Folding display device and rear case thereof

Abstract

A rear case of a folding display device, relating to the technical field of display. The rear case comprises a fixing part and supporting parts disposed on two sides of the fixing part. The supporting parts are connected to the fixing part by means of a flexible connecting part, and the rigidity of the flexible connecting part is less than that of the supporting parts and the fixing part. By bending the flexible connecting part, the rear case can be switched at least between an unfolded form and a folded form. In the unfolded form, the supporting parts and the flexible connecting part are coplanar; and in the folded form, the flexible connecting part is arc-shaped and the supporting parts are stacked. The risk of abnormal display can be reduced.

Description

Foldable display device and its back cover

[0001] Cross-referencing

[0002] This disclosure claims priority to Chinese Patent Application No. 202410684051.4, filed on May 29, 2024, entitled "Foldable Display Device and Rear Sheet Thereof," the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of display technology, and more specifically, to a foldable display device and its rear cover. Background Technology

[0004] With the development of flexible display technology, foldable display devices such as foldable phones are being widely used. However, existing foldable display devices may experience display abnormalities during use.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] This disclosure provides a foldable display device and a rear cover for the foldable display device.

[0007] According to one aspect of this disclosure, a rear shell of a foldable display device is provided, including a fixing part and support parts disposed on both sides of the fixing part, wherein the support parts are connected to the fixing part through a flexible connecting part, and the stiffness of the flexible connecting part is less than the stiffness of the support part and the fixing part.

[0008] The flexible connecting portion can be bent to allow the rear shell to switch between at least an unfolded and a folded state; in the unfolded state, the supporting portion and the flexible connecting portion are coplanarly distributed; in the folded state, the flexible connecting portion is arc-shaped, and the supporting portion is stacked.

[0009] In one exemplary embodiment of this disclosure, the flexible connection is a flat plate structure and its material is an elastic material.

[0010] In one exemplary embodiment of this disclosure, the material of the flexible connection includes at least one of silicone and rubber.

[0011] In one exemplary embodiment of this disclosure, the flexible connecting part is a plate-like structure and has a first side and a second side facing away from each other. The first side is attached to the supporting part, and the second side is attached to the fixing part.

[0012] In one exemplary embodiment of this disclosure, one of the surfaces of the first side and the flexible connecting portion that abut against the first side is provided with a first protrusion, and the other is provided with a first recess, wherein the first protrusion is fitted into the first recess;

[0013] One of the second side surface and the surface of the fixing part that abuts with the second side surface is provided with a second protrusion, and the other is provided with a second recess, with the second protrusion fitting into the second recess.

[0014] In one exemplary embodiment of this disclosure, the surface of the support portion that abuts the first side and the surface of the fixing portion that abuts the second side are uneven surfaces, the first side engages with the surface of the support portion, and the second side engages with the fixing portion.

[0015] In one exemplary embodiment of this disclosure, the support portion and the fixing portion are provided with insertion holes, the insertion holes are provided with a stop block, the flexible connecting portion is provided with a flange, and one end of the flexible connecting portion is inserted into the insertion hole, so that the flange blocks the side of the stop block near the bottom of the insertion hole.

[0016] In one exemplary embodiment of this disclosure, the flexible connection portion is a pleated structure.

[0017] In one exemplary embodiment of this disclosure, the flexible connection is a wave structure, which includes a plurality of peaks and valleys that are alternately distributed from the fixed part to the supporting part.

[0018] In one exemplary embodiment of this disclosure, the height of the peak and the depth of the valley are not greater than the thickness of the fixing portion.

[0019] In one exemplary embodiment of this disclosure, the material of the flexible connection includes at least one of spring steel and copper alloy.

[0020] In one exemplary embodiment of this disclosure, the flexible connecting part is a plate-like structure and has multiple through holes.

[0021] In one exemplary embodiment of this disclosure, the flexible connection portion satisfies the following relationship:

[0022] ΔL=πR-2R;

[0023] ΔL is the difference between the length of the flexible connecting part in the folded state and the length in the unfolded state, and R is the radius of the flexible connecting part in the folded state.

[0024] In one exemplary embodiment of this disclosure, the support includes a base plate and a flange extending along the edge of the base plate, the flange surrounding an area capable of accommodating a portion of a flexible display panel.

[0025] In one exemplary embodiment of this disclosure, the flange is an open frame structure having an opening facing the fixing part.

[0026] In one exemplary embodiment of this disclosure, the fixing part includes a base plate and an annular retaining wall disposed on one side of the base plate; the area surrounded by the retaining wall can accommodate at least a portion of the hinge device.

[0027] In one exemplary embodiment of this disclosure, the substrate is provided with a fixing post, which can be connected to the hinge device by screws.

[0028] In one exemplary embodiment of this disclosure, the surface of the retaining wall away from the substrate is provided with a slot, which can be inserted into a tongue on the hinge device.

[0029] In one exemplary embodiment of this disclosure, the fixing part and the supporting part are made of the same material.

[0030] According to one aspect of this disclosure, a foldable display device is provided, comprising:

[0031] The back cover described in any of the above;

[0032] A hinge device is connected to the fixed part;

[0033] A flexible display panel is disposed on the side of the hinge device away from the rear shell and is connected to the hinge device and the support portion; the flexible display panel has a bending portion that overlaps with the fixing portion.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0036] Figure 1 is an exploded view of one embodiment of the display device of this disclosure.

[0037] Figure 2 is a schematic diagram of the first type of implementation of the rear shell in its unfolded form.

[0038] Figure 3 is a schematic diagram of the first type of implementation of the rear shell switching from an unfolded form to a folded form.

[0039] Figure 4 is a frontal view of the second type of implementation of the rear shell in the unfolded state.

[0040] Figure 5 is a schematic diagram of the rear side of the second embodiment of the rear shell in the unfolded state.

[0041] Figure 6 is a partial schematic diagram of the second type of implementation of the rear shell.

[0042] Figure 7 is a schematic diagram from one perspective showing the second type of implementation of the rear shell switching from an unfolded form to a folded form.

[0043] Figure 8 is a schematic diagram from another perspective showing the second type of implementation of the rear shell switching from an unfolded form to a folded form.

[0044] Figure 9 is a partial schematic diagram of the first type of implementation of the rear shell switching from an unfolded form to a folded form.

[0045] Figure 10 is a partial schematic diagram of the first type of embodiment of the rear shell in the unfolded state. Detailed Implementation

[0046] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0047] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0048] In this article, the "overlap" of features A and B means that the orthographic projections of features A and B on a plane at least partially coincide; the plane can be the surface of a flexible display panel, a driving backplane, a substrate, etc.

[0049] This disclosure provides a foldable display device, which can be an electronic device with display function such as a mobile phone or tablet computer, and can realize a folding function, which will not be listed here. As shown in FIG1, the foldable display device may include a flexible display panel 1, a hinge device and a back shell 2, wherein:

[0050] The flexible display panel 1 can be a display panel that can be bent at any position, or it can be a display panel that is only bent partially. In some embodiments of this disclosure, the flexible display panel 1 may include a bent portion 11 and two non-bent portions 12 connected to both sides of the bent portion 11. Both the bent portion 11 and the non-bent portions 12 can display images, and the degree of bending of the bent portion 11 can be adjusted by applying an external force to the flexible display panel 1, so that the two non-bent portions 12 are at a certain angle or parallel. For example, by bending the bent portion 11, the flexible display panel 1 can switch between an unfolded state and a folded state. In the unfolded state, the flexible display panel 1 is flat, that is, the bent portion 11 is not bent and is coplanar with the two non-bent portions 12 (extending along the same plane). In the folded state, the bent portion 11 is arc-shaped, and the two non-bent portions 12 are parallel. It should be noted that, considering factors such as process limitations and measurement errors, the plane and parallelism mentioned herein are not limited to geometrically perfect planes and parallelism.

[0051] The flexible display panel 1 can be a liquid crystal display panel or a self-emissive display panel using light-emitting diodes as light-emitting devices, as long as it can be bent. The flexible display panel 1 has a display area and a peripheral area located outside the display area. The peripheral area can be a continuous annular area surrounding the display area, or it can be a discontinuous area surrounding the display area, for example, the peripheral area can be distributed on both sides of the display area. The display area can emit light to display images, while the peripheral area does not emit light. The aforementioned bent portion 11 and non-bent portion 12 both include parts of the aforementioned display area, that is, both the bent portion 11 and non-bent portion 12 can display images.

[0052] Taking a self-emissive display panel as an example, the flexible display panel 1 may include a driving backplate and multiple light-emitting devices disposed on one side of the driving backplate, wherein:

[0053] The driving backplane has a driving circuit that drives the light-emitting device to emit light to display an image. In some embodiments of this disclosure, the driving backplane may include a substrate and a circuit layer located on one side of the substrate. The circuit layer includes the aforementioned driving circuit. For example, the driving circuit may include pixel circuits located in the display area and peripheral circuits located in the peripheral area. Both the pixel circuits and the peripheral circuits may employ multiple thin-film transistors and capacitors; the specific structure is not particularly limited here. Furthermore, the transistors may be top-gate or bottom-gate transistors. Each transistor may include an overlapping active layer and a gate, with the active layers of each transistor disposed on the same semiconductor layer; alternatively, multiple semiconductor layers may be disposed, with the active layers of different transistors distributed on different semiconductor layers. The material of the semiconductor layer may be polycrystalline silicon or metal oxide; no particular limitation is made here.

[0054] The light-emitting device can be located within the display area. It can be an OLED (organic light-emitting diode) using organic light-emitting materials, or a Mini LED (sub-millimeter light-emitting diode with a size of 100μm-200μm), Micro LED (micro light-emitting diode with a size of no more than 100μm), or LED (light-emitting diode with a size of more than 200μm) using inorganic light-emitting materials. No special restrictions are imposed here, as long as it can emit light.

[0055] Taking OLED as an example, the light-emitting device may include a first electrode, a light-emitting layer, and a second electrode stacked sequentially in a direction away from the driving backplane. By applying an electrical signal to the first and second electrodes, the light-emitting layer can be excited to emit light; the specific light-emitting principle will not be detailed here. The first electrode can serve as the anode, and the second electrode can serve as the cathode; both are made of conductive materials such as metals and metal oxides. Simultaneously, the display panel may also include a pixel definition layer separating the light-emitting devices. This layer can be located on the same surface of the driving backplane as the light-emitting devices and covers a portion of each first electrode, having pixel openings that expose each first electrode, thereby defining the range of each light-emitting device.

[0056] The bending portion 11 of the flexible display panel 1 can be bent by using a substrate of flexible material or by providing openings in the substrate of the bending portion 11. No specific limitation is made here on the specific scheme for achieving bending.

[0057] The hinge device can be located on the backlight side of the flexible display panel 1, i.e., the side where no image is displayed, and is connected to the non-bending part 12. It can bend synchronously with the bending of the flexible display panel 1. Through the transmission of the hinge device, the non-bending part 12 connected to it can rotate synchronously. At the same time, the hinge device can provide damping for the rotation of the non-bending part 12. A certain external force is required to switch between the unfolded and folded states. After the external force is stopped, the damping prevents the non-bending part 12 from staying in any position. For example, in the unfolded state, by applying an external force to the non-bending part 12, the flexible display panel 1 is bent towards the folded state. However, the external force does not need to continue to the folded state. It is only necessary to bend the flexible display panel 1 at a certain angle. Even without external force, the flexible display panel 1 can be bent into the folded state under the damping of the hinge device. Of course, when returning to the unfolded state, the aforementioned damping needs to be overcome so that the bending part 11 no longer bends and returns to the unfolded state.

[0058] Furthermore, the non-bending portion 12 can be stopped at any position by the damping of the hinge device, thereby forming any included angle. Therefore, when switching between the unfolded and folded forms, an external force needs to be continuously applied.

[0059] To achieve the above-mentioned different functions, hinge devices with different structures can be used. Among them, the above-mentioned damping can be provided by elastic elements such as springs, and synchronous rotation can be achieved by gears. The specific structure is not specifically limited here.

[0060] As shown in Figures 1, 2, and 4, the back cover 2 can be divided into multiple parts, including a fixed part 21 and support parts 22 located on both sides of the fixed part 21. The support parts 22 can rotate relative to the fixed part 21. A hinge device can be fixed to the fixed part 21. The flexible display panel 1 is located on the side of the hinge device away from the back cover 2, and the non-bending part 12 can be fixed to the two fixed parts 21 respectively. The bending part 11 can overlap with the hinge device and the fixed part 21. The support part 22 and the non-bending part 12 connected thereto can move synchronously, so that the back cover 2 can also switch between a folded state and an unfolded state. That is, when the flexible display panel 1 is in a folded state, the back cover 2 is also in a folded state, and when the flexible display panel 1 is in an unfolded state, the back cover 2 is also in an unfolded state.

[0061] Furthermore, as shown in Figure 1, the foldable display device may also include a non-flexible secondary display panel 3, which can be fixed to the rear shell 2 and located on the side of the hinge device away from the flexible display panel 1. Simultaneously, the size of the secondary display panel 3 is smaller than that of the flexible display panel 1, and it can be located on one side of the fixing part 21, overlapping only with one non-bending part 12 of the flexible display panel 1. That is, the size of the secondary display panel 3 is less than half that of the flexible display panel 1, and the secondary display panel 3 emits light towards the side away from the flexible display panel 1, meaning the light emission directions of the secondary display panel 3 and the flexible display panel 1 are opposite. In the folded state, the flexible display panel 1 is folded inward, meaning the light-emitting surfaces of the two non-bending parts 12 are facing each other. At this time, the flexible display panel 1 is off and cannot be viewed; the secondary display panel 3 can be used to display images. In the unfolded state, the secondary display panel 3 is off, and the flexible display panel 1 displays images.

[0062] The secondary display panel 3 can be a liquid crystal display panel or a self-emissive display panel using light-emitting diodes as light-emitting devices, etc. There are no special restrictions on its structure, as long as it can display images. At the same time, the secondary display panel 3 does not need to be bent, so there are no restrictions on whether it can be a flexible display panel.

[0063] To ensure that the support part 22 can rotate relative to the fixed part 21, a certain gap can be made between the support part 22 and the fixed part 21. In the unfolded state, the support part 22 and the fixed part 21 can be distributed on the same plane. In the folded state, the two support parts 22 can be arranged in parallel, and the fixed part 21 is located between the support parts 22. However, the inventors have found that because there is a large gap between the support part 22 and the fixed part 21, foreign objects such as sand can enter the display device through this gap. Even a single grain of sand can affect the rotation of the hinge device, causing changes in the bending trajectory of the flexible display panel 1, resulting in abnormal stress, damaging the display function, and easily causing display malfunctions.

[0064] Therefore, as shown in Figures 2 and 4, the inventors adjusted the structure of the back cover 2, using a flexible connecting part 23 to connect the fixing part 21 and the supporting part 22, thus connecting the supporting part 22 and the fixing part 21 into a whole. By bending the flexible connecting part 23, the back cover 2 can switch between an unfolded form and a folded form. During the switching process, the gap between the supporting part 22 and the fixing part 21 is always covered by the flexible connecting part 23, which can prevent foreign objects such as sand and gravel from entering the interior of the folded display device through the gap and damaging the flexible display panel 1, thereby reducing the risk of display abnormalities.

[0065] The following is a detailed description of each part of the aforementioned rear shell 2:

[0066] As shown in Figures 2, 4, and 6, the fixing part 21 is made of a rigid material and is non-bending, which can fix the hinge device. In some embodiments of this disclosure, the fixing part 21 includes a base plate 211 and a retaining wall 212, wherein:

[0067] As shown in Figures 2 and 6, the substrate 211 can be a flat plate structure, and the baffle 212 can be disposed on one side of the substrate 211. The baffle 212 can be a closed annular structure or an open annular structure, and its specific shape is not specifically limited here. The shape of the outline of the baffle 212 can be the same as the shape of the electrode plate; for example, both can be rectangular. The baffle 212 can be disposed on the surface of the substrate 211 and extend along the edge of the substrate 211. At least a portion of the hinge device can be disposed within the area surrounded by the baffle 212. The baffle 212 and the substrate 211 can be an integral structure; of course, they can also be independent structures, connected by means of snap-fit, welding, bonding, or using screws or other connectors.

[0068] Furthermore, as shown in Figures 2 and 6, a fixing post 213 is provided on the base plate 211. The fixing post 213 is located within the area surrounded by the retaining wall 212 and has an axially extending screw hole. The hinge device can be fixed to the base plate 211 by engaging the screw hole of the fixing post 213 with a threaded part such as a screw or bolt. The fixing post 213 and the base plate 211 can be an integral structure or connected by snap-fit, welding, bonding or other methods.

[0069] Furthermore, as shown in Figure 6, in some embodiments, the surface of the retaining wall 212 away from the substrate 211, i.e., the top surface of the retaining wall 212, may be provided with a slot 214. The depth of the slot 214 is not greater than the thickness of the retaining wall 212. The shape of the slot 214 may be rectangular, circular, etc., which are specifically limited here. At the same time, the hinge device may be provided with a tongue, which can be inserted into the slot 214 to position the hinge device. There may be multiple slots 214, which are distributed along the extension trajectory of the retaining wall 212. The number of tongues is the same as the number of slots 214, and they are inserted into each slot 214 in a one-to-one correspondence.

[0070] The fixing part 21 can be made of a rigid material. For example, the material of the fixing part 21 can be a non-metallic material such as plastic, such as PC (polycarbonate), PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene copolymer), etc., and can be manufactured by injection molding or other processes; or, the material of the fixing part 21 can also be a metallic material, such as magnesium-aluminum alloy, stainless steel, etc., without special limitation, and can be manufactured by sheet metal stamping or other processes.

[0071] Of course, the various parts of the fixing part 21 are not a single integrated structure, and different parts can be made of different materials. For example, if the base plate 221 and the retaining wall 212 are not a single integrated structure, then they can be made of different materials.

[0072] In addition, in other embodiments of this disclosure, the fixing part 21 may also adopt other structures, depending on the structure of the hinge device, as long as it can play the role of fixing and limiting.

[0073] As shown in Figures 2, 4, 6, and 8, the support portion 22 is used to support and position the non-bending portion 12 of the flexible display panel 1. It can also be used to fix and position the sub-display panel 3. Taking one support portion 22 as an example, in some embodiments of this disclosure, the support portion 22 includes a base plate 221 and a flange 222 disposed at the edge of the base plate 221, wherein:

[0074] The base plate 221 can be a flat structure, and the flange 222 can extend along the edge of the base plate 221 and protrude to one side of the base plate 221 to form an open frame structure. The area surrounded by the flange 222 can accommodate at least a portion of the non-bent portion 12 of the flexible display panel 1. The frame structure has an opening facing the fixing part 21 to avoid interference with the flexible display panel 1. The flange 222 and the base plate 221 can be an integral structure to simplify the process. Of course, the flange 222 and the base plate 221 can also be independent structures connected by means of bonding, snap-fitting, etc. In addition, in some embodiments, the support part 22 may not have a flange 222.

[0075] The two non-bending portions 12 of the flexible display panel 1 can be respectively located within the range surrounded by the flanges 222 of the two support portions 22. The flanges 222 can act as a frame and can rotate synchronously with the non-bending portions 12. Of course, the flexible display panel 1 itself can also have a frame and be limited within the range surrounded by the flanges 222. The bending portion 11 can overlap with the hinge device and the fixing portion 21.

[0076] As shown in Figures 2, 4, 6, and 8, the base plate 221 and the flange 222 can be rectangular or polygonal, with multiple corners, each of which can be rounded. Correspondingly, the corners of the flange 222 are arc-shaped. Simultaneously, the flange 222 can be perpendicular to the base plate 221, or the flange 222 can be an flared structure expanding away from the base plate 221 to accommodate the flexible display panel 1. Furthermore, the edges of the flange 222 and the base plate 221 can smoothly transition to prevent sharp edges.

[0077] The support part 22 can be made of rigid materials. For example, the material of the support part 22 can be non-metallic materials such as plastics, such as PC (polycarbonate), PVC (polyvinyl chloride), ABS (acrylonitrile-butadiene-styrene copolymer), etc., and can be manufactured by injection molding or other processes; or, the material of the support part 22 can also be metallic materials, such as magnesium-aluminum alloy, stainless steel, etc., without special limitation, and can be manufactured by sheet metal stamping or other processes.

[0078] Both the fixing part 21 and the supporting part 22 are rigid, non-bendable, and non-stretchable structures to ensure they provide stable support and fixation. In some embodiments of this disclosure, the fixing part 21 and the supporting part 22 may be made of the same material to simplify the manufacturing process and ensure uniform mechanical properties; for example, both may be made of plastic or stainless steel. Of course, this disclosure does not preclude embodiments in which the fixing part 21 and the supporting part 22 are made of different materials.

[0079] As described above, the support portion 22 and the fixing portion 21 can be connected by the flexible connecting portion 23, which covers the gap between the support portion 22 and the fixing portion 21 while ensuring that the folding function is not interfered with. For two support portions 22, one support portion 22 can be connected to the fixing portion 21 by one flexible connecting portion 23, so the number of flexible connecting portions 23 is also two.

[0080] To ensure the smooth implementation of the folding function, the stiffness of the flexible connecting part 23 can be less than that of the supporting part 22 and the fixing part 21. By bending the flexible connecting part 23, the rear shell 2 and the flexible display panel 1 can switch between folded and unfolded states. In the unfolded state, the supporting part 22 and the flexible connecting part 23 are coplanarly distributed, and the flexible display panel 1 is unfolded in a planar manner. In the folded state, the flexible connecting part 23 is arc-shaped, and the supporting parts 22 are stacked. For the supporting parts 22 with base plates 221, the base plates 221 of the two supporting parts 22 can be arranged in parallel.

[0081] As shown in Figures 2 and 4, in some embodiments of this disclosure, the flexible connecting part 23 may be a strip-shaped structure extending along the first direction Y, and the supporting part 22 and the flexible connecting part 23 may be distributed along the second direction X. The width of the flexible connecting part 23 in the second direction X is smaller than that of the supporting part 22 and the fixing part 21; the first direction Y and the second direction X.

[0082] The inventors propose that the above-mentioned stiffness requirement can be met by selecting a bendable elastic material, or by using a non-elastic material and designing a special structure to achieve the required stiffness. An example is provided below:

[0083] First type of implementation

[0084] As shown in Figures 2 and 3, the flexible connecting part 23 is made of an elastic material. The elasticity of the material itself makes its stiffness less than that of the supporting part 22 and the fixing part 21, allowing for bending. For example, the material of the flexible connecting part 23 may include silicone such as liquid silicone, rubber, or other polymers such as polyurethane. Because of the use of an elastic material, the flexible connecting part 23 can be bent, allowing the back shell 2 and the flexible display panel 1 to switch between folded and unfolded states under external force. Simultaneously, the elasticity of the material itself provides a certain degree of damping, which helps to reduce or eliminate the need for damping components such as springs in the hinge device, thus simplifying the structure.

[0085] The flexible connecting part 23 can be connected to the supporting part 22 and the fixing part 21 by means of bonding, snap-fitting, etc. Alternatively, the supporting part 22 and the fixing part 21 can be made of plastic. The flexible connecting part 23 can be connected to the supporting part 22 and the fixing part 21 by means of a mold with a cavity that can inject multiple materials, and can be formed by mixed injection molding. Although the materials are different, they can be formed by a one-time injection molding process, eliminating the need for special installation.

[0086] In some embodiments, the flexible connecting part 23 has a plate-like structure and has a first side and a second side facing away from each other. The first side can fit against the support part 22, and the second side can fit against the fixing part 21. In order to improve the bonding force between the flexible connecting part 23 and the support part 22 and the fixing part 21, and to make it less likely to fall off, a first protrusion can be provided on one of the surfaces of the first side and the support part 22 that abuts against the first side, and a first recess can be provided on the other side, with the first protrusion fitting into the first recess. At the same time, a second protrusion can be provided on one of the surfaces of the second side and the fixing part 21 that abuts against the second side, and a second recess can be provided on the other side, with the second protrusion fitting into the second recess. This increases the contact area between the flexible connecting part 23 and the support part 22 and the fixing part 21, and also plays a certain limiting role, reducing the risk of loosening.

[0087] The shape and size of the first protrusion, second protrusion, first recess, and second recess are not specifically limited here, and the heights of different first protrusions and different second protrusions can be different, as long as the above-mentioned structure of protrusion and recess engaging can be formed. For example, both the first side and the second side can be uneven surfaces. Correspondingly, the surface of the support part 22 that fits against the first side and the surface of the fixing part 21 that fits against the second side are also uneven surfaces. The uneven first side engages with the surface of the support part 22, and the uneven second side engages with the fixing part 21.

[0088] In addition, in some embodiments, the support part 22 and the fixing part 21 may be provided with insertion holes, the insertion holes may be provided with a stop block, and the flexible connection part 23 may be provided with a flange. One end of the flexible connection part 23 can be inserted into the insertion hole, so that the flange blocks the side of the stop block near the bottom of the insertion hole to prevent the flexible connection part from coming out. Since the flexible connection part 23 is an elastic material, it can undergo a certain deformation. Therefore, the flexible connection part 23 can be squeezed into the insertion hole by means of extrusion or other means, and limited by the stop block.

[0089] Second type of implementation

[0090] As shown in Figures 4-10, the flexible connection 23 can adopt a pleated structure, meaning it is not a flat plate but has certain undulations, thus having low stiffness without relying on the elasticity of the material itself, in order to achieve bending. Even if a non-elastic alloy is used, this wave structure can still be bent. Of course, this disclosure does not exclude the use of elastic materials with wave structures. For example, the material of the flexible connection 23 can be spring steel such as low-manganese spring steel or chromium-manganese spring steel, or it can be copper alloy, or both spring steel and copper alloy, so as to be manufactured by processes such as stamping and bending.

[0091] As shown in Figure 10, in some embodiments, the flexible connecting portion 23 is obtained by bending a flat plate structure, which can be a wave structure. The wave structure includes multiple peaks 231 and valleys 232 alternately distributed from the fixed portion 21 to the supporting portion 22. For example, there are two peaks 231 and three valleys 232. The cross-sectional contours of the peaks 231 and valleys 232 can be arc-shaped, parabolic, triangular, trapezoidal, etc. Furthermore, the height of the peaks 231 and the depth of the valleys 232 are not greater than the thickness of the fixed portion 21 to prevent the flexible connecting portion 23 from compressing the flexible display panel 1 during bending.

[0092] In the second type of embodiment, the support part 22 and the fixing part 21 can also be connected to the flexible connecting part 23 by means of bonding, snapping or screw connection, and if the support part 22, the fixing part 21 and the flexible connecting part 23 are all made of metal, they can also be connected by welding.

[0093] In addition, the flexible connecting part 23 has a first side and a second side facing away from each other. The first side can fit with the support part 22, and the second side can fit with the fixing part 21. In order to facilitate positioning and make the connection of the flexible connecting part 23 more secure, the flexible connecting part 23 and the support part 22, as well as the flexible connecting part 23 and the fixing part 21, can be connected by means of a socket and a plug. For example, the socket is provided in the support part 22 and the fixing part 21, and the plug is provided in the flexible connecting part 23.

[0094] In some embodiments of this disclosure, the flexible connection portion 23 of any of the above embodiments may also satisfy the following relationship:

[0095] ΔL=πR-2R;

[0096] ΔL is the difference between the length of the flexible connector 23 in the folded state and the length in the unfolded state, and R is the radius of the flexible connector 23 in the folded state.

[0097] The length of the flexible connecting part 23 is different in the folded and unfolded states. When bending from the unfolded state to the folded state, the flexible connecting part 23 can not only bend but also stretch. Therefore, in addition to bending, the flexible connecting part 23 should also have a telescopic function. The first and second types of embodiments described above can achieve this function.

[0098] In other embodiments of this disclosure, the flexible connection 23 can also be made bendable in other ways, for example:

[0099] The flexible connection part 23 is a plate-shaped structure, which can be made of elastic material or rigid material. Multiple through holes can be opened on the flexible connection part 23 to give it a certain degree of flexibility so that it can be bent, thereby meeting the requirement that the stiffness is lower than that of the support part 22 and the fixing part 21.

[0100] The outline of the through hole can be circular, rectangular, oval, etc., and the through holes can be arranged in an array. For example, the outline of the through hole can be oval, and the through holes can be divided into multiple groups. Each group includes multiple through holes distributed along the first direction Y. The through holes in each group are distributed along the second direction X. Furthermore, the through holes in adjacent groups are staggered to avoid the flexible connection 23 from breaking locally.

[0101] Furthermore, the aforementioned through holes can also be combined with the first and second type embodiments, that is, through holes can be provided for both the flexible connecting part 23 of the elastic material and the flexible connecting part 23 of the pleated structure, so as to facilitate bending.

[0102] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A rear shell of a foldable display device, comprising a fixing part and support parts disposed on both sides of the fixing part, wherein the support parts are connected to the fixing part via a flexible connecting part, and the stiffness of the flexible connecting part is less than the stiffness of the support part and the fixing part; The flexible connecting portion can be bent to allow the rear shell to switch between at least an unfolded and a folded state; in the unfolded state, the supporting portion and the flexible connecting portion are coplanarly distributed; in the folded state, the flexible connecting portion is arc-shaped, and the supporting portion is stacked.

2. The rear shell according to claim 1, wherein, The flexible connection is made of an elastic material.

3. The rear shell according to claim 2, wherein, The flexible connector is made of at least one of silicone and rubber.

4. The rear shell according to claim 1, wherein, The flexible connecting part is a plate-shaped structure with a first side and a second side facing away from each other. The first side is attached to the supporting part, and the second side is attached to the fixing part.

5. The rear shell according to claim 4, wherein, One of the first side surface and the surface of the support portion that abuts the first side surface is provided with a first protrusion, and the other is provided with a first recess, wherein the first protrusion is fitted into the first recess. One of the second side surface and the surface of the fixing part that abuts with the second side surface is provided with a second protrusion, and the other is provided with a second recess, with the second protrusion fitting into the second recess.

6. The rear shell according to claim 5, wherein, The surfaces of the support portion that fit against the first side and the surfaces of the fixing portion that fit against the second side are uneven surfaces. The first side engages with the surface of the support portion, and the second side engages with the fixing portion.

7. The rear shell according to claim 1, wherein, The support part and the fixing part are provided with insertion holes, the insertion holes are provided with a stop block inside, the flexible connection part is provided with a flange, one end of the flexible connection part is inserted into the insertion hole, so that the flange blocks the side of the stop block near the bottom of the insertion hole.

8. The rear shell according to claim 1, wherein, The flexible connection part has a pleated structure.

9. The rear shell according to claim 8, wherein, The flexible connection part has a wave structure, which includes multiple peaks and valleys that are alternately distributed from the fixed part to the supporting part.

10. The rear shell according to claim 9, wherein, The height of the peak and the depth of the valley are not greater than the thickness of the fixed part.

11. The rear shell according to claim 8, wherein, The material of the flexible connection includes at least one of spring steel and copper alloy.

12. The rear shell according to claim 1, wherein, The flexible connection part has a plate-like structure and is provided with multiple through holes.

13. The rear shell according to any one of claims 1-12, wherein, The flexible connection satisfies the following relationship: ΔL=πR-2R; ΔL is the difference between the length of the flexible connecting part in the folded state and the length in the unfolded state, and R is the radius of the flexible connecting part in the folded state.

14. The rear shell according to any one of claims 1-12, wherein, The support includes a base plate and a flange extending along the edge of the base plate, the area surrounded by the flange being capable of accommodating a portion of the flexible display panel.

15. The rear shell according to claim 14, wherein, The flange is an open frame structure with an opening facing the fixing part.

16. The rear shell according to any one of claims 1-12, wherein, The fixing part includes a base plate and an annular retaining wall disposed on one side of the base plate; the area surrounded by the retaining wall can accommodate at least a portion of the hinge device.

17. The rear shell according to claim 16, wherein, The base plate is provided with a fixing post, which can be connected to the hinge device by screws.

18. The rear shell according to claim 16, wherein, The surface of the retaining wall away from the substrate has a slot, which can be inserted into the tongue on the hinge device.

19. The rear shell according to any one of claims 1-12, wherein, The fixing part and the supporting part are made of the same material.

20. A foldable display device, comprising: The rear shell as described in any one of claims 1-19; A hinge device is connected to the fixed part; A flexible display panel is disposed on the side of the hinge device away from the rear shell and is connected to the hinge device and the support portion; the flexible display panel has a bending portion that overlaps with the fixing portion.

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