CN113964163A - Display substrate and display device - Google Patents

Abstract

The embodiment of the application provides a display substrate and a display device, and relates to the technical field of display; the display substrate includes: a substrate; the pixel units are positioned on the substrate and comprise a plurality of sub-pixels, each sub-pixel comprises a transistor, a light-emitting element and a first auxiliary wiring, and a first pole of the transistor is electrically connected with an anode of the light-emitting element through the first auxiliary wiring; at least one of the sub-pixels further includes a second auxiliary trace, the second auxiliary trace is electrically connected to the first auxiliary trace and the anode, and an overlapping region exists between an orthographic projection of the second auxiliary trace on the substrate and an orthographic projection of the first auxiliary trace on the substrate. The display substrate can improve the color cast problem of a white picture under a low temperature condition and improve the display effect.

Description

Display substrate and display device

Technical Field

The application relates to the technical field of display, in particular to a display substrate and a display device.

Background

With the continuous development of display technology, people have higher and higher requirements for the image quality of display products. For an OLED (Organic Light-Emitting Diode) display product, the variation range of the respective turn-on voltages of the OLED Light-Emitting materials of the sub-pixels with different colors is different under the condition of the external temperature variation.

In practical application, when the OLED display product is used under low temperature conditions, the variation of the light emission intensity of the sub-pixels with different colors is different due to the different variation of the turn-on voltages of the sub-pixels with different colors, so that when a white picture is displayed, the white balance is destroyed, the color cast problem of the white picture occurs, and the display effect is reduced.

Currently, a new display substrate is needed to solve the above problems.

Disclosure of Invention

Embodiments of the present application provide a display substrate and a display device, where the display substrate can improve the color shift problem of a white picture under a low temperature condition, and improve a display effect.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in one aspect, an embodiment of the present application provides a display substrate, including:

a substrate;

the pixel units are positioned on the substrate and comprise a plurality of sub-pixels, each sub-pixel comprises a transistor, a light-emitting element and a first auxiliary wiring, and a first pole of the transistor is electrically connected with an anode of the light-emitting element through the first auxiliary wiring;

at least one of the sub-pixels further includes a second auxiliary trace, the second auxiliary trace is electrically connected to the first auxiliary trace and the anode, and an overlapping region exists between an orthographic projection of the second auxiliary trace on the substrate and an orthographic projection of the first auxiliary trace on the substrate.

In some embodiments, the display substrate further includes a plurality of signal lines, the sub-pixel further includes a third auxiliary trace, and the signal line is electrically connected to the second electrode of the transistor through the third auxiliary trace;

the sub-pixel provided with the second auxiliary wiring further comprises a fourth auxiliary wiring, the fourth auxiliary wiring is electrically connected with the third auxiliary wiring and the signal line respectively, and an overlapping area exists between an orthographic projection of the fourth auxiliary wiring on the substrate and an orthographic projection of the third auxiliary wiring on the substrate.

In some embodiments, the display substrate further includes a plurality of power traces, the sub-pixel further includes a storage capacitor and a fifth auxiliary trace, and the first electrode of the storage capacitor is electrically connected to the power traces through the fifth auxiliary trace;

the sub-pixel provided with the second auxiliary wiring further comprises a sixth auxiliary wiring, the sixth auxiliary wiring is electrically connected with the fifth auxiliary wiring and the power supply wiring respectively, and an overlapping area exists between an orthographic projection of the sixth auxiliary wiring on the substrate and an orthographic projection of the fifth auxiliary wiring on the substrate.

In some embodiments, the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace are disposed at the same layer as the first electrode of the transistor;

the second auxiliary trace, the fourth auxiliary trace and the sixth auxiliary trace are arranged on the same layer.

In some embodiments, there is an overlap region between an orthographic projection of the second auxiliary trace on the substrate and an orthographic projection of the first pole of the transistor on the substrate; and an overlapping region exists between the orthographic projection of the fourth auxiliary routing wire on the substrate and the orthographic projection of the second pole of the transistor on the substrate.

In some embodiments, the pixel unit includes three of the sub-pixels divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel;

the red sub-pixel and the blue sub-pixel both include the second auxiliary trace, the fourth auxiliary trace, and the sixth auxiliary trace.

In some embodiments, the pixel unit includes three of the sub-pixels divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel;

the red sub-pixel and the green sub-pixel each include the second auxiliary trace, the fourth auxiliary trace, and the sixth auxiliary trace.

In some embodiments, the pixel unit includes three of the sub-pixels divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel;

the green sub-pixel and the blue sub-pixel comprise the second auxiliary trace, the fourth auxiliary trace and the sixth auxiliary trace.

In some embodiments, the sub-pixel comprises a buffer layer, an active layer, a first insulating layer, a gate layer, a second insulating layer, a capacitor electrode layer, a third insulating layer, a source-drain metal layer, a first flat layer, an anode, a pixel defining layer and a light emitting function layer, which are sequentially arranged;

the sub-pixel provided with the second auxiliary routing further comprises an auxiliary conducting layer and a second flat layer, the auxiliary conducting layer is located on one side, away from the source drain metal layer, of the second flat layer, and the first flat layer covers the auxiliary conducting layer;

the first pole of the transistor, the second pole of the transistor and the first auxiliary wiring form part of the source-drain metal layer, and the second auxiliary wiring forms part of the auxiliary conductive layer.

In some embodiments, in addition to the sub-pixels provided with the first auxiliary traces, the other sub-pixels further include the second flat layer;

the second flat layer is located between the source-drain metal layer and the first flat layer, and the second flat layer is configured to enable the distance between the light-emitting function layer of each sub-pixel and the substrate to be equal along the direction perpendicular to the substrate.

In another aspect, embodiments of the present application provide a display device including the display substrate as described above.

An embodiment of the present application provides a display substrate and a display device, the display substrate including: a substrate; the pixel unit comprises a plurality of sub-pixels, each sub-pixel comprises a transistor, a light-emitting element and a first auxiliary wiring, and a first pole of the transistor is electrically connected with an anode of the light-emitting element through the first auxiliary wiring; the at least one sub-pixel further comprises a second auxiliary wiring, the second auxiliary wiring is electrically connected with the first auxiliary wiring and the anode respectively, and an overlapping area exists between the orthographic projection of the second auxiliary wiring on the substrate and the orthographic projection of the first auxiliary wiring on the substrate.

Therefore, as the first auxiliary wiring is arranged on part of the sub-pixels in the display substrate, and the first auxiliary wiring and the second auxiliary wiring are arranged in the rest part of the sub-pixels; compared with the part of sub-pixels only provided with the first auxiliary wiring, the driving circuit in the sub-pixels provided with the first auxiliary wiring and the second auxiliary wiring has lower impedance, so that the partial voltage of the wiring in the driving circuit of the part of sub-pixels is reduced, the voltage actually applied to two ends of the light-emitting element is improved, and the light-emitting intensity of the part of sub-pixels is improved; by the mode, the luminous intensity of the sub-pixels with different colors is changed, the aim of balancing the luminous intensity of the sub-pixels with different colors is fulfilled, the problem of color cast of a white picture is further solved, and the display effect is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1a and FIG. 1b are voltage-current curves of three color sub-pixels at different temperatures according to an embodiment of the present disclosure;

fig. 2a, fig. 2b and fig. 2c are schematic structural diagrams of three different display substrates according to an embodiment of the present disclosure;

fig. 3 is an equivalent circuit diagram of a pixel driving circuit according to an embodiment of the present application;

fig. 4 is a graph comparing voltage and current curves of a sub-pixel with (or without) an auxiliary metal layer at different temperatures according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Throughout the specification and claims, the term "comprising" is to be interpreted in an open, inclusive sense, i.e., as "including, but not limited to," unless the context requires otherwise. In the description herein, the terms "one embodiment," "some embodiments," "example," "certain examples," or "some examples" or the like are intended to indicate that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

In the embodiments of the present application, the terms "first", "second", "third", "fourth", "fifth", "sixth", and the like are used for distinguishing the same or similar items with substantially the same functions and actions, and are used only for clearly describing technical solutions of the embodiments of the present application, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

The OLED display device has become a mainstream display product in the market because of its advantages of wide color gamut, high resolution, high contrast, low power consumption, flexibility, and the like. With the wide use of OLED display devices, the requirements for display stability of display products are higher and higher under different external conditions.

Fig. 1a shows the voltage-luminance curves at 25 ℃ for different colors of OLED light-emitting materials, specifically, the luminance of the red light-emitting element in the red sub-pixel is L2 and the luminance of the red light-emitting element in the green sub-pixel is L3, in case that the voltages applied to both ends of the different light-emitting elements are all 3V. Fig. 1b shows the voltage-luminance curves at-20 ℃ for different colors of OLED light-emitting materials, specifically, the luminance of the red light-emitting element in the red sub-pixel is L4 and the luminance of the red light-emitting element in the green sub-pixel is L5, in case that the voltages applied to both ends of the different light-emitting elements are all 3V. For the same display product, in the case where the ambient temperature is decreased from 25 ℃ to-20 ℃, the luminance of the red light emitting element in the red sub-pixel is changed from L2 to L4, the luminance of the green light emitting element in the green sub-pixel is changed from L3 to L5, and L2-L4 ≠ L3-L5. It can be understood that when the temperature is decreased, the mobility rate of carriers in the light emitting material of the OLED is decreased, resulting in an increase in the turn-on voltage of the OLED, so that the luminance in a low temperature environment is decreased under the same applied voltage.

If the ambient temperature is 25 ℃, the display product can maintain white balance, and the white balance is destroyed because the reduction amplitude of the luminous intensity of the luminous elements with different colors is different when the temperature is reduced, so that the white picture formed by mixing the color lights of the three colors is different from that when the ambient temperature is 25 ℃ under the low temperature condition. In practical applications, if the temperature decrease causes the maximum variation of the turn-on voltage of the red light emitting device, the brightness of the red light emitting device decreases to a greater extent, so that the display screen is more bluish in white. If the maximum variation of the turn-on voltage of the blue light emitting element is caused by the temperature decrease, the brightness of the blue light emitting element is reduced to a greater extent, so that the display frame is yellow in a white frame.

To this end, an embodiment of the present application provides a display substrate, as shown with reference to fig. 2a, including:

a substrate 100;

a plurality of pixel units P arranged in an array on the substrate 100, each pixel unit P including a plurality of sub-pixels (for example, including a sub-pixel P1, a sub-pixel P2, and a sub-pixel P3), each sub-pixel including a transistor 1, a light emitting element (not labeled in fig. 2 a), and a first auxiliary trace (not drawn in fig. 2 a), wherein the first electrode 14 of the transistor 1 and the anode 3 of the light emitting element are electrically connected through the first auxiliary trace;

at least one sub-pixel further comprises a second auxiliary trace 4, the second auxiliary trace 4 is electrically connected to the first auxiliary trace and the anode 3, and an overlapping region exists between an orthographic projection of the second auxiliary trace 4 on the substrate 100 and an orthographic projection of the first auxiliary trace on the substrate 100.

In an exemplary embodiment, at least one sub-pixel further includes a second auxiliary trace 4, specifically: taking an example that one pixel unit P includes three sub-pixels with different colors, one sub-pixel may include the second auxiliary trace 4; alternatively, the two sub-pixels shown in fig. 2a may include the second auxiliary traces 4 respectively.

In practical application, a part of sub-pixels including the second auxiliary trace 4 can be set according to actual use requirements; part of the sub-pixels do not comprise the second auxiliary trace 4.

In an exemplary embodiment, the pixel unit P may include three sub-pixels, for example: the red sub-pixel, the green sub-pixel and the blue sub-pixel are sequentially arranged; alternatively, the pixel unit P may include four sub-pixels, for example: the red sub-pixel, the green sub-pixel, the blue sub-pixel and the white sub-pixel are sequentially arranged; or the red sub-pixel, the green sub-pixel, the blue sub-pixel and the green sub-pixel are sequentially arranged; or a green sub-pixel, a red sub-pixel and a blue sub-pixel which are arranged in sequence. The specific method can be determined according to actual conditions, and is not limited herein.

In an exemplary embodiment, the first auxiliary trace and the first and second poles of the transistor 1 are disposed at the same layer. In practical applications, the first auxiliary trace, the first electrode 14 of the transistor 1 and the second electrode 11 of the transistor 1 may form part of a source-drain metal layer. In an exemplary embodiment, the first auxiliary trace and the second auxiliary trace 4 are made of the same conductive material, and are in direct contact with each other.

It should be noted that, in the case that the first auxiliary trace and the second auxiliary trace 4 are made of the same conductive material, the structure of the sub-pixel without the second auxiliary trace 4 may be referred to as a single source drain metal layer structure (single SD), and the structure of the sub-pixel with the second auxiliary trace 4 may be referred to as a double source drain metal layer structure (double SD).

In an exemplary embodiment, the overlapping area existing between the orthographic projection of the second auxiliary trace 4 on the substrate 100 and the orthographic projection of the first auxiliary trace on the substrate 100 may be: the orthographic projection of the second auxiliary trace 4 on the substrate 100 and the orthographic projection of the first auxiliary trace on the substrate 100 at least partially overlap.

For example: the orthographic projection of the second auxiliary trace 4 on the substrate 100 is positioned within the orthographic projection of the first auxiliary trace on the substrate 100; or, the orthographic projection profile of the second auxiliary trace 4 on the substrate 100 overlaps with the orthographic projection profile of the first auxiliary trace on the substrate 100; alternatively, the orthographic projection of the second auxiliary trace 4 on the substrate 100 covers the orthographic projection of the first auxiliary trace on the substrate 100.

In an exemplary embodiment, the transistor 1 may be a driving transistor, or may also be a switching transistor, which is determined by an actual pixel driving circuit, and is not limited herein.

The first pole 14 of the transistor 1 may be a source, and the second pole 11 of the transistor 1 may be a drain; alternatively, the second pole 11 of the transistor 1 may be a source, and the first pole 14 of the transistor 1 may be a drain; and may be determined specifically according to the design of the pixel driving circuit.

In addition, referring to fig. 2a, the transistor 1 further comprises a gate electrode 12, and the partial region of the active layer 102 at the first pole 14 and the second pole 11 constitutes a semiconductor region 13 of the transistor 1.

In an exemplary embodiment, the light emitting element includes an OLED light emitting element, which may include a light emitting functional layer (e.g., a red light emitting functional layer 114, a green light emitting functional layer 115, or a blue light emitting functional layer 116 as shown in fig. 2 a), an anode 3, and a cathode (not shown in fig. 2 a).

Among them, the light emitting function layer may include a plurality of film layers, including, for example: the light-emitting element comprises an electron transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer and a hole transport layer, and in practical application, the light-emitting color of the light-emitting element is changed by changing the material of the light-emitting layer.

It should be noted that the display substrate provided in the embodiments of the present application is an OLED display substrate. In practical applications, the OLED display substrate includes an AMOLED (Active-matrix organic light emitting diode) display substrate and a PMOLED (Passive-matrix organic light emitting diode) display substrate, and the PMOLED is simply formed in a matrix form by a cathode and an anode, and does not include components such as transistors.

An embodiment of the present application provides a display substrate including: a substrate 100; a plurality of pixel units P located on the substrate 100, each pixel unit P includes a plurality of sub-pixels, each sub-pixel includes a transistor 1, a light emitting element, and a first auxiliary trace, and a first electrode 14 of the transistor 1 is electrically connected to an anode 3 of the light emitting element through the first auxiliary trace; at least one sub-pixel further comprises a second auxiliary trace 4, the second auxiliary trace 4 is electrically connected to the first auxiliary trace and the anode 3, and an overlapping region exists between an orthographic projection of the second auxiliary trace 4 on the substrate 100 and an orthographic projection of the first auxiliary trace on the substrate 100.

Therefore, as the first auxiliary wiring is arranged on part of the sub-pixels in the display substrate, and the first auxiliary wiring and the second auxiliary wiring 4 are arranged in the rest part of the sub-pixels; compared with the part of sub-pixels only provided with the first auxiliary wiring, the driving circuit in the sub-pixels provided with the first auxiliary wiring and the second auxiliary wiring 4 has smaller impedance, so that the voltage division of the wiring in the driving circuit of the part of sub-pixels is reduced, the voltage actually applied to two ends of the light-emitting element is improved, and the luminous intensity of the part of sub-pixels is improved; by the mode, the luminous intensity of the sub-pixels with different colors is changed, the aim of balancing the luminous intensity of the sub-pixels with different colors is fulfilled, the problem of color cast of a white picture is further solved, and the display effect is improved.

Specifically, in the case of a display product prepared by the display substrate with a bluish white color (the red sub-pixel has more color attenuation than the green sub-pixel and the blue sub-pixel under low temperature conditions, and the bluish white color is likely to appear), according to the principle of light color mixing, it is necessary to reduce the intensity of the green color or increase the intensity of the red color for improvement, as shown in fig. 2a, the pixel unit P includes three sub-pixels P1, P2 and P3, wherein the sub-pixel P1 is a red sub-pixel, the sub-pixel P2 is a green sub-pixel, and the sub-pixel P3 is a blue sub-pixel; each sub-pixel is provided with a first auxiliary wiring, the red sub-pixel and the blue sub-pixel are also provided with a second auxiliary wiring 4, and the green sub-pixel is not provided with the second auxiliary wiring 4, so that the impedance of the wiring in the pixel driving circuit of the green sub-pixel is higher, the voltage actually applied to the anode 3 of the green light-emitting element is smaller, and the green light emitted by the green light-emitting element is lower in brightness; the red sub-pixel and the blue sub-pixel are respectively provided with a second auxiliary wiring 4, so that the voltage actually applied to the anode 3 of the red light-emitting element and the anode 3 of the blue light-emitting element is higher, the brightness of red light emitted by the red light-emitting element is higher, and the brightness of blue light emitted by the blue light-emitting element is higher; after the three color lights are mixed, the problem that the white picture of the display product is too green is greatly reduced.

It should be noted that, in practical applications, it may be determined that the intensity of the red light is improved by arranging the second auxiliary trace 4 in the red sub-pixel according to the degree of the color of the white picture being bluish; or, the second auxiliary wiring 4 is arranged in each of the red sub-pixel and the blue sub-pixel, and the color light intensity of the red light and the blue light is improved at the same time, so that the color of the white picture is balanced.

In some embodiments, the display substrate further includes a plurality of signal lines (not shown), the sub-pixel further includes a third auxiliary trace, and the signal lines are electrically connected to the second electrode 11 of the transistor 1 through the third auxiliary trace;

the sub-pixel provided with the second auxiliary trace 4 further includes a fourth auxiliary trace 5, the fourth auxiliary trace 5 is electrically connected to the third auxiliary trace and the signal line, and an overlapping region exists between an orthographic projection of the fourth auxiliary trace 5 on the substrate 100 and an orthographic projection of the third auxiliary trace on the substrate 100.

In an exemplary embodiment, the signal lines may include one or a combination of a plurality of signal lines such as a Data signal line (Data), an Initial signal line (Initial), a reset signal line (Vinit), and the like; the specific structure of the pixel driving circuit in the display substrate can be determined, and is not limited herein.

In an exemplary embodiment, the overlapping region exists between the orthographic projection of the fourth auxiliary trace 5 on the substrate 100 and the orthographic projection of the third auxiliary trace on the substrate 100: the orthographic projection of the fourth auxiliary trace 5 on the substrate 100 and the orthographic projection of the third auxiliary trace on the substrate 100 at least partially overlap.

For example: the orthographic projection of the fourth auxiliary trace 5 on the substrate 100 is positioned within the orthographic projection of the third auxiliary trace on the substrate 100; or, the orthographic projection profile of the fourth auxiliary trace 5 on the substrate 100 overlaps with the orthographic projection profile of the third auxiliary trace on the substrate 100; alternatively, the orthographic projection of the fourth auxiliary trace 5 on the substrate 100 covers the orthographic projection of the third auxiliary trace on the substrate 100.

In an exemplary embodiment, the third auxiliary trace and the fourth auxiliary trace 5 are made of the same conductive material, and are in direct contact with each other.

In the embodiment of the present application, referring to fig. 2a, in the case that the white picture color of the display product prepared by the display substrate is very cyan, by providing the fourth auxiliary trace 5 in the sub-pixels (red sub-pixel and blue sub-pixel) provided with the second auxiliary trace 4, the impedance of the trace of the driving circuit in the red sub-pixel and the blue sub-pixel can be further reduced, the voltage actually applied to the two ends of the light emitting element is increased, so that the intensity of the red light emitted by the red light emitting element and the intensity of the blue light emitted by the blue light emitting element are increased, and the problem that the white picture is very cyan is further improved after the three color lights are mixed.

In some embodiments, the display substrate further includes a plurality of power traces (not shown), the sub-pixel further includes a storage capacitor 2 and a fifth auxiliary trace 7, and the first electrode 21 of the storage capacitor 2 is electrically connected to the power traces through the fifth auxiliary trace 7;

the sub-pixel provided with the second auxiliary trace 4 further includes a sixth auxiliary trace 6, the sixth auxiliary trace 6 is electrically connected to the fifth auxiliary trace 7 and the power trace, respectively, and an overlapping region exists between an orthographic projection of the sixth auxiliary trace 6 on the substrate 100 and an orthographic projection of the fifth auxiliary trace 7 on the substrate 100.

In an exemplary embodiment, the power trace may be a first power trace (VDD), or may also be a second power trace (VSS), and the power trace provided in the embodiment of the present application takes the first power trace (VDD) as an example, and the first power trace (VDD) is electrically connected to the first electrode 21 of the storage capacitor 2.

In an exemplary embodiment, the cathode of the light emitting element is electrically connected to a second power supply line (VSS).

In the exemplary embodiment, the overlapping region exists between the orthographic projection of the sixth auxiliary trace 6 on the substrate 100 and the orthographic projection of the fifth auxiliary trace 7 on the substrate 100: the orthographic projection of the sixth auxiliary trace 6 on the substrate 100 and the orthographic projection of the fifth auxiliary trace 7 on the substrate 100 at least partially overlap.

For example: the orthographic projection of the sixth auxiliary trace 6 on the substrate 100 is located within the orthographic projection of the fifth auxiliary trace 7 on the substrate 100; or, the orthographic projection profile of the sixth auxiliary trace 6 on the substrate 100 overlaps with the orthographic projection profile of the fifth auxiliary trace 7 on the substrate 100; alternatively, the orthographic projection of the sixth auxiliary trace 6 on the substrate 100 covers the orthographic projection of the fifth auxiliary trace 7 on the substrate 100.

In an exemplary embodiment, the fifth auxiliary trace and the sixth auxiliary trace 6 are made of the same conductive material, and are in direct contact with each other.

In the embodiment of the present application, referring to fig. 2a, in the case that the white picture color of the display product prepared by the display substrate is very cyan, by providing the sixth auxiliary trace 6 in the sub-pixels (red sub-pixel and blue sub-pixel) provided with the second auxiliary trace 4, the impedance of the trace of the driving circuit in the red sub-pixel and the blue sub-pixel can be further reduced, the voltage actually applied to the two ends of the light emitting element is increased, so that the intensity of the red light emitted by the red light emitting element and the intensity of the blue light emitted by the blue light emitting element are increased, and the problem that the white picture is very cyan is further improved after the three color lights are mixed.

In some embodiments, referring to fig. 2a, the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace 7 are all disposed at the same layer as the first electrode 14 of the transistor 1;

the second auxiliary trace 4, the fourth auxiliary trace 5 and the sixth auxiliary trace 6 are disposed on the same layer.

In an exemplary embodiment, the same layer arrangement refers to fabrication using a one-time patterning process. The one-step patterning process refers to a process of forming a desired layer structure through one exposure. The primary patterning process includes masking, exposing, developing, etching, and stripping processes.

In an exemplary embodiment, the conductive layer formed by the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace 7 together with the first electrode 14 of the transistor 1 may be referred to as a source-drain metal layer, and a material of the source-drain metal layer may be copper (Cu).

In an exemplary embodiment, the conductive layer formed by the second auxiliary trace 4, the fourth auxiliary trace 5 and the sixth auxiliary trace 6 may be referred to as an auxiliary metal layer, and the material of the auxiliary metal layer may be copper (Cu).

The source-drain metal layer and the auxiliary metal layer can be made of the same material, so that the contact resistance of the first auxiliary wire and the second auxiliary wire 4, the contact resistance of the third auxiliary wire and the fourth auxiliary wire 5, and the contact resistance of the fifth auxiliary wire and the sixth auxiliary wire 6 are reduced.

In some embodiments, referring to fig. 2a, there is an overlap region between the orthographic projection of the second auxiliary trace 4 on the substrate 100 and the orthographic projection of the first electrode 14 of the transistor 1 on the substrate 100; there is an overlap region between the orthographic projection of the fourth auxiliary trace 5 on the substrate 100 and the orthographic projection of the second pole 11 of the transistor 1 on the substrate 100.

In an exemplary embodiment, a partial region of the second auxiliary trace 4 may be in direct contact with the first electrode 14 of the transistor 1, and a partial region of the fourth auxiliary trace 5 may be in direct contact with the second electrode 11 of the transistor 1, so as to further reduce impedance between the first electrode 14 and the second electrode 11 of the transistor and the trace, thereby increasing voltage actually applied to two ends of the light emitting element of the sub-pixel where the second auxiliary trace 4, the fourth auxiliary trace 5, or the sixth auxiliary trace 6 is disposed, and increasing light emitting intensity of the light emitting element, thereby achieving the purpose of adjusting light intensities of sub-pixels with different colors, and further balancing colors of white pictures.

In some embodiments, the pixel unit P includes three of the sub-pixels, the three sub-pixels being divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel; the red sub-pixel and the blue sub-pixel each include a second auxiliary trace 4, a fourth auxiliary trace 5 or a sixth auxiliary trace 6.

In the case of a display product prepared by a display substrate with a bluish white color (the red sub-pixel has more color attenuation than the green sub-pixel and the blue sub-pixel under low temperature conditions, and the bluish white color is likely to appear), according to the principle of light color mixing, it is necessary to reduce the intensity of the green color light, or increase the intensity of the red color light for improvement, as shown in fig. 2a, a pixel unit P includes three sub-pixels P1, P2, and P3, wherein the sub-pixel P1 is a red sub-pixel, the sub-pixel P2 is a green sub-pixel, and the sub-pixel P3 is a blue sub-pixel; the first auxiliary wiring, the third auxiliary wiring and the fifth auxiliary wiring are arranged in each sub-pixel, and the second auxiliary wiring 4, the fourth auxiliary wiring 5 or the sixth auxiliary wiring 6 are also arranged in the red sub-pixel and the blue sub-pixel.

Therefore, the impedance of the wiring in the pixel driving circuit of the green sub-pixel is larger, so that the voltage actually applied to the anode 3 of the green light-emitting element is smaller, and the green light emitted by the green light-emitting element has lower brightness; the impedance of the wiring in the pixel driving circuit of the red sub-pixel and the blue sub-pixel is larger, so that the voltage actually applied to the anode 3 of the red light-emitting element and the anode 3 of the blue light-emitting element is smaller, the brightness of red light and blue light emitted by the red light-emitting element and the blue light-emitting element is higher, and after the three kinds of color light are mixed, the problem that the color of a white picture of a display product is very green is greatly reduced.

In some embodiments, the pixel unit P includes three of the sub-pixels, the three sub-pixels being divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel; the red sub-pixel and the green sub-pixel each include a second auxiliary trace 4, a fourth auxiliary trace 5 or a sixth auxiliary trace 6.

In the case of a display product prepared by a display substrate having a yellow white color, it is necessary to reduce the brightness of blue light and increase the brightness of red light and green light for improvement according to the principle of color mixing of light. Referring to FIG. 2b, the sub-pixel P1 is a red sub-pixel, the sub-pixel P2 is a green sub-pixel, and the sub-pixel P3 is a blue sub-pixel; the first auxiliary wiring, the third auxiliary wiring and the fifth auxiliary wiring are arranged in each sub-pixel, and the second auxiliary wiring 4, the fourth auxiliary wiring 5 or the sixth auxiliary wiring 6 are also arranged in the red sub-pixel and the green sub-pixel.

Thus, the impedance of the wiring in the pixel driving circuit of the blue sub-pixel is larger, so that the voltage actually applied to the anode 3 of the blue light-emitting element is smaller, and the brightness of the blue light emitted by the blue light-emitting element is lower; the impedance of the wiring in the pixel driving circuit of the red sub-pixel and the green sub-pixel is larger, so that the voltage actually applied to the anode 3 of the red light-emitting element and the anode 3 of the green light-emitting element is smaller, the brightness of the red light and the green light emitted by the red light-emitting element and the green light-emitting element is higher, and after the three kinds of color light are mixed, the problem that the color of a white picture of a display product is yellow is reduced to a great extent.

In some embodiments, the pixel unit P includes three of the sub-pixels, the three sub-pixels being divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel; the green sub-pixel and the blue sub-pixel each include a second auxiliary trace 4, a fourth auxiliary trace 5 or a sixth auxiliary trace 6.

In practical application, under the condition that the white picture color of a display product prepared by a display substrate is purple, the brightness of red light needs to be reduced and the brightness of blue light and green light needs to be improved according to the color mixing principle of colored light; a first auxiliary wire, a third auxiliary wire and a fifth auxiliary wire are arranged in each sub-pixel, and a second auxiliary wire 4, a fourth auxiliary wire 5 or a sixth auxiliary wire 6 are arranged in the blue sub-pixel and the green sub-pixel.

Thus, the impedance of the wiring in the pixel driving circuit of the red sub-pixel is relatively large, so that the voltage actually applied to the anode 3 of the red light-emitting element is relatively small, and the brightness of the red light emitted by the red light-emitting element is relatively low; the impedance of the wiring in the pixel driving circuit of the blue sub-pixel and the green sub-pixel is large, so that the voltage actually applied to the anode 3 of the blue light-emitting element and the anode 3 of the green light-emitting element is small, the brightness of the blue light and the green light emitted by the blue light-emitting element and the green light-emitting element is high, and after the three kinds of color light are mixed, the problem that the color of a white picture of a display product is purple is reduced to a great extent.

Fig. 3 provides an equivalent circuit diagram of a pixel circuit. Referring to fig. 3, the voltage between the first power trace (VDD) and the second power trace (VSS) is V_VDD-V_VSSIn practical applications, if the load (Loading) of the trace is large, i.e., V1 and V5 are large, the voltage V2 actually applied to the driving transistor (DTFT) and the voltage V4 applied to the light emitting element (OLED) are correspondingly reduced. In fig. 3, VDD IR Drop refers to a voltage Drop of the first power supply trace, VSS IR Drop refers to a voltage Drop of the second power supply trace, and STFT refers to a switching transistor in the driving circuit. As can be seen from the equivalent circuit diagram shown in fig. 3, in the driving circuit, the voltage V2 actually applied to the driving transistor (DTFT) and the voltage V4 actually applied to the light emitting element (OLED) can be increased by reducing the voltage drop of the trace, so that the current intensity for controlling the light emission of the light emitting device is increased, and the light emission intensity of the light emitting device is increased.

Fig. 4 provides an output characteristic curve (curve labeled Vgs) of a drive transistor (DTFT) and a current-voltage characteristic curve (I-V curve) of an OLED. For the output characteristic curve of the driving transistor, the abscissa is the source-drain voltage Vds, and the ordinate is the current; for the current-voltage characteristic of an OLED, the abscissa is voltage and the ordinate is current. In addition, the current-voltage characteristic curve of the OLED provided with the second auxiliary trace 4, the fourth auxiliary trace 5, or the sixth auxiliary trace 6 is marked as Y, and the current-voltage characteristic curve of the OLED not provided with the second auxiliary trace 4, the fourth auxiliary trace 5, or the sixth auxiliary trace 6 is marked as N.

As shown in fig. 3 and 4, for the sub-pixel without the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 (labeled N), the load (Loading) of the pixel circuit is larger, the divided voltage V2 of the corresponding driving transistor (DTFT) and the divided voltage V4 applied to the light emitting element (OLED) are reduced, and in the case of inputting the same data signal (Vdata), the I-V operating curve of the sub-pixel without the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 (labeled N) is closer to the linear region of the output characteristic curve of the driving transistor (DTFT) than the I-V operating curve of the sub-pixel with the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 (labeled Y); whereas closer to the linear region of the output characteristic curve of the drive transistor (DTFT), an equal amount of voltage variation will cause more current variation. It can be understood that the operating current of the light emitting device of the sub-pixel where the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 (labeled N) is not disposed is more sensitive to the voltage variation than the operating current of the light emitting device of the sub-pixel where the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 (labeled Y) is disposed. In addition, as shown in fig. 4, as the temperature is decreased, the operating current of the light emitting device is more sensitive to a change in voltage.

When the OLED display substrate works in a low-temperature environment, because the variation of the voltage actually applied to the OLED sub-pixels with different colors is different, the reduction ratios of the working currents of the OLED sub-pixels with different colors are also different, so that the brightness reduction of the OLED sub-pixels with different colors is inconsistent, the color of a white picture is changed, the white balance is damaged, and the display effect is reduced. Based on the above characteristics, by performing differential design on the driving circuits of the sub-pixels with different colors, the second auxiliary wiring 4, the fourth auxiliary wiring 5, or the sixth auxiliary wiring 6 (dual SD structure) is arranged in some of the sub-pixels, so as to reduce the impedance (or load) of the wirings in the sub-pixels, thereby improving the voltage division actually applied to the light emitting element, improving the working current of the light emitting element, and further improving the light emitting intensity of some colors. Specifically, according to the color shift of the white picture, the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 is selectively arranged in the sub-pixel of at least one color of the red, green or blue sub-pixels, so as to improve the luminous intensity of the sub-pixels of at least one color, thereby improving the color shift of the white picture.

In practical application, at least one of the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 is arranged in the sub-pixel of one or two colors with large voltage change (large reduction amplitude of working current) of the OLED under a low temperature condition, and only the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace 7 are arranged in the sub-pixels of the rest colors, because the sub-pixels with the second auxiliary trace 4, the fourth auxiliary trace 5 or the sixth auxiliary trace 6 are arranged with small load, the partial pressure of the light emitting elements actually applied to the sub-pixels of the part is large, and the working current is also large, so that the reduction of the working current under the low temperature condition is balanced, the problem of white balance damage caused by inconsistent reduction of the brightness of the sub-pixels with different colors under the low temperature is solved, the image quality temperature of the OLED display product under the low temperature is ensured, and the display effect is improved.

In some embodiments, referring to fig. 2c, the sub-pixel includes a buffer layer 101, an active layer 102, a first insulating layer 103, a gate layer 104, a second insulating layer 105, a capacitor electrode layer 106 (formed by the second electrode 22 of the storage capacitor), a third insulating layer 107, a source-drain metal layer 108, a first planarization layer 111, an anode electrode 3, a pixel defining layer 113, and a light emitting function layer, which are sequentially disposed;

the sub-pixel provided with the second auxiliary trace 4 further comprises an auxiliary conductive layer 110 and a second flat layer 109, the auxiliary conductive layer 110 is located on one side of the second flat layer 109, which is far away from the source drain metal layer 108, and the first flat layer 111 covers the auxiliary conductive layer 110;

the first electrode 14 of the transistor 1, the second electrode 11 of the transistor 1 and the first auxiliary trace form part of the source-drain metal layer 108, and the second auxiliary trace 4 forms part of the auxiliary conductive layer 110.

In an exemplary embodiment, the gate layer 104 includes the gate 12 of the transistor 1 and the first electrode 21 of the storage capacitor 2.

In an exemplary embodiment, the light emitting functional layer included in the red sub-pixel is a red light emitting functional layer 114, the light emitting functional layer included in the green sub-pixel is a green light emitting functional layer 115, and the light emitting functional layer included in the blue sub-pixel is a blue light emitting functional layer 116.

In an exemplary embodiment, the conductive layer formed by the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace 7 together with the first electrode 14 of the transistor 1 may be referred to as a source-drain metal layer, and a material of the source-drain metal layer may be copper (Cu).

In an exemplary embodiment, the conductive layer formed by the second auxiliary trace 4, the fourth auxiliary trace 5 and the sixth auxiliary trace 6 may be referred to as an auxiliary metal layer, and the material of the auxiliary metal layer may be copper (Cu).

The source-drain metal layer and the auxiliary metal layer can be made of the same material, so that the contact resistance of the first auxiliary wire and the second auxiliary wire 4, the contact resistance of the third auxiliary wire and the fourth auxiliary wire 5, and the contact resistance of the fifth auxiliary wire and the sixth auxiliary wire 6 are reduced.

In an exemplary embodiment, the material of the buffer layer 101 may be an inorganic material, for example: at least one or a combination of silicon nitride, silicon oxide and silicon oxynitride.

In an exemplary embodiment, the material of the active layer 102 may be at least one of amorphous silicon (a-Si), single crystal silicon (Si), polycrystalline silicon (p-Si), and Oxide (Oxide), which may be determined according to actual circumstances.

In an exemplary embodiment, the materials of the first insulating layer 103, the second insulating layer 105, and the third insulating layer 107 may be inorganic materials, or may also be organic materials. For example: the inorganic material may be at least one of silicon nitride, silicon oxide, and silicon oxynitride; the organic material may be a resin.

In an exemplary embodiment, the materials of the gate layer 104, the capacitor electrode layer 106, and the source-drain metal layer 108 may all be the same, or may be different, which may be determined according to actual situations. In order to reduce the difficulty of the manufacturing process, the materials of the gate layer 104, the capacitor electrode layer 106 and the source-drain metal layer 108 may be copper (Cu).

In addition, the display substrate provided in the embodiment of the present application further includes a supporting layer 117 as shown in fig. 2a, for preventing scratches from occurring between the mask and the light emitting functional layer in the evaporation process.

In some embodiments, referring to fig. 2a or fig. 2b, in addition to the sub-pixels provided with the first auxiliary trace 4, other sub-pixels further include a second planarization layer 109;

the second planarization layer 109 is located between the source-drain metal layer 108 and the first planarization layer 111, and the second planarization layer 109 is configured to equalize the distance between the light-emitting functional layer (114, 115, or 116) of each sub-pixel and the substrate 100 in the direction perpendicular to the substrate 100.

Therefore, the problem of reduction of display effect caused by difference of light emitting paths of light emitting function layers of the sub-pixels can be avoided, in addition, the second flat layers 109 are arranged in the sub-pixels, the existing mask can be used for forming all the second flat layers 109 simultaneously through a one-time composition process, the difficulty of a manufacturing process is reduced, the purchase of a new mask is avoided, and therefore the cost is reduced.

Embodiments of the present application provide a display substrate that further includes other structures and components such as the support layer 117, and only the structures and components related to the inventive aspects of the present application are described herein, and the display substrate includes other structures and components that can be referred to in the related art.

Embodiments of the present application provide a display device including the display substrate as described above.

The display device provided by the embodiment of the application is an OLED display device. In practical applications, the OLED display device includes an AMOLED (Active-matrix organic light emitting diode) display device and a PMOLED (Passive-matrix organic light emitting diode) display device, and the PMOLED simply forms a matrix with a cathode and an anode, and does not include a transistor and other components.

In addition, the display device can be any product or component with a display function, such as a television, a digital camera, a mobile phone, a tablet computer, a bracelet and the like.

In the display device provided by the embodiment of the application, because the first auxiliary trace is arranged in part of the sub-pixels of the display substrate, and the first auxiliary trace and the second auxiliary trace 4 are arranged in the rest part of the sub-pixels; compared with the part of sub-pixels only provided with the first auxiliary wiring, the driving circuit in the sub-pixels provided with the first auxiliary wiring and the second auxiliary wiring 4 has smaller impedance, so that the voltage division of the wiring in the driving circuit of the part of sub-pixels is reduced, the voltage actually applied to two ends of the light-emitting element is improved, and the luminous intensity of the part of sub-pixels is improved; by the mode, the luminous intensity of the sub-pixels with different colors is changed, the aim of balancing the luminous intensity of the sub-pixels with different colors is fulfilled, the problem of color cast of a white picture is further solved, and the display effect is improved.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (11)

1. A display substrate, comprising:

a substrate;

the pixel units are positioned on the substrate and comprise a plurality of sub-pixels, each sub-pixel comprises a transistor, a light-emitting element and a first auxiliary wiring, and a first pole of the transistor is electrically connected with an anode of the light-emitting element through the first auxiliary wiring;

at least one of the sub-pixels further includes a second auxiliary trace, the second auxiliary trace is electrically connected to the first auxiliary trace and the anode, and an overlapping region exists between an orthographic projection of the second auxiliary trace on the substrate and an orthographic projection of the first auxiliary trace on the substrate.

2. The display substrate according to claim 1, wherein the display substrate further comprises a plurality of signal lines, the sub-pixels further comprise third auxiliary traces, and the signal lines are electrically connected to the second electrodes of the transistors through the third auxiliary traces;

the sub-pixel provided with the second auxiliary wiring further comprises a fourth auxiliary wiring, the fourth auxiliary wiring is electrically connected with the third auxiliary wiring and the signal line respectively, and an overlapping area exists between an orthographic projection of the fourth auxiliary wiring on the substrate and an orthographic projection of the third auxiliary wiring on the substrate.

3. The display substrate according to claim 2, wherein the display substrate further comprises a plurality of power traces, the sub-pixel further comprises a storage capacitor and a fifth auxiliary trace, and a first electrode of the storage capacitor is electrically connected to the power trace through the fifth auxiliary trace;

the sub-pixel provided with the second auxiliary wiring further comprises a sixth auxiliary wiring, the sixth auxiliary wiring is electrically connected with the fifth auxiliary wiring and the power supply wiring respectively, and an overlapping area exists between an orthographic projection of the sixth auxiliary wiring on the substrate and an orthographic projection of the fifth auxiliary wiring on the substrate.

4. The display substrate according to claim 3, wherein the first auxiliary trace, the third auxiliary trace and the fifth auxiliary trace are disposed on the same layer as the first electrode of the transistor;

the second auxiliary trace, the fourth auxiliary trace and the sixth auxiliary trace are arranged on the same layer.

5. The display substrate according to claim 3, wherein there is an overlap region between an orthographic projection of the second auxiliary trace on the substrate and an orthographic projection of the first electrode of the transistor on the substrate; and an overlapping region exists between the orthographic projection of the fourth auxiliary routing wire on the substrate and the orthographic projection of the second pole of the transistor on the substrate.

6. The display substrate of claim 4, wherein the pixel unit comprises three sub-pixels, and the three sub-pixels are divided into a red sub-pixel, a green sub-pixel and a blue sub-pixel;

the red sub-pixel and the blue sub-pixel both include the second auxiliary trace, the fourth auxiliary trace, and the sixth auxiliary trace.

7. The display substrate of claim 4, wherein the pixel unit comprises three sub-pixels, and the three sub-pixels are divided into a red sub-pixel, a green sub-pixel and a blue sub-pixel;

the red sub-pixel and the green sub-pixel each include the second auxiliary trace, the fourth auxiliary trace, and the sixth auxiliary trace.

8. The display substrate of claim 4, wherein the pixel unit comprises three sub-pixels, and the three sub-pixels are divided into a red sub-pixel, a green sub-pixel and a blue sub-pixel;

the green sub-pixel and the blue sub-pixel comprise the second auxiliary trace, the fourth auxiliary trace and the sixth auxiliary trace.

9. The display substrate according to any one of claims 1 to 8, wherein the sub-pixel comprises a buffer layer, an active layer, a first insulating layer, a gate layer, a second insulating layer, a capacitor electrode layer, a third insulating layer, a source-drain metal layer, a first flat layer, an anode, a pixel defining layer, and a light emitting functional layer, which are sequentially disposed;

the sub-pixel provided with the second auxiliary routing further comprises an auxiliary conducting layer and a second flat layer, the auxiliary conducting layer is located on one side, away from the source drain metal layer, of the second flat layer, and the first flat layer covers the auxiliary conducting layer;

the first pole of the transistor, the second pole of the transistor and the first auxiliary wiring form part of the source-drain metal layer, and the second auxiliary wiring forms part of the auxiliary conductive layer.

10. The display substrate according to claim 9, wherein the other sub-pixels, except the sub-pixels provided with the second auxiliary trace, further comprise the second planarization layer;

the second flat layer is located between the source-drain metal layer and the first flat layer, and the second flat layer is configured to enable the distance between the light-emitting function layer of each sub-pixel and the substrate to be equal along the direction perpendicular to the substrate.

11. A display device comprising the display substrate according to any one of claims 1 to 10.

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