Elastic member and display device including the thereof

Abstract

The elastic member according to the embodiment is an elastic member including a first region and a second region, wherein the elastic member includes a surface rough portion having a length direction, the first region is defined as a folding region, the second region is defined as an unfolding region, and a first pattern portion having a long direction and a short direction is formed in the first region of the elastic member, the long direction of the first pattern portion being different from the length direction of the surface rough portion.

Description

Technical Field

[0001] The embodiments relate to an elastic member and a display device including the elastic member. Background Technology

[0002] Recently, there has been an increasing demand for flexible or foldable display devices, which are convenient for carrying various applications and displaying images on large screens.

[0003] This flexible or foldable display device is folded or partially bent when carried or stored, and can be achieved by a display that unfolds when displaying images. Therefore, the image display area can be increased, and the display can be easily carried by the user.

[0004] After a flexible or foldable display device is folded or bent, the process of unfolding the flexible display device again can be repeated.

[0005] In other words, because flexible or foldable display devices involve repeated folding and unfolding operations, the substrate of the flexible display device needs to have predetermined strength and elasticity, and there should be no cracking or deformation in the substrate during folding and unfolding.

[0006] Meanwhile, the display substrate, which is an elastic component constituting a flexible or foldable display device, can undergo a pretreatment process of rolling the substrate to obtain flexible or foldable characteristics.

[0007] This rolling process can form a surface roughness on the surface of the elastic member, and the elastic member can have different physical properties depending on the direction in which the surface roughness is formed.

[0008] Therefore, there is a need for an elastic member with a new structure that can ensure the folding properties and reliability of elastic members with different physical properties depending on the orientation. Summary of the Invention

[0009] Technical issues

[0010] The embodiments are intended to provide an elastic member with improved folding properties and reliability.

[0011] Technical solution

[0012] An elastic member including a first region and a second region, wherein the elastic member includes a surface rough portion having a longitudinal direction, wherein the first region is defined as a folded region and the second region is defined as an unfolded region, wherein a first pattern portion having a longitudinal direction and a short direction is formed in the first region of the elastic member, wherein the longitudinal direction of the first pattern portion is different from the longitudinal direction of the surface rough portion.

[0013] Beneficial effects

[0014] In the elastic member according to the embodiment, a hole-shaped or groove-shaped pattern portion formed on the elastic member may be formed along the length direction of the surface rough portion of the elastic member.

[0015] Specifically, the longitudinal direction of the patterned portion can be formed in a direction different from the longitudinal direction of the surface roughness portion. That is, the longitudinal direction of the patterned portion can be set to be closer to the vertical direction than the horizontal direction relative to the longitudinal direction of the surface roughness portion.

[0016] Therefore, the folding characteristics that may occur due to the difference in physical properties caused by the direction perpendicular to the rolling direction of the roller formed on the surface of the elastic member through the rolling process can be improved.

[0017] In other words, since the longitudinal direction of the patterned portion is formed in a direction that is close to the longitudinal direction of the rough surface portion, that is, a direction similar to the vertical direction, the surface remaining on the elastic member after the patterned portion is formed can be the surface in the direction of roller movement, rather than the surface in the vertical direction.

[0018] Therefore, since the surface of the roll with a large elastic modulus is more residual in the rolling direction than in the vertical direction, plastic deformation caused by stress generated when the elastic member folds or recovers can be minimized.

[0019] Therefore, since the plastic deformation that occurs when the elastic member is folded can be minimized, the folding characteristics and reliability of the elastic member can be improved. Attached Figure Description

[0020] Figure 1 This is a perspective view showing the elastic member according to an embodiment.

[0021] Figure 2 This is a perspective view showing the elastic member according to an embodiment.

[0022] Figure 3 This is a view showing the elastic member according to an embodiment before folding.

[0023] Figure 4 This is a view showing the elastic member according to an embodiment after folding.

[0024] Figure 5 This is a top view showing the first surface of the elastic member according to an embodiment.

[0025] Figure 6 This is a top view showing the second surface of the elastic member according to an embodiment.

[0026] Figure 7 This is a view used to illustrate the rolling process performed on the elastic member according to the embodiment.

[0027] Figure 8 This is a view used to illustrate the direction of the surface roughness formed on the elastic member according to the embodiment.

[0028] Figure 9 This is an enlarged view showing a region of the elastic member according to an embodiment.

[0029] Figure 10 This is a top view showing the first surface of the elastic member according to another embodiment.

[0030] Figures 11 to 14 These are views showing cross-sectional views of the layered structure based on the various elastic members according to the embodiments.

[0031] Figure 15 This is a view used to illustrate an application example of the elastic member according to an embodiment. Detailed Implementation

[0032] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the spirit and scope of the invention are not limited to the portion of the described embodiments and can be implemented in various other forms. Furthermore, one or more elements of the embodiments can be selectively combined and substituted within the spirit and scope of the invention. Moreover, unless otherwise explicitly defined and described, terms (including technical and scientific terms) used in the embodiments of the invention may be interpreted as having the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and terms such as those defined in common dictionaries may be interpreted as having a meaning consistent with their meaning in the context of the relevant field.

[0033] Furthermore, the terminology used in the embodiments of this invention is for describing the embodiments and is not intended to limit the invention. In this specification, unless specifically stated in the wording, the singular form may also include the plural form, and when described as "at least one (or more) of A (and), B and C", it may include at least one of all combinations that can be combined with A, B and C.

[0034] Furthermore, when describing the elements of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are used only to distinguish elements from other elements, and are not limited to the nature, order, or sequence of the elements.

[0035] Furthermore, when an element is described as being “connected” or “combined” to another element, it can include not only cases where the element is directly “connected” or “combined” to the other element, but also cases where the element is “connected” or “combined” through another element between the element and the other element.

[0036] Furthermore, when described as being formed or set “above” or “below” each element, “above” or “below” can include not only cases where two elements are directly connected to each other, but also cases where one or more other elements are formed or set between the two elements.

[0037] Furthermore, when expressed as "above" or "below", it may include not only the upward direction based on a single element, but also the downward direction based on a single element.

[0038] In the following description, the elastic member according to an embodiment will be described with reference to the accompanying drawings.

[0039] Figure 1 This is a perspective view of a display device including an elastic member according to an embodiment. The display device according to the embodiment may be a flexible display device or a foldable display device capable of bending in one direction.

[0040] refer to Figure 1 According to an embodiment, the display device 1000 includes an elastic member 100, a display panel 200 disposed on the elastic member 100, and a touch panel 300 disposed on the display panel 200.

[0041] The elastic member 100 can support the display panel 200 and the touch panel 300. That is, the elastic member 100 can be a support substrate that supports the display panel 200 and the touch panel 300.

[0042] Meanwhile, the touch panel 300 can be integrally formed with the display panel 200. For example, the touch panel 300 can be integrally formed with the display panel 200 in an on-cell or in-cell manner.

[0043] The elastic member 100 may comprise a metallic material. For example, the elastic member 100 may comprise a metal, a metal alloy, a plastic, a composite material (e.g., carbon fiber reinforced plastic, magnetic or conductive material, glass fiber reinforced material, etc.), a ceramic, sapphire, glass, etc. For example, the elastic member 100 may comprise stainless steel (SUS).

[0044] The elastic member 100 can be formed as a single layer or as a multilayer comprising multiple layers.

[0045] The elastic member 100 can be flexible or foldable. That is, the elastic member 100 can be folded or bent in one direction. In other words, the elastic member 100 can be a substrate of a display used in a flexible display device or a foldable display device.

[0046] The elastic member 100 can be defined in a first direction 1D and a second direction 2D different from the first direction 1D. For example, the first direction 1D can be defined as the same direction as the folding axis direction of the elastic member 100, and the second direction can be a direction perpendicular to the first direction.

[0047] Either the first direction 1D or the second direction 2D can be defined as the width direction of the elastic member 100, and the other direction can be defined as the length direction of the elastic member 100.

[0048] The elastic member 100 can be folded using either its width or length direction as a folding axis.

[0049] In the following text, for ease of description, the first direction is defined as the same direction as the folding axis. Furthermore, the first direction is defined as the width direction of the elastic member 100, and the second direction is defined as the length direction of the elastic member 100.

[0050] The elastic member 100 may include at least two regions. Specifically, the elastic member 100 may include a first region 1A and a second region 2A.

[0051] The first region 1A can be defined as the region where the elastic member 100 is folded. That is, the first region 1A can be a folded region.

[0052] Furthermore, the second region 2A can be defined as the region where the elastic member 100 is not folded. That is, the second region 2A can be an unfolded region.

[0053] The first region 1A and the second region 2A will be described in detail below.

[0054] The display panel 200 can be mounted on the elastic member 100.

[0055] Display panel 200 may include multiple pixels, which may include switching thin-film transistors, driving thin-film transistors, power storage devices, and organic light-emitting diodes (OLEDs). In the case of OLEDs, deposition can be performed at relatively low temperatures, and OLEDs are primarily used in flexible display devices for reasons such as low power consumption and high brightness. Here, a pixel refers to the smallest unit used to display an image, and the display panel displays images through multiple pixels.

[0056] The display panel 200 may include a substrate, gate lines disposed on the substrate, data lines that intersect the gate lines and are isolated from each other, and a common power line. Typically, a pixel can be defined by the gate lines, data lines, and common power line.

[0057] The substrate may include a flexible material, such as a plastic film, and the display panel 200 may be realized by setting organic light-emitting diodes and pixel circuits on the flexible film.

[0058] Touch panel 300 can be disposed on display panel 200. Touch panel 300 can realize touch function in flexible display device, and can be omitted in foldable display device that only displays images and does not have touch function.

[0059] The touch panel 300 may include a substrate and touch electrodes disposed on the substrate. The touch electrodes may be capacitive or resistive to sense the position of an input device touched on a foldable or flexible display device.

[0060] The substrate of the touch panel 300 may contain a material with flexible properties, such as a plastic film, and the touch panel 300 may be realized by configuring touch electrodes on the flexible film.

[0061] As described above, when the touch panel 300 and the display panel 200 are integrally formed, the substrate of the touch panel 300 can be the substrate of the display panel or a part of the display panel. Therefore, the touch panel 300 and the display panel 200 can be integrally formed, and the thickness of the display device can be reduced.

[0062] Meanwhile, the elastic member 100 and the display panel 200 can have different sizes.

[0063] For example, the area of ​​the elastic member 100 may be more than 90% and less than 110% of the area of ​​the display panel 200. Specifically, the area of ​​the elastic member 100 may be more than 95% and less than 105% of the area of ​​the display panel 200. More specifically, the area of ​​the elastic member 100 may be more than 97% and less than 100% of the area of ​​the display panel 200.

[0064] When the area of ​​the elastic member 100 is less than 90% of the area of ​​the display panel 200, the supporting force of the elastic member 100 on the display panel 200 or touch panel 300 may decrease, which may cause curling in the unfolded area of ​​the elastic member 100. Therefore, when the user visually identifies the screen area, visibility may be reduced, and when a touch is activated, touch malfunction may occur because the screen in the touch area is incomplete due to the curled area.

[0065] Furthermore, when the area of ​​the elastic member 100 is greater than 110% of the area of ​​the display panel 200, the support force for the display panel or touch panel can be ensured by the elastic member 100, but the bezel area of ​​the display device, including the substrate, display panel, and touch panel, may increase. As a result, since the screen area available to the user cannot be widened, this may lead to inconvenience in using the display device.

[0066] Additionally, although not shown in the accompanying drawings, (when the touch panel is omitted) a cover window for protecting the foldable or flexible display device may be additionally provided on the touch panel 300 or the display panel 200.

[0067] Meanwhile, the elastic member 100, the display panel 200, and the touch panel 300 can be bonded together with an adhesive layer or the like.

[0068] As described above, the display device includes an elastic member 100.

[0069] refer to Figure 2 The elastic member 100 can be bent in one direction.

[0070] Specifically, the elastic member 100 may include a first surface 1S and a second surface 2S opposite to the first surface 1S. In the elastic member 100, the first surface 1S or the second surface 2S can be bent to face each other. That is, the surface on which the panel is disposed can be bent to face each other, or the surface opposite to the surface on which the panel is disposed can be bent to face each other.

[0071] However, the embodiments are not limited thereto; the second surface and the first surface of the elastic member 100 may be bent to face each other alternately. That is, the elastic member 100 may include a plurality of first regions and a plurality of second regions.

[0072] In the following description, such as Figure 2 As shown, the main description will focus on the bending of the first surface 1S in the elastic member 100 in a direction facing each other.

[0073] As described above, the first region 1A and the second region 2A can be defined in the elastic member 100. The first region 1A and the second region 2A can be regions defined when the first surface 1S in the elastic member 100 bends in a direction facing each other.

[0074] In detail, the elastic member 100 bends in one direction, and the elastic member 100 can be divided into a first region 1A and a second region 2A, the first region 1A being a folded region and the second region 2B being an unfolded region.

[0075] refer to Figure 3 and Figure 4 The elastic member 100 may include a first region 1A, which is a region where the elastic member 100 bends. The elastic member 100 may include a second region 2A, which does not bend and is disposed adjacent to the first region 1A.

[0076] For example, the second region 2A can be formed on the left and right sides of the first region 1A based on the bending direction of the elastic member 100. That is, the second region 2A can be located at both ends of the first region 1A. In other words, the first region 1A can be located between the second regions 2A.

[0077] However, the embodiments are not limited thereto, and the first region 1A may be further formed outside the second region 2A.

[0078] The first region 1A and the second region 2A can be formed on the same elastic member 100. That is, the first region 1A and the second region 2A can be integrally formed on the same elastic member 100 without being separated.

[0079] The dimensions of the first region 1A and the second region 2A can be different from each other. Specifically, the dimension of the second region 2A can be larger than the dimension of the first region 1A.

[0080] Furthermore, the area of ​​the first region 1A of the elastic member 100 can be more than 1% and less than 30% of the total area of ​​the elastic member 100. Specifically, the area of ​​the first region 1A of the elastic member 100 can be more than 5% and less than 20% of the total area of ​​the elastic member 100. The area of ​​the first region 1A of the elastic member 100 can be more than 10% and less than 15% of the total area of ​​the elastic member 100.

[0081] When the area of ​​the first region 1A of the elastic member 100 is less than 1% of the total area of ​​the substrate 100, cracks may form on the boundary surface between the folded area and the unfolded area when the elastic member is repeatedly folded and unfolded, which may reduce the folding reliability of the elastic member 100.

[0082] Furthermore, when the area of ​​the first region 1A of the elastic member 100 exceeds 30% of the total area of ​​the elastic member 100, curling may occur in the folded area of ​​the display panel 200 when the elastic member is folded. Therefore, visibility may be reduced when the user visually identifies the screen area, and touch malfunction may occur when a touch is activated due to the incomplete screen in the touch area caused by the curled area.

[0083] Although the accompanying drawings show the first region 1A located at the central portion of the elastic member 100, the embodiment is not limited thereto. That is, the first region 1A may be located at one end and the end region of the elastic member 100. In other words, the first region 1A may be located at one end and the end region of the elastic member 100, such that the size of the first region 1A is asymmetrical.

[0084] Figure 4 This is a side view of the elastic member after it has been folded.

[0085] refer to Figure 4 The elastic member 100 can be folded in one direction around the folding axis. Specifically, the first surface 1S can be folded along the folding axis in a direction where they face each other.

[0086] Since the elastic member 100 is folded in one direction, a first region 1A and a second region 2A can be formed on the elastic member 100. That is, a folded region formed by folding the elastic member 100 in one direction and an unfolded region located at both ends of the folded region can be formed in the elastic member 100.

[0087] The folded region can be defined as the region that forms curvature R, and the unfolded region can be defined as the region that does not form curvature R or whose curvature is close to zero.

[0088] refer to Figure 3 and Figure 4 The elastic member 100 can be folded in one direction and can be formed in the order of unfolded area, folded area and unfolded area.

[0089] Multiple patterned portions for reducing and dispersing stress generated when the elastic member 100 is folded can be formed in at least one of the first region 1A and the second region 2A. The patterned portions will be described in detail below.

[0090] At the same time, despite Figure 4 The first surface 1S of the elastic member 100 is shown to be folded so that they face each other, but the embodiment is not limited to this, and the second surface 2S can also be folded so that they face each other.

[0091] Hereinafter, the elastic members according to various embodiments will be described in detail with reference to the accompanying drawings.

[0092] Figure 5and Figure 6 This is a top view of the elastic member according to an embodiment. In detail, Figure 5 This is a top view of the first surface 1S of the elastic member 100. Figure 6 This is a top view of the second surface 2S of the elastic member 200.

[0093] refer to Figure 5 and Figure 6 According to the embodiment, the elastic member may include a plurality of patterned portions PA. Specifically, the elastic member 100 may include a first patterned portion PA1 disposed in the first region 1A.

[0094] The first pattern part PA1 can be formed as a hole or a groove.

[0095] In detail, the first patterned part PA1 can be formed as a hole through the first surface 1S and the second surface 2S of the elastic member, or it can be formed as a groove in the first surface 1S or the second surface 2S.

[0096] When the elastic member 100 is folded, the first pattern portion PA1 provided in the first region 1A can facilitate the folding of the elastic member 100. The first region 1A is the area where the elastic member is folded. Specifically, since the thickness of the elastic member 100 decreases in the region where the elastic member is folded through the first pattern portion PA1, the compressive stress is reduced, so the elastic member 100 can be easily folded.

[0097] Meanwhile, in the first region 1A where the elastic member 100 is folded, the compressive and tensile stresses generated during the folding and restoring of the elastic member are greater than those generated in the second region 2A. As a result, during the folding and restoring of the elastic member 100, plastic deformation due to stress may occur in the first region 1A.

[0098] According to the embodiment, the elastic member 100 adjusts the shape of the first pattern portion PA1 provided in the first region 1A according to the direction of the surface rough portion formed on the surface of the elastic member 100, so as to minimize the plastic deformation that occurs in the first region 1A, thereby minimizing the plastic deformation that occurs in the first region 1A.

[0099] In detail, the first pattern part PA1 can be formed into a shape having a long direction (LD) and a short direction (SD).

[0100] For example, refer to Figure 5 The first pattern part PA1 can be formed into a shape having a long direction LD and a short direction SD extending in a direction perpendicular to the long direction LD.

[0101] A folding axis of the elastic member 100 can be formed in a direction corresponding to the longitudinal direction LD of the first patterned part PA1.

[0102] The extension directions of the long direction LD and the short direction SD of the first patterned part PA1 can be related to the surface roughness formed on the surface of the elastic member 100.

[0103] A surface rough portion may be formed on the elastic member 100. That is, a surface rough portion may be formed on at least one of the first surface 1S and the second surface 2S of the elastic member 100, so that the surface of the elastic member 100 may have a surface rough portion.

[0104] A surface roughness can be formed on the elastic member 100 along a specific direction.

[0105] The surface roughness of the elastic member 100 can be formed during the pretreatment process of the elastic member 100.

[0106] Specifically, the elastic member 100 is pre-treated before the first patterned portion 100 is formed. For example, before forming the first patterned portion PA1 in the first region 1A of the elastic member 100, a rolling process can be performed to reduce the thickness of the elastic member and increase the tensile force and hardness. For example, a cold rolling process can be performed before forming the first patterned portion PA1 of the elastic member 100.

[0107] refer to Figure 7 The elastic member can be cold-rolled while passing between two rotating rollers at a low temperature. The cold-rolled elastic member 100 has a reduced thickness and increased tensile strength and stiffness. Therefore, when the elastic member 100 is used in flexible or foldable display devices, its folding characteristics can be improved.

[0108] In this case, by applying pressure and / or friction to the elastic member 100 during the cold rolling process, surface roughness can be formed on the first surface 1S and the second surface 2S of the elastic member 100 that are in contact with the roll. Therefore, surface roughness formed in a specific direction can be formed on the first surface 1S and the second surface 2S of the elastic member 100.

[0109] In other words, such as Figure 8 As shown, a plurality of surface roughness portions SR can be formed on the first surface 1S and the second surface 2S of the elastic member 100, extending from the starting point to the ending point of the surface roughness portion.

[0110] In other words, a surface roughness having a length direction in a specific direction can be formed on the surface of the elastic member 100. Here, the length direction SRD of the surface roughness can be defined as the length direction of a virtual line VL connecting the start and end points of the surface roughness. Alternatively, when the length direction of the surface roughness includes multiple directions that are similar to each other, the length direction of the surface roughness can be defined as the average direction of the multiple directions.

[0111] The length direction (SRD) of the surface roughness portion can be changed through the rolling process. Specifically, the length direction (SRD) of the surface roughness portion can be formed in a direction corresponding to the rolling direction (RD) of the roll. That is, the length direction (SRD) of the surface roughness portion can be formed in a direction equal to or close to the rolling direction (RD) of the roll.

[0112] Furthermore, the length direction SRD of the surface roughness portion can be different from the vertical direction TD, which is perpendicular to the rolling direction RD of the roll. That is, the length direction SRD of the surface roughness portion can be perpendicular to or close to the vertical direction TD.

[0113] The shape of the first patterned portion PA1 can be changed according to the length direction of the surface rough portion formed on the elastic member 100.

[0114] Specifically, the first patterned portion PA1 formed in the first region 1A may have a longitudinal direction LD and a short direction SD, and the longitudinal direction LD of the first patterned portion PA1 may extend in a direction different from the longitudinal direction SRD of the surface rough portion. That is, the longitudinal direction LD of the first patterned portion may not be parallel to the longitudinal direction SRD of the surface rough portion.

[0115] Figure 9 yes Figure 5 An enlarged view of one of the regions.

[0116] refer to Figure 9 The first pattern portion PA1 may have a longitudinal direction LD and a short direction SD. The first pattern portion PA1 may have a length direction along the longitudinal direction LD and a width direction along the short direction SD.

[0117] The long direction LD and short direction SD of the first patterned part PA1 can extend in directions perpendicular to each other. In detail, the long direction LD of the first patterned part PA1 can be defined as the direction corresponding to the folding axis FA direction of the elastic member 100, and the short direction SD of the first patterned part PA1 can extend in a direction perpendicular to both the folding axis direction and the long direction LD.

[0118] refer to Figure 9The longitudinal direction LD of the first patterned portion PA1 may differ from the longitudinal direction SRD of the surface roughened portion. That is, the longitudinal direction LD of the first patterned portion PA1 may not be parallel to the longitudinal direction SRD of the surface roughened portion. Specifically, the angle θ between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion may be 50° or more. More specifically, the angle θ between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion may be from 50° to 130°. In other words, the acute angle θ1 between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion may be from 50° to 90°, and the obtuse angle θ2 between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion may be from 90° to 130°.

[0119] Therefore, the angle between the folding axis FA direction of the elastic member 100 and the length direction of the surface roughness can be 50° to 130°.

[0120] More specifically, the angle θ between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion can be from 60° to 120°. More specifically, the angle θ between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion can be from 70° to 110°. More specifically, the angle θ between the longitudinal direction LD of the first patterned portion PA1 and the longitudinal direction SRD of the surface roughened portion can be from 80° to 100°.

[0121] In other words, the longitudinal direction LD of the first patterned part PA1 can be formed to be closer to the direction perpendicular to the longitudinal direction SRD of the surface rough part than the horizontal direction.

[0122] When a rolling process is performed before forming the patterned portion of the elastic member 100, the surface of the elastic member 100 may have a surface rough portion, and the elastic member 100 may have different physical properties depending on the length direction of the surface rough portion.

[0123] For example, when a rolling process is performed on the second direction 2A of the elastic member 100, that is, when the rolling direction of the roll is performed on the second direction 2A of the elastic member, the length direction of the surface rough portion formed on the first or second surface of the elastic member 100 may be parallel to or close to the second direction 2A.

[0124] That is, the rolling direction RD of the roll can be formed to be equal to or close to the second direction 2A, and the vertical direction can be formed to be equal to or close to the first direction 1A.

[0125] In this case, the physical properties of the elastic member 100 can be changed in a second direction 2A, similar to the rolling direction RD of the roll, and in a first direction 1A, similar to the vertical direction TD. Specifically, the elastic member 100 can have different elastic moduli and elastic coefficients in the first direction 1A and the second direction 2A.

[0126] The elastic modulus E refers to the degree of strain that occurs when an elastic material is subjected to stress, and can be defined by the following formula 1.

[0127] [Formula 1]

[0128] E(KN / mm 2 )=σ / ε

[0129] (Here, σ represents yield strength, and ε represents unit strain.)

[0130] Furthermore, the elastic modulus refers to the strain energy per unit volume required to increase the stress to the yield point, and can be defined by Equation 2 below.

[0131] [Equation 2]

[0132]

[0133] In other words, referring to Equation 2, it can be seen that the greater the yield strength, the smaller the elastic modulus and the greater the elastic coefficient.

[0134] The elastic modulus of the elastic member 100, which has undergone the cold rolling process, is smaller in the rolling direction RD of the roll than in the vertical direction TD. Therefore, the elastic coefficient calculated from the elastic modulus and yield strength can be larger in the rotation direction RD of the roll than in the vertical direction TD.

[0135] In other words, after the first patterned portion is formed on the elastic member 100, a first residual region SA1 in the rolling direction RD of the roll or the length direction of the elastic member and a second residual region SA2 in the vertical direction TD or the width direction of the elastic member 100 can remain in the elastic member.

[0136] At this time, as more surface remains on the rolling direction RD of the roll, the remaining surface after the first pattern portion is formed on the elastic member 100 can withstand the same stress for a longer period of time.

[0137] Therefore, in the elastic member according to the embodiment, the longitudinal direction of the first pattern portion is formed in a direction different from the longitudinal direction of the roughness, the longitudinal direction of the roughness corresponding to or similar to the rolling direction RD of the roll, thereby retaining a large amount of residual surface on the rolling direction RD of the roll, thereby minimizing the plastic deformation of the elastic member due to compressive stress or tensile stress when the elastic member is folded.

[0138] Therefore, the elastic member according to this embodiment can improve folding characteristics and folding reliability.

[0139] According to embodiments, the invention will be described in more detail below by measuring the yield strength, elastic modulus, and elastic coefficient based on the rolling direction of the roll of the elastic member and the perpendicular direction of the elastic member according to the embodiments. These embodiments are merely examples for describing the invention in more detail. Therefore, the invention is not limited to these embodiments.

[0140] Example 1

[0141] The cold rolling process is performed by passing the SUS 301EH between two rolls.

[0142] Then, the yield strength, elastic modulus, and elastic coefficient of SUS 301EH in the rolling direction RD and the vertical direction TD were measured.

[0143] Example 2

[0144] After performing the cold rolling process in the same manner as in Example 1, except that SUS 301FH is used, the yield strength, elastic modulus and elastic coefficient of SUS301EH in the rolling direction RD and the vertical direction TD are measured.

[0145] Example 3

[0146] After performing the cold rolling process in the same manner as in Example 1, except that SUS 316HN1 was used, the yield strength, elastic modulus and elastic coefficient of SUS301EH in the rolling direction RD and the vertical direction TD of the roll were measured.

[0147] Example 4

[0148] After performing the cold rolling process in the same manner as in Example 1, except that SUS 316L is used, the yield strength, elastic modulus and elastic coefficient of SUS301EH in the rolling direction RD and the vertical direction TD are measured.

[0149] Example 5

[0150] After performing the cold rolling process in the same manner as in Example 1, except that nickel silver was used, the yield strength, elastic modulus and elastic coefficient of the SUS301EH in the rolling direction RD and the vertical direction TD of the roll were measured.

[0151] [Table 1]

[0152]

[0153] Referring to Table 1, it can be seen that the elastic members according to Examples 1 to 1 have different yield strengths, elastic moduli and elastic coefficients depending on the pressing direction of the roller, i.e. the rolling direction RD and the vertical direction TD.

[0154] In other words, the yield strength of the elastic member according to Examples 1 to 5 can have similar dimensions in the rolling direction RD and the vertical direction TD of the roll.

[0155] Furthermore, it can be seen that the elastic modulus according to Examples 1 to 5 is smaller in the rolling direction RD of the roll than in the vertical direction TD.

[0156] Furthermore, it can be seen that the elasticity coefficients according to Examples 1 to 5 are larger in the rolling direction RD of the roll than in the vertical direction TD.

[0157] In other words, it can be seen that the elastic coefficient calculated from the yield strength and elastic modulus is larger in the rolling direction RD of the roll with a smaller elastic modulus than in the vertical direction TD.

[0158] Therefore, if the rolling surface of the elastic member roll remains larger than the vertical surface after the patterned portion of the elastic member is formed, the elastic member can withstand the stress generated when the elastic member is folded for a longer period of time. Thus, it can be seen that the occurrence of plastic deformation can be minimized.

[0159] At the same time, refer to Figure 10 According to another embodiment, the elastic member may further include a second patterned portion PA2 disposed in the second region 2A.

[0160] The second pattern part PA2 can be formed into a hole shape or a groove shape.

[0161] In detail, the second patterned part PA2 can be formed as a hole through the first surface 1S and the second surface 2S of the elastic member, or it can be formed as a groove in the first surface 1S or the second surface 2S.

[0162] The second patterned portion PA2, located in the second region 2A, can maintain similar physical properties to the first region 1A and the second region 2B. The second patterned portion PA2 is the region where the elastic member 100 does not fold.

[0163] In detail, the deformation difference caused by heat from the first region 1A where the first patterned portion PA1 is provided can be mitigated by the second patterned portion PA1. That is, when heat is applied to the elastic member 100, the deformation difference caused by heat in the first region 1A and the second region 2A can be mitigated by forming a patterned portion in both the first region 1A and the second region 2A. Therefore, bending or twisting of the elastic member 100 can be prevented.

[0164] Furthermore, by forming the second pattern portion PA2 in the second region 2A, the stress unevenness between the first region 1A and the second region 2A can be alleviated, thereby preventing the bending of the elastic member 100.

[0165] When the panel or the like is joined by the adhesive layer on the elastic member 100, the adhesive material is provided together with the second pattern portion PA2 formed in the second region 2A and fills the interior of the first pattern portion PA1 of the second region 2A and the second pattern portion PA2 of the second region 2A, thereby preventing the adhesive layer from forming a step between the first region and the second region.

[0166] The second pattern portion PA2 can be formed in the same or similar shape as the first pattern portion PA1. In detail, the second pattern portion PA2 is formed in a shape having a long direction and a short direction, the long direction of the second pattern portion and the long direction of the first pattern portion PA1 extend in the same or similar directions, and the short direction of the second pattern portion and the short direction of the first pattern portion PA1 can extend in the same or similar directions.

[0167] Therefore, in the second region 2A, the length direction of the second patterned portion may be different from the length direction of the surface rough portion, so that after the second patterned portion is formed, the residual area of ​​the elastic member remaining in the second region may have more of the rolling direction of the roll compared to the vertical direction.

[0168] Therefore, when the elastic member 100 is folded, plastic deformation can be prevented from occurring in the second region.

[0169] Furthermore, by making the long and short directions of the patterned portions in the first and second regions the same or similar to each other, the difference in elastic coefficients between the first and second regions can be minimized. Therefore, when the elastic member is folded, the bending or deformation of the elastic member caused by the difference in elastic coefficients can be minimized.

[0170] The following will refer to Figures 11 to 14 Various embodiments of elastic members formed by a single layer or multiple layers are described.

[0171] Figures 11 to 14 These are cross-sectional views of the layered structure of each elastic member according to the embodiment.

[0172] refer to Figure 11 The elastic member 100 can be formed as a single layer. More specifically, the elastic member can be formed from a single layer containing the aforementioned metallic material.

[0173] Furthermore, the first patterned portion PA1 and the second patterned portion PA2 can be formed to pass through the elastic member 100.

[0174] refer to Figures 12 to 14The elastic member 100 can be formed in multiple layers.

[0175] refer to Figure 12 The elastic member 100 may include a first layer 110 and a second layer 120. The first layer 110 and the second layer 120 may be bonded to each other by an adhesive layer 50.

[0176] The first layer 110 and the second layer 120 may contain different materials. For example, the first layer 110 may have a higher yield strength than the second layer 120, and the second layer 120 may have a higher thermal conductivity than the first layer 110.

[0177] For example, the first layer 110 may contain stainless steel (SUS), and the second layer 120 may contain copper. Therefore, the second layer 120 can be used as a heat dissipation layer.

[0178] Furthermore, the first layer 110 and the second layer 120 can be formed to have different thicknesses. For example, the thickness of the first layer 110 can be greater than the thickness of the second layer 120.

[0179] The first pattern portion PA1 and the second pattern portion PA2 can be formed on the first layer 110. That is, the first pattern portion PA1 and the second pattern portion PA2 can pass through the first layer 110.

[0180] refer to Figure 13 The elastic member 100 may include a first layer 110 and a second layer 120. The first layer 110 and the second layer 120 may be configured to be in direct contact with each other. For example, the first layer 110 and the second layer 120 may be manufactured in a clad manner so that they are in direct contact with each other.

[0181] The first layer 110 and the second layer 120 may contain different materials. For example, the first layer 110 may have a higher yield strength than the second layer 120, and the second layer 110 may have a higher thermal conductivity than the first layer 110.

[0182] For example, the first layer 110 may contain stainless steel (SUS), and the second layer 120 may contain copper. Therefore, the second layer 120 can be used as a heat dissipation layer.

[0183] Furthermore, the first layer 110 and the second layer 120 can be formed to have different thicknesses. For example, the thickness of the first layer 110 can be less than the thickness of the second layer 120.

[0184] The first pattern portion PA1 and the second pattern portion PA2 can be formed on the second layer 120. That is, the first pattern portion PA1 and the second pattern portion PA2 can be formed to pass through the second layer 120.

[0185] refer to Figure 14The elastic member 100 may include a first layer 110, a second layer 120, and a third layer 130. The first layer 110, the second layer 120, and the third layer 130 are configured to be in direct contact with each other. For example, the first layer 110, the second layer 120, and the third layer 130 may be manufactured in an overlay manner so that they are in direct contact with each other.

[0186] The first layer 110 may contain a material different from that of the second layer 120 and the third layer 130. For example, the first layer 110 may have a higher yield strength than the second layer 120 and the third layer 130, and the second layer 110 and the second layer 130 may have higher thermal conductivity than the first layer 110.

[0187] For example, the first layer 110 may contain stainless steel (SUS), and the second layer 120 and the third layer 130 may contain copper. Therefore, the second layer 120 and the third layer 130 can be used as heat dissipation layers.

[0188] Furthermore, the first layer 110 can be formed to have a thickness different from that of the second layer 120 and the third layer 130. For example, the thickness of the first layer 110 can be less than the thickness of the second layer 120 and the third layer 130.

[0189] The first pattern portion PA1 and the second pattern portion PA2 can be formed on the second layer 120 and the third layer 130. That is, the first pattern portion PA1 and the second pattern portion PA2 can be formed to pass through the second layer 120 and the third layer 130.

[0190] Figure 15 This is a view used to illustrate an example of applying an elastic member according to an embodiment.

[0191] refer to Figure 15 The elastic member according to the embodiment can be applied to a flexible or foldable display device for displaying content.

[0192] For example, the elastic member according to the embodiment can be applied to flexible display devices for mobile phones and tablet computers.

[0193] This elastic component can be applied to flexible, bendable, or foldable flexible display devices such as mobile phones and tablets.

[0194] Elastic components can be applied to flexible, bendable, or foldable flexible display devices such as mobile phones or tablets, and can improve the reliability of flexible display devices by increasing the folding reliability of display devices that are repeatedly folded or restored.

[0195] The features, structures, and effects described in the above embodiments are included in at least one embodiment, but are not limited to one embodiment. Furthermore, those skilled in the art can combine or modify the features, structures, and effects shown in each embodiment for other embodiments. Therefore, it should be understood that anything related to such combinations and modifications is included within the scope of this invention.

[0196] Furthermore, while the foregoing has primarily described embodiments, these embodiments are merely examples and do not limit the scope of the embodiments. Those skilled in the art will understand that numerous variations and applications not given above can be made without departing from the essential characteristics of the embodiments. For example, each component specifically illustrated in the embodiments can be modified and implemented. Moreover, it should be understood that differences relating to such variations and applications are included within the scope of the invention as defined in the appended claims.

Claims

1. An elastic member applied to a display device, said elastic member comprising a first region and a second region, in, The elastic member can be folded relative to the folding axis. The elastic member includes a surface roughness portion having a length direction. The first region is defined as the folded region, and the second region is defined as the unfolded region. Specifically, a first pattern portion having a longitudinal direction and a short direction is formed in the first region of the elastic member. Wherein, the longitudinal direction of the first patterned portion is the same as the extension direction of the folding axis and different from the longitudinal direction of the surface rough portion. The elastic member is made of rolled metal. In the rolling process of the rolled metal, the length direction of the surface rough portion is set to be equal to or close to the rolling direction of the rolled metal, and The first patterned portion is formed in the shape of a hole or a groove.

2. The elastic member according to claim 1, wherein, The length direction of the surface roughness is defined as the direction of a virtual line connecting the start and end points of the surface roughness.

3. The elastic member according to claim 1, wherein, The surface roughness includes multiple directions. The length direction of the rough surface portion is defined as the average direction of the plurality of directions.

4. The elastic member according to claim 1, wherein, The longitudinal direction of the first patterned portion and the longitudinal direction of the surface rough portion are not parallel.

5. The elastic member according to claim 1, wherein, The long direction and the short direction are perpendicular to each other.

6. The elastic member according to claim 1, wherein, The angle between the longitudinal direction of the first patterned portion and the longitudinal direction of the surface rough portion is 50° to 130°.

7. The elastic member according to claim 1, wherein, The angle between the longitudinal direction of the first patterned portion and the longitudinal direction of the surface rough portion is 50° to 90°.

8. The elastic member according to claim 1, wherein, The angle between the longitudinal direction of the first patterned portion and the longitudinal direction of the surface rough portion is 90° to 130°.

9. The elastic member according to claim 1, wherein, The angle between the folding axis direction of the elastic member and the length direction of the surface roughness is 50° to 130°.

10. The elastic member according to claim 1, wherein, The elastic member includes a first direction approaching the length direction of the rough surface portion and a second direction approaching the length direction of the first patterned portion. Wherein, the elastic modulus of the elastic member in the first direction is less than the elastic modulus in the second direction.

11. The elastic member according to claim 10, wherein, The elastic coefficient of the elastic member in the first direction is greater than the elastic coefficient in the second direction.

12. The elastic member according to claim 1, further comprising a second patterned portion disposed in the second region. in, The longitudinal direction of the second patterned portion corresponds to the longitudinal direction of the first patterned portion.

13. The elastic member according to claim 1, wherein, The elastic member comprises a first layer and a second layer. The first pattern portion is formed on the first layer.

14. The elastic member according to claim 13, further comprising an adhesive layer disposed between the first layer and the second layer.

15. The elastic member according to claim 13, wherein, The second layer is disposed in the second area.

16. The elastic member according to claim 14, wherein, The adhesive layer is disposed in the second region.

17. The elastic member according to claim 1, wherein, The elastic member comprises a first layer, a second layer, and a third layer. The first layer is disposed between the second layer and the third layer. The first pattern portion is disposed on the second layer and the third layer.

18. A display device, comprising: The elastic member according to claim 1; as well as A panel, the panel being disposed on the elastic member and including at least one of a display panel and a touch panel.

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