turn off, the high-level initial signal provided by the initial signal controls the second driving module 120 to turn on, the scan line 230 stops sending the high-level scan signal, and the first node N1 retains the data line 240 of the previous frame to provide the data voltage. The data voltage of the first node N1 controls the fourth driving module 132 to turn on, and the initial voltage is written to the third node N3 to reset the light-emitting device 133, and the light-emitting device 133 does not emit light.

[0096] During the compensation phase, the low-level initial signal provided by the initial signal controls the second driving module 120 to be turned off, the high-level dimming signal provided by the dimming signal controls the first driving module 110 to be turned on, the working voltage provided by the working power line 210 is written into the second node N2, the high-level scanning signal provided by the scanning line 230 controls the third driving module 131 to be turned on, the reference voltage provided by the data line 240 is written into the first node N1, the reference voltage controls the fourth driving module 132 to be turned on, and the working voltage charges the third node N3 until the voltage of the third node N3 rises to the preset interval voltage, then the fourth driving module 132 is turned off, and the light-emitting device 133 does not emit light.

[0097] In the writing stage, the low-level dimming signal provided by the dimming signal controls the first driving module 110 to turn off, the high-level scanning signal provided by the scanning line 230 controls the third driving module 131 to turn on, and the data voltage provided by the data line 240 is written to the first node N1. The voltage of the third node N3 is the coupling voltage, the driving voltage of the fourth driving module 132 is the coupling driving voltage, and the light-emitting device 133 does not emit light.

[0098] In the light-emitting stage, the high-level dimming signal provided by the dimming signal controls the first driving module 110 to be turned on, and the fourth driving module 132 generates a driving current driven by the coupled driving voltage, and the driving current drives the light-emitting device 133 to emit light.

[0099] Among them, the data voltage Vdata(n-1) and the reference voltage Vref of the previous frame are both greater than or equal to the initial voltage Vini, Vref≧Vini+Vth, and Vinterval≧Vini-Vth, the coupling voltage is V_N3, the coupling driving voltage is VGS, the operating voltage is VDD, the threshold voltage of the fourth driving module 132 is Vth, the preset interval voltage is Vinterval, the dimming signal is EM, the initial signal is INI, and the data voltage provided by the data line 240 is Vdata.

[0100] In one embodiment, combined Figure 5 、 Figure 9 In the reset stage, the low-level dimming signal provided by the dimming signal EM controls the first thin film transistor Td1 to be turned off, the high-level initial signal provided by the initial signal INI controls the second thin film transistor Ti1 to be turned on, the scan line 230 stops sending the high-level scan signal, the first node N1 retains the data voltage Vdata(n-1) provided by the data line 240 of the previous frame, the data voltage of the first node N1 controls the fourth thin film transistor DT to be turned on, the initial voltage Vini is written into the third node N3, the organic light emitting diode OLED is reset, and the organic light emitting diode OLED does not emit light.

[0101] During the compensation stage, the low-level initial signal provided by the initial signal INI controls the second thin-film transistor Ti1 to be turned off, the high-level dimming signal provided by the dimming signal EM controls the first thin-film transistor Td1 to be turned on, the working voltage VDD provided by the working power line 210 is written into the second node N2, the high-level scan signal provided by the scan line 230 controls the third thin-film transistor T1 to be turned on, and the reference voltage Vref provided by the data line 240 is written into the first node N1. Since the reference voltage Vref is greater than the threshold voltage Vth of the fourth driving module 132, the reference voltage Vref controls the fourth thin-film transistor DT to be turned on, and the working voltage VDD charges the third node N3 until the voltage of the third node N3 rises to the preset interval voltage Vinterval, and then the fourth thin-film transistor DT is turned off, and the organic light-emitting diode OLED does not emit light.

[0102] In the writing stage, the low-level dimming signal provided by the dimming signal EM controls the first thin film transistor Td1 to be turned off, and the high-level scanning signal provided by the scanning line 230 controls the third thin film transistor T1 to be turned on. The data voltage Vdata provided by the data line 240 is written to the first node N1, and the voltage of the third node N3 is the coupling voltage V_N3, V_N3 = Vref - Vth + α × (Vdata - Vref). At this time, the driving voltage of the fourth thin film transistor DT is the coupling driving voltage VGS, VGS = (1 - α) × (Vdata - Vref) + Vth, and the organic light emitting diode OLED does not emit light.

[0103] In the light emitting stage, the high-level dimming signal provided by the dimming signal EM controls the first thin film transistor Td1 to be turned on, and the fourth thin film transistor DT generates a driving current driven by the coupled driving voltage VGS, and the driving current drives the organic light emitting diode OLED to emit light.

[0104] In one embodiment, the coupling voltage is calculated as:

[0105] V_N3=Vref-Vth+α×(Vdata-Vref);

[0106] The calculation formula of the coupling drive voltage is:

[0107] VGS=(1-α)×(Vdata-Vref)+Vth;

[0108] Wherein, V_N3 is the coupling voltage, VGS is the coupling driving voltage, Vref is the reference voltage, Vth is the threshold voltage of the fourth driving module 132 , Vdata is the data voltage, α is the capacitance coefficient, and α=C1 / (C1+C2).

[0109] In one embodiment, the value range of the preset interval voltage is: Vinterval≧Vref-Vth;

[0110] Wherein, Vinterval is a preset interval voltage, Vref is a reference voltage, and Vth is a threshold voltage of the fourth driving module 132 .

[0111] In one embodiment, in order to ensure the light-emitting duration of the organic light-emitting diode OLED, the ratio of the sum of the time of the reset stage, the compensation stage and the writing stage to the time of the light-emitting stage is 2:8, and the ratio of the time of the reset stage, the compensation stage and the writing stage is 1:1:1.

[0112] In one embodiment, the pixel driving circuit can drive a row of pixels or a preset number of pixels, and repeat the above-mentioned reset, compensation, writing and light-emitting stages for the pixel driving circuits of all pixels, and so on. After completing the reset, compensation, writing and light-emitting stages, the pixel driving circuits of each row will keep emitting light for one frame.

[0113] The driving method of this embodiment reduces the number of thin film transistors in each pixel and expands the effective light-emitting area of ​​the light-emitting device in each pixel, thereby improving display brightness uniformity and reducing driving costs.

[0114] In a fourth aspect, an embodiment of the present application provides a display device comprising a pixel driving circuit as described in any one of the second aspects.

[0115] The beneficial effects of this embodiment are described in detail in the second aspect and will not be repeated here.

[0116] Fifthly, Figure 10 As shown, an embodiment of the present application provides a method for manufacturing a pixel structure, comprising:

[0117] S100 , forming a driving substrate 1 .

[0118] S200 , forming a first pixel definition layer 2 , a pixel anode 3 and a second pixel definition layer 4 in sequence on the driving substrate 1 , wherein the first pixel definition layer 2 and the second pixel definition layer 4 are not in contact with each other.

[0119] S300 , forming a first metal structure 5 on the first pixel definition layer 2 and a second metal structure 6 on the second pixel definition layer 4 , and extending the pixel anode 3 in the second pixel definition layer 4 to a corresponding position below the second metal structure 6 .

[0120] S400 , forming a first insulating structure 7 on the first metal structure 5 and a second insulating structure 8 on the second metal structure 6 , wherein the first metal structure 5 and the first insulating structure 7 , and the second metal structure 6 and the second insulating structure 8 all form an eaves structure.

[0121] S500 , forming an electroluminescent layer 9 covering a portion of the first pixel definition layer 2 , a portion of the pixel anode 3 , and a portion of the second pixel definition layer 4 , and the electroluminescent layer 9 is located between the first metal structure 5 and the second metal structure 6 .

[0122] S600 , forming a pixel cathode 10 covering the electroluminescent layer 9 , wherein two ends of the pixel cathode 10 are connected to the first metal structure 5 and the second metal structure 6 respectively.

[0123] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0124] The beneficial effects of this embodiment are described in detail in the first aspect and will not be repeated here.

[0125] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0126] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0127] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0128] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A driving method, characterized in that: Used to drive the pixel driving circuit, including: In the reset phase, the low-level dimming signal provided by the dimming signal controls the first driving module to turn off, the high-level initial signal provided by the initial signal controls the second driving module to turn on, the scan line stops sending the high-level scan signal, the first node retains the data line of the previous frame to provide the data voltage, the data voltage of the first node controls the fourth driving module to turn on, the initial voltage is written to the third node, the light-emitting device is reset, and the light-emitting device does not emit light; In the compensation phase, the initial signal provides a low-level initial signal to control the second driving module to be turned off, the dimming signal provides a high-level dimming signal to control the first driving module to be turned on, the working voltage provided by the working power line is written to the second node, the high-level scan signal provided by the scan line controls the third driving module to be turned on, the reference voltage provided by the data line is written to the first node, the reference voltage controls the fourth driving module to be turned on, the working voltage charges the third node until the voltage of the third node rises to a preset interval voltage, the fourth driving module is turned off, and the light-emitting device does not emit light; In the writing phase, the low-level dimming signal provided by the dimming signal controls the first driving module to be turned off, the high-level scanning signal provided by the scanning line controls the third driving module to be turned on, the data voltage provided by the data line is written to the first node, the voltage of the third node is the coupling voltage, the driving voltage of the fourth driving module is the coupling driving voltage, and the light-emitting device does not emit light; In the light-emitting stage, the high-level dimming signal provided by the dimming signal controls the first driving module to be turned on, and the fourth driving module generates a driving current driven by the coupled driving voltage, and the driving current drives the light-emitting device to emit light; Wherein, the data voltage and the reference voltage of the previous frame are both greater than or equal to the initial voltage; The pixel driving circuit includes: a first driving module, wherein a control end of the first driving module is used to receive a dimming signal, an input end of the first driving module is connected to a working power line for receiving a working voltage, and an output end of the first driving module is respectively connected to first ends of a plurality of pixel circuits for transmitting the working voltage to the first ends of the respective pixel circuits; a second driving module, wherein a control end of the second driving module is used to receive an initial signal, an input end of the second driving module is connected to an initial power line for receiving an initial voltage, and an output end of the second driving module is respectively connected to the first end of each pixel circuit for sending the initial voltage to the first end of each pixel circuit; a scan line, the scan line being connected to the second end of each pixel circuit, and being used to send a scan signal to the second end of each pixel circuit; a data line corresponding to each pixel circuit, wherein any of the data lines is connected to a third terminal of the pixel circuit corresponding to the data line, and is used to send a reference voltage or a data voltage to the third terminal of the corresponding pixel circuit; a common ground line, the common ground line being connected to the fourth end of each pixel circuit, for grounding the fourth end of each pixel circuit; Wherein, any of the pixel circuits includes: a third driving module, wherein a control end of the third driving module is connected to the scan line, an input end of the third driving module is connected to the corresponding data line, and an output end of the third driving module is connected to the first node; a fourth driving module, wherein a control end of the fourth driving module is connected to the first node, an input end of the fourth driving module is connected to a second node, the second node is connected to an output end of the first driving module and an output end of the second driving module, and an output end of the fourth driving module is connected to a third node; a light-emitting device, wherein an anode of the light-emitting device is connected to the third node, and a cathode of the light-emitting device is connected to the common ground line; a first storage unit, wherein a first end of the first storage unit is connected to the first node, and a second end of the first storage unit is connected to the third node and the first end of the second storage unit; The second end of the second storage unit is connected to the cathode of the light emitting device and the common ground line.

2. The driving method according to claim 1, wherein: The calculation formula of the coupling voltage is: V_N3=Vref-Vth+α×(Vdata-Vref); The calculation formula of the coupling driving voltage is: VGS=(1-α)×(Vdata-Vref)+Vth; Wherein, V_N3 is the coupling voltage, VGS is the coupling driving voltage, Vref is the reference voltage, Vth is the threshold voltage of the fourth driving module, Vdata is the data voltage, α is the capacitance coefficient, and α=C1 / (C1+C2).

3. The driving method according to claim 1, wherein: The value range of the preset interval voltage is: Vinterval≧Vref-Vth; Wherein, Vinterval is the preset interval voltage, Vref is the reference voltage, and Vth is the threshold voltage of the fourth driving module.

4. The driving method according to claim 3, wherein: The pixel driving circuit further includes: a fifth driving module, wherein a control end of the fifth driving module is used to receive the dimming signal, an input end of the fifth driving module is connected to the working power line for receiving the working voltage, and an output end of the fifth driving module is respectively connected to the first end of a preset number of the pixel circuits for sending the working voltage to the first end of each of the pixel circuits; a sixth driving module, wherein a control end of the sixth driving module is used to receive the initial signal, an input end of the sixth driving module is used to be connected to the initial power line for receiving an initial voltage, and an output end of the sixth driving module is respectively connected to the first end of each of the pixel circuits for sending the initial voltage to the first end of each of the pixel circuits; a scan line, the scan line being connected to the second end of each pixel circuit, and being used to send the scan signal to the second end of each pixel circuit; a data line corresponding to each pixel circuit, wherein any one of the data lines is connected to a third terminal of the pixel circuit corresponding to the data line, and is configured to send the reference voltage or the data voltage to the third terminal of the corresponding pixel circuit; A common ground line is connected to the fourth end of each pixel circuit and is used to ground the fourth end of each pixel circuit.

5. The driving method according to claim 4, wherein: The first driving module, the second driving module, the third driving module, the fourth driving module, the fifth driving module and the sixth driving module are all thin film transistors; The first storage unit and the second storage unit are both capacitors.

6. The driving method according to claim 1, wherein: The pixel driving circuit is disposed on a driving substrate, which is disposed on a pixel structure. A first pixel definition layer, a pixel anode, and a second pixel definition layer are sequentially distributed on the driving substrate, and the first pixel definition layer is not in contact with the second pixel definition layer. The pixel structure further includes: a first metal structure disposed on the first pixel definition layer and a second metal structure disposed on the second pixel definition layer, wherein the pixel anode extends in the second pixel definition layer to a corresponding position below the second metal structure; a first insulating structure provided on the first metal structure and a second insulating structure provided on the second metal structure, wherein the first metal structure and the first insulating structure, and the second metal structure and the second insulating structure all form an eaves structure; an electroluminescent layer covering a portion of the first pixel definition layer, a portion of the pixel anode, and a portion of the second pixel definition layer, wherein the electroluminescent layer is located between the first metal structure and the second metal structure; a pixel cathode covering the electroluminescent layer, wherein two ends of the pixel cathode are respectively connected to the first metal structure and the second metal structure; The pixel anode and the pixel cathode form a first patch capacitor, and the pixel anode and the second metal structure form a second patch capacitor; the thickness of the first pixel definition layer and the thickness of the second pixel definition layer are both greater than the thickness of the pixel anode.

7. The driving method according to claim 6, wherein: The thickness of the first metal structure or the thickness of the second metal structure is greater than the thickness of the first insulating structure; the thickness of the first metal structure or the thickness of the second metal structure is greater than the thickness of the second insulating structure; The thickness of the pixel anode is greater than the thickness of the pixel cathode.

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