Display device
By using a multi-layer foam structure with different densities and porosities in flexible display devices, the problems of irregularity and insufficient impact resistance during folding are solved, resulting in improved surface quality and recovery performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SAMSUNG DISPLAY CO LTD
- Filing Date
- 2021-09-01
- Publication Date
- 2026-07-03
AI Technical Summary
Flexible display devices are prone to irregularities and visibility issues during folding, and they also lack impact resistance.
A multi-layer foam structure is adopted, in which each layer has a different density and porosity, including a first foam layer, a second foam layer and a third foam layer. By setting different densities and porosities, the surface quality and impact resistance are improved.
It improves the surface quality and impact resistance of flexible display devices, reduces irregularities during the folding process, and enhances the device's recovery performance.
Smart Images
Figure CN114155787B_ABST
Abstract
Description
[0001] Cross-references to related applications
[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0113975, filed on September 7, 2020, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This disclosure relates herein to display devices, and more particularly, to display devices comprising a foam layer. Background Technology
[0004] Display devices display various images on a screen to provide information to the user. Typically, display devices display information within a designated screen area. Display devices can be used to display images on various electronic devices, such as smartphones, laptops, and televisions.
[0005] In recent years, flexible display devices, including flexible display panels, have been developed. Unlike rigid display devices, flexible display devices are foldable, rollable, or bendable. The ability to be formed into various shapes allows for easy portability and enhances user-friendliness.
[0006] However, flexible display devices may have drawbacks such as irregularities in the folded areas and / or visibility of these irregularities. Therefore, there is a need to develop a technology to overcome the disadvantages and limitations of flexible display devices. Summary of the Invention
[0007] This disclosure provides a display device that has improved surface quality and improved impact resistance by including multiple foam layers, each of which may have a different density.
[0008] The embodiment provides a display device that may include a display panel and a cushion layer disposed below the display panel. The cushion layer may include a first foam layer that may have a first density, a second foam layer that may be disposed above the first foam layer and may have a second density less than the first density, and a third foam layer that is disposed above the second foam layer and placed closer to the display panel than the first foam layer. The third foam layer may have a third density greater than the first density.
[0009] The first density can be approximately 0.5 g / cm³. 3 Approximately 0.7 g / cm³ 3 Within a certain range, the second density can be approximately 0 g / cm³. 3 To approximately 0.2 g / cm 3 Within the range, and the third density can be approximately 0.8 g / cm³. 3 Approximately 0.9 g / cm³ 3Within the range.
[0010] Each of the first and third foam layers can have a smaller thickness than the second foam layer.
[0011] Each of the first and third foam layers can have a thickness of about 80 μm to about 120 μm.
[0012] The first foam layer, the second foam layer, and the third foam layer may include polyurethane.
[0013] The display device may further include a first surface layer disposed on the lower surface of the first foam layer, a second surface layer disposed on the upper surface of the first foam layer, a third surface layer disposed on the lower surface of the third foam layer, and a fourth surface layer disposed on the upper surface of the third foam layer.
[0014] The first, second, third, and fourth surface layers may include polyurethane.
[0015] The second foam layer can be placed directly above the second surface layer, and the third surface layer can be placed directly above the second foam layer.
[0016] In one embodiment, the display device may include a display panel and a padding layer disposed below the display panel. The padding layer may include a first foam layer having a first pore, a second foam layer disposed above the first foam layer and having a second pore, and a third foam layer disposed above the second foam layer and having a third pore. The porosity of the first foam layer may be less than that of the second foam layer and may be greater than that of the third foam layer.
[0017] The third foam layer can be positioned closer to the display panel than the first foam layer.
[0018] The first foam layer can be positioned closer to the display panel than the third foam layer.
[0019] At least a portion of the first holes can be connected to each other to form a first hole assembly, and the third holes can be spaced apart from each other.
[0020] At least a portion of the first holes can be connected to each other. At least a portion of the second holes can be connected to each other. The ratio of the number of connected second holes to the total number of second holes can be greater than the ratio of the number of connected first holes to the total number of first holes.
[0021] The first foam layer may have a porosity in the range of about 20% to about 60%, the second foam layer may have a porosity in the range of about 90% to about 99%, and the third foam layer may have a porosity in the range of about 5% to about 15%.
[0022] The size of the first hole assembly can be larger than the size of each of the third holes.
[0023] In one embodiment, the display device may include a display panel and a padding layer displayed beneath the display panel. The padding layer may include: a first foam layer, which may include a first hole having a semi-closed-cell structure; a second foam layer disposed above the first foam layer and including a second hole having an open-cell structure; and a third foam layer disposed above the second foam layer and including a third hole having a closed-cell structure. The third foam layer may be disposed closer to the display panel than the first foam layer.
[0024] The display panel can be foldable relative to a virtual folding axis extending in the first direction.
[0025] The display device may include a first support member and a second support member, which are disposed below the display panel and spaced apart from each other in a second direction perpendicular to the first direction. A padding layer may be disposed between the display panel and the support members. Attached Figure Description
[0026] The accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the embodiments. In the drawings:
[0027] Figure 1 This is a schematic perspective view of a display device according to an embodiment;
[0028] Figure 2 It indicates that it is in a folded state. Figure 1 A schematic diagram of a display device;
[0029] Figure 3 This is an exploded schematic perspective view of the display device according to the embodiment;
[0030] Figure 4 It is along Figure 3 A schematic cross-sectional view of the display device taken by line I-I';
[0031] Figure 5 This is an enlarged schematic cross-sectional view of a padding layer included in a display device according to an embodiment;
[0032] Figure 6 This is a schematic perspective view of a first foam layer included in a display device according to an embodiment;
[0033] Figure 7A This is a schematic perspective view of a second foam layer included in a display device according to an embodiment;
[0034] Figure 7BThis is an enlarged schematic diagram of a portion of a second foam layer included in a display device according to an embodiment;
[0035] Figure 8 This is a schematic perspective view of a third foam layer included in a display device according to an embodiment; and
[0036] Figure 9 This is an enlarged schematic cross-sectional view of a padding layer included in a display device according to an embodiment. Detailed Implementation
[0037] In the specification, when a component (or area, layer, part, etc.) is described as being "on", "connected to", or "attached to" another component, it means that the component can be directly placed on / connected to / attached to the other component, or a third component can be placed between the component and the other component.
[0038] The same reference numerals denote the same elements. Furthermore, in the accompanying drawings, the thickness, proportions, and dimensions of the elements are exaggerated for the purpose of effectively depicting the technical content.
[0039] The term "and / or" includes any and all combinations of one or more of the related listed items.
[0040] It should be understood that while the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the embodiments. Unless the context clearly indicates otherwise, the singular form of the term may include multiple forms.
[0041] Furthermore, terms such as "below," "lower part," "above," and "upper part" are used to describe the relationships of the configurations shown in the accompanying drawings. These terms are used as relative concepts and are described with reference to the directions shown in the accompanying drawings.
[0042] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments pertain. It should also be understood that terms defined in common dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and are expressly defined herein unless they are interpreted in an ideal or overly formal sense.
[0043] It should be understood that the terms “comprising” or “having” are intended to specify the presence of features, integers, steps, operations, elements, components or combinations thereof stated in this disclosure, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components or combinations thereof.
[0044] In the following description, a display device according to an embodiment will be described with reference to the accompanying drawings.
[0045] Figure 1 This is a schematic perspective view of a display device according to an embodiment. Figure 2 It indicates that it is in a folded state. Figure 1 A schematic diagram of a display device.
[0046] Reference Figure 1 According to the embodiments, the display device DD may have a rectangular shape, having a long side extending in a first direction DR1 and a short side extending in a second direction DR2 intersecting the first direction DR1. However, the embodiments are not limited to this, and the display device DD may have various shapes such as a circular shape or a polygonal shape. The display device DD may be a flexible display device DD.
[0047] In the following text, the direction substantially perpendicular to the plane defined by the first direction DR1 and the second direction DR2 is defined as the third direction DR3. In the specification, "in a plan view" may be defined as viewed from the third direction DR3.
[0048] The display device DD may include a first non-foldable region NFA1, a second non-foldable region NFA2, and a foldable region FA disposed between the first non-foldable region NFA1 and the second non-foldable region NFA2. The first non-foldable region NFA1, the foldable region FA, and the second non-foldable region NFA2 may be arranged sequentially in a first direction DR1.
[0049] The diagram shows a folded region FA and two non-folded regions NFA1 and NFA2, but the number of folded regions FA and non-folded regions NFA1 and NFA2 is not limited to this. For example, a display device DD may include two or more non-folded regions and a folded region disposed between the non-folded regions.
[0050] The upper surface of the display device DD can be defined as a display surface DS, and can have a plane defined by a first direction DR1 and a second direction DR2. An image IM generated in the display device DD can be provided to the user via the display surface DS.
[0051] The display surface DS may include a display area DA and a non-display area NDA surrounding the display area DA. The display area DA may display an image, and the non-display area NDA may not display an image. The non-display area NDA may surround the display area DA and define the edge of the display device DD, and the edge of the display device DD may be printed with color.
[0052] Reference Figure 2 The display device DD can be a foldable display device DD that can be folded or unfolded. For example, the display device DD can be folded relative to a virtual folding axis FX extending in the second direction DR2. The folding axis FX can be defined as an axis parallel to the short side of the display device DD.
[0053] When the display device DD is folded relative to the folding axis, the upper surfaces of the first non-folding region NFA1 and the second non-folding region NFA2 can face each other. Therefore, the display device DD can be folded inward so that the display surface DS is not exposed to the outside.
[0054] In this embodiment, the display device DD is described as folded relative to a folding axis extending in the second direction DR2, but the embodiment is not limited thereto. The display device DD can be folded into different shapes. For example, the display device DD can be folded relative to a folding axis extending in the first direction DR1.
[0055] Figure 3 This is an exploded perspective view of a display device according to an embodiment. Figure 4 It is along Figure 3 A schematic cross-sectional view of the display device taken by line I-I'.
[0056] Reference Figure 3 and Figure 4 The display device DD according to the embodiment may include a display panel DP, a protective film PF, a pad CL, and a support member MP.
[0057] The display panel DP can have a rectangular shape, having a long side extending in a first direction DR1 and a short side extending in a second direction DR2. The display panel DP may include a first non-folding region NFA1, a second non-folding region NFA2, and a folded region FA disposed between the first non-folding region NFA1 and the second non-folding region NFA2. The first non-folding region NFA1, the second non-folding region NFA2, and the folded region FA can be arranged sequentially in the first direction DR1. The display panel DP can be a flexible display panel DP. For example, the folded region FA of the display panel DP can be folded relative to the folding axis FX (see reference). Figure 2 The protective film PF supporting the display panel DP can be located below the display panel DP.
[0058] The support member MP can be disposed below the display panel DP. The support member MP can have sufficient rigidity to support the display panel DP. For example, the support member MP can include a metallic material.
[0059] The support member MP may include a first support member MP1 and a second support member MP2. Both the first support member MP1 and the second support member MP2 may be rigid substrates. The first support member MP1 may be configured to partially overlap with a first non-folded region NFA1 and a folded region FA. The second support member MP2 may be configured to partially overlap with a second non-folded region NFA2 and a folded region FA. In a plan view, the first support member MP1 and the second support member MP2 may have rectangular shapes.
[0060] The second support member MP2 can be spaced apart from the first support member MP1 in the first direction DR1. Therefore, a gap can be provided between the first support member MP1 and the second support member MP2. The gap formed between the first support member MP1 and the second support member MP2 can overlap with the folding region FA.
[0061] An adhesive (not shown) may be disposed between the support member MP and the display panel DP. For example, the adhesive may be a pressure-sensitive adhesive. However, the type of adhesive is not limited to this. The adhesive may be disposed between the first support member MP1 and the first non-folding area NFA1, and between the second support member MP2 and the second non-folding area NFA2.
[0062] A protective film PF can be disposed below the display panel DP to protect the display panel DP. The protective film PF may include a flexible resin. For example, the protective film PF may include polyethylene terephthalate (PET).
[0063] A padding layer CL can be disposed between the support member MP and the protective layer PF. The padding layer CL can overlap the entire display panel DP, thereby reducing irregularities visible on the display surface of the display panel DP at the portions where the first support member MP1 and the second support member MP2 are spaced apart. The padding layer CL protects the display panel DP from external impacts. The padding layer CL will... Figure 5 Detailed description is provided.
[0064] Figure 5 It is an enlarged schematic cross-sectional view of the padding layer included in the display device of the embodiment. Figure 6 This is a schematic 3D diagram of the first foam layer. Figure 7A This is a schematic 3D diagram of the second foam layer. Figure 7B This is an enlarged schematic diagram of a portion of the second foam layer. Figure 8 This is a schematic 3D diagram of the third foam layer. It will be referred to below. Figures 5 to 8 A display device for describing the implementation method in detail.
[0065] Reference Figures 5 to 8 In one embodiment, the padding layer CL may include a first foam layer FL1, a second foam layer FL2 disposed above the first foam layer FL1, and a third foam layer FL3 disposed above the second foam layer FL2. The first foam layer FL1, the second foam layer FL2, and the third foam layer FL3 may include polyurethane.
[0066] The first foam layer FL1 can have a first density, the second foam layer FL2 can have a second density less than the first density, and the third foam layer FL3 can have a third density greater than the first density. The first density can be approximately 0.5 g / cm³. 3 Approximately 0.7 g / cm³ 3 Within a certain range, the second density can be approximately 0 g / cm³. 3 To approximately 0.2 g / cm 3 Within the range, and the third density can be approximately 0.8 g / cm³. 3 Approximately 0.9 g / cm³ 3 Within the range.
[0067] Among the foam layers FL1, FL2, and FL3 included in the padding layer CL, the third foam layer FL3 can be positioned closest to the display panel DP. Therefore, the third foam layer FL3 can be positioned closer to the display panel DP than the first foam layer FL1. However, the implementation is not limited to this, and in some embodiments, among the foam layers FL1, FL2, and FL3 included in the padding layer CL, the first foam layer FL1 can be positioned closest to the display panel DP. The first foam layer FL1 can be positioned closer to the display panel DP than the third foam layer FL3.
[0068] A high-density third foam layer FL3 can reduce irregularities visible on the surface of the display panel DP, but may have limitations in protecting the display panel DP from external impacts due to poor compressive and recovery properties when an external impact is applied. A lower-density first foam layer FL1 and second foam layer FL2 can have improved compressive and recovery properties, and thus can protect the display panel DP from external impacts. However, the first foam layer FL1 and second foam layer FL2 cannot prevent irregularities from becoming visible on the surface of the display panel DP. The second foam layer FL2 has low durability, resulting in a high probability of tearing. The padding layer CL of this embodiment together includes the first foam layer FL1, the second foam layer FL2, and the third foam layer FL3. In this embodiment, all these layers (each with a different density) can be included together to reduce irregularities visible on the surface of the display panel DP while protecting the display panel DP from external impacts.
[0069] The first foam layer FL1 may have a first thickness T1, the second foam layer FL2 may have a second thickness T2, and the third foam layer FL3 may have a third thickness T3. The first thickness T1 and the third thickness T3 may each be less than the second thickness T2. The first thickness T1 and the third thickness T3 may each be independently within the range of approximately 80 μm to approximately 120 μm. For example, the first thickness T1 may be less than the third thickness T3, the first thickness T1 may be greater than the third thickness T3, or the first thickness T1 may be the same as the third thickness T3.
[0070] The first foam layer FL1 may include a first pore PO1, the second foam layer FL2 may include a second pore PO2, and the third foam layer FL3 may include a third pore PO3. The first pore PO1 and the third pore PO3 may be closed pores in which air is filled, and the second pore PO2 may be an open pore through which air passes.
[0071] The volume occupied by the first pore PO1 relative to the total volume of the first foam layer FL1 can be smaller than the volume occupied by the second pore PO2 relative to the total volume of the second foam layer FL2, and can be larger than the volume occupied by the third pore PO3 relative to the total volume of the foam layer FL3.
[0072] The porosity of the first foam layer FL1 can be less than that of the second foam layer FL2 and greater than that of the third foam layer FL3. The first foam layer FL1 can have a porosity in the range of about 20% to about 60%, the second foam layer FL2 can have a porosity in the range of about 90% to about 99%, and the third foam layer FL3 can have a porosity in the range of about 5% to about 15%. Higher porosity results in lower durability but higher recovery performance, while lower porosity results in higher density and better surface properties but higher vulnerability to external impacts. The display device DD of the embodiment includes foam layers FL1, FL2, and FL3, each with different porosities, and thus can provide a display device with improved recovery performance, surface properties, and durability.
[0073] Some of the first holes PO1 can be connected to each other. In the specification, a hole is defined as connected when air can pass through from one hole to another among multiple holes. Some of the first holes PO1 can be connected to each other to form a hole assembly POA. Most of the second holes PO2 can be connected to each other. The ratio of the number of connected second holes PO2 to the total number of second holes PO2 can be greater than the ratio of the number of connected first holes PO1 to the total number of first holes PO1. The third holes PO3 can be spaced apart from each other. Each of the third holes PO3 can be smaller in size than the hole assembly POA. As the ratio of connected holes to the total number of holes increases, the foam layer can have improved impact resistance and resilience. That is, the first foam layer FL1 has better impact resistance and resilience than the third foam layer FL3, and the second foam layer FL2 has better impact resistance and resilience than the first foam layer FL1.
[0074] The first pore PO1 can have a semi-closed-cell structure, where some pores are interconnected and external air can be prevented from entering. The second pore PO2 can have an open-cell structure, where most pores are interconnected and external air can be introduced. The third pore PO3 can have a closed-cell structure, where pores are spaced apart and external air cannot be introduced. The second foam layer FL2 allows external air to be introduced into the second pore PO2, thus providing good recovery and impact resistance for the first pore PO1 and the third pore PO3.
[0075] Reference Figure 6 and Figure 8 The first hole PO1 and the third hole PO3 can have circular cross-sections. The first hole PO1 and the third hole PO3 can also have spherical three-dimensional shapes. However, the implementation is not limited to these, and the structure of the foam layer is not restricted, as long as the structure can provide shock absorption. For example, each hole in the foam layer can have an elliptical, polygonal, or irregular cross-section.
[0076] Reference Figure 7A and Figure 7B The second pore of PO2 can have a hexagonal cross-section. The second pore of PO2 can have a three-dimensional hexagonal prism shape. However, the implementation is not limited to this, and the structure of the foam layer is not restricted, as long as the structure can provide shock absorption. For example, each pore of the foam layer can have an elliptical, polygonal, or irregular cross-section.
[0077] The second pores PO2 can be arranged regularly at regular intervals. However, the implementation is not limited to this, and each of the pores can be randomly arranged in the second foam layer FL2.
[0078] The second pore (PO2) can have an open shape without upper and lower surfaces. (See reference...) Figure 7BThe second hole PO2 located on the front surface is represented by a solid line, and the second hole PO2 located on the rear surface is represented by a dashed line. The second hole PO2 can be an open hole, and therefore the hole located on the rear surface can be exposed through the hole located on the front surface.
[0079] Figure 9 This is an enlarged schematic cross-sectional view of the padding layer included in an embodiment of the display device. Referring below, reference will be made to... Figure 9 A detailed description includes the padding CL-1 in the display device of the embodiment. (This is not repeated from the above references.) Figures 1 to 8 The descriptions of those padding layers (CL) are identical in detail, and the main focus will be on the differences.
[0080] Reference Figure 9 According to the embodiment, the padding layer CL-1 may include a first surface layer SL1 disposed on the lower surface of the first foam layer FL1, a second surface layer SL2 disposed on the upper surface of the first foam layer FL1, a third surface layer SL3 disposed on the lower surface of the third foam layer FL3, and a fourth surface layer SL4 disposed on the upper surface of the third foam layer FL3.
[0081] The first surface layer SL1, the second surface layer SL2, the third surface layer SL3, and the fourth surface layer SL4 may comprise polyurethane. For example, the first surface layer SL1, the second surface layer SL2, the third surface layer SL3, and the fourth surface layer SL4 may comprise thermoplastic polyurethane.
[0082] The thickness of each of the surface layers SL1, SL2, SL3, and SL4 may be less than the thickness of each of the foam layers FL1, FL2, and FL3. The thickness of each of the surface layers SL1, SL2, SL3, and SL4 is shown to be the same, but the implementation is not limited to this, and the thicknesses of the surface layers SL1, SL2, SL3, and SL4 may be different.
[0083] Although not shown, the padding layer CL-1 can be formed by injecting resin for forming a first foam layer FL1 between the separately prepared first surface layer SL1 and second surface layer SL2 to form a first foam layer FL1, injecting resin for forming a third foam layer FL3 between the separately prepared third surface layer SL3 and fourth surface layer SL4 to form a third foam layer FL3, and injecting resin for forming a second foam layer FL2 between the second surface layer SL2 and the third surface layer SL3 to form a second foam layer FL2. That is, the second foam layer FL2 can be directly disposed on the second surface layer SL2 without an adhesive layer. The third foam layer FL3 can be directly disposed on the third surface layer SL3 without an adhesive layer.
[0084] According to one embodiment, a display device with improved surface quality, impact resistance, and resilience can be provided by including three foam layers beneath the display panel, each foam layer having a different density, porosity, and pore arrangement.
[0085] The display device according to the embodiment includes multiple foam layers, each with a different density, thereby exhibiting improved surface finish, impact resistance, and resilience.
[0086] Embodiments have been disclosed herein, and although terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be apparent to those skilled in the art, features, characteristics, and / or elements described in connection with embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise specifically instructed. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as set forth in the appended claims.
Claims
1. A display device, including: The display panel is foldable relative to a virtual folding axis extending in the first direction; as well as A cushion layer is disposed below the display panel. The cushion layer includes: The first foam layer has a first density; A second foam layer is disposed above the first foam layer and has a second density less than the first density; and A third foam layer is positioned closer to the display panel than the first foam layer and is disposed above the second foam layer. The third foam layer has a third density greater than the first density. The first density is 0.5 g / cm³. 3 Up to 0.7 g / cm 3 Within the range, The second density is 0 g / cm³ 3 Up to 0.2 g / cm 3 Within the scope, and The third density is 0.8 g / cm³. 3 Up to 0.9 g / cm 3 Within the range.
2. The display device according to claim 1, wherein, Each of the first foam layer and the third foam layer has a smaller thickness than the second foam layer.
3. The display device according to claim 1, wherein, Each of the first foam layer and the third foam layer has a thickness in the range of 80 μm to 120 μm.
4. The display device according to claim 1, wherein, The first foam layer, the second foam layer, and the third foam layer comprise polyurethane.
5. The display device according to claim 1, further comprising: A first surface layer is disposed on the lower surface of the first foam layer; The second surface layer is disposed on the upper surface of the first foam layer; A third surface layer is disposed on the lower surface of the third foam layer; as well as The fourth surface layer is disposed on the upper surface of the third foam layer.
6. A display device, including: The display panel is foldable relative to a virtual folding axis extending in the first direction; as well as A cushion layer is disposed below the display panel. The cushion layer includes: The first foam layer includes multiple first pores; A second foam layer is disposed above the first foam layer and includes a plurality of second pores; and A third foam layer is disposed above the second foam layer and includes a plurality of third pores. The porosity of the first foam layer is less than that of the second foam layer, but greater than that of the third foam layer; The first density of the first foam layer is 0.5 g / cm³. 3 Up to 0.7 g / cm 3 Within the range, The second density of the second foam layer is 0 g / cm³. 3 Up to 0.2 g / cm 3 Within the scope, and The third density of the third foam layer is 0.8 g / cm³. 3 Up to 0.9 g / cm 3 Within the range.
7. The display device according to claim 6, wherein, The third foam layer is positioned closer to the display panel than the first foam layer.
8. The display device according to claim 6, wherein, The first foam layer is positioned closer to the display panel than the third foam layer.
9. The display device according to claim 6, wherein At least a portion of the plurality of first holes are connected to each other to form a first hole assembly, and The plurality of third holes are spaced apart from each other.
10. The display device according to claim 6, wherein: At least a portion of the plurality of first holes are connected to each other. At least a portion of the plurality of second holes are connected to each other, and The ratio of the number of the plurality of second holes connected to each other to the total number of the plurality of second holes is greater than the ratio of the number of the plurality of first holes connected to each other to the total number of the plurality of first holes.
11. The display device according to claim 6, wherein: The first foam layer has a porosity in the range of 20% to 60%; The second foam layer has a porosity in the range of 90% to 99%; as well as The third foam layer has a porosity in the range of 5% to 15%.
12. The display device according to claim 9, wherein, The size of the first hole assembly is larger than the size of each of the third holes.
13. A display device, including: The display panel is foldable relative to a virtual folding axis extending in the first direction; as well as A cushion layer is disposed below the display panel. The cushion layer includes: The first foam layer includes a plurality of first pores having a semi-closed-cell structure; A second foam layer is disposed above the first foam layer and includes a plurality of second holes having an open-cell structure; and A third foam layer is disposed above the second foam layer and includes a plurality of third holes having a closed-cell structure. The third foam layer is positioned closer to the display panel than the first foam layer. The first density of the first foam layer is 0.5 g / cm³. 3 Up to 0.7 g / cm 3 Within the range, The second density of the second foam layer is 0 g / cm³. 3 Up to 0.2 g / cm 3 Within the scope, and The third density of the third foam layer is 0.8 g / cm³. 3 Up to 0.9 g / cm 3 Within the range.