Driver substrate, electronic paper display device and electronic equipment

Abstract

This utility model discloses a driving substrate, an electronic paper display device, and an electronic device, relating to the technical field of display devices. The driving substrate includes multiple pixel units, each pixel unit including a bottom substrate, a thin-film transistor assembly, and a driving electrode. The driving electrode is electrically connected to the thin-film transistor. The thin-film transistor assembly includes a first gate, a first semiconductor, a second gate, and a second semiconductor. The first gate and the second gate are distributed along a first direction, and the first semiconductor and the first gate are stacked in a second direction. The second semiconductor and the second gate are stacked in a second direction. In the first direction, the size of the first gate is smaller than the size of the first semiconductor, and the size of the second gate is larger than the size of the second semiconductor.

Description

Technical Field

[0001] This utility model relates to a display device, and more particularly to a driving substrate, an electronic paper display device, and an electronic device. Background Technology

[0002] Electronic paper, with its passive light emission and paper-like image display characteristics, is widely used in display fields such as e-readers and electronic tags.

[0003] In related technologies, the base plate in an electronic paper display device can face upwards to serve as the display surface. In this case, because the metal layer near the first side of the base plate fails to completely block the semiconductor in the thin-film transistor, light shines through the base plate onto the semiconductor, causing the semiconductor to be photosensitive and generate a small current. As a result, even when the electronic paper display device is turned off, a small current still flows through the thin-film transistor, which can easily damage the electronic paper display device. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a driving substrate to improve yield.

[0005] According to a first aspect of the present invention, a driving substrate includes a plurality of pixel units, each pixel unit including a bottom substrate, a thin film transistor assembly and a driving electrode, wherein the driving electrode is electrically connected to the thin film transistor.

[0006] The thin-film transistor assembly includes a first gate, a first semiconductor, a second gate, and a second semiconductor. The first gate and the second gate are distributed along a first direction, the first semiconductor and the first gate are stacked in a second direction, and the second semiconductor and the second gate are stacked in the second direction.

[0007] In the first direction, the size of the first gate is smaller than the size of the first semiconductor, and the size of the second gate is larger than the size of the second semiconductor.

[0008] According to some embodiments of the present invention, the driving substrate further includes an elastic abutment member, which is connected to the fixing member on the side facing the receiving cavity.

[0009] In some embodiments, the thin-film transistor assembly further includes a source, a drain, and a connection layer, wherein the source is connected to the second semiconductor, the drain is connected to the first semiconductor, and the connection layer is located between the first semiconductor and the second semiconductor and is connected to both the first semiconductor and the second semiconductor.

[0010] In some embodiments, the thin-film transistor assembly further includes a source, a drain, and a connection layer, wherein the source is connected to the first semiconductor, the drain is connected to the second semiconductor, and the connection layer is located between the first semiconductor and the second semiconductor and is connected to both the first semiconductor and the second semiconductor.

[0011] In some embodiments, the driving substrate includes a first metal layer and a second metal layer stacked in the second direction, the first gate and the second gate being formed on the first metal layer, and the source, the drain and the interconnect layer being formed on the second metal layer.

[0012] In some embodiments, the pixel unit includes a first insulating layer and a second insulating layer;

[0013] The first insulating layer is disposed on the surface of the first metal layer, and the first insulating layer is located between the first metal layer and the first semiconductor in the second direction;

[0014] The second insulating layer is disposed on the surface of the second metal layer, and the second insulating layer is located between the second metal layer and the driving electrode in the second direction.

[0015] In some embodiments, a through hole is provided on the second insulating layer, and the driving electrode is electrically connected to the drain electrode at the through hole.

[0016] In some embodiments, the pixel unit further includes a leveling layer disposed in a second direction between the second insulating layer and the driving electrode.

[0017] In some embodiments, the leveling layer has openings corresponding to the connecting holes.

[0018] A second aspect of this application provides an electronic paper display device, the electronic paper display device including a top substrate, a driving substrate as described in any one of the first aspects of this application, and a dielectric layer, the top substrate including a top electrode, the dielectric layer including an electronic paste, the dielectric layer being located between the top electrode and the driving electrode.

[0019] A third aspect of this application provides an electronic device including an electronic paper display device as described in a second aspect of this application.

[0020] As can be seen from the above embodiments, the thin-film transistor assembly in this application is configured such that the second gate and the second semiconductor are sized such that the second gate can block the second semiconductor, thereby preventing light from directly shining on the second semiconductor and causing leakage when the power is off. The first gate and the first semiconductor are configured such that the first semiconductor blocks the first gate in the first direction, thereby preventing leakage at the first semiconductor when the power is on.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 This is a schematic diagram of the hierarchical structure of the electronic paper display device in an embodiment of this utility model;

[0024] Figure 2 This is a schematic diagram of the planar structure of any pixel unit in the driving substrate in an embodiment of this utility model;

[0025] Figure 3 for Figure 2 A cross-sectional view of the marked AA point of any pixel unit in the driving substrate;

[0026] Figure 4 for Figure 2 A schematic diagram of the planar structure of the first metal layer, the first semiconductor, and the second semiconductor of any pixel unit in the driving substrate;

[0027] Figure 5 for Figure 2 A schematic diagram of the planar structure of the first metal layer, the first semiconductor, the second semiconductor, and the second metal layer of any pixel unit in the driving substrate;

[0028] Figure 6 This is a schematic diagram of the electronic device provided in the embodiments of this utility model.

[0029] Reference numerals: 100, electronic paper display device; 101, top substrate; 102, dielectric layer; 103, driving substrate; 110, first metal layer; 111, first gate; 112, second gate; 120, second metal layer; 121, source; 122, drain; 123, interconnect layer; 130, first semiconductor; 140, second semiconductor; 150, first insulating layer; 160, second insulating layer; 161, via; 170, leveling layer; 180, bottom side plate; 190, driving electrode; 200, electronic device. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0031] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0032] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0033] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0034] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] Electronic paper (ePaper) is a novel reflective display technology. Its core technology uses electronic ink to display images and text, achieving a display effect close to traditional paper. It boasts unique advantages such as paper-like display, low power consumption, and eye-friendliness. Major applications of ePaper include e-book readers, electronic tags, educational equipment, smart wearable devices, IoT displays, and advertising and information displays. With continuous technological advancements, the application scenarios of ePaper are expected to expand further, making it one of the important future development directions for display technology.

[0037] Microcavity electronic paper displays (MEDs) primarily involve creating a dam structure on the surface of a thin-film transistor (TFT) assembly to surround each pixel unit. An electronic paste containing black and white particles for imaging is then used to fill the dielectric layer 102, and finally, the display is encapsulated with a top glass panel. The cavity formed by the multiple dam structures in the MED is thus called the microcavity structure. MEDs can control the color changes of the particles in the electronic paste using an electric field, achieving high contrast, high reflectivity, and a wide color gamut display effect through particle reflection.

[0038] In related technologies, the electronic paper display device 100 uses a substrate (array) as a driving switch to control the electric field, and uses the electric field to control the movement of particles in the electronic paste to display the desired image. In some current electronic paper display devices 100, the side closest to the substrate (array) is used as the display surface. However, in most electronic paper display devices 100, the gate size of the thin-film transistor is smaller than the size of the corresponding semiconductor, causing light to directly shine on the semiconductor in the power-off state, resulting in leakage current in the semiconductor. The substrate (array) is the driving substrate 103 in this application.

[0039] To solve the above-mentioned technical problems, this application provides an electronic paper display device 100. By setting the dimensions of the first gate 111 and the first semiconductor 130, the first semiconductor 130 is arranged to block the first gate 111 in a first direction, thereby preventing leakage at the first semiconductor 130 when power is on. By setting the dimensions of the second gate 112 and the second semiconductor 140, the second gate 112 can block the second semiconductor 140, thereby preventing light from directly shining on the second semiconductor 140 and causing leakage when power is off.

[0040] For example, the electronic paper display device 100 provided in this application can be a micro-cavity electronic paper display (MED) or other electronic paper display devices 100, without specific limitations.

[0041] Please see Figure 1 This application provides a driving substrate 103, which can be applied to an electronic paper display device 100. The electronic paper display device 100 includes a top substrate 101, a driving substrate 103, and a dielectric layer 102.

[0042] The top substrate 101 includes a top electrode, and the driving substrate 103 includes multiple pixel units. Each pixel unit includes a bottom side plate 180, a thin film transistor assembly, and a driving electrode 190. The driving electrode 190 is electrically connected to the thin film transistor. The dielectric layer 102 includes an electronic paste and is located between the top electrode and the driving electrode 190. The current is controlled by the thin film transistor assembly to form an electric field between the driving electrode 190 and the top electrode, thereby controlling the movement of the electronic paste to display the image.

[0043] For example, the dielectric layer 102 is formed with a sealed cavity, and an electronic paste is disposed in the sealed cavity. The electronic paste includes a filling liquid and conductive particles distributed in the filling liquid. Specifically, the conductive particles may include black particles and white particles with different electrical properties.

[0044] Black and white particles can have different electrical charges. For example, white particles may carry a negative charge and black particles may carry a positive charge; or white particles may carry a positive charge and black particles may carry a negative charge. No specific limitation is made here.

[0045] Black and white particles can undergo electrophoresis under the influence of voltage, controlling their positional distribution within the dielectric layer 102 and thus creating different grayscale levels on the screen surface. Utilizing the principle of attraction between positive and negative particles, when an electric field is applied, corresponding black or white particles move to the top of the dielectric layer 102, allowing the user to see black or white within that area (pixel unit). Applying different voltages to the same dielectric layer 102 will result in a half-black, half-white appearance at the top, allowing the user to see gray within that area (pixel unit).

[0046] For example, the side of the top substrate 101 facing away from the driving substrate 103 forms the display surface of the electronic paper display device 100. When the electronic paper display device 100 is in a flat position, the top substrate 101 is generally disposed on the top of the electronic paper display device 100, and the driving substrate 103 is disposed on the bottom of the electronic paper display device 100. Therefore, the driving substrate 103 can also be called the bottom substrate. Since an array of pixel units is formed on the driving substrate 103, the area covered by multiple pixel units forms the display area of ​​the driving substrate 103, and the driving substrate 103 can also be called an array substrate. An electric field is formed between the top electrode in the top substrate 101 and the driving electrode 190 in the driving substrate 103.

[0047] For example, the side of the driving substrate 103 facing away from the top substrate 101 can also form the display surface of the electronic paper display device 100. In this embodiment, the pixel unit needs to be provided with a light-transmitting part, and the ratio of the area of ​​the light-transmitting part to the area of ​​the pixel unit is the ratio of the area of ​​the effective area through which light can pass in the driving substrate 103 to the area of ​​the entire pixel unit area.

[0048] The area of ​​each pixel unit generally includes a light-transmitting area and a non-light-transmitting area. The non-light-transmitting area is generally occupied by devices such as circuits, thin-film transistor components, and storage capacitors.

[0049] To ensure the display effect of the electronic paper display device 100, the ratio of the area of ​​the light-transmitting portion to the area of ​​the pixel unit is at least greater than 50%, and is generally 70%-80%. In the electronic paper display device 100, it is generally necessary to maximize the aperture ratio to maximize the area through which light passes, thereby improving the brightness and energy efficiency of the electronic paper display device 100. Therefore, in this embodiment, while ensuring that the circuitry and chip select (CS) signals meet the requirements, the ratio of the area of ​​the light-transmitting portion to the area of ​​the pixel unit can be increased as much as possible, thereby effectively improving the brightness and energy efficiency of the electronic paper display device 100. For example, the shape of the light-transmitting portion includes square, rectangular, circular, and hexagonal shapes, etc., and is not specifically limited here.

[0050] Please see Figure 2 , Figure 3 The thin-film transistor assembly includes a first gate 111, a first semiconductor 130, a second gate 112, and a second semiconductor 140. The first gate 111 and the second gate 112 are distributed along a first direction, and the first semiconductor 130 and the first gate 111 are stacked along a second direction, which can be understood as the thickness direction of the driving substrate 103. The second semiconductor 140 and the second gate 112 are also stacked along the second direction. In the first direction, the size of the first gate 111 is smaller than the size of the first semiconductor 130, and the size of the second gate 112 is larger than the size of the second semiconductor 140. The dimensions of the first gate 111 are L1, the dimensions of the second gate 112 are L2, the dimensions of the first semiconductor 130 are L3, and the dimensions of the second semiconductor 140 are L4, satisfying L1 < L3 and L2 > L4.

[0051] It is understood that the size of the first gate 111 in the first direction is smaller than the size of the first semiconductor 130, so that the first semiconductor 130 blocks the first gate 111, thereby preventing the first gate 111 from overlapping with other metal layers and causing leakage at the first semiconductor 130 when the first gate 111 is energized. The size of the second gate 112 in the first direction is larger than the size of the second semiconductor 140. Correspondingly, in the extension direction of the second gate 112, the size of the second gate 112 should also be larger than the size of the second semiconductor 140, so that the second gate 112 can block the second semiconductor 140 on the side near the bottom plate 180, preventing light from directly illuminating the second semiconductor 140 and preventing leakage at the second semiconductor 140 when power is off. By simultaneously setting the first semiconductor 130 and the second semiconductor 140 within the thin-film transistor assembly to improve leakage, the yield of the electronic paper display device 100 is improved.

[0052] Please see Figure 4 , Figure 5 In some embodiments, the thin-film transistor assembly further includes a source 121, a drain 122, and a connection layer 123. The source 121 is connected to the second semiconductor 140, the drain 122 is connected to the first semiconductor 130, and the connection layer 123 is located between the first semiconductor 130 and the second semiconductor 140 and connected to both the first semiconductor 130 and the second semiconductor 140. It is understood that the first semiconductor 130 and the second semiconductor 140 are connected in series.

[0053] Alternatively, the source 121 can be connected to the first semiconductor 130, the drain 122 can be connected to the second semiconductor 140, and the connection layer 123 can be located between the first semiconductor 130 and the second semiconductor 140 and connected to the first semiconductor 130 and the second semiconductor 140. That is, the positions of the first gate 111 and the second gate 112 are interchanged, and the positions of the first semiconductor 130 and the second semiconductor 140 are also interchanged accordingly.

[0054] In some embodiments, the driving substrate 103 includes a first metal layer 110 and a second metal layer 120 stacked together. A first gate 111 and a second gate 112 are formed on the first metal layer 110, and a source 121, a drain 122 and a connection layer 123 are formed on the second metal layer 120. That is, the first gate 111 and the second gate 112 are located in the same structural layer and are formed by processing the first metal layer 110. The source 121, the drain 122 and the connection layer 123 are located in the same structural layer and are formed by processing the second metal layer 120.

[0055] The pixel unit includes a first insulating layer 150 and a second insulating layer 160. The first insulating layer 150 is disposed on the surface of the first metal layer 110 and is located between the first metal layer 110 and the first semiconductor 130 in the second direction. The second insulating layer 160 is disposed on the surface of the second metal layer 120 and is located between the second metal layer 120 and the driving electrode 190 in the second direction, so as to prevent the first metal layer 110 and the second metal layer 120 from directly contacting each other, which would cause leakage and short circuit.

[0056] A through hole 161 is provided on the second insulating layer 160, and the driving electrode 190 is electrically connected to the drain electrode 122 at the through hole 161, so that the driving electrode 190 and the thin film transistor assembly are electrically connected.

[0057] The pixel unit also includes a leveling layer 170, which is disposed in the second direction between the second insulating layer 160 and the driving electrode 190. The leveling layer 170 is disposed to form a flat surface to facilitate the placement of the driving electrode 190. An opening is provided on the leveling layer 170 at the corresponding through hole 161 to facilitate the connection of the driving electrode 190 with the drain electrode 122.

[0058] The second aspect of this application also provides an electronic paper display device 100. It is understood that the electronic paper display device 100 is the same as the electronic paper display device 100 mentioned in the first aspect of this application, and will not be described again here.

[0059] Please see Figure 6 The third aspect of this application also provides an electronic device 200, which includes the electronic paper display device 100 provided in the second aspect of the application, which will not be described again here.

[0060] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A drive substrate, characterized by, It includes multiple pixel units, each pixel unit including a bottom substrate, a thin film transistor assembly and a driving electrode, wherein the driving electrode is electrically connected to the thin film transistor; The thin-film transistor assembly includes a first gate, a first semiconductor, a second gate, and a second semiconductor. The first gate and the second gate are distributed along a first direction, the first semiconductor and the first gate are stacked in a second direction, and the second semiconductor and the second gate are stacked in the second direction. In the first direction, the size of the first gate is smaller than the size of the first semiconductor, and the size of the second gate is larger than the size of the second semiconductor.

2. The drive substrate according to claim 1, wherein The thin-film transistor assembly further includes a source, a drain, and a connection layer. The source is connected to the second semiconductor, the drain is connected to the first semiconductor, and the connection layer is located between the first semiconductor and the second semiconductor and is connected to both the first semiconductor and the second semiconductor.

3. The drive substrate according to claim 1, wherein The thin-film transistor assembly further includes a source, a drain, and a connection layer. The source is connected to the first semiconductor, the drain is connected to the second semiconductor, and the connection layer is located between the first semiconductor and the second semiconductor and is connected to both the first semiconductor and the second semiconductor.

4. The drive substrate according to any one of claims 2 or 3, characterized in that, The driving substrate includes a first metal layer and a second metal layer stacked in the second direction, the first gate and the second gate are formed on the first metal layer, and the source, the drain and the interconnect layer are formed on the second metal layer.

5. The drive substrate according to claim 4, wherein The pixel unit includes a first insulating layer and a second insulating layer; The first insulating layer is disposed on the surface of the first metal layer, and the first insulating layer is located between the first metal layer and the first semiconductor in the second direction; The second insulating layer is disposed on the surface of the second metal layer, and the second insulating layer is located between the second metal layer and the driving electrode in the second direction.

6. The drive substrate according to claim 5, wherein The second insulating layer has a through hole, and the driving electrode is electrically connected to the drain electrode at the through hole.

7. The drive substrate according to claim 6, wherein The pixel unit further includes a leveling layer, which is disposed in a second direction between the second insulating layer and the driving electrode.

8. The drive substrate according to claim 7, wherein The leveling layer has openings corresponding to the connecting holes.

9. An electronic paper display device, characterized by include: The top substrate includes a top electrode; The driving substrate as described in any one of claims 1-8; A dielectric layer, comprising an electronic paste, is located between the top electrode and the driving electrode.

10. An electronic device, characterized by Includes the electronic paper display device as described in claim 9.

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