Flexible display module and display device

Abstract

A flexible display module (100) and a display device. The flexible display module (100) comprises a display panel (10), a cover plate layer (20) arranged on an emergent light side of the display panel (10), and a protective layer (30); the cover plate layer (20) comprises first ultra-thin glass (21) and a first covering layer (22) covering the first ultra-thin glass (21); the protective layer (30) comprises a first substrate layer (31) and a second surface coating (32) arranged on the side of the first substrate layer (31) away from the cover plate layer (20); and at least one of the first substrate layer (31) and the second surface coating (32) is made of glass or a glass-like material.

Description

Flexible display modules and display devices Technical Field

[0001] This application relates to the field of display technology, and in particular to a flexible display module and display device. Background Technology

[0002] Foldable display devices represent a future trend in display technology. Currently, organic light-emitting diode (OLED) display devices are attracting considerable attention due to their unique bending and folding characteristics, which allow them to be manufactured into various forms of foldable display devices that are easy to carry and store, thus gaining widespread market attention.

[0003] Currently, the cover plates in foldable display products use a large number of polymer film layers, which makes the superposition of plastic deformation more obvious, resulting in obvious creases and poor resistance to indentation. Secondly, the composite of multiple polymer film layers requires the use of more adhesive layers, which reduces the compressive strength because the modulus of the adhesive layer is at the kPa level, which has almost no compressive strength. Under the force of a fingernail or an electromagnetic pen, the surface indentation is very obvious. In addition, in foldable products, there are dislocations between layers. The use of more polymer film layers and adhesive layers means that the risk of peeling between film layers is increased.

[0004] Furthermore, the repair layer in current foldable display products typically uses a composite of a polymer film layer and an adhesive layer, with a surface pencil hardness between B and H. Even if a hard coating is applied to the surface of the repair layer, the plastic deformation of the polymer film as the substrate cannot be ignored, resulting in noticeable creases and poor resistance to indentation. Therefore, the problems of noticeable creases and poor resistance to indentation in current foldable display products urgently need to be addressed. Invention Overview

[0005] This application provides a flexible display module and display device to alleviate the technical problems of obvious creases and poor pressure resistance in foldable display products.

[0006] The technical solution provided in this application is as follows:

[0007] In a first aspect, embodiments of this application provide a flexible display module, which includes a display area and a non-display area adjacent to the display area; the flexible display module further includes:

[0008] Display panel;

[0009] A cover layer is disposed on the light-emitting side of the display panel. The cover layer is located in the display area and the non-display area. The cover layer includes a first ultra-thin glass, a first cover layer, and a first surface coating on the side of the first cover layer away from the first ultra-thin glass. The first cover layer covers the surface of the first ultra-thin glass away from the display panel and the side surface of the first ultra-thin glass.

[0010] A protective layer is disposed on the side of the cover layer away from the display panel. The protective layer is recessed relative to the cover layer and is correspondingly disposed in the display area.

[0011] The protective layer includes a first substrate layer and a second surface coating disposed on the side of the first substrate layer away from the cover plate layer, wherein at least one of the first substrate layer and the second surface coating is made of glass or glass-like material.

[0012] Secondly, embodiments of this application also provide a display device, which includes the flexible display module described in one of the foregoing embodiments. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 illustrates a partial cross-sectional structure of a flexible display module.

[0015] Figure 2 illustrates a partial cross-sectional structure of a non-foldable display module.

[0016] Figure 3 is a schematic diagram of the first cross-sectional structure of the flexible display module provided in the embodiment of this application.

[0017] Figure 4 is a schematic diagram showing the detailed structure of the cover plate layer in Figure 3.

[0018] Figure 5 is a schematic diagram of the structure of the hard coating material on the protective layer in Figure 1.

[0019] Figure 6 is a schematic diagram of the structure of the second surface coating material in Figure 3.

[0020] Figure 7 is a schematic diagram of a second cross-sectional structure of the flexible display module provided in an embodiment of this application.

[0021] Figure 8 is a schematic diagram showing the detailed structure of the cover plate layer in Figure 7.

[0022] Figure 9 is a schematic diagram of the third cross-sectional structure of the flexible display module provided in the embodiment of this application.

[0023] Figure 10 is a schematic diagram showing the detailed structure of the protective layer in Figure 9.

[0024] Figure 11 is a schematic diagram showing the detailed structure of the cover plate layer in Figure 9.

[0025] Figure 12 is a schematic diagram of the fourth cross-sectional structure of the flexible display module provided in the embodiments of this application.

[0026] Figure 13 is a schematic diagram showing the detailed structure of the cover plate layer in Figure 12.

[0027] Figure 14 is a schematic diagram showing the detailed structure of the protective layer in Figure 12. Embodiments of the present invention

[0028] The following descriptions of the embodiments are with reference to the accompanying illustrations, illustrating specific embodiments in which this application can be implemented. Directional terms used in this application, such as [up], [down], [front], [back], [left], [right], [inner], [outer], [side], etc., are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustration and understanding of this application, and not for limiting this application. In the figures, structurally similar units are denoted by the same reference numerals. In the figures, the thickness of some layers and regions is exaggerated for clarity and ease of description. That is, the dimensions and thicknesses of each component shown in the figures are arbitrarily shown, but this application is not limited thereto.

[0029] To address the issues of noticeable creases and poor resistance to indentation in foldable display products, the inventors of this application discovered in their research that: Referring to Figure 1, which illustrates a partial cross-sectional structural diagram of a flexible display module, the flexible display module 100' is a foldable display module, and the flexible display module 100' includes a display panel, a cover layer 20' located on the light-emitting side of the display panel 10', and a protective layer 30'. The display panel 10' includes a panel layer and a polarizer or polyethylene terephthalate (PET) layer disposed on the panel layer (referred to as POL / POP in Figure 1 and hereinafter). The cover layer 20' includes a polyethylene terephthalate layer (referred to as PET1+HC in Figure 1 and hereinafter) with a hard coating, a colorless polyimide (CPI) layer, or an ultra-thin glass (UTG) layer (referred to as CPI / UTG in Figure 1 and hereinafter). PET1+HC is connected to CPI / UTG via optical adhesive OCA1, and CPI / UTG is connected to POL / POP via optical adhesive OCA2. The cover layer 20' also includes an ink layer disposed on the side of PET1+HC near CPI / UTG. The protective layer 30' includes a polyethylene terephthalate layer with a hard coating (referred to as PET0+HC in Figure 1 and hereinafter), which is connected to the cover layer 20' via optical adhesive OCA0. The protective layer 30' is a replaceable layer. After the protective layer 30' is damaged and fails, it can be directly peeled off from the flexible display module 100' and replaced with a new protective layer.

[0030] As can be seen from the flexible display module 100' stacked structure in Figure 1, the cover layer 20' uses a large number of polymer film layers and optical adhesive layers, making the plastic deformation more pronounced. This results in obvious creases and poor indentation resistance of the flexible display module 100'. Secondly, the large number of optical adhesive layers reduces compressive strength because the modulus of the adhesive layer is at the Kpa level, which has almost no compressive strength. Under the force of a fingernail or an electromagnetic pen, the surface indentation is very obvious. In addition, in foldable products, there are dislocations between layers. The use of more polymer film layers and adhesive layers means that the risk of peeling between film layers is increased. Moreover, the protective layer 30' is a composite of polymer film layers and adhesive layers, and the surface pencil hardness is between B and H. Even if a hard coating is applied to the surface of the protective layer 30', the plastic deformation of the polymer film as the substrate cannot be ignored, resulting in obvious creases and poor indentation resistance.

[0031] The inventors of this application discovered in practice that, referring to Figure 2, which illustrates a partial cross-sectional structural diagram of a non-folding display module 100'', the non-folding display module 100'' includes a display panel 10'', a cover layer 20'' and a protective layer 30'' located on the light-emitting side of the display panel 10'', and a support layer 40'' located on the side of the display panel 10'' away from the light-emitting side. The display panel 10'' includes a panel layer and a polarizer or polyethylene terephthalate (PET) layer disposed on the panel layer (referred to as POL / POP in Figure 1 and hereinafter). The cover layer 20'' includes a glass cover plate CG, which is connected to the POL / POP layer by optical adhesive OCA. The glass cover plate CG provides a layer for the surface strength of the overall non-folding display module 100'', with a thickness ranging from 400-600um, exhibiting good impact resistance, and a steel ball level of over 50mm. The protective layer 30'' is connected to the glass cover plate. The protective layer 30'' can be a tempered glass film or a high-transparency PET film. The support layer 40'' includes a backplate BP and a composite functional layer SCF. The protective layer 30'' is a replaceable layer on the non-folding display module 100''. Due to the high surface strength of the glass cover plate, the protective layer 30'' is optional for the non-folding display module 100''. Compared with the multilayer polymer film layer and multilayer adhesive layer in Figure 1, the glass cover plate has greater surface hardness, stronger compressive strength, and a good smooth glass surface feel.

[0032] Based on this, the inventors of this application propose a flexible display module and display device. Under the premise that the flexible display module can be bent and folded, the cover layer and protective layer of the flexible display module are aligned with the cover layer 20'' and protective layer 30'' in the non-foldable display module shown in Figure 2. This improves the surface feel, hardness, and resistance to creases and indentations of the flexible display module, reduces the risk of creases and indentations, and improves the problems of obvious creases and poor resistance to indentations in foldable display products.

[0033] Please refer to Figures 1 to 6. Figure 3 is a schematic diagram of the first cross-sectional structure of the flexible display module provided in this application embodiment. Figure 4 is a schematic diagram of the detailed structure of the cover layer in Figure 3. Figure 5 is a schematic diagram of the structure of the hard coating material on the protective layer in Figure 1. Figure 6 is a schematic diagram of the structure of the second surface coating material in Figure 3. Referring to Figure 3, the flexible display module 100 includes a display area NA and a non-display area NA adjacent to the display area NA. For example, the non-display area NA may surround the display area NA. The display area NA is used to display an image.

[0034] The flexible display module 100 further includes a display panel 10 and a cover layer 20 and a protective layer 30 disposed on the light-emitting side of the display panel 10. The display panel 10 is located in the display area NA and the non-display area NA, and the cover layer 20 is connected to the display panel 10 such that the cover layer 20 is also located in the display area NA and the non-display area NA.

[0035] The cover layer 20 includes a first ultra-thin glass 21, a first cover layer 22, and a first surface coating 23 located on the side of the first cover layer 22 away from the first ultra-thin glass 21. The first cover layer 22 covers the surface of the first ultra-thin glass 21 away from the display panel 10 and the side surface of the first ultra-thin glass 21.

[0036] The protective layer 30 is disposed on the side of the cover layer 20 away from the display panel 10 and is connected to the cover layer 20. The protective layer 30 is recessed relative to the cover layer 20 and is correspondingly disposed in the display area NA. The protective layer 30 includes a first substrate layer 31 and a second surface coating 32 disposed on the side of the first substrate layer 31 away from the cover layer 20. At least one of the first substrate layer 31 and the second surface coating 32 is made of glass or a glass-like material, such that the surface hardness of the protective layer 30 away from the cover layer 20 is greater than 7H and less than or equal to 9H.

[0037] In this embodiment, a cover layer 20 is formed by covering an ultra-thin glass with a cover layer, and directly connected to a protective layer 30 with a high surface hardness. This removes a large amount of polymer film and adhesive layers from the cover layer in current foldable products, and increases the surface hardness of the repair layer. For example, compared to the flexible display module 100' in Figure 1, the flexible display module 100 exemplified in Figure 3 of this application removes a large amount of polymer film and adhesive layers from the cover layer 20, and increases the surface hardness of the protective layer 30. This improves the surface feel, hardness, and anti-crease and anti-indentation capabilities of the flexible display module 100 while ensuring that the flexible display module 100 is bendable, reduces the risk of creases and indentations in the flexible display module 100, and improves the problems of obvious creases and poor anti-indentation capabilities in current foldable display products.

[0038] Specifically, in one embodiment, referring to FIG3, the display panel 10 includes a panel layer 11 and a first buffer layer 12 disposed on the panel layer 11. The first buffer layer 12 includes one of a polarizer and a PET layer, for example, when the display panel 10 uses a polarizer, the first buffer layer 12 is the polarizer; when the display panel 10 uses depolarizer technology, a color filter layer is disposed on the panel layer 11 to replace the polarizer, in which case the first buffer layer 12 is the PET layer. In addition to compensating for optical characteristics, the buffer layer can also reduce the impact absorption of the panel layer 11 and extend its service life.

[0039] In some embodiments, the panel layer 11 may include a substrate and a thin-film transistor layer disposed on the substrate, the thin-film transistor layer being located on the side of the substrate closer to the cover plate layer 20. The substrate may be a polyimide substrate. When the substrate is a flexible substrate, it may be formed of multiple sub-substrates of the same material, such as polyimide, with adjacent sub-substrates bonded together by adhesive sub-layers.

[0040] In some embodiments, the thin-film transistor layer includes a thin-film transistor, which includes a semiconductor located on a substrate. The semiconductor may be formed of polycrystalline silicon or a metal oxide (such as indium gallium zinc oxide). The semiconductor is divided into a channel region and source and drain regions formed on either side of the channel region. The thin-film transistor layer also includes a first gate insulating layer covering the semiconductor. The thin-film transistor also includes a first gate formed on the first gate insulating layer, overlapping the channel region. The first gate may be formed as multiple layers or a single layer comprising a low-resistance material such as Al, Ti, Mo, Cu, Ni, or alloys thereof, or a material with high corrosion resistance. The thin-film transistor layer also includes a second gate insulating layer covering the first gate. The thin-film transistor also includes a second gate located on the second gate insulating layer, overlapping the first gate. The second gate may be formed as multiple layers or a single layer comprising a low-resistance material such as Al, Ti, Mo, Cu, Ni, or alloys thereof, or a material with high corrosion resistance. The thin-film transistor layer also includes a first interlayer insulating layer formed on the second gate. The first interlayer insulating layer, the first gate insulating layer, and the second gate insulating layer include source contact holes and drain contact holes, and the source region and the drain region are exposed through the source contact holes and drain contact holes, respectively.

[0041] The thin-film transistor also includes a source and a drain disposed on the same layer, both formed on the first interlayer insulating layer. The source is connected to the source region through a source contact hole, and the drain is connected to the drain region through a drain contact hole. The source and drain can be multiple layers or a single layer formed of low-resistance materials such as Al, Ti, Mo, Cu, Ni, or their alloys, or materials with high corrosion resistance. For example, the source and drain can be a triple layer of Ti / Cu / Ti, Ti / Ag / Ti, Ti / Al / Ti, or Mo / Al / Mo, or other single-layer or multi-layer structures.

[0042] In some embodiments, panel layer 11 further includes a planarization layer located between thin-film transistor layer and light-emitting layer, the planarization layer covering source and drain.

[0043] In some embodiments, the panel layer 11 further includes an anode layer located on the side of the planarization layer away from the thin-film transistor layer. The anode layer includes a plurality of anodes, each anode corresponding to a pixel unit. Each anode is electrically connected to a thin-film transistor. The planarization layer includes anode contact holes through which the anodes contact the source or drain of the thin-film transistor.

[0044] In some embodiments, panel layer 11 further includes a pixel definition layer disposed on the side of the planarization layer away from the thin-film transistor layer. The pixel definition layer includes pixel definition portions and openings located between the pixel definition portions. Panel layer 11 also includes a light-emitting layer comprising a plurality of pixel units. The pixel units are located within the openings. The openings expose a portion of the anode and cover the edge of the anode. The pixel units may include red pixel units, green pixel units, and blue pixel units.

[0045] In some embodiments, panel layer 11 further includes a cathode layer covering the light-emitting layer. In the direction from the anode to the cathode layer, the light-emitting layer includes a hole-injecting organic layer, a light-emitting material layer, and an electronic organic layer stacked sequentially. The hole-injecting organic layer may include a hole injection layer and a hole transport layer, with the hole injection layer in direct contact with the anode and the hole transport layer located between the hole injection layer and the light-emitting material layer. The hole-injecting organic layer may also include an electron blocking layer located between the hole transport layer and the light-emitting material layer. The electronic organic layer may include an electron injection layer and an electron transport layer, with the electron injection layer in direct contact with the cathode layer and the electron transport layer located between the electron injection layer and the light-emitting material layer. The electronic organic layer may also include a hole blocking layer located between the electron transport layer and the light-emitting layer.

[0046] In some embodiments, the panel layer 11 further includes an encapsulation layer located on the side of the cathode layer away from the light-emitting layer. The encapsulation layer is formed by alternating stacking of multiple inorganic and organic film layers. For example, along the direction from the substrate to the thin-film transistor layer, the encapsulation layer includes a first inorganic encapsulation sublayer, a first organic encapsulation sublayer, and a second inorganic encapsulation sublayer.

[0047] In some embodiments, panel layer 11 further includes a touch layer located on the side of the encapsulation layer away from the light-emitting layer. The touch layer can implement touch functionality in a self-capacitive or mutual-capacitive manner. When the touch layer implements touch functionality in a self-capacitive manner, the touch layer may have only one touch metal layer.

[0048] When the touch layer implements touch functionality using capacitive touch, the touch layer includes a first touch metal layer, a touch insulating layer, and a second touch metal layer. The touch insulating layer is located on the side of the first touch metal layer furthest from the encapsulation layer, and the second touch metal layer is also located on the side of the touch insulating layer furthest from the encapsulation layer. The first touch metal layer can be directly disposed on the encapsulation layer, or a spacer layer can be disposed between the first touch layer and the encapsulation layer. The spacer layer can include an inorganic spacer layer and / or an organic spacer layer. The first touch metal layer includes a first touch electrode, a second touch electrode, and a first bridging wire; the second touch metal layer includes a second bridging wire. Both the first and second touch electrodes are metal networks. Alternatively, the second touch metal layer includes a first touch electrode, a second touch electrode, and a first bridging wire, and the first touch metal layer includes a second bridging wire.

[0049] In some embodiments, when the display panel 10 employs depolarization technology, the color filter layer used to replace the polarizer is located on the side of the light-emitting layer away from the thin-film transistor layer.

[0050] In some embodiments, referring to Figures 3 and 4, the cover layer 20 is connected to the display panel 10, for example, the cover layer 20 is connected to the first buffer layer 12 on the display panel 10. The cover layer 20 includes a first ultra-thin glass 21, a first cover layer 22, and a third adhesive layer 24. The cover layer 20 is connected to the display panel 10 through the third adhesive layer 24. The first ultra-thin glass 21 includes a second upper surface 211 and a second lower surface 212 opposite to each other, and a second side surface 213 connecting the second upper surface 211 and the second lower surface 212. The second upper surface 211 is located on the side of the first ultra-thin glass 21 away from the display panel 10.

[0051] The thickness of the first ultra-thin glass 21 ranges from 30 to 100 μm. When the thickness of the first ultra-thin glass 21 is less than 30 μm, the mechanical properties of the glass are too poor and insufficient to meet the requirements of the folding cover. When the thickness of the first ultra-thin glass 21 is greater than 100 μm, the bending radius is greater than R3.0 and the rebound force is too large, which the entire machine's rotating shaft cannot meet.

[0052] The first cover layer 22 covers at least the second upper surface 211. For example, in one embodiment, the first cover layer 22 covers both the second upper surface 211 and the second side surface 213. The first ultra-thin glass layer 21 is connected to the display panel 10 via the third adhesive layer 24. Optionally, the material of the first cover layer 22 includes transparent polyimide, polyethylene terephthalate (PET), thermoplastic polyurethane rubber (TPU), or polymethyl methacrylate (PMMA), etc. The material of the third adhesive layer 24 includes transparent optical adhesives, such as OCR or OCA.

[0053] In one embodiment, the thickness D1 of the first cover layer 22 covering the second side 213 in the direction away from the first ultra-thin glass 21 is greater than or equal to 0.1 mm and less than or equal to 0.4 mm, so as to avoid the front frame pressing on the portion of the first cover layer 22 covering the second side 213 when the front frame is assembled on the flexible display module 100, which would cause damage to that portion of the first cover layer 22.

[0054] Referring again to Figures 3 and 4, the cover layer 20 further includes a first surface coating 23, which is located on the side of the first cover layer 22 away from the first ultrathin glass 21 to further improve the surface compressive strength.

[0055] Optionally, the elastic modulus of the first surface coating 23 is greater than or equal to 3 GPa and less than or equal to 7 GPa, and the thickness of the first surface coating 23 can be greater than or equal to 3 micrometers and less than or equal to 10 micrometers, for example, it can be 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers or 10 micrometers.

[0056] The material of the first surface coating 23 can be a composite material that is a mixture or hybrid of organic and inorganic phases. The material of the first surface coating 23 can be selected from silicon-containing inorganic-organic materials. For example, the material of the first surface coating 23 can be selected from at least one of composite materials having silicon oxide and / or silicon nitride, polymers of siloxane and acrylic, semi-siloxane polymers, and aliphatic or aromatic polymers containing inorganic silicon groups.

[0057] When the first surface coating 23 is selected from a composite material that is a mixture or hybrid of organic and inorganic phases, the surface of the first surface coating 23 away from the first cover layer 22 has both high surface hardness and good recovery performance. For example, when the material of the first surface coating 23 is selected from a polymer containing siloxanes, due to the good recovery performance of such materials, when a stylus or other hard object is slid with greater force on the surface of the first surface coating 23 away from the first cover layer 22, a fine mark may be left on the surface. When the stylus or other hard object leaves the surface, the fine mark will automatically recover and disappear.

[0058] In some embodiments, the surface hardness of the first surface coating 23 on the side away from the first cover layer 22 is greater than or equal to 3H, and the surface hardness of the first surface coating 23 on the side away from the first cover layer 22 is less than or equal to 9H. For example, it can be 4H, 5H, 6H, 7H, 8H, etc.

[0059] The cover layer 20 further includes a light-shielding layer 25 located on the side of the first ultra-thin glass 21 near the display panel 10. The light-shielding layer 25 is located in the non-display area NA and surrounds the display area NA, serving to shield the non-display area NA from light leakage. The material of the light-shielding layer 25 includes light-shielding ink, etc.

[0060] Referring again to Figure 3, the protective layer 30 is connected to the cover layer 20. The orthographic projection of the protective layer 30 on the display panel 10 is separate from the orthographic projection of the light-shielding layer 25 on the display panel 10, that is, there is no overlapping area between the orthographic projection of the protective layer 30 on the display panel 10 and the orthographic projection of the light-shielding layer 25 on the display panel 10.

[0061] Optionally, the orthographic projection of the light-shielding layer 25 on the display panel 10 is located outside the orthographic projection of the protective layer 30 on the display panel 10, and there is a gap between the orthographic projection of the light-shielding layer 25 on the display panel 10 and the orthographic projection of the protective layer 30 on the display panel 10, so that the protective layer 30 is completely located within the display area NA, so that the protective layer 30 can be torn off and replaced after it is damaged or fails, and the protective layer 30 is a replaceable layer.

[0062] The protective layer 30 includes a first substrate layer 31, a second surface coating 32, and a first adhesive layer 33. The second surface coating 32 is located on the side of the first substrate layer 31 away from the cover plate layer 20. The first substrate layer 31 is connected to the cover plate layer 20 through the first adhesive layer 33.

[0063] Optionally, the material of the first substrate layer 31 includes PET and CPI. The material of the first adhesive layer 33 includes a transparent optical adhesive, such as OCA adhesive.

[0064] Referring to Figures 5 and 6, the second surface coating 32 includes a substrate 320 and hyperbranched polymer 321, rigid nanoparticles 323, and linear prepolymer 322 doped within the substrate 320. The substrate 320 includes either PET or CPI. The linear prepolymer 322 corresponds to the hyperbranched polymer 321 and serves as a carrier for the polymerization of the hyperbranched polymer 321. The structures of the hyperbranched polymer 321, the rigid nanoparticles 323, and the linear prepolymer 322 are shown in Figure 6(a). The hyperbranched polymer 321, the rigid nanoparticles 323, and the linear prepolymer 322 are doped into the substrate 320 and then cured by UV light to form the polymer structure shown in Figure 6(b).

[0065] The hard coating on the protective layer 30' in Figure 1 includes a substrate 320' and an acrylic polymer 321' and a linear prepolymer 322' doped within the substrate 320'. The substrate 320' includes either PET or CPI. The structure of the acrylic polymer 321' and the corresponding linear prepolymer 322' is shown in Figure 5(a). The acrylic polymer 321' and the corresponding linear prepolymer 322' are doped into the substrate 320' and, after UV curing, form the polymer structure shown in Figure 5(b).

[0066] Compared to acrylic polymer 321', the hyperbranched polymer 321 can significantly increase the crosslinking density, forming a high-hardness surface. This results in the surface hardness of the second surface coating 32 being greater than 7H and less than or equal to 9H, for example, reaching 9H, similar to the texture of glass. Furthermore, compared to the linear prepolymer 322' in Figure 5(a), the rigid nanoparticles 323 are better able to block the spread of damage, that is, the ability to prevent crack propagation is greatly improved.

[0067] The overall thickness of the protective layer 30 can be maintained at 100-150 μm, and the light transmittance is greater than 92%. Compared with the protective layer 30'' in the example of Figure 2, which is a PET high-transmittance film with a thickness of 100-300 μm, a light transmittance greater than 88%, and a surface hardness between HB and 9H, the protective layer 30 in this embodiment, while reducing the thickness to meet the requirements of bendability and foldability, has high surface hardness and high light transmittance, exhibiting glass-like characteristics, greater surface hardness, stronger compressive strength, and a good smooth glass surface feel. Its properties are superior to those of the PET high-transmittance film.

[0068] Referring again to Figure 3, the flexible display module 100 further includes a support layer 40 disposed on the side of the display panel 10 away from the cover layer 20, and the support layer 40 serves to support and protect the display panel 10. The support layer 40 may include a back plate 41 and a support plate 42 sequentially stacked on the side of the display panel 10 away from the cover layer 20. Optionally, the support layer 40 may also include a second buffer layer 43 located between the back plate 41 and the support plate 42. The back plate 41 is disposed on the side of the display panel 10 away from the cover layer 20, and the material of the back plate 41 includes PET; the second buffer layer 43 is disposed on the side of the back plate 41 away from the display panel 10, and the material of the second buffer layer 43 may be selected from black, easily bendable materials, such as black polyimide; the support layer 40 is disposed on the side of the second buffer layer 43 away from the back plate 41, and the material of the support plate 42 may be selected from metal materials with good heat dissipation, such as stainless steel.

[0069] Referring to Figures 1 to 8, Figure 7 is a second cross-sectional structural diagram of the flexible display module 100 provided in this application embodiment, and Figure 8 is a detailed structural diagram of the cover layer 20 in Figure 7. Referring to Figures 7 and 8, the difference from the flexible display module 100 exemplified in Figure 3 is that the first cover layer 22 also covers the second side surface 213 and the second lower surface 212, so that the first cover layer 22 completely encloses the first ultra-thin glass 21 and the light-shielding layer 25. The first cover layer 22 is connected to the display panel 10 through the third adhesive layer 24. Other descriptions are as described in the above embodiments and will not be repeated here.

[0070] Referring to Figures 1 to 11, Figure 9 is a third cross-sectional structural diagram of the flexible display module 100 provided in this embodiment, Figure 10 is a detailed structural diagram of the protective layer 30 in Figure 9, and Figure 11 is a detailed structural diagram of the cover layer 20 in Figure 9. Referring to Figures 9, 10, and 11, the difference between this and the flexible display module 100 exemplified in Figure 3 is that the structures of the cover layer 20 and the protective layer 30 are different.

[0071] The first substrate layer 31 includes a second ultrathin glass 311 and a second cover layer 312. The second ultrathin glass 311 includes a first upper surface 3111 and a first lower surface 3112 opposite to each other, and a first side surface 3113 connecting the first upper surface 3111 and the first lower surface 3112. The first upper surface 3111 is located on the side of the second ultrathin glass 311 away from the cover layer 20. The second cover layer 312 covers the first upper surface 3111, the first side surface 3113, and the first lower surface 3112 of the second ultrathin glass 311, thereby encapsulating the second ultrathin glass 311. The second cover layer 312 is connected to the cover layer 20 via the first adhesive layer 33. The material of the second cover layer 312 may be the same as the material of the first cover layer 22.

[0072] The thickness of the second ultra-thin glass 311 ranges from 30 to 100 μm. When the thickness of the second ultra-thin glass 311 is less than 30 μm, the mechanical properties of the glass are too poor and insufficient to meet the requirements of the folding cover. When the thickness of the second ultra-thin glass 311 is greater than 100 μm, the bending radius is greater than R3.0 and the rebound force is too large, which the entire machine's rotating shaft cannot meet.

[0073] The second surface coating 32 is located on the side of the second cover layer 312 away from the cover plate layer 20. The second surface coating 32 can be made of the same material as the first surface coating 23, or the same material as the second surface coating 32 in the example of FIG. 3. In this embodiment, the protective layer 30 is glass, just like the protective layer 30'' in the example of FIG. 2, which is a tempered film. Therefore, the feel is consistent. The thickness of tempered film is generally between 100-400um, while the thickness of the protective layer 30 in this embodiment is between 100-200um. The protective layer 30 in this embodiment, while reducing the thickness to meet the requirements of bendability and foldability, has high surface hardness and the characteristics of glass. It has greater surface hardness, stronger compressive strength, and a good smooth glass surface feel.

[0074] The display area NA includes a bent area FA and a non-bent area NFA adjacent to the bent area FA. The first ultra-thin glass 21 has a first groove 210 at a position corresponding to the bent area FA, and the third adhesive layer 24 fills the first groove 210. To ensure the flatness of the surface, the first groove 210 is located on the side of the first ultra-thin glass 21 closest to the display panel 10, that is, the first groove 210 is formed on the second lower surface 212. The third adhesive layer 24 can be a transparent optical adhesive (OCR), in which case OCR technology can be used to directly fill the first groove 210.

[0075] The thickness of the first ultra-thin glass 21 in the bending region FA is less than the thickness of the first ultra-thin glass 21 in the non-bending region NFA. For example, the thickness of the first ultra-thin glass 21 in the bending region FA is 10 μm less than the thickness of the first ultra-thin glass 21 in the non-bending region NFA. In this embodiment, the first ultra-thin glass 21 adopts a non-uniform thickness design. The non-bending region NFA, which has a large area, can use ultra-thin glass with a thickness greater than 50 μm, while the bending region FA can be thinned to meet different overall bending requirements. For example, the thickness of the ultra-thin glass in the non-bending region NFA is 100 μm, and the thickness of the ultra-thin glass in the bending region FA is 50 μm.

[0076] The thickness of the first ultrathin glass 21 is less than or equal to the thickness of the second ultrathin glass 311. For example, the ratio of the thickness of the first ultrathin glass 21 to the thickness of the second ultrathin glass 311 is in the range of 1 / 3 to 1 / 1, such as a thickness ratio of 1 / 3, 1 / 2, 2 / 3, 3 / 4, 2 / 5, 3 / 5, 4 / 5, 5 / 6, 3 / 7, 4 / 7, 5 / 7, 6 / 7, 1 / 1, etc. Optionally, the thickness of the first ultrathin glass 21 is 30 μm and the thickness of the second ultrathin glass is 90 μm; or, the thickness of the first ultrathin glass 21 is 33 μm and the thickness of the second ultrathin glass is 99 μm; or, the thickness of the first ultrathin glass 21 is 50 μm and the thickness of the second ultrathin glass is 100 μm; or, the thickness of the first ultrathin glass 21 is 80 μm and the thickness of the second ultrathin glass is 90 μm.

[0077] By making the thickness of the first ultra-thin glass 21 less than the thickness of the second ultra-thin glass 311, the thickness of the first ultra-thin glass 21 can be reduced, while the thickness of the second ultra-thin glass 311 can be increased. The thickness of the second ultra-thin glass 311 does not affect the overall thickness of the device, and increasing the thickness of the second ultra-thin glass 311 enhances the surface strength of the flexible display module 100. Thus, through the special design of the first ultra-thin glass 21 and the second ultra-thin glass 311, the surface strength of the flexible display module 100 can be further enhanced without increasing its overall thickness, or, while maintaining its surface strength, the overall thickness of the flexible display module 100 can be reduced. Other explanations are provided in the above embodiments and will not be repeated here.

[0078] Referring to Figures 1 to 14, Figure 12 is a fourth cross-sectional structural diagram of the flexible display module 100 provided in this embodiment of the application, Figure 13 is a detailed structural diagram of the cover layer 20 in Figure 12, and Figure 14 is a detailed structural diagram of the protective layer 30 in Figure 12. Referring to Figures 12, 13, and 14, the difference from the flexible display module 100 exemplified in Figure 9 is that the structures of the cover layer 20 and the protective layer 30 are different.

[0079] The first substrate layer 31 includes a second ultra-thin glass 311, a second cover layer 312, a support layer 313, and a second adhesive layer 314. The second ultra-thin glass 311 includes a first upper surface 3111 and a first lower surface 3112 opposite to each other, and a first side surface 3113 connecting the first upper surface 3111 and the first lower surface 3112. The first upper surface 3111 is located on the side of the second ultra-thin glass 311 away from the cover layer 20. The second cover layer 312 covers the first upper surface 3111 and the first side surface 3113 of the second ultra-thin glass 311. The support layer 313 is disposed on the side of the second ultra-thin glass 311 close to the cover layer 20. The support layer 313 is connected to the cover layer 20 through the first adhesive layer 33, and the support layer 313 is also connected to the second ultra-thin glass 311 through the second adhesive layer 314. The support layer 313 is provided to facilitate removal and replacement after the protective layer 30 is damaged or fails. The material of the support layer 313 includes PET, etc.

[0080] The display area NA includes a bent area FA and a non-bent area NFA adjacent to the bent area FA. The first ultra-thin glass 21 has a first groove 210 at a position corresponding to the bent area FA. The first cover layer 22 covers the second upper surface 211, the second side surface 213, and the second lower surface 212, and fills the first groove 210. Other details are as described in the above embodiment and will not be repeated here.

[0081] Based on the same inventive concept, this application also provides a display device, which includes the flexible display module 100 described in one of the foregoing embodiments. The display device can be a mobile phone, tablet, television, or other display terminal, and is not limited thereto.

[0082] As can be seen from the above embodiments:

[0083] This application provides a flexible display module and a display device. The flexible display module includes a display panel and a cover layer and a protective layer disposed on the light-emitting side of the display panel. The cover layer is located in the display area and the non-display area of ​​the display panel. The cover layer includes a first ultra-thin glass, a first cover layer covering the surface of the first ultra-thin glass away from the display panel, and the side surface of the first ultra-thin glass. The protective layer is disposed on the side of the cover layer away from the display panel. The protective layer is recessed relative to the cover layer and is correspondingly disposed in the display area. The protective layer includes a first substrate layer and a second cover layer disposed on the side of the first substrate layer away from the cover layer. The surface coating, at least one of the first substrate layer and the second surface coating, is made of glass or a glass-like material. Thus, by using an ultra-thin glass to cover the cover layer to form a cover layer, and directly connecting it with a protective layer with a high surface hardness, the polymer film layer and adhesive layer that are more common on the cover layer of current foldable products are removed, and the surface hardness of the repair layer is increased. This improves the surface feel, hardness, and anti-crease and anti-indentation ability of the flexible display module while achieving the flexibility of the flexible display module. It also reduces the risk of creases and indentations in the flexible display module and improves the problems of obvious creases and poor anti-indentation ability in current foldable display products.

[0084] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0085] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A flexible display module, comprising a display area and a non-display area adjacent to the display area; The flexible display module also includes: Display panel; A cover plate layer is disposed on the light-emitting side of the display panel. The cover plate layer is located in the display area and the non-display area. The cover plate layer includes a first ultra-thin glass, a first cover layer, and a first surface coating layer located on the side of the first cover layer away from the first ultra-thin glass. The first cover layer covers the surface of the first ultra-thin glass away from the display panel and the side surface of the first ultra-thin glass. A protective layer is disposed on the side of the cover layer away from the display panel. The protective layer is recessed relative to the cover layer and is correspondingly disposed in the display area. The protective layer includes a first substrate layer and a second surface coating disposed on the side of the first substrate layer away from the cover plate layer, wherein at least one of the first substrate layer and the second surface coating is made of glass or a glass-like material.

2. The flexible display module according to claim 1, wherein, The cover layer also includes a light-shielding layer, which is located on the side of the first ultra-thin glass close to the display panel and in the non-display area. The orthographic projection of the protective layer on the display panel is separate from the orthographic projection of the light-shielding layer on the display panel.

3. The flexible display module according to claim 2, wherein, The material of the first substrate layer includes PET and CPI, and the second surface coating is a glass-like material.

4. The flexible display module according to claim 3, wherein, The second surface coating includes a substrate and hyperbranched polymers, rigid nanoparticles, and linear prepolymers doped within the substrate.

5. The flexible display module according to claim 2, wherein, The first substrate layer includes: The second ultrathin glass includes a first upper surface and a first lower surface opposite to each other, and a first side surface connecting the first upper surface and the first lower surface, wherein the first upper surface is located on the side of the second ultrathin glass away from the cover layer; The second cover layer covers the first upper surface, the first side surface, and the first lower surface of the second ultra-thin glass, and the second cover layer is connected to the cover plate layer through the first adhesive layer; The second surface coating is located on the side of the second cover layer away from the second ultrathin glass.

6. The flexible display module according to claim 2, wherein, The first substrate layer includes: The second ultra-thin glass includes a first upper surface and a first lower surface opposite to each other, and a first side surface connecting the first upper surface and the first lower surface, wherein the first upper surface is located on the side of the second ultra-thin glass away from the cover plate layer. A second covering layer covers the first upper surface and the first side surface of the second ultrathin glass; A support layer is disposed on the side of the second ultra-thin glass near the cover layer. The support layer is connected to the cover layer through a first adhesive layer and is also connected to the second ultra-thin glass through a second adhesive layer.

7. The flexible display module according to claim 6, wherein, The ratio of the thickness of the first ultrathin glass to the thickness of the second ultrathin glass is in the range of 1 / 3 to 1 / 1.

8. The flexible display module according to any one of claims 1 to 7, wherein, The first ultrathin glass includes a second upper surface and a second lower surface opposite to each other, and a second side surface connecting the second upper surface and the second lower surface, wherein the second upper surface is located on the side of the first ultrathin glass away from the display panel; The first cover layer covers the second upper surface and the second side surface, and the cover layer is connected to the display panel through a third adhesive layer.

9. The flexible display module according to claim 8, wherein, The display area includes a bent area and a non-bent area adjacent to the bent area; The first ultra-thin glass has a first groove at the position corresponding to the bending area, and the third adhesive layer fills the first groove.

10. The flexible display module according to claim 8, wherein, The thickness of the first cover layer covering the second side in the direction away from the first ultra-thin glass is greater than or equal to 0.1 mm and less than or equal to 0.4 mm.

11. The flexible display module according to claim 8, wherein, The first cover layer also covers the second side surface and the second lower surface, and the first cover layer is connected to the display panel through the third adhesive layer.

12. The flexible display module according to claim 11, wherein, The display area includes a bent area and a non-bent area adjacent to the bent area; The first ultrathin glass has a first groove at the position corresponding to the bending area, and the first covering layer fills the first groove.

13. A display device comprising a flexible display module, the flexible display module including a display area and a non-display area adjacent to the display area; The flexible display module also includes: Display panel; A cover plate layer is disposed on the light-emitting side of the display panel. The cover plate layer is located in the display area and the non-display area. The cover plate layer includes a first ultra-thin glass, a first cover layer, and a first surface coating layer located on the side of the first cover layer away from the first ultra-thin glass. The first cover layer covers the surface of the first ultra-thin glass away from the display panel and the side surface of the first ultra-thin glass. A protective layer is disposed on the side of the cover layer away from the display panel. The protective layer is recessed relative to the cover layer and is correspondingly disposed in the display area. The protective layer includes a first substrate layer and a second surface coating disposed on the side of the first substrate layer away from the cover plate layer, wherein at least one of the first substrate layer and the second surface coating is made of glass or a glass-like material.

14. The display device according to claim 13, wherein, The cover layer also includes a light-shielding layer, which is located on the side of the first ultra-thin glass close to the display panel and in the non-display area. The orthographic projection of the protective layer on the display panel is separate from the orthographic projection of the light-shielding layer on the display panel.

15. The display device according to claim 14, wherein, The material of the first substrate layer includes PET and CPI, and the second surface coating is a glass-like material.

16. The display device according to claim 15, wherein, The second surface coating includes a substrate and hyperbranched polymers, rigid nanoparticles, and linear prepolymers doped within the substrate.

17. The display device according to claim 14, wherein, The first substrate layer includes: The second ultrathin glass includes a first upper surface and a first lower surface opposite to each other, and a first side surface connecting the first upper surface and the first lower surface, wherein the first upper surface is located on the side of the second ultrathin glass away from the cover layer; The second cover layer covers the first upper surface, the first side surface, and the first lower surface of the second ultra-thin glass, and the second cover layer is connected to the cover plate layer through the first adhesive layer; The second surface coating is located on the side of the second cover layer away from the second ultrathin glass.

18. The display device according to claim 14, wherein, The first substrate layer includes: The second ultra-thin glass includes a first upper surface and a first lower surface opposite to each other, and a first side surface connecting the first upper surface and the first lower surface, wherein the first upper surface is located on the side of the second ultra-thin glass away from the cover plate layer. A second covering layer covers the first upper surface and the first side surface of the second ultrathin glass; A support layer is disposed on the side of the second ultra-thin glass near the cover layer. The support layer is connected to the cover layer through a first adhesive layer and is also connected to the second ultra-thin glass through a second adhesive layer.

19. The display device according to claim 18, wherein, The ratio of the thickness of the first ultrathin glass to the thickness of the second ultrathin glass is in the range of 1 / 3 to 1 / 1.

20. The display device according to any one of claims 13 to 19, wherein, The first ultrathin glass includes a second upper surface and a second lower surface opposite to each other, and a second side surface connecting the second upper surface and the second lower surface, wherein the second upper surface is located on the side of the first ultrathin glass away from the display panel; The first cover layer covers the second upper surface and the second side surface, and the cover layer is connected to the display panel through a third adhesive layer.

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