Display module and electronic equipment

Abstract

The embodiment of the utility model provides a display module and electronic equipment, the display module comprises an effective display area and a binding area, and the effective display area is connected with the binding area; the display module comprises a display layer, a first back film and a second back film, the first back film is bonded with the display layer through a first adhesive, the first back film is located on the backlight side of the display layer and located in the effective display area, the second back film is located in the binding area, and the second back film is bonded to the binding area through a second adhesive. The normal-temperature modulus of the second adhesive is equal to that of the first adhesive; the modulus of the first back film is larger than that of the second back film. According to the embodiment of the invention, the reliability and thinning of the display module can be considered.

Description

Technical Field

[0001] This application relates to the field of display technology, and more particularly to a display module and an electronic device. Background Technology

[0002] To meet the demand for thinner electronic devices, display modules are also trending towards thinner designs. However, as display modules become thinner, their impact and compression resistance decreases, affecting their reliability. In particular, the back side of the display module typically has weaker impact and compression resistance, making thinner designs more significant for its reliability. Utility Model Content

[0003] This application provides a display module and an electronic device that can improve the reliability of the display module and also achieve thinner design.

[0004] In a first aspect, embodiments of this application provide a display module, including an effective display area and a bonding area, which are connected together. The display module includes a display layer, a first back film, and a second back film. The first back film is stacked on top of the display layer and bonded to it with a first adhesive. The first back film is located on the backlight side of the display layer and may be located in the effective display area. The second back film is located in the bonding area and is bonded to the bonding area with a second adhesive. The room temperature modulus of the second adhesive is equal to or approximately equal to the room temperature modulus of the first adhesive. The modulus of the first back film is greater than that of the second back film.

[0005] In this embodiment, the display module can be divided into an effective display area and a bonding area, etc., from a planar perspective. From a layering perspective, the display module can be divided into a display layer and a back film, etc. The back film can include a first back film and a second back film, arranged side-by-side. By making the modulus of the backlight side of the display layer larger, and by making the modulus of the first back film greater than that of the second back film, the back films of the effective display area and the bonding area are designed differently. This allows the first back film with the larger modulus to increase the rigidity of the display module from the back side of the display layer, thereby effectively improving the impact and compression resistance of the back side of the display module and ensuring its reliability. Based on the premise of guaranteed display module reliability, the thickness of the effective display area can be reduced, achieving thinning of the effective display area and even the entire display module. Therefore, the solution of this embodiment can overcome the limitation of conventional solutions using the same specification of back film in the effective display area and the bonding area, and can balance the reliability and thinning of the display module.

[0006] In this embodiment, the room temperature modulus of the adhesive refers to the modulus of the adhesive at room temperature (approximately 20°C to 25°C). By making the room temperature moduli of the first adhesive and the second adhesive equal or approximately equal, product requirements can be met. For example, when the room temperature modulus of the first adhesive is low, the room temperature modulus of the second adhesive is also low, which can reduce the stress of the adhesive on the back film, facilitating the bending and opening / closing of the display module.

[0007] In one implementation of the first aspect, the modulus of the first back film is greater than or equal to 30 GPa. This modulus specification of the first back film can effectively improve the impact and compression resistance of the back side of the display module, and is easy to manufacture industrially.

[0008] In one implementation of the first aspect, the modulus of the second backsheet is greater than or equal to 3 GPa and less than or equal to 10 GPa. This modulus specification of the second backsheet can better meet the stiffness requirements of the bonding region and is easy to manufacture industrially.

[0009] In one implementation of the first aspect, the thickness of the first back film is less than or equal to the thickness of the second back film. In this implementation, based on the premise that the reliability of the display module is guaranteed, reducing the thickness of the first back film in the effective display area compared to the second back film in the bonding area is beneficial to achieving thinning of the effective display area and even the entire display module.

[0010] In one implementation of the first aspect, the first back film includes a stainless steel layer with a thickness of 15μm-30μm. When the material of the first back film is stainless steel, the high modulus of stainless steel can greatly improve the reliability of the display module from the back of the display module. Therefore, the thickness of the stainless steel can be made smaller, for example, only about 15μm-30μm, which can significantly reduce the thickness of the display module.

[0011] In one implementation of the first aspect, the material of the first backsheet can be ultra-thin glass UTG, titanium alloy, or nickel-based high-temperature alloy; that is, the first backsheet can be an ultra-thin glass UTG layer, a titanium alloy layer, or a nickel-based high-temperature alloy layer. The first backsheet manufactured from the above materials has good mechanical properties and can meet product requirements.

[0012] In one implementation of the first aspect, the material of the second backing film is polyethylene terephthalate (PET) or transparent polyimide (CPI), meaning the second backing film can be a PET layer or a CPI layer. The second backing film manufactured from these materials has good performance, is a mature technology, and can meet product requirements.

[0013] In one implementation of the first aspect, the display module further includes a support layer. The display layer, the first back film, and the support layer are stacked sequentially, with the support layer located in the effective display area. The support layer disposed behind the first back film provides support and also has good bending performance. The support layer can be a bamboo book, or it can include stacked bamboo books and other support structures. In this implementation, since a high-modulus first back film is used in the effective display area, it is sufficient to ensure the reliability of the effective display area. Therefore, the support layer can retain the bamboo book shape without other support structures, which is beneficial for thinning.

[0014] In one implementation of the first aspect, the room temperature modulus of the first adhesive is less than or equal to 40 kPa. Using a material with a lower modulus for the first adhesive can reduce the stress of the first adhesive on the first back film and can also partially offset the large bending force of the high-modulus first back film (e.g., SUS stainless steel), thereby facilitating the bending and opening / closing of the display module.

[0015] In one implementation of the first aspect, the thickness of the first adhesive is 15μm-25μm, and / or the thickness of the second adhesive is 15μm-25μm. In this implementation, setting the thickness of the first adhesive within the aforementioned smaller range facilitates the reduction of the effective display area. Setting the thickness of the second adhesive within this range satisfies product requirements. The thicknesses of the first and second adhesives can be the same, approximately the same, or different. When the thicknesses of the second and first adhesives are the same, it simplifies the manufacturing process of the display module and reduces costs.

[0016] In one implementation of the first aspect, the first back film has multiple through holes, all of which penetrate the first back film along its thickness direction. In this implementation, a photosensitive sensor can be arranged beneath the first back film. By providing through holes in the first back film, the light transmittance of the first back film can be improved, ensuring the performance of the photosensitive sensor.

[0017] Secondly, embodiments of this application provide an electronic device, including a housing and a display module, with the display module fixed to the housing. This electronic device includes, but is not limited to, mobile phones (candybar phones or foldable phones), tablets, laptops, smart screen devices, in-vehicle devices, wearable devices, augmented reality (AR) glasses, AR headsets, virtual reality (VR) glasses, VR headsets, and personal digital assistants (PDAs). This electronic device can be either non-foldable or foldable. Due to the presence of the display module, this electronic device can combine reliability with a slim and lightweight design.

[0018] In one implementation of the second aspect, the housing includes a first housing and a second housing; the electronic device also includes a hinge connecting the first housing and the second housing. The first housing, the hinge, and the second housing are located on the same side of the display surface of the display module, and the display module is fixedly connected to both the first housing and the second housing. The hinge is used to generate mechanical movement, causing the first housing to rotate relative to the second housing and deforming the display module, thereby folding or unfolding the electronic device. The electronic device of this implementation can be a foldable electronic device, such as a bi-folding or tri-folding phone. This implementation can improve the reliability and thinness of foldable electronic devices.

[0019] In one implementation of the second aspect, when the electronic device is in a folded state, at least a portion of the display module is located between the first housing and the second housing. The foldable electronic device in this implementation can be an inward-folding screen device or a triple-folding device. This implementation can improve the reliability and slimness of such a foldable electronic device.

[0020] In one implementation of the second aspect, the effective display area includes a bending area, which is fixed to the pivot. The display module also includes a support layer. The display layer, the first back film, and the support layer are stacked sequentially. The support layer is located in the effective display area, and there is a gap between the portion of the support layer located in the bending area and the pivot. In this implementation, the support layer is located after the first back film and in the effective display area, providing support and good bending performance. By creating a gap between the portion of the support layer located in the bending area and the pivot, the under-screen buffer layer between the bending area and the pivot in conventional solutions can be eliminated. This reduces structural complexity, lowers the uncertainty in the assembly and fit between the display module and the pivot, avoids frictional noise between the under-screen buffer layer and the pivot when the pivot moves, reduces the gap between the display module and the first and second housings, and avoids occupying the thickness allocated to the pivot.

[0021] In one implementation of the second aspect, the first back film has multiple through holes, all of which penetrate the first back film along its thickness direction. The electronic device also includes a light sensor, which is located on the side of the display module facing the housing, within the effective display area. The light sensor is used to receive light passing through the multiple through holes. In this implementation, the light sensor can be used to sense ambient light passing through the display module to detect the intensity of ambient light, enabling the electronic device to automatically adjust the screen display effect (e.g., adjust brightness or color temperature) or perform other functions according to the lighting conditions. By providing through holes in the first back film, the light transmittance of the first back film can be improved, ensuring the performance of the light sensor. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural schematic diagram of an electronic device in one embodiment;

[0023] Figure 2 yes Figure 1 The diagram shows the exploded structure of the electronic device.

[0024] Figure 3 This is a three-dimensional structural diagram of an electronic device in another embodiment;

[0025] Figure 4 yes Figure 3 The diagram shows the exploded structure of the electronic device.

[0026] Figure 5 yes Figure 3 The diagram shows the structure of the electronic device in its folded state.

[0027] Figure 6 yes Figure 5 A schematic diagram of the AA cross-sectional structure of the electronic equipment in the diagram;

[0028] Figure 7 This is a three-dimensional structural diagram of an electronic device in another embodiment;

[0029] Figure 8 This is a top view of the display module in one embodiment;

[0030] Figure 9 This is a partial cross-sectional view of an electronic device in its unfolded state, according to one embodiment.

[0031] Figure 10 This is a schematic diagram of the stacked support layer in one embodiment;

[0032] Figure 11 This is a partial cross-sectional view of the display panel and electrical connection structure in one embodiment;

[0033] Figure 12 This is a schematic diagram of the stacking of a display module in one embodiment;

[0034] Figure 13 This is a comparison diagram of the creases in this embodiment and the conventional embodiment;

[0035] Figure 14 This is a top view of the display module in another embodiment;

[0036] Figure 15 This is a partial cross-sectional view of the display panel and electrical connection structure in another embodiment;

[0037] Figure 16 yes Figure 15 A schematic diagram of a backsheet opening in the ambient light aperture area;

[0038] Figure 17 yes Figure 15Another backsheet opening diagram in the ambient light aperture area;

[0039] Figure 18 yes Figure 15 Another backsheet opening diagram in the ambient light aperture area;

[0040] Figure 19 This is a partial cross-sectional view of the display panel and electrical connection structure in another embodiment. Detailed Implementation

[0041] This application provides an electronic device, including but not limited to mobile phones (candybar phones or foldable phones), tablet computers, laptop computers, smart screen devices, in-vehicle devices, wearable devices, augmented reality (AR) glasses, AR helmets, virtual reality (VR) glasses, VR helmets, personal digital assistants (PDAs), etc.

[0042] In this embodiment, the electronic device can be a non-foldable electronic device (e.g., a candybar phone, tablet computer, or smart screen device) or a foldable electronic device (e.g., a foldable phone). In this embodiment, the electronic device may include a display module and a housing. The display module can be fixed to the housing, and the display surface of the display module can be exposed outside the housing to display an image. The display module can also be called a screen or display panel. Display modules include, but are not limited to, organic light-emitting diode (OLED) displays, active-matrix organic light-emitting diode (AMOLED) displays, mini organic light-emitting diode (MLED) displays, micro organic light-emitting diode (MOLED) displays, quantum dot light-emitting diode (QLED) displays, or liquid crystal displays (LCDs).

[0043] In this embodiment, the display module can be a flat screen or a curved screen. The display module can have flexible bending properties and can be applied to foldable electronic devices or some non-foldable electronic devices. Alternatively, the display module may not have flexible bending properties and can be applied to foldable electronic devices or non-foldable electronic devices.

[0044] The basic structures of electronic devices in several embodiments of this application will be illustrated below.

[0045] Figure 1 and Figure 2 This illustration shows an electronic device 1 in one embodiment. Electronic device 1 can be, for example, a non-foldable electronic device, such as a candybar phone. Figure 1 and Figure 2 As shown, the electronic device 1 may include a display module 11 and a housing 12, etc. The housing 12 may be a shell assembly composed of several sub-housings, for example, it may include a middle frame and a rear shell. The display module 11 is fixed to one side of the housing 12, for example, the display module 11 is mounted on one side of the middle frame, and the rear shell is mounted on the other side of the middle frame. The structure of the electronic device 1 described above is merely an example and is not intended to limit the embodiments of this application.

[0046] Figures 3-5 Another embodiment of an electronic device 1 is illustrated. Electronic device 1 can be, for example, a foldable electronic device, such as a foldable mobile phone. This foldable mobile phone can be folded into two layers, and therefore can be called a double-folding phone or a bi-folding phone. For ease of explanation, an XYZ coordinate system can be defined, where the Z-axis direction is the thickness direction of electronic device 1, and also the thickness direction of the display module 2 within electronic device 1.

[0047] like Figures 3-5 As shown, the electronic device 1 may include a display module 2, a first housing 31, a rotating shaft 32, and a second housing 33. The rotating shaft 32 connects the first housing 31 and the second housing 33. The rotating shaft 32 may be assembled from multiple components and is capable of generating mechanical movement, causing the first housing 31 to rotate relative to the second housing 33, thereby opening or closing the first housing 31 and the second housing 33. For example, Figure 3 When the first housing 31 and the second housing 33 are fully extended, the angle between them can be approximately 180° (slight deviations are allowed, such as an angle of 165°, 177°, or 185°). For example, Figure 5 The first housing 31 and the second housing 33 shown can be completely closed to be parallel to each other (a slight deviation is allowed).

[0048] like Figures 3-5As shown, in this embodiment, the first housing 31 and the second housing 33 can be collectively referred to as the housing. When the first housing 31 and the second housing 33 are fully closed, the housing is in a folded state, that is, the electronic device 1 is in a folded state. When the first housing 31 and the second housing 33 are fully unfolded, the housing is in an unfolded state, that is, the electronic device 1 is in an unfolded state. Therefore, the electronic device 1 can switch between the unfolded state and the folded state through the mechanism of the pivot 32. In this embodiment, the state in which the electronic device 1 is fully folded to its minimum volume is called the folded state; the state in which the electronic device 1 is fully unfolded to its maximum volume is called the unfolded state.

[0049] like Figure 3 and Figure 4 As shown, the display module 2 can cover the first housing 31, the rotating shaft 32, and the second housing 33. The first housing 31, the rotating shaft 32, and the second housing 33 can be located on the same side of the display surface 2z of the display module 2. The display surface 2z is the surface on which the display image of the display module 2 is displayed; the display surface 2z faces away from the rotating shaft 32 and can face the user. For example, as... Figure 3 and Figure 4 As shown, the first housing 31, the rotating shaft 32, and the second housing 33 can all be located on the lower side of the display surface 2z.

[0050] The display module 2 in this embodiment has flexible bending properties. For example... Figure 3 and Figure 4 As shown, the display module 2 can be divided into a first non-bending area 2a, a bending area 2b, and a second non-bending area 2c arranged sequentially. The bending area 2b connects the first non-bending area 2a and the second non-bending area 2c. When the display module 2 is folded, the first non-bending area 2a and the second non-bending area 2c do not undergo bending deformation or do not undergo significant bending deformation, but can maintain or largely maintain their original flat state; the bending area 2b, however, undergoes bending deformation.

[0051] like Figure 5 As shown, in this embodiment, the electronic device 1 can be an inward-folding screen device, that is, when the electronic device 1 is in the folded state, the display module 2 can be entirely located between the first housing 31 and the second housing 33. In another embodiment, the electronic device 1 can also be an outward-folding screen device, that is, when the electronic device 1 is in the folded state, the display module 2 can be covered outside the first housing 31 and the second housing 33.

[0052] Figure 6 for Figure 5 A schematic diagram of a partial cross-sectional view of the AA structure. (See attached diagram.) Figure 6As shown, the display module 2 can be fixedly connected to the first housing 31, the rotating shaft 32, and the second housing 33. For example, the first non-bending area 2a can be fixedly connected to the first housing 31, the second non-bending area 2c can be fixedly connected to the second housing 33, and the bending area 2b can be fixedly connected to the rotating shaft 32. For example, the bending area 2b can be fixedly connected to the door panel 321 in the rotating shaft 32. The following will provide a more detailed description.

[0053] like Figure 4 and Figure 6 As shown, the pivot 32 may include a door panel 321 and a main shaft 322 (or keel), etc. The main shaft 322 may be located between the first housing 31 and the second housing 33. The main shaft 322 may be a hollow rod-shaped component extending in a straight line. The interior of the main shaft 322 may form multiple movable spaces communicating with the outside of the main shaft 322. The door panel 321 may be a long strip-shaped structure. There may be two door panels 321, which may be symmetrically or substantially symmetrically arranged on both sides of the main shaft 322. The door panels 321 may move relative to the main shaft 322. The door panels 321 may serve as components in the pivot 32 that are fixedly connected to the bending area 2b. When the pivot 32 performs mechanical movement, both door panels 321 may rotate relative to the main shaft 322, thereby causing the bending area 2b to unfold or fold. It is understandable that the fixed connection between the bending area 2b and the door panel 321 in the pivot 32 is just an example, and the connection between the bending area 2b and the pivot 32 is not limited to this.

[0054] like Figure 6 As shown, exemplarily, when electronic device 1 is an inward-folding screen device, the bending area 2b can be bent into a shape similar to a water droplet. It is understood that this is merely an example and not a limitation of the embodiments of this application.

[0055] like Figure 3 and Figure 5 As shown, for example, electronic device 1 can be a large folding device, which can be folded from the left and right sides towards the middle when the user holds electronic device 1 normally. In another embodiment, electronic device 1 can also be a small folding device, which can be folded from the top and bottom sides towards the middle when the user holds electronic device 1 normally.

[0056] Figure 7 The illustration shows an electronic device 1 in another embodiment. Electronic device 1 can be a foldable electronic device, such as a foldable mobile phone. This foldable mobile phone can be folded into three layers, and therefore can be called a tri-fold phone. The state in which the tri-fold phone is fully unfolded and reaches its maximum volume can be called the unfolded state. The state in which the tri-fold phone is fully folded and reaches its minimum volume can be called the folded state. Figure 7 As shown, the electronic device 1 may include a display module 2, a housing 34, a pivot 35, a housing 36, a pivot 38, and a housing 37.

[0057] like Figure 7 As shown, shaft 35 connects housing 34 and housing 36, and shaft 38 connects housing 36 and housing 37. Both shafts 35 and 38 can be assembled from multiple components. Shaft 35 can generate mechanical movement, causing housing 34 to rotate relative to housing 36, thus allowing housing 34 and housing 36 to unfold or close; shaft 38 can generate mechanical movement, causing housing 36 to rotate relative to housing 37, thus allowing housing 36 and housing 37 to unfold or close. In this embodiment, one of the two adjacent housings connected by a shaft can be called the first housing, and the other can be called the second housing. For example, housing 34 and housing 36 connected by shaft 35, housing 34 can be called the first housing (or the second housing), and housing 36 can be called the second housing (or the first housing). Similarly, housing 36 and housing 37 connected by shaft 38, housing 36 can be called the first housing (or the second housing), and housing 37 can be called the second housing (or the first housing).

[0058] like Figure 7 As shown, the display module 2 can cover the housing 34, the pivot 35, the housing 36, the pivot 38, and the housing 37. The first housing 31, the pivot 32, and the second housing 33 can be located on the same side of the display surface 2z of the display module 2. The display surface 2z is the surface on which the display screen of the display module 2 is displayed, and the display surface 2z can face the user. For example, as... Figure 7 As shown, housing 34, pivot 35, housing 36, pivot 38, and housing 37 can all be located on the side of the display surface 2z facing outwards from the drawing. In this embodiment, the display module 2 can be fixedly connected to housing 34, pivot 35, housing 36, pivot 38, and housing 37.

[0059] The display module 2 in this embodiment has flexible bending properties. For example... Figure 7 As shown, the display module 2 can be divided into a non-bending area 2a, a bending area 2b, a non-bending area 2c, a bending area 2d, and a non-bending area 2e arranged sequentially. The bending area 2b connects the non-bending areas 2a and 2c, and the bending area 2d connects the non-bending areas 2c and 2e. When the display module 2 is folded, the non-bending areas 2a, 2c, and 2e do not undergo or substantially do not undergo bending deformation, but maintain or substantially maintain their original flat state; the bending areas 2b and 2d both undergo bending deformation. For example, the non-bending area 2a can be fixedly connected to the housing 34, the bending area 2b can be fixedly connected to the rotating shaft 35, the non-bending area 2c can be fixedly connected to the housing 36, the bending area 2d can be fixedly connected to the rotating shaft 38, and the non-bending area 2e can be fixedly connected to the housing 37.

[0060] refer to Figure 7As shown, in this embodiment, the electronic device 1 may include an inward folding portion and an outward folding portion. When the electronic device 1 is in a folded state, the non-bending area 2a, the bending area 2b, and the non-bending area 2c of the display module 2 can all be located between the housing 34 and the second housing 36, and the non-bending area 2e of the display module 2 can be covered outside the housing 37.

[0061] To meet the thinning requirements of electronic device 1, display module 2 also exhibits a thinning trend. As display module 2 becomes thinner, its impact and compression resistance decreases, affecting its reliability. In particular, the back side of display module 2 (the side facing away from display surface 2z, or the side facing the housing) typically has weaker impact and compression resistance; therefore, thinning display module 2 has a significant impact on the reliability of its back side.

[0062] For foldable electronic devices, the multiple layers of the display module 2 utilize flexible polymer materials. After the display module 2 is thinned, it is highly susceptible to failure such as black spots and bright spots when subjected to impacts like drops or sharp pressure, affecting display and touch functionality. For inward-folding devices, the bending area of ​​the display module 2 can resemble a teardrop shape when folded. To accommodate the need for thinner overall thickness, the display module 2 needs to be thinner to achieve a smaller teardrop radius. This not only affects the reliability of the display module 2 but also exacerbates creases, impacting the overall light and shadow effect (the combined optical and image performance of the display module 2 in its unfolded state) and reducing its overall refinement. Furthermore, to ensure the bending performance of the display module 2, the stiffness of the back side of the display module 2 located in the bending area needs to be designed to be low. This further worsens the pressure and impact resistance, crease problems, and overall light and shadow performance of the back side of the display module 2.

[0063] In view of this, the embodiments of this application provide an improved solution that can enhance the reliability of the back side of the display module 2, balance the reliability and thinning of the display module 2, and also improve the creases and large-area light and shadow of the foldable electronic device. A detailed description will follow.

[0064] Figure 8 A top view of the display module 2 in the unfolded state in one embodiment is shown below. Figure 8As shown, the display module 2 may include an active display area (AA) 2f and a bonding area 2g connected together, with the bonding area 2g located on one side of the active display area 2f. The active display area 2f has multiple pixels for displaying images. The display surface 2z may be the surface of the active display area 2f. The bonding area 2g has electrical connection structures, including but not limited to flexible circuit boards, driver chips, connectors, and packaging structures, used to achieve electrical connection between the display module 2 and the circuit board in the electronic device 1. The bonding area 2g can be bent to the back side of the active display area 2f. It is understood that... Figure 8 The positional relationship and size ratio of the effective display area 2f and the binding area 2g shown are only illustrative and are not limited in this embodiment.

[0065] like Figure 8 As shown, for example, the display module 2 can be a flexible screen used in a bi-folding phone. The first non-bending area 2a, the bending area 2b, and the second non-bending area 2c can all be within the effective display area 2f. The binding area 2g can be arranged parallel or substantially parallel to the bending area 2b and spaced apart. It is understood that this is merely an example and not a limitation on the embodiments of this application. In another embodiment, the display module 2 can also be a flexible screen used in a tri-folding phone, or the display module 2 can be used in non-foldable electronic devices such as candybar phones. For ease of explanation, the following description will continue with the example of electronic device 1 being a bi-folding phone and display module 2 being the flexible screen in that bi-folding phone.

[0066] Figure 9 A partial sectional view is used to illustrate the side sectional structure of the display module 2 and its assembly position within the electronic device 1, wherein the electronic device 1 is in an unfolded state. Figure 9 The diagram illustrates the portion of the effective display area 2f corresponding to electronic device 1.

[0067] like Figure 9As shown, a connecting layer 4, such as a copper foil, can be provided between the area corresponding to the first non-bending area 2a of the display module 2 and the first housing 31; similarly, a connecting layer 4, such as a copper foil, can be provided between the area corresponding to the second non-bending area 2c of the display module 2 and the second housing 33. For example, a gap can exist between the bending area 2b of the display module 2 and the rotating shaft 32, meaning they are directly spaced apart without any other structure, only air. For example, a gap can exist between the bending area 2b and the main shaft 322. This gap design eliminates the need for an under-screen buffer layer between the bending area 2b and the rotating shaft 32, reducing structural complexity and uncertainty in the assembly and fit of the display module 2 and the rotating shaft 32. It also avoids frictional noise between the under-screen buffer layer and the rotating shaft 32 during mechanical movement, reduces the gap between the display module 2 and the first housing 31 and the second housing 33, and avoids occupying the thickness allocated to the rotating shaft 32. It is understood that this gap design is merely an example and is not essential to the embodiments of this application. For example, in another embodiment, an under-screen buffer layer may be provided between the bending area 2b and the pivot 32 to buffer and protect the bending area 2b. The basic stacked structure of the display module 2 will be summarized below, and then the improved stacked structure in the display module 2 will be described in detail.

[0068] like Figure 9 As shown, the display module 2 may include a protective film 21, a protective layer 22, a display panel 23, and a support layer 24, which are stacked sequentially. The protective film 21 faces away from the housing and serves as a user-touchable interface, while the support layer 24 faces the housing. For example, the various layers can be connected using optically clear adhesive (OCA). OCA has high light transmittance, which can reliably connect the layers while reducing light loss and ensuring optimal display performance.

[0069] like Figure 9 As shown, the protective film 21 covers the front of the display panel 23. The protective film 21 is used to protect the display panel 23 and can be replaced. In another embodiment, the protective film 21 may not be part of the display module 2, but may be supplied separately and attached to the front of the display panel 23.

[0070] like Figure 9As shown, the protective layer 22 can be located between the protective film 21 and the display panel 23. The protective layer 22 is used to protect the display panel 23, ensuring that the display panel 23 is not easily subjected to compression and impact. The protective layer 22 can also be called a cover. In this embodiment, the material of the protective layer 22 includes, but is not limited to, polyethylene terephthalate (PET), colorless polyimide (CPI), or ultra-thin glass (UTG). For example, the protective layer 22 can include two or more layers of protective material, each layer of protective material can be PET, CPI, or UTG. For example, the first layer of protective material facing the protective film 21 can be PET or CPI, and the remaining layers of protective material can be UTG, PET, or CPI. The layers of protective material can be connected by adhesive layers of different thicknesses (e.g., OCA) to enhance the absorption capacity of the front side of the display panel 23 (i.e., the side facing the protective film 21) against compression and impact energy. The thickness of the protective layer 22 can be determined as needed. For example, the thickness of the PET layer can be about 50 μm, the thickness of the CPI layer can be about 50 μm, and the thickness of the UTG layer can be about 30 μm. It is understood that the structure of the protective layer 22 described above is only illustrative. In another embodiment, in order to achieve thinning, the protective layer 22 can also have fewer layers of protective material, and the thickness of the OCA can also be reduced.

[0071] like Figure 9 As shown, in this embodiment, at least a portion of the display panel 23 may be located in the effective display area 2f. The display panel 23 may include a display layer and a back film, which are stacked together. The back film is located on the backlight side of the display layer, which is the side facing away from the display surface (the side displaying the image) of the display layer. Alternatively, the back film is located between the display layer and the support layer 24. The display layer and the back film can be connected by adhesive, for example, by pressure-sensitive adhesive (PSA), which may be, for example, OCA. Exemplarily, the display layer may include a thin-film transistor (TFT) substrate and an OLED light-emitting structure, and the display layer is used to display images. The back film can support and protect the display layer from the backlight side of the display layer, ensuring the reliability of the backlight side of the display layer. The back film will continue to be described below.

[0072] like Figure 9 As shown, the support layer 24 is located between the display panel 23 and the housing, and the support layer 24 can be located in the effective display area 2f. The support layer 24 can support and protect the display panel 23. The support layer 24 can also be called a support plate (BKT).

[0073] Figure 10 This is a schematic diagram of the stacked structure of the support layer 24 in one embodiment. For example... Figure 10 As shown, the support layer 24 may include an adhesive layer 24a and a bamboo book 24b. (Combined) Figure 9 and Figure 10 As shown, adhesive layer 24a can bond the display panel 23 and the bamboo book 24b. The material of adhesive layer 24a can be determined as needed, for example, it can be OCA. The thickness of adhesive layer 24a can be determined as needed. The material of bamboo book 24b includes, but is not limited to, stainless steel, titanium alloy, or carbon fiber. For example, bamboo book 24b can be made of carbon fiber, and the position of bamboo book 24b corresponding to the bending area 2b can be perforated to reduce stiffness, thereby ensuring the bending performance of display module 2 in bending area 2b. Bamboo book 24b can absorb the extrusion and impact energy of the back side of display panel 23, thereby protecting the back side of display panel 23 from damage. In addition, bamboo book 24b can also play a supporting role. In this embodiment, the number of stacked layers of support layer 24 is small, which is beneficial to the overall thinning of the device. In another embodiment, as needed, support layer 24 can also include support structures such as PI tape, wherein the stacked structure of support layer 24 can be: OCA - support structure - OCA - bamboo book 24b.

[0074] It is understood that the stacked structure of the support layer 24 described above is only an illustrative example, and the embodiments of this application do not specifically limit it.

[0075] The embodiments of this application have designed the back film and other components in the display panel 23, which will be described in detail below.

[0076] Figure 11 This is a partial cross-sectional view of the display panel 23 and the electrical connection structure 25 in one embodiment. (See attached image.) Figure 11 As shown, at least a portion of the display panel 23 may be located in the effective display area 2f, and the electrical connection structure 25 may be located in the bonding area 2g. The electrical connection structure 25 is a physical structure within the bonding area 2g. The electrical connection structure 25 can be connected to the display panel 23 and is used to realize the electrical connection between the display panel 23 and the circuit board in the electronic device 1.

[0077] like Figure 11As shown, the display panel 23 may include a display layer 23a, a first adhesive 23b, and a first back film 23c stacked sequentially. The first adhesive 23b connects the display layer 23a and the first back film 23c. The first back film 23c is used to protect the back side of the display layer 23a. The electrical connection structure 25 may include a base layer 25a, a second adhesive 25b, and a second back film 25c stacked sequentially. The second adhesive 25b connects the base layer 25a and the second back film 25c. The base layer 25a is the main structure of the electrical connection structure 25, which can realize the circuit function of the electrical connection structure 25. It may include, for example, a flexible circuit board, a driver chip, a connector, etc. The second back film 25c is used to protect the back side of the base layer 25a. Alternatively, the second back film 25c can be considered to be bonded to the bonding area 2g by the second adhesive 25b. In this embodiment, both the first back film 23c and the second back film 25c can be referred to as back films.

[0078] refer to Figure 11 As shown, in this embodiment, the modulus of the first back film 23c located in the effective display area 2f can be greater than the modulus of the second back film 25c located in the bonding area 2g. For example, the modulus of the first back film 23c can be greater than or equal to 30 GPa, such as 30 GPa or 195 GPa. For example, the modulus of the second back film 25c can be greater than or equal to 3 GPa and less than or equal to 10 GPa, such as 3 GPa, 5 GPa, or 10 GPa.

[0079] In conventional solutions, the effective display area and bonding area of ​​the display module use the same back film. Given the material properties of this back film, its thickness needs to be relatively large to ensure the reliability of the display module, which is not conducive to the thinning of the display module. Therefore, conventional solutions cannot achieve both the reliability and thinning of the display module.

[0080] In this embodiment, by making the modulus of the first back film 23c of the effective display area 2f greater than the modulus of the second back film 25c of the bonding area 2g, the back films of the effective display area 2f and the bonding area 2g can be designed differently. This allows the first back film 23c, with its larger modulus, to increase the rigidity of the display module 2 from the back side, thereby effectively improving the impact and compression resistance of the back side of the display module 2 and ensuring its reliability. Based on the premise that the reliability of the display module 2 is guaranteed, the thickness of the effective display area 2f can be reduced, for example, by making the thickness of the first back film 23c less than the thickness of the second back film 25c, achieving a thinner effective display area 2f and even the entire display module 2. Therefore, the solution of this embodiment can overcome the limitation of conventional solutions that use the same specification of back film in the effective display area and the bonding area, and can balance the reliability and thinning of the display module 2.

[0081] In this embodiment, when the electronic device 1 is a foldable electronic device, by differentiating the back film of the effective display area 2f and the bonding area 2g, the impact and compression resistance of the back side of the flexible display module 2 can be significantly improved, effectively ensuring the reliability of the display module 2 and improving or avoiding failure problems such as black spots and bright spots. Since it can balance thinning and reliability, the solution of this embodiment can be well applied to inward folding screen devices, which is beneficial to reducing the bending radius of the display module 2, improving the crease of the display module 2, ensuring the light and shadow effect of the large surface, and ensuring the refinement of the display module 2.

[0082] Understandably, given that the modulus of the first back film 23c is greater than that of the second back film 25c, the thickness of the first back film 23c can also be equal to or close to the thickness of the second back film 25c, depending on product requirements. This can also improve the impact and compression resistance of the back side of the display module 2 and ensure the reliability of the display module 2.

[0083] In another embodiment, the selection of backing film material and / or product structure design can be combined to make the modulus of the first backing film 23c equal to or close to the modulus of the second backing film 25c. This embodiment can also meet product requirements.

[0084] In one embodiment, the material of the first backsheet 23c includes, but is not limited to, high-modulus materials such as stainless steel, UTG, titanium alloys, and nickel-based superalloys.

[0085] For example, the material of the first back film 23c can be SUS stainless steel, and the thickness of the first back film 23c can be 15μm to 30μm, such as 15μm, 18μm, 20μm, 25μm or 30μm. Among them, a thinner SUS stainless steel, such as 15μm SUS stainless steel, can be used to effectively reduce the thickness of the display module 2 while ensuring reliability.

[0086] For example, the material of the first back film 23c can be UTG, and the thickness of the first back film 23c can be 30μm to 50μm, for example, 30μm, 40μm or 50μm.

[0087] For example, the material of the first back film 23c can be titanium alloy, and the thickness of the first back film 23c can be 20μm to 40μm, such as 20μm, 30μm or 40μm.

[0088] For example, the material of the first back film 23c can be a nickel-based high-temperature alloy, and the thickness of the first back film 23c can be 15μm to 25μm, for example, 15μm, 20μm or 25μm.

[0089] In one embodiment, the bonding region 2g needs to have a certain degree of light transmittance so that the device in the bonding region 2g can perform optical precision detection. Based on this, the material of the second back film 25c can be a light-transmitting material such as PET, CPI, or PI. For example, the material of the second back film 25c can be PET, with a thickness of approximately 50 μm. Alternatively, the material of the second back film 25c can be CPI, with a thickness of approximately 50 μm. CPI has a higher modulus than PET, and the second back film 25c made of CPI has greater stiffness, which is beneficial for improving the modulus and reliability of the bonding region 2g. In addition, the second back film 25c made of light-transmitting materials such as PET or CPI is less prone to heat generation, which can avoid affecting the reliability of the bonding region 2g. In another embodiment, the material of the second back film 25c is not limited to those described above, but can be determined as needed. For example, the second back film 25c can also be made of SUS stainless steel.

[0090] In one embodiment, the room temperature modulus of the first adhesive 23b can be less than or equal to 40 kPa, for example, its room temperature modulus can be 40 kPa, 25 kPa, etc. Here, room temperature modulus refers to the modulus of the first adhesive 23b at room temperature (approximately 20°C to 25°C). Using a material with a lower modulus for the first adhesive 23b can reduce the stress exerted by the first adhesive 23b on the first back film 23c, and can also partially offset the larger bending force of the high-modulus first back film 23c (e.g., SUS stainless steel), thus facilitating the bending and opening / closing of the display module 2. In one embodiment, the first adhesive 23b and the second adhesive 25b can be made of the same material, for example, both being PSA with a room temperature modulus less than or equal to 40 kPa.

[0091] In one embodiment, the thickness of the first adhesive 23b can be 15μm-25μm, such as 15μm, 20μm, 25μm, etc. A thinner first adhesive 23b within this thickness range is beneficial for achieving a thinner effective display area 2f.

[0092] In one embodiment, the thickness of the second adhesive 25b can be 15μm-25μm, such as 15μm, 20μm, 25μm, etc. Setting the thickness of the second adhesive 25b within this range can meet product requirements. The thickness of the second adhesive 25b can be the same as, approximately the same as, or different from the thickness of the first adhesive 23b. When the thickness of the second adhesive 25b can be the same as the thickness of the first adhesive 23b, it is beneficial to simplify the manufacturing process of the display module 2 and reduce costs.

[0093] Figure 12 This is a schematic diagram of the effective display area 2f stacked in one embodiment of the display module 2. For example... Figure 12As shown, in one embodiment, in the effective display area 2f, the display module 2 may include a protective layer 22, a display panel 23, and a support layer 24 stacked sequentially. For example, the protective layer 22 may include a protective material 22a, an adhesive layer 22b, a protective material 22c, and an adhesive layer 22d stacked together. The protective material 22a may be PET, the adhesive layer 22b may be OCA, the protective material 22c may be UTG, and the adhesive layer 22d may be OCA. The display panel 23 may include a display layer 23a, a first adhesive 23b, and a first back film 23c stacked together. The first adhesive 23b may be OCA, and the first back film 23c may be SUS stainless steel with a thickness of 20 μm. The support layer 24 may include an adhesive layer 24a and a back film 24b stacked together. The adhesive layer 24a may be OCA. For example, the total thickness of the display module 2 may be 415 μm. In conventional display modules 2, the display panel 23 uses a first back film 23c made of PET. To meet strength requirements, its thickness is at least 50 μm, which is much greater than the 20 μm thickness of the first back film 23c in this embodiment. Compared to conventional display modules, the display module 2 in this embodiment is thinner, which is beneficial for reducing the overall thickness of the device.

[0094] In one embodiment, by setting the material of the first back film 23c to SUS stainless steel with a thickness of 20 μm, the display module 2's resistance to compression and impact can be enhanced, as well as its creep resistance and crease effect can be improved. This will be explained below with reference to simulation results.

[0095] Table 1 compares the compression and impact resistance of the solution in this embodiment with that of the conventional solution. The semi-folded state compression test (weak point in the axial area) refers to the test where, with the electronic device 1 in a semi-folded state (the angle between the first housing 31 and the second housing 33 is approximately 90°), a pointed tip is used to compress the bending area 2b of the display module 2 with a set force (kgf), testing the force required for the screen to fail (e.g., produce bright spots). According to Table 1, in this embodiment, with the electronic device 1 in a semi-folded state, the screen only fails when the pointed tip compresses the bending area 2b with a force of 5.33 kgf. However, in the conventional solution, only a force of 3.14 kgf is required to cause screen failure. This demonstrates that the compression resistance of the display module 2 is significantly improved compared to the conventional solution in this embodiment.

[0096] In Table 1, the whole-machine impact (weak point in the shaft area) refers to the impact of a pointed object falling naturally from a set height onto the bending area 2b of the display module 2, testing at what height the screen will fail (e.g., produce bright spots). According to Table 1, in this embodiment, when the electronic device 1 is in a semi-folded state, the screen will only fail when the pointed object is dropped from a height of 3.72cm onto the bending area 2b. However, in conventional solutions, the screen will fail when the pointed object is dropped from a height of only 2.64cm onto the bending area 2b. This indicates that the impact resistance of the display module 2 is significantly improved compared to conventional solutions in this embodiment.

[0097] Therefore, the solution in this embodiment greatly improves the resistance to compression and impact of the display module 2, and the screen is less prone to failure compared to conventional solutions.

[0098] plan This embodiment Conventional solution Whole machine semi-folded extrusion (weak point in shaft area) / kgf 5.33 3.14 Overall impact (weak point in shaft area) / cm 3.72 2.64

[0099] Table 1 Comparison of compression resistance and impact resistance between this embodiment and conventional solutions

[0100] Figure 13 This is a comparison image of the creases after the display module switches from a bent state to a flattened state in this embodiment and the conventional embodiment. The horizontal axis represents the horizontal position of the display module 2 in μm, with the zero point representing the location of the main axis 233; the vertical axis represents the bulge height in μm, with the zero point representing the height reference of the flattened surface of the display module 2. According to... Figure 13 As can be seen, after the electronic device 1 is bent several times, both the display module in this embodiment and the conventional solution show slight indentations near the main axis. However, the display module 2 in this embodiment remains essentially horizontal and close to zero on both sides of the indentation, making the crease and shadow less noticeable; the display module 2 in the conventional solution shows significant bulges on both sides of the indentation, resulting in obvious creases and greatly affecting the visual experience. Therefore, the solution in this embodiment significantly improves the crease and enhances the screen display's refinement.

[0101] Figure 14 This is a top view of the display module 2 in its unfolded state in one embodiment. Figure 15 for Figure 14 A partial cross-sectional view of the display panel 23 and electrical connection structure 25 in the display module 2.

[0102] In one embodiment, the electronic device 1 may further include a light sensor, which may be located below the display module 2, i.e., on the side of the display module 2 facing the housing, and may be located in the effective display area 2f. This design helps to increase the screen-to-body ratio of the electronic device 1 and achieve a narrow bezel effect. The light sensor is used to sense the ambient light passing through the display module 2 to detect the intensity of ambient light, enabling the electronic device 1 to automatically adjust the screen display effect (e.g., adjust brightness or color temperature) or perform other functions according to the lighting conditions.

[0103] To meet the light transmission requirements of display module 2, combined with Figure 14 and Figure 15 As shown, exemplarily, the display module 2 may also be provided with an ambient light aperture area 2h. Along the thickness direction of the display module 2, the orthographic projection of the ambient light aperture area 2h onto the display layer 23a is located within the boundary of the display layer 23a, or in other words, within the effective display area 2f. The shape of the ambient light aperture area 2h is not limited; for example, it can be circular. The ambient light aperture area 2h allows ambient light to pass through. A light sensor can be located below the ambient light aperture area 2h.

[0104] like Figure 15 As shown, in this embodiment, multiple through holes 231c can be formed in the region corresponding to the ambient light aperture region 2h of the first back film 23c. These through holes 231c can be arranged in an array according to a certain pattern. The shape, aperture, spacing, and number of through holes 231c can be determined as needed, and this embodiment does not impose any limitations. For example... Figure 16 , Figure 17 and Figure 18 Several patterns of through holes 231c on the first back film 23c are illustrated. By arranging multiple through holes 231c in an array, the area of ​​the first back film 23c corresponding to the ambient light aperture region 2h can both transmit light, meeting the light transmission requirements of the display module 2, and ensure that the first back film 23c has sufficient strength to support and protect the display panel 23. In this embodiment, the area of ​​the display layer 23a corresponding to the ambient light aperture region 2h can have sufficient light transmission performance, and this area of ​​the display layer 23a may not have through holes.

[0105] In another embodiment, depending on the product requirements, a larger through hole 231c may be formed on the first back film 23c, instead of multiple smaller through holes 231c.

[0106] Based on the above embodiments, Figure 19 A partial cross-sectional view of the display panel 23 and electrical connection structure 25 in another embodiment is shown. For example... Figure 19 As shown, in this embodiment, several holes 231a can also be formed in the area corresponding to the ambient light aperture area 2h of the display layer 23a. Along the thickness direction of the display panel 23 (e.g.) Figure 19In the Z-direction of the display layer 23a, these holes 231a can form a light channel with the through hole 231c. The number of holes 231a can match the number of through holes 231c; for example, the two numbers can be the same or close, or they can differ significantly. The aperture and position of the holes 231a can match the aperture and position of the through holes 231c to achieve better light transmission. It is understood that the display layer 23a can be composed of multiple layers of materials, and the holes 231a can penetrate only some layers (e.g., the light-shielding layer) of the display layer 23a, or they can penetrate the entire display layer 23a. This embodiment does not specifically limit this. In this embodiment, by further providing holes 231a on the display layer 23a, the light transmission performance of the ambient light aperture area 2h can be enhanced.

[0107] In the description of the embodiments in this application, unless otherwise stated, "multiple" means two or more.

[0108] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0109] The term "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Similarly, "fixation" should also be interpreted broadly. For example, "fixation" can be direct fixation or indirect fixation through an intermediate medium.

[0110] The directional terms mentioned in the embodiments of this application, such as "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "side," "top," and "bottom," are only for reference to the directions in the accompanying drawings. These directional terms are used to better and more clearly explain and understand the embodiments of this application, and are not intended to explicitly or implicitly suggest that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, etc., and therefore should not be construed as limiting the embodiments of this application.

[0111] In the description of the embodiments in this application, unless otherwise stated, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0112] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A display module, characterized in that, the display module comprises an effective display area and a binding area, the effective display area is connected with the binding area; the display module comprises a display layer, a first back film and a second back film, the first back film is bonded to the display layer by a first adhesive, the first back film is located at the backlight side of the display layer, the second back film is bonded to the binding area by a second adhesive, the modulus of the second adhesive at room temperature is equal to the modulus of the first adhesive at room temperature; the modulus of the first back film is greater than the modulus of the second back film.

2. The display module according to claim 1, characterized in that, the modulus of the first back film is greater than or equal to 30Gpa.

3. The display module according to claim 1, characterized in that, the modulus of the second back film is ∈[3Gpa, 10Gpa].

4. The display module according to claim 1, characterized in that, the thickness of the first back film is less than or equal to the thickness of the second back film.

5. The display module according to claim 1, characterized in that, the first back film comprises a stainless steel layer, the thickness of the stainless steel layer is 15μm-30μm.

6. The display module according to claim 1, characterized in that, the first back film comprises an ultra-thin glass (UTG) layer, a titanium alloy layer or a nickel-based superalloy layer.

7. The display module according to any one of claims 1-6, characterized in that, the second back film is polyethylene terephthalate (PET) or transparent polyimide (CPI).

8. The display module according to any one of claims 1-6, characterized in that, the modulus of the first adhesive at room temperature is less than or equal to 40Kpa.

9. The display module according to any one of claims 1-6, characterized in that, the thickness of the first adhesive is 15μm-25μm, and / or the thickness of the second adhesive is 15μm-25μm.

10. The display module according to any one of claims 1-6, characterized in that, the first back film is provided with a plurality of through holes, the plurality of through holes all penetrate the first back film along the thickness direction of the first back film.

11. An electronic device, characterized in that, comprising a shell and the display module according to any one of claims 1-10, the display module is fixed to the shell.

12. The electronic device according to claim 11, characterized in that, the shell comprises a first shell and a second shell; the electronic device further comprises a rotating shaft, the rotating shaft connects the first shell and the second shell, the first shell, the rotating shaft and the second shell are located on the same side of the display surface of the display module, and the display module is fixedly connected with the first shell and the second shell; the rotating shaft is used to generate mechanism movement, so that the first shell rotates relative to the second shell and drives the display module to deform, so that the electronic device is folded or unfolded.

13. The electronic device according to claim 12, characterized in that, in the folded state, at least a part of the display module is located between the first shell and the second shell.

14. The electronic device of claim 12, wherein the effective display area comprises a bending area, and the bending area is fixed to the rotating shaft. The display module further comprises a support layer, the display layer, the first back film and the support layer are stacked in sequence, and the support layer is located in the effective display area; and a gap is formed between the part of the support layer located in the bending area and the rotating shaft.

15. The electronic device of any one of claims 11-14, wherein the first back film is provided with a plurality of through holes, and the plurality of through holes all penetrate the first back film along the thickness direction of the first back film. The electronic device further comprises a light sensor, the light sensor is arranged on the side of the display module facing the shell, and the light sensor is located in the effective display area; and the light sensor is configured to receive light passing through the plurality of through holes. ​ ​

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