Display module and display device

Abstract

The utility model provides a display module and a display device. The display module comprises a display area and a non-display area located on at least one side of the display area, the display module comprises a substrate, a driving circuit layer located on one side of the substrate, a shading layer located on the side, away from the substrate, of the driving circuit layer and a plurality of sub-pixels, and the sub-pixels are located in the display area. The driving circuit layer comprises a pixel circuit located in the display area and a driving circuit located in the non-display area, the driving circuit is electrically connected with the pixel circuit, the driving circuit comprises thin film transistors, and the orthographic projection of the shading layer on the substrate covers the orthographic projection of the channel area of each thin film transistor of the driving circuit on the substrate. According to the display module provided by the embodiment of the invention, the shading layer can shield the channel region of the thin film transistor to prevent external light from irradiating the channel region, so that the thin film transistor is prevented from generating leakage current, and the display effect and the display quality of the display module are improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display module and a display device. Background Art

[0002] With the development of display technology, a variety of display devices such as electronic paper have emerged, each of which has unique performance and advantages and is suitable for different application scenarios.

[0003] A gate driving circuit is provided in the frame area of ​​the display device. The gate driving circuit includes a thin film transistor. The leakage current of the thin film transistor affects the display effect of the display device. Summary of the invention

[0004] A first aspect of an embodiment of the present application provides a display module. The display module includes a display area and a non-display area located at least on one side of the display area;

[0005] The display module comprises a substrate, a driving circuit layer located on one side of the substrate, a light shielding layer located on a side of the driving circuit layer away from the substrate, and a plurality of sub-pixels;

[0006] Each of the sub-pixels is located in the display area, the driving circuit layer includes a pixel circuit located in the display area and a driving circuit located in the non-display area, and the driving circuit is electrically connected to the pixel circuit; the driving circuit includes a thin film transistor, and the orthographic projection of the shading layer on the substrate covers the orthographic projection of the channel region of each of the thin film transistors of the driving circuit on the substrate.

[0007] In one embodiment, the orthographic projection of the light shielding layer on the substrate covers the orthographic projection of each of the thin film transistors on the substrate.

[0008] In one embodiment, the orthographic projection of the light shielding layer on the substrate covers the orthographic projection of the driving circuit on the substrate, and an edge of the orthographic projection of the light shielding layer on the substrate is located outside the orthographic projection of the driving circuit on the substrate.

[0009] In one embodiment, the light shielding layer covers the non-display area.

[0010] In one embodiment, the light shielding layer is made of insulating material.

[0011] In one embodiment, the light shielding layer is adhesive and adheres to a surface of the driving circuit layer away from the substrate.

[0012] In one embodiment, the display module further comprises a protective layer, wherein the protective layer is located on a side of the sub-pixel away from the substrate;

[0013] The protection layer covers a partial area of ​​the light shielding layer, and the orthographic projection of the protection layer on the substrate covers the orthographic projection of the driving circuit on the substrate.

[0014] In one embodiment, the distance between the surface of the protection layer away from the substrate and the substrate is the same as the maximum distance between the surface of the light shielding layer away from the substrate and the substrate.

[0015] In one embodiment, the driving circuit is a gate driving circuit; and / or, the sub-pixel includes an electrophoretic capsule.

[0016] A second aspect of an embodiment of the present application provides a display device, which includes the above-mentioned display module.

[0017] In the display module provided by the embodiment of the present application, since the orthographic projection of the shading layer on the substrate covers the orthographic projection of the channel region of each thin film transistor of the driving circuit on the substrate, the shading layer can prevent external ambient light from irradiating to the channel region of each thin film transistor of the driving circuit, thereby reducing the leakage current generated by the thin film transistor, improving the phenomenon that the signal output by the driving circuit to the pixel circuit is changed due to the leakage current of the thin film transistor, and then causing the display screen of the display module to appear abnormal, thereby improving the display quality of the display module.

[0018] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0020] Figure 1 A schematic diagram of the positional relationship between a display area and a non-display area in a display module provided in an embodiment of the present application;

[0021] Figure 2 A partial structural schematic diagram of a display module provided in one embodiment of the present application;

[0022] Figure 3 A schematic diagram of the structure of a gate drive circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0023] Here, the technical solutions in the embodiments (or "implementations") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0024] If there are terms involving directional indications or positional relationships in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first", "second", etc. involved in the embodiments of the present application are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance.

[0025] The display module and the display device of the embodiment of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can complement or be combined with each other.

[0026] The present application embodiment provides a display module. Figure 1 and Figure 2 As shown, the display module 100 includes a display area 10 and a non-display area 11 located at at least one side of the display area 10 .

[0027] The display module 100 includes a substrate 20, a driving circuit layer 21 located on one side of the substrate 20, and a pixel structure layer 22 and a light shielding layer 23 located on a side of the driving circuit layer 21 away from the substrate 20. The pixel structure layer 22 includes a plurality of sub-pixels located in a display area.

[0028] The driving circuit layer 21 includes a pixel circuit located in the display area 10 and a driving circuit 211 located in the non-display area 11, the driving circuit 211 includes a thin film transistor, and the orthographic projection of the shading layer 23 on the substrate 20 covers the orthographic projection of the channel region of each thin film transistor of the driving circuit 211 on the substrate 20.

[0029] The display module 100 displays images in the display area 10 , and does not display images in the non-display area 11 . The non-display area 11 may be provided with conductive structures such as signal lines and driving circuits.

[0030] Under the control of the gate voltage, the electrons of the thin film transistor in the driving circuit 211 can flow from the source to the drain or from the drain to the source through the channel region of the thin film transistor. When the thin film transistor works under light conditions, photogenerated carriers, that is, electron-hole pairs, will be generated in the channel region of the thin film transistor. At this time, even if the gate voltage of the thin film transistor is low or there is no gate voltage, the electron-hole pairs will cause current to be generated in the channel region of the thin film transistor, thereby causing leakage current to be generated in the thin film transistor. The leakage current of the thin film transistor makes it impossible for the voltage of the sub-pixel to be maintained at its desired voltage value, thereby affecting the display effect.

[0031] In the display module 100 provided in the embodiment of the present application, since the orthographic projection of the light-shielding layer 23 on the substrate 20 covers the orthographic projection of the channel region of each thin-film transistor of the driving circuit 211 on the substrate 20, the light-shielding layer 23 can prevent external ambient light from irradiating the channel region of each thin-film transistor of the driving circuit 211, thereby reducing the leakage current generated by the thin-film transistor, improving the phenomenon that the signal output by the driving circuit to the pixel circuit is changed due to the leakage current of the thin-film transistor, and then causing the display screen of the display module to be abnormal, thereby improving the display quality of the display module.

[0032] In one embodiment, the non-display area 11 surrounds the display area 10 .

[0033] In one embodiment, the substrate 20 may be a flexible substrate or a rigid substrate. The material of the flexible substrate may include one or more of polyimide, polyethylene terephthalate, polycarbonate, and organic resin materials, and the organic resin material may include epoxy resin, triazine, silicone resin, or polyimide. The rigid substrate includes any one of a glass substrate, a quartz substrate, a sapphire substrate, and the like.

[0034] In one embodiment, the driving circuit layer 21 includes a plurality of pixel circuits located in the display area 10. The pixel circuits correspond to the sub-pixels one by one, and each pixel circuit drives the corresponding sub-pixel. The pixel circuits may include thin film transistors and capacitors.

[0035] In one embodiment, the orthographic projection of the light shielding layer 23 on the substrate 20 covers the orthographic projection of each thin film transistor on the substrate 20. When each thin film transistor is covered by the light shielding layer, it can more effectively prevent the ambient light incident on the display module from different angles from being incident on the channel region in the thin film transistor, thereby effectively preventing the thin film transistor from generating leakage current; and the light shielding layer 23 can prevent the external ambient light from being incident on the conductive structure of the driving circuit and then being reflected, causing a poor appearance.

[0036] In one embodiment, the orthographic projection of the light shielding layer 23 on the substrate 20 covers the orthographic projection of the driving circuit 211 on the substrate 20, and the edge of the orthographic projection of the light shielding layer 23 on the substrate 20 is located outside the orthographic projection of the driving circuit 211 on the substrate 20. With such a configuration, the light shielding layer 23 can effectively block the ambient light incident on the display module from different angles from irradiating the driving circuit 211, thereby preventing the thin film transistor of the driving circuit 211 from generating leakage current, thereby ensuring the display effect. The orthographic projection of the driving circuit 211 on the substrate may be an irregular shape. In some embodiments, the light shielding layer 23 may also be a regular shape, such as a rectangle, and it is only necessary to ensure that the edge of the light shielding layer 23 covers or exceeds the outermost part of the driving circuit 211.

[0037] In one embodiment, the edge of the light shielding layer 23 exceeds the edge of the driving circuit 211 by at least 0.2 mm. With such a configuration, the light shielding layer 23 can fully shield the light and ensure the display effect of the display device.

[0038] In one embodiment, the light shielding layer 23 covers the non-display area 11. With such a configuration, the light shielding layer 23 can fully shield the light, and the preparation process of the light shielding layer 23 covering the non-display area 11 is relatively simple, which can simplify the preparation process and save process costs.

[0039] In one embodiment, the material of the light shielding layer 23 is an insulating material. In this way, no parasitic capacitance is formed between the light shielding layer 23 and the conductive structure of the driving circuit 211. Compared with the solution of using metal materials to block light, the influence of the parasitic capacitance on the output signal of the driving circuit can be avoided, which helps to improve the display quality of the display module.

[0040] In one embodiment, the driving circuit 211 is a gate driving circuit. For the gate driving circuit, when leakage current is generated in the thin film transistor, the output waveform of the gate driving circuit may be distorted, thereby causing the display screen of the display module to have display abnormalities such as horizontal stripes. When the light shielding layer 23 covers the channel region of the thin film transistor of the gate driving circuit, it can avoid the display screen of the display module from having horizontal stripes, thereby improving the display quality of the display module.

[0041] In one embodiment, the light shielding layer 23 is sticky and adheres to the surface of the driving circuit layer 21 away from the substrate 20. The light shielding layer 23 can shield light and, at the same time, serve as an adhesive layer to achieve adhesion between different film layers of the display module. There is no need to set an adhesive layer between the light shielding layer 23 and the driving circuit layer 21, thereby reducing production costs and manufacturing complexity.

[0042] In some embodiments, the light shielding layer 23 may be a black light shielding glue, wherein the mass proportion of each component in the black light shielding glue may be: epoxy resin accounts for 35% to 75%; curing agent accounts for 10% to 25%; γ-glycidyl ether propyl trimethoxy silane accounts for 1% to 10%; carbon black accounts for 1% to 10%. In this way, the black light shielding glue can have better light shielding performance and better film-forming performance.

[0043] In one embodiment, the display module 100 further includes a protective layer 24, the protective layer 24 is located on a side of the sub-pixel away from the substrate 20, the protective layer 24 covers a portion of the light shielding layer 23, and the orthographic projection of the protective layer 24 on the substrate 20 covers the orthographic projection of the driving circuit 211 on the substrate 20. The protective layer 24 can not only protect the sub-pixels in the display area 10 from external factors such as physical damage, moisture, and dust, but also protect the light shielding layer 23 and the driving circuit 211 located below the light shielding layer 23 from damage by external factors, thereby ensuring the stability and reliability of the driving circuit 211.

[0044] In one embodiment, the distance between the surface of the protective layer 24 away from the substrate 20 and the substrate 20 is the same as the maximum distance between the surface of the light shielding layer 23 away from the substrate 20 and the substrate 20. This arrangement can prevent the surface of the light shielding layer 23 away from the substrate 20 from exceeding the surface of the protective layer 24 away from the substrate 20, causing tactile discomfort to the user. Figure 2 In the embodiment shown, from the edge of the display area 10 to the non-display area 11, the distance from the surface of the light shielding layer 23 away from the substrate 20 to the substrate 20 gradually decreases, and the surface of the light shielding layer 23 away from the substrate 20 is generally an arc surface. When the material of the light shielding layer 23 is a light shielding glue, the light shielding layer 23 can be formed by coating the light shielding glue. After coating the light shielding glue, the light shielding glue will flow, so that the morphology of the light shielding layer 23 is as follows: Figure 2 shown.

[0045] In one embodiment, the display module 100 may be an electronic paper, and the sub-pixel includes an electrophoretic capsule. Each electrophoretic capsule may include a capsule body, an electrophoretic liquid and charged particles in the capsule body, wherein the charged particles may include black particles, white particles or colored particles.

[0046] In one embodiment, the sub-pixel further includes a pixel electrode and a common electrode that are arranged opposite to each other, and the electrophoretic capsule is located between the pixel electrode and the common electrode.

[0047] In one embodiment, the display area 10 of the display module 100 includes a main display area 101 and a display transition area 102 located between the main display area 101 and the non-display area 11, and some sub-pixels are located in the display transition area 102. The portion of the driving circuit layer 21 located in the display transition area 102 is provided with a pixel circuit for driving the sub-pixels located in the display transition area 102.

[0048] Figure 3 is a circuit diagram of a gate drive circuit provided by the present application, Figure 3 The gate drive circuit is an 11T1C structure, including 11 thin film transistors M1-M11 and a capacitor C1. The connection relationship between the 11 thin film transistors and the capacitor is shown in FIG. Figure 3 ; The gate of the thin film transistor M1 is connected to the signal terminal Input, and the drain is connected to the signal terminal VDS; the gate of the thin film transistor M2 is connected to the signal terminal Reset, and the source is connected to the signal terminal VSD; the gate of the thin film transistor M3 is connected to the signal terminal Source is connected to the signal terminal Output, and the drain is connected to the signal terminal CLK; the gate of the thin film transistor M4 is connected to the signal terminal STV0; the sources of the thin film transistors M6, M7, M8, M10, and M11 are all connected to the signal terminal VGL; the gate of the thin film transistor M7 is connected to the signal terminal GCL; the drain of the thin film transistor M7 is connected to the signal terminal GCH.

[0049] The embodiment of the present application detects the leakage current of the gate drive circuit of two display modules, one of which is the display module provided in the embodiment of the present application, and the other display module is different from the display module provided in the embodiment of the present application in that an EC glue layer (epoxy resin type thermosetting glue) is used to replace the light shielding layer, and the EC glue layer is a colorless, transparent or white film layer. The leakage current of the gate drive circuit of the two display modules is detected under the same lighting environment and different temperatures, and the detection results are shown in Table 1. In Table 1, the first display module and the second display module are display modules using EC glue layers, and the third display module and the fourth display module are display modules provided in the embodiment of the present application; the unit of leakage current is mA.

[0050] Table 1

[0051]

[0052]

[0053] It can be seen from Table 1 that under the same test temperature and the same lighting conditions, the leakage current of the gate drive circuit of the display module using white EC glue is significantly greater than the leakage current of the gate drive circuit of the display module provided in the embodiment of the present application, indicating that the display module provided in the embodiment of the present application can effectively reduce the leakage current of the gate drive circuit, thereby reducing the power consumption of the display module and improving the quality of the display picture of the display module.

[0054] When the display module provided by the embodiment of the present application is an electronic paper display module, the display module provided by the embodiment of the present application and the display module without a light shielding layer are observed to show that the display module provided by the embodiment of the present application has a clear picture pattern under strong light irradiation and no abnormality occurs, while the display module without a light shielding layer has obvious horizontal stripes under strong light irradiation, and the pattern is blurred and the picture color becomes lighter. The display module provided by the embodiment of the present application can effectively improve the quality of the display picture.

[0055] The present application also provides a display device, which includes the above-mentioned display module 100. The display device can be a flexible OLED display device or an electronic paper display device, and can be applied to any device with a display function, such as an electronic paper price tag, a mobile phone, a tablet computer, a television, a laptop computer, a vehicle-mounted device, etc.

[0056] In one embodiment, the display device further includes a housing, and the display module is disposed in the housing.

[0057] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A display module, characterized in that: The display module includes a display area and a non-display area located at least on one side of the display area; The display module comprises a substrate, a driving circuit layer located on one side of the substrate, a light shielding layer located on a side of the driving circuit layer away from the substrate, and a plurality of sub-pixels; Each of the sub-pixels is located in the display area, the driving circuit layer includes a pixel circuit located in the display area and a driving circuit located in the non-display area, and the driving circuit is electrically connected to the pixel circuit; the driving circuit includes a thin film transistor, and the orthographic projection of the shading layer on the substrate covers the orthographic projection of the channel region of each of the thin film transistors of the driving circuit on the substrate.

2. The display module according to claim 1, characterized in that: The orthographic projection of the light shielding layer on the substrate covers the orthographic projection of each thin film transistor on the substrate.

3. The display module according to claim 2, characterized in that: The orthographic projection of the light shielding layer on the substrate covers the orthographic projection of the driving circuit on the substrate, and the edge of the orthographic projection of the light shielding layer on the substrate is located outside the orthographic projection of the driving circuit on the substrate.

4. The display module according to claim 3, characterized in that: The light shielding layer covers the non-display area.

5. The display module according to claim 1, characterized in that: The material of the light shielding layer is insulating material.

6. The display module according to claim 1, characterized in that: The light shielding layer is sticky and adheres to the surface of the driving circuit layer away from the substrate.

7. The display module according to claim 1, characterized in that: The display module further includes a protective layer, wherein the protective layer is located on a side of the sub-pixel away from the substrate; The protection layer covers a partial area of ​​the light shielding layer, and the orthographic projection of the protection layer on the substrate covers the orthographic projection of the driving circuit on the substrate.

8. The display module according to claim 7, characterized in that: The distance between the surface of the protection layer away from the substrate and the substrate is the same as the maximum distance between the surface of the light shielding layer away from the substrate and the substrate.

9. The display module according to claim 1, characterized in that: The driving circuit is a gate driving circuit; and / or, The sub-pixel includes an electrophoretic capsule.

10. A display device, characterized in that: The display device comprises the display module according to any one of claims 1 to 9.

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