A cover plate for flexible display and foldable display device

Abstract

The present disclosure provides a cover plate for flexible display and a foldable display device, wherein the cover plate comprises: a first impact-resistant layer having a first thickness; a second impact-resistant layer having a second thickness; a first bonding layer, wherein the first impact-resistant layer and the second impact-resistant layer are bonded to each other through the first bonding layer; and the first thickness is greater than the second thickness. The present disclosure stacks impact-resistant layers of different thicknesses, uses the thicker first impact-resistant layer to improve the impact strength of the cover plate, and uses the thinner second impact-resistant layer to achieve the bending function of the cover plate, so that the cover plate has better performance and is suitable for the production of more diverse electronic devices.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a cover plate for flexible display and a foldable display device. Background Art

[0002] As people's demand for the use of electronic devices increases, foldable electronic devices are purchased and used by more and more users. The foldable display panel that realizes the folding display function of the device and the cover for flexible display are the core display components in foldable devices.

[0003] In fact, when the glass thickness reaches below 100 microns (μm), the flexibility of the glass is revealed. Compared with polymer materials, glass materials have a higher Young's modulus and are better than polymer materials in deformation recovery after bending. When it is used as a display cover for folding screens, it can significantly improve the crease problem of folding displays. However, in order to ensure that the folding display has good bending performance, the thickness of the glass must be very thin. The thickness of the ultra-thin glass that is currently used is basically 30 to 70μm. When the glass thickness reaches 70μm or less, the impact strength of the glass is extremely weak, that is, the impact strength and bending performance of the glass cannot be taken into account at the same time. Summary of the invention

[0004] The purpose of the embodiments of the present disclosure is to provide a cover plate for flexible display and a foldable display device, so as to solve the problem in the prior art that the impact resistance and bending performance of glass cannot be taken into account at the same time when glass is used as a display cover plate.

[0005] The embodiments of the present disclosure adopt the following technical solution: a cover plate for a flexible display, comprising: a first impact-resistant layer having a first thickness; a second impact-resistant layer having a second thickness; a first bonding layer, the first impact-resistant layer and the second impact-resistant layer being bonded to each other through the first bonding layer; the first thickness is greater than the second thickness.

[0006] In some embodiments, the first bonding layer is an optical adhesive layer.

[0007] In some embodiments, the thickness of the optical adhesive layer is between 20 micrometers and 30 micrometers.

[0008] In some embodiments, the first impact-resistant layer includes a first glass structure and a second glass structure that are symmetrically disposed, with a gap region between the first glass structure and the second glass structure.

[0009] In some embodiments, the width of the gap region is between 20 and 40 mm.

[0010] In some embodiments, the invention further includes: a first flattening layer, wherein the first flattening layer covers surfaces of the first glass structure and the second glass structure on a side away from the second impact-resistant layer, and the thickness of the first flattening layer is between 10 and 30 microns.

[0011] In some embodiments, the first planarization layer is further used to fill the gap region, and the thickness of the first planarization layer in the gap region also includes the first thickness.

[0012] In some embodiments, the second impact-resistant layer includes a third glass structure.

[0013] In some embodiments, the orthographic projection of the third glass structure perpendicular to the thickness of the cover plate at least completely covers the orthographic projection of the gap area perpendicular to the thickness of the cover plate; the orthographic projection of the third glass structure perpendicular to the thickness of the cover plate and the orthographic projection of the first glass structure perpendicular to the thickness of the cover plate have a first bonding area between them, and the orthographic projection of the third glass structure perpendicular to the thickness of the cover plate and the orthographic projection of the second glass structure perpendicular to the thickness of the cover plate have a second bonding area between them.

[0014] In some embodiments, the widths of the first bonding area and the second bonding area are the same and are both greater than or equal to 20 mm.

[0015] In some embodiments, the invention further includes: a second flattening layer, wherein the second flattening layer at least covers a surface of the third glass structure that is away from the first impact-resistant layer, and the thickness of the second flattening layer is between 10 and 30 micrometers.

[0016] In some embodiments, the second planarizing layer is also used to cover unbonded areas of the first and second glass structures on the surface close to the third glass structure that are not covered by the third glass structure, and the thickness of the second planarizing layer in the unbonded areas also includes the second thickness.

[0017] In some embodiments, the first planarizing layer and the second planarizing layer are made of an optically clear resin material.

[0018] In some embodiments, the refractive index of the first planarizing layer and the second planarizing layer is between 1.5 and 1.52.

[0019] In some embodiments, the first thickness is at least three times the second thickness.

[0020] In some embodiments, the first thickness has a value greater than 100 microns.

[0021] In some embodiments, the first thickness has a value between 100 microns and 200 microns.

[0022] In some embodiments, the second thickness has a value less than 50 microns.

[0023] In some embodiments, the second thickness has a value between 30 microns and 40 microns.

[0024] An embodiment of the present disclosure further provides a foldable display device, comprising: a display panel; and a cover plate as claimed in any one of claims 1 to 19, wherein the cover plate is located on a light emitting side of the display panel.

[0025] In some embodiments, the display panel includes at least a folding area and a non-folding area; the orthographic projection of the non-folding area at a direction perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the first glass structure and the second glass structure at a direction perpendicular to the thickness of the display device; the orthographic projection of the folding area at a direction perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the gap area at a direction perpendicular to the thickness of the display device; wherein the first glass structure and the second glass structure are symmetrically arranged as the first impact-resistant layer, and the gap area is the gap between the first glass structure and the second glass structure.

[0026] In some embodiments, it also includes: a support layer located on the side of the display panel away from the cover plate; the support layer includes at least a pattern area and a non-pattern area, wherein the orthographic projection of the pattern area at right angles to the thickness of the display device completely overlaps with the orthographic projection of the folding area at right angles to the thickness of the display device; the orthographic projection of the non-pattern area at right angles to the thickness of the display device completely overlaps with the orthographic projection of the non-folding area at right angles to the thickness of the display device; the pattern of the pattern area is used to provide support to the folding area when the folding area is in a bent state.

[0027] In some embodiments, the support layer is made of a metal material.

[0028] In some embodiments, the thickness of the support layer is greater than or equal to 100 microns.

[0029] In some embodiments, the invention further includes: a hardening layer located on a side of the cover plate away from the display panel.

[0030] In some embodiments, the material of the hardening layer is acrylate.

[0031] The beneficial effect of the embodiment of the present disclosure is that by stacking impact-resistant layers of different thicknesses, the impact resistance of the cover plate is improved by using the thicker first impact-resistant layer, and the bending function of the cover plate is realized by using the thinner second impact-resistant layer, so that the cover plate has better performance and is suitable for the production of more diverse electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 is a schematic diagram of the cross-sectional structure of a cover plate for flexible display in the first embodiment of the present disclosure;

[0034] Figure 2 is another schematic cross-sectional structure diagram of a cover plate for a flexible display in the first embodiment of the present disclosure;

[0035] Figure 3 is a cross-sectional schematic diagram of a foldable display device in a second embodiment of the present disclosure;

[0036] Figure 4 A schematic diagram of pattern arrangement of the pattern area in the second embodiment of the present disclosure;

[0037] Figure 5 is another cross-sectional schematic diagram of a foldable display device in the second embodiment of the present disclosure;

[0038] Figure 6 FIG. 4 is another cross-sectional schematic diagram of a foldable display device in the second embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] Various aspects and features of the present disclosure are described herein with reference to the drawings.

[0040] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present disclosure will occur to those skilled in the art.

[0041] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0042] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the attached drawings.

[0043] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the features of the claims and are therefore within the scope of protection defined thereby.

[0044] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0045] Specific embodiments of the present disclosure are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments claimed are merely examples of the present disclosure, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any suitable detailed structure.

[0046] This specification may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0047] As people's demand for the use of electronic devices increases, foldable screen mobile phones and foldable screen computers are purchased and used by more and more users, and the folding cover that realizes the folding display function of the device is the core display component in the foldable device.

[0048] In fact, when the glass thickness reaches below 100 microns (μm), the flexibility of the glass is revealed. Compared with polymer materials, glass materials have a higher Young's modulus and are better than polymer materials in deformation recovery after bending. When it is used as a display cover for folding screens, it can significantly improve the crease problem of folding displays. However, in order to ensure that the folding display has good bending performance, the thickness of the glass must be very thin. The thickness of the ultra-thin glass that is currently used is basically 30 to 70μm. When the glass thickness reaches 70μm or less, the impact strength of the glass is extremely weak, that is, the impact strength and bending performance of the glass cannot be taken into account at the same time.

[0049] In the prior art, it is possible to simultaneously meet the impact resistance and bending performance by manufacturing a panel with different thicknesses, for example, the panel at the bending part is made thinner to facilitate bending. However, for such panels with different thicknesses in different regions, when performing the strengthening operation, the specific strengthening operation and the degree of strengthening cannot achieve the optimal strengthening performance in each region, which may easily lead to excessive strengthening or strengthening failure in some regions, affecting the performance of the display cover. At the same time, the production of panels with different thicknesses will increase the manufacturing cost, which is not conducive to mass production.

[0050] In order to solve the above problems, the first embodiment of the present disclosure provides a cover plate for a flexible display, and a schematic cross-sectional structure thereof is shown in FIG. Figure 1 As shown, two impact-resistant layers of different thicknesses are stacked to achieve the bending function of the cover plate while ensuring the impact resistance of the plate. Figure 1 As shown, the cover plate 100 mainly includes a first impact-resistant layer 10 with a first thickness and a second impact-resistant layer 20 with a second thickness. Both impact-resistant layers have a certain impact resistance and can protect the panel when used as a cover plate of the display panel.

[0051] In this embodiment, the first thickness of the first impact-resistant layer 10 is greater than the second thickness of the second impact-resistant layer 20, so that the first impact-resistant layer 10 has better impact resistance and the second impact-resistant layer 20 has better bending ability. The cover plate formed by stacking the two can be used in flexible display panels while improving the overall strength of the cover plate, so that the cover plate has better performance and is suitable for the production of more diverse electronic devices.

[0052] The first impact-resistant layer 10 and the second impact-resistant layer 20 are bonded and fixed by the first bonding layer 30 to achieve the fixing effect between the two impact-resistant layers. In some embodiments, the first bonding layer 30 is an optical adhesive (OCA, Optically Clear Adhesive) layer with good optical properties, and its thickness is limited by the existing process level, usually between 20 and 30 microns, generally about 25 microns. If the process allows, the thickness of the first bonding layer 30 is as thin as possible.

[0053] In some embodiments, Figure 1 As shown, the first impact-resistant layer 10 includes a first glass structure 11 and a second glass structure 12 that are symmetrically arranged. Generally, the first glass structure 11 and the second glass structure 12 are two pieces of glass with completely identical sizes, which are arranged in the same layer and have a certain gap area 13 (such as Figure 1The first glass structure 11 and the second glass structure 12 are located in the same area as the second impact-resistant layer 20, and the first glass structure 11 and the second glass structure 12 are located in the same area as the second impact-resistant layer 20. ...

[0054] It should be understood that the bending radius of the bendable part of the folding device is usually within 5 mm, and the arc length required for bending does not exceed 20 mm. Therefore, the width of the bending zone is not less than 20 mm. In this embodiment, in order to make the bending area of ​​the cover plate have higher strength, the width of the bending zone is limited to between 20 and 40 mm. Therefore, the width of the gap area 13 corresponds to 20 to 40 mm, which can be adjusted within the above range according to actual needs.

[0055] like Figure 2 As shown, the second impact-resistant layer 20 includes a third glass structure, which has a thinner thickness and better bending properties than the first glass structure 11 and the second glass structure 12. As the bending part of the cover plate, it cooperates with the flexible display panel, that is, it can be used as a foldable display component in various electronic devices. Specifically, the third glass structure is perpendicular to the thickness of the cover plate (i.e. Figure 1 The orthographic projection of the gap area 13 in the direction perpendicular to the cover plate thickness at least completely covers the orthographic projection of the gap area 13, so as to meet the requirement that the third glass structure can be bent at the position corresponding to the gap area 13 as the bendable part.

[0056] At the same time, the orthographic projection of the third glass structure perpendicular to the thickness of the cover plate also overlaps with the orthographic projections of the first glass structure 11 and the second glass structure 12 perpendicular to the thickness of the cover plate, forming a first bonding area 111 and a second bonding area 121 (such as Figure 1 In the figure, the third glass structure is fixed to the first glass structure 11 and the second glass structure 12 at positions corresponding to the first bonding area 111 and the second bonding area 121 through the first bonding layer 30. It should be understood that, in general, the first bonding area 111 and the second bonding area 121 have the same size, that is, the bonding area between the third glass structure and the first glass structure 11 and the bonding area between the third glass structure and the second glass structure 12 are the same, so as to ensure the consistency of the bonding strength on both sides. When actually bonding, it can also be adjusted according to the size of the first glass structure 11 and the second glass structure 12 and actual needs, and this embodiment does not limit this.

[0057] To ensure firm bonding, in this embodiment, the widths of the first bonding area 111 and the second bonding area 121 are both set at 20 mm or above, and the widths of the first bonding area 111 and the second bonding area 121 may be further limited to between 20 and 40 mm. Figure 2 Another structural schematic diagram of the cover plate is shown. Figure 1 The difference is that the third glass structure completely covers the first glass structure 11, the second glass structure 12 and the gap area 13. At this time, there are two layers of glass structure in the non-bending area, which further improves the strength of the area and makes it have better impact resistance. However, the thinner the glass, the higher the production cost. Figure 1 The scheme shown, Figure 2 The solution requires a third glass structure with a larger area, and its production cost will increase accordingly. Therefore, the specific structure used to make the cover plate can be set according to actual needs, and this embodiment does not limit it.

[0058] Furthermore, the cover plate further includes a first flattening layer 40, which is mainly arranged on the surface of the first glass structure 11 and the second glass structure 12 away from the second impact-resistant layer 20 (ie Figure 1 The first glass structure 11 and the second glass structure 12 are used to level the surface of the first impact-resistant layer 10 and further improve its impact resistance. In this embodiment, the thickness of the first leveling layer 40 is set between 10 and 30 microns, and is generally set to 20 microns. At the same time, in order to achieve a leveling effect, the gap area 13 is also filled with the first leveling layer 40, and it is necessary to ensure that the surface of the first leveling layer 40 in the gap area 13 is on the same plane as the surface of the first leveling layer 40 on the first glass structure 11 and the second glass structure 12 to achieve a good leveling effect. Therefore, in the gap area 13, the thickness of the first leveling layer also needs to include the first thickness of the first impact-resistant layer 10, and increase it by 10 to 30 microns.

[0059] Accordingly, the cover plate further includes a second flat layer 50, which at least covers the surface of the third glass structure away from the first impact-resistant layer 10 (ie Figure 1 The second flattening layer 50 is used to cover the surface of the first glass structure 11 and the second glass structure 12 on the side close to the third glass structure (i.e., the lower surface of the third glass structure in the middle). The thickness of the second flattening layer 50 is the same as that of the first flattening layer 40. It flattens the surface and strengthens the second impact-resistant layer 20. At the same time, in order to achieve a flattening effect, the second flattening layer 50 is also used to cover the surface of the first glass structure 11 and the second glass structure 12 on the side close to the third glass structure (i.e., Figure 1 The unbonded area (i.e., the lower surface of the first glass structure 11 and the second glass structure 12) not covered by the third glass structure Figure 1In order to ensure the flatness of the plane, the thickness of the second smoothing layer 50 in the unbonded area is increased by 10 to 30 microns on the basis of the second thickness of the second impact-resistant layer 20, so that the surface of the second smoothing layer 50 on the third glass structure and the surface of the unbonded area are on the same plane.

[0060] In some embodiments, the first flat layer 40 and the second flat layer 50 can be made of an optically clear resin material (OCR), which has good optical properties and ductility. When the second impact-resistant layer 20 is bent, the flat layer at the corresponding position can be deformed accordingly to play a protective role. Furthermore, the refractive index of the flat layer is preferably ensured to be the same as the refractive index of the glass structure to ensure that the optical effect of the light passing through the glass structure is the same as the effect when passing through the flat layer. In some embodiments, the refractive index of the flat layer is between 1.5 and 1.52, typically 1.515. In some embodiments, the main components of the optically clear resin are polyester polyurethane, 1-10 parts by mass of aromatic polyether polyurethane, 50-80 parts by mass of dimethylformamide, 10-20 parts by mass of butyl acetate, and 0.1-5 parts by mass of adhesion promoter, and the mass ratio of the above components is 9:8:65:15:3.

[0061] When the first impact-resistant layer 10 and the second impact-resistant layer 20 are actually manufactured, the first thickness can be limited to at least three times the second thickness, so that the first impact-resistant layer 10 has a good impact resistance effect and the second impact-resistant layer 20 has a good bending function.

[0062] Specifically, the value of the first thickness can be limited to be greater than 100 microns. In the present embodiment, it can be preferably set between 100 microns and 200 microns. Generally speaking, panels less than 100 microns have lower strength and poorer impact resistance. When a glass structure with a thickness exceeding 200 microns is used, it is necessary to fill the gap area 13 with more than 200 microns of OCR material to ensure the flatness of the panel. At this time, the thickness of the OCR glue layer is too high, which can easily affect the light emission effect on the cover plate.

[0063] In order to ensure the bending function of the second impact-resistant layer 20, the second thickness is generally limited to less than 50 microns. In the present embodiment, it is preferably set to between 30 and 40 microns. Generally speaking, when the thickness of the glass structure is less than 30 microns, its impact resistance will be significantly reduced, seriously affecting the actual service life of the cover. If the thickness of the glass structure is greater than 40 microns, the bending performance of the second impact-resistant layer 20 will be reduced. Therefore, setting it between 30 and 40 microns can ensure a certain panel strength while satisfying the bending effect, thereby making the cover performance better.

[0064] The panels of the first impact-resistant layer 10 and the second impact-resistant layer 20 used in this embodiment are both ultra-thin glass panels that have been chemically strengthened, and different degrees of strengthening are performed on glass panels of different thicknesses to achieve their optimal strengthening performance as shown in Table 1:

[0065] Table 1

[0066]

[0067] Among them, CS is the surface compressive stress, DOL is the stress layer depth, and CT is the central tensile stress, which are all parameters indicating the strengthening performance of the glass panel. When the parameter performance of the glass panels of different thicknesses is consistent with the parameter values ​​of each performance shown in Table 1 or is within the range described therein, it is proved that its strengthening performance reaches the optimal level.

[0068] For this embodiment, the first impact-resistant layer 10 and the second impact-resistant layer 20 are made of independent panels of different thicknesses. During the strengthening process, they can also be strengthened separately with reference to the selected thicknesses, so that each part is in the optimal state. Then, through stacking, the thicker first impact-resistant layer 10 is used to improve the impact strength of the display cover plate, and the thinner second impact-resistant layer 20 is used to achieve the bending function of the display cover plate, so that the cover plate has better performance and is suitable for the production of more diverse electronic devices. At the same time, the production cost of the first impact-resistant layer 10 is lower. Compared with the prior art that uses ultra-thin glass panels of about 30 to 40 microns as raw materials for the production of flexible display cover plates, the disclosed embodiment can further save production costs and improve production efficiency.

[0069] A second embodiment of the present disclosure provides a foldable display device, a cross-sectional schematic diagram of the display device is shown in FIG. Figure 3 As shown, it at least includes a display panel 200 and a cover plate 100, wherein the cover plate 100 is located on the light-emitting side of the display panel 200 and is mainly used to protect the display panel. In this embodiment, the display panel 200 is a flexible panel that can be bent under the action of an external force, and is preferably an OLED panel. The cover plate 100 uses the cover plate structure disclosed in the first embodiment of the present disclosure, and by setting two impact-resistant layers of different thicknesses, the impact resistance of the cover plate is ensured while the display panel 200 is bent, so as to protect the display panel 200.

[0070] Specifically, Figure 3As shown, the display panel 200 at least includes a folding area 201 and a non-folding area 202, wherein the folding area 201 is an area that is bent under the action of an external force, and its orthographic projection in the direction perpendicular to the thickness of the display device is completely coincident with the orthographic projection of the gap area in the cover plate 100 in the direction perpendicular to the thickness of the display device, so as to achieve simultaneous bending of the cover plate 100 and the display panel 200 under the action of an external force; the orthographic projection of the non-folding area 202 in the direction perpendicular to the thickness of the display device is completely coincident with the orthographic projection of the first glass structure and the second glass structure in the cover plate 100 in the direction perpendicular to the thickness of the display device. Since the first glass structure and the second glass structure are rigid structures, even if the non-folding area of ​​the display panel 200 is also a flexible panel, it will not be deformed by external force after being arranged at corresponding positions of the first glass structure and the second glass structure, thereby forming a rigid panel area. Among them, the first glass structure and the second glass structure are symmetrically arranged as the first impact-resistant layer in the cover plate 100, and there is a gap area between the two to facilitate the second impact-resistant layer to achieve the bending effect of the cover plate. The first impact-resistant layer has a higher thickness and better strength, and is mainly used to achieve the protection of the display panel 200.

[0071] Figure 3 The display device shown is provided on a side of the display panel 200 away from the cover plate 100 (i.e. Figure 3 A support layer 300 is also provided on the bottom side of the display panel 200 to support and protect the flexible display panel 200. It is usually made of metal material, which not only provides strong support performance, but also has better heat dissipation performance, which is conducive to the display panel 200 dissipating the heat generated when displaying the picture, and preventing the display panel 200 from being overheated and causing wiring burns and other problems that affect the display effect. In some embodiments, the support layer 300 can be made of stainless steel material, or other metal materials with strong support performance and heat dissipation performance, which is not limited in this embodiment.

[0072] Furthermore, the support layer 300 is specifically divided into a pattern area 301 and a non-pattern area 302, wherein the orthographic projection of the pattern area 301 perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the folding area 201 perpendicular to the thickness of the display device, and the orthographic projection of the non-pattern area 302 perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the non-folding area 202 perpendicular to the thickness of the display device. In actual use, since the main function of the support layer 300 is to support the display panel 200, for the non-folding area 202, since it will not deform, the corresponding support layer 300 only needs to set a rigid structural layer with good supporting performance, and its surface does not need to be set with additional patterns; while for the folding area 201, it will bend under the action of external force, and the corresponding area of ​​the support layer 300 needs to deform together with the display panel 200. Usually, the materials selected for the support layer 300 are all high-strength metal materials with poor bending performance. It can affect the use of the display panel 200. If the supporting layer 300 is not provided here, the strength of the display device may be reduced, and it may be inconvenient to connect other structures in the device. Therefore, in this embodiment, a pattern area 301 is provided at the supporting layer 300 corresponding to the folding area 201, and a hollow pattern is made at the corresponding position to reduce the stress in the area, so that the supporting layer has better bending performance in the area, which is convenient for changing with the display panel 200. At the same time, the folding area 201 can also support the folding area when it is in a bent state, thereby achieving the purpose of improving the overall strength of the display device.

[0073] It should be noted that Figure 4 A schematic diagram of the setting of a specific pattern of the pattern area 301 is shown, which improves the bending performance of the support layer 300 in the area by setting a hollow area. Of course, in actual use, the pattern of the pattern area 301 can also be set to other shapes as long as the same effect can be achieved. This embodiment does not limit the specific pattern.

[0074] Figure 5 Another cross-sectional structural schematic diagram of a foldable display device is shown. Figure 5 As shown, in Figure 3 On the basis of FIG. 1 , other functional levels required for manufacturing the display device are also shown, for example, on the side of the cover plate 100 away from the display panel 200 (i.e. Figure 5 A hard coating 400 is also provided on one side of the top surface of the middle cover plate 100, which is mainly used to further reinforce the cover plate 100 to improve the overall strength of the display device. The material used to make it is mainly acrylic, which increases the strength of the display device while also improving its heat and cold resistance, making the display device suitable for use in harsher environments.

[0075] Figure 5 The hardening layer 400 further includes a side away from the cover plate 100 (ie Figure 5 The anti-fingerprint layer 500 (on the top side of the hardening layer 400) is usually made of perfluoropolyether material, which can prevent users from leaving fingerprints on the display device when using an electronic device with the display device, affecting the overall display effect. In addition, a polarizer layer 210 is also arranged between the display panel 200 and the cover plate 100, which is mainly used to realize the modulation of the light output by the display panel 200, and it can also be integrated with the OLED panel as a hierarchical structure of the display panel 200; an optical adhesive layer 600 is also arranged between the polarizer layer 210 and the cover plate 100, which is used to fix the connection between the cover plate 100 and the display panel 200, and also ensures good optical performance; a foam layer 700 is also arranged between the display panel 200 and the support layer 300, which can prevent the rigid support layer 300 from being directly connected to the display panel 200 to cause damage to the flexible panel, and can play a certain degree of buffering role to further protect the display panel 200.

[0076] It should be noted that Figure 5 The anti-fingerprint layer 500, polarizer layer 210, optical adhesive layer 600, and foam layer 700 shown in the figure can be directly set using the setting scheme in the prior art, and other layers can be added according to actual needs to realize other functions of the display device, such as a touch layer, a pressure sensing layer, etc. This embodiment does not impose specific restrictions. When the above-mentioned layers are produced, the thickness of the layers can be based on the process level, and the layered structure can be made as thin as possible to reduce the volume and weight of the display device. For example, the anti-fingerprint layer 500 is set to 0.01 microns, the hardening layer 400 is set to 10 microns, the optical adhesive layer 600 is set between 20 and 30 microns, the polarizer layer 210 is set to 50 microns, the display panel 200 is 50 microns, and the foam layer 700 is 50 microns; however, it should be emphasized that in order to ensure the supporting performance of the supporting layer 300, its thickness should not be too low. In this embodiment, it is preferably set to 100 microns or other thicknesses above 100 microns. The specific thickness selection can be made according to the manufacturing material and the size or support requirements of the display device, which will not be described in detail in this embodiment.

[0077] in addition, Figure 5 The structure of the cover plate of the corresponding display device is Figure 1 same, Figure 6 It shows the use of Figure 2 The structure diagram of the display device formed by the cover plate shown in FIG. Figure 5 In comparison, except for the different cover plate structure, it is the same as the hierarchical structure and will not be repeated here.

[0078] In this embodiment, a cover plate structure is formed by using two impact-resistant layers of different thicknesses. The impact resistance of the cover plate is ensured while cooperating with the display panel to bend, thereby protecting the display panel. At the same time, a support layer with a pattern is further provided in the folding area of ​​the display panel to ensure the overall strength of the display device and achieve better use effect.

[0079] Multiple embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications to the embodiments based on the concepts of the present disclosure, and these variations and modifications should all fall within the scope of protection required by the present disclosure.

Claims

1. A cover plate for a flexible display, characterized in that: include: a first impact resistant layer having a first thickness; a second impact resistant layer having a second thickness; a first bonding layer, wherein the first impact-resistant layer and the second impact-resistant layer are bonded to each other via the first bonding layer; The first thickness is greater than the second thickness; The first impact-resistant layer comprises a first glass structure and a second glass structure that are symmetrically arranged, and a gap region is provided between the first glass structure and the second glass structure; Also includes: a first flattening layer, wherein the first flattening layer covers a surface of the first glass structure and the second glass structure on a side away from the second impact-resistant layer, and the thickness of the first flattening layer is between 10 and 30 micrometers; The second impact-resistant layer comprises a third glass structure; the orthographic projection of the third glass structure perpendicular to the thickness of the cover plate at least completely covers the orthographic projection of the gap area perpendicular to the thickness of the cover plate; The third glass structure has a first bonding area between an orthographic projection perpendicular to the thickness of the cover plate and an orthographic projection perpendicular to the thickness of the cover plate of the first glass structure, and the third glass structure has a second bonding area between an orthographic projection perpendicular to the thickness of the cover plate and an orthographic projection perpendicular to the thickness of the cover plate of the second glass structure; The first thickness is at least three times the second thickness.

2. The cover plate according to claim 1, characterized in that: The first bonding layer is an optical adhesive layer.

3. The cover plate according to claim 2, characterized in that: The thickness of the optical adhesive layer is between 20 micrometers and 30 micrometers.

4. The cover plate according to claim 1, characterized in that: The width of the gap region is between 20 and 40 mm.

5. The cover plate according to claim 1, characterized in that: The first planarization layer is further used to fill the gap region, and the thickness of the first planarization layer in the gap region also includes the first thickness.

6. The cover plate according to claim 1, characterized in that: The widths of the first bonding area and the second bonding area are the same and are both greater than or equal to 20 mm.

7. The cover plate according to claim 1, characterized in that: Also includes: A second planarization layer, wherein the second planarization layer at least covers a surface of the third glass structure that is away from the first impact-resistant layer, and the thickness of the second planarization layer is between 10 and 30 microns.

8. The cover plate according to claim 7, characterized in that: The second planarizing layer is also used to cover the unbonded areas of the first and second glass structures on the surfaces close to the third glass structure that are not covered by the third glass structure, and the thickness of the second planarizing layer in the unbonded areas also includes the second thickness.

9. The cover plate according to claim 7, characterized in that: The first planarizing layer and the second planarizing layer are made of an optically clear resin material.

10. The cover plate according to claim 7, characterized in that: The refractive index of the first planarizing layer and the second planarizing layer is between 1.5 and 1.

52.

11. The cover plate according to claim 1, characterized in that: The first thickness has a value greater than 100 micrometers.

12. The cover plate according to claim 11, characterized in that: The first thickness has a value between 100 micrometers and 200 micrometers.

13. The cover plate according to claim 1, characterized in that: The second thickness has a value less than 50 micrometers.

14. The cover plate according to claim 13, characterized in that: The second thickness has a value between 30 micrometers and 40 micrometers.

15. A foldable display device, characterized in that: include: Display panel; The cover plate according to any one of claims 1 to 14, wherein the cover plate is located on a light emitting side of the display panel.

16. The display device according to claim 15, characterized in that: The display panel at least includes a folding area and a non-folding area; The orthographic projection of the non-folding area perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the first glass structure and the second glass structure perpendicular to the thickness of the display device; The orthographic projection of the folding area perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the gap area perpendicular to the thickness of the display device; The first glass structure and the second glass structure are symmetrically arranged as the first impact-resistant layer, and the gap area is the gap between the first glass structure and the second glass structure.

17. The display device according to claim 16, characterized in that: Also includes: A support layer located on a side of the display panel away from the cover plate; The support layer at least includes a pattern area and a non-pattern area, wherein the orthographic projection of the pattern area perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the folding area perpendicular to the thickness of the display device; the orthographic projection of the non-pattern area perpendicular to the thickness of the display device completely overlaps with the orthographic projection of the non-folding area perpendicular to the thickness of the display device; The pattern of the pattern area is used to provide support to the folding area when the folding area is in a bent state.

18. The display device according to claim 17, characterized in that: The supporting layer is made of metal material.

19. The display device according to claim 17, characterized in that: The thickness of the support layer is greater than or equal to 100 micrometers.

20. The display device according to any one of claims 15 to 19, characterized in that: Also includes: A hardening layer is located on a side of the cover plate away from the display panel.

21. The display device according to claim 20, characterized in that: The material of the hardening layer is acrylate.

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