Rotating shaft mechanism and foldable electronic device

Abstract

Disclosed is a rotating shaft mechanism (13). The rotating shaft mechanism (13) is applied to a foldable electronic device (1), has an unfolded state and a folded state, and comprises: a main shaft (100); an inner support plate (200), which is movably connected to two sides of the main shaft in a width direction; and an outer support plate (300), which is located on two sides of the main shaft in the width direction and movably connected to one side of the inner support plate away from the main shaft. A plurality of support bulges (310) are formed on the surface of one side of the outer support plate away from a foldable screen (20) of the foldable electronic device; the plurality of support bulges are located on one side of the outer support plate close to the inner support plate; the support bulges are arranged in sequence along a width direction of the outer support plate; and at least some support bulges are configured to support a flexible printed circuit board (30) which penetrates the rotating shaft mechanism. Further disclosed is a foldable electronic device comprising the rotating shaft mechanism. The flexible printed circuit board is supported by the support bulges; on the basis of not affecting the stiffness of a support plate assembly or a decorative plate, the redundant space of the flexible printed circuit board can be significantly enlarged; and a bend radius of a first bending section of the flexible printed circuit board is increased, such that the overall bending of the flexible printed circuit board is more gentle, thereby improving the reliability and service life of the flexible printed circuit board.

Description

Hinge mechanism and foldable electronic device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on March 13, 2023, with application number 202310290599.6 and application name “Hinge mechanism and foldable electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of electronic devices, and in particular to a hinge mechanism and a foldable electronic device. Background Art

[0003] Foldable electronic devices can switch between unfolded and folded states, have the advantages of large screen display and easy portability, and are becoming increasingly popular among consumers.

[0004] The two main bodies of a foldable electronic device are connected by a hinge mechanism. The movement of the hinge mechanism enables relative rotation between the two bodies, enabling the foldable device to switch between its unfolded and folded states. In foldable electronic devices, a flexible circuit board (PCB) must pass through the hinge mechanism to connect the circuit boards within the two main bodies. During repeated folding of the device, the portion of the PCB located within the hinge mechanism will also bend repeatedly. Therefore, a certain amount of deformation margin is typically required for the PCB to meet reliability requirements.

[0005] However, with the trend of ultra-thin foldable electronic devices, the redundant space for accommodating flexible circuit boards in the hinge mechanism is getting smaller and smaller, and flexible circuit boards are prone to small-angle bending, which affects the reliability and service life of the flexible circuit boards.

[0006] Summary of the Invention

[0007] The present application provides a hinge mechanism and a foldable electronic device. The hinge mechanism can increase the redundant space of the flexible circuit board, avoid the flexible circuit board from bending at a small angle, make the bending posture of the flexible circuit board more smooth, and improve the reliability and service life of the flexible circuit board.

[0008] In one aspect, the present application provides a hinge mechanism for use in a foldable electronic device, which has an unfolded state and a folded state. The hinge mechanism includes:

[0009] spindle;

[0010] An inner support plate, movably connected to both sides of the main shaft in the width direction;

[0011] The outer support plates are located on both sides of the main shaft in the width direction and are movably connected to the side of the inner support plate facing away from the main shaft;

[0012] Among them, the surface of the outer support plate on one side facing away from the folding screen of the foldable electronic device has multiple support protrusions, and the multiple support protrusions are located on the side of the outer support plate close to the inner support plate, and the support protrusions are arranged in sequence along the width direction of the outer support plate, and at least some of the support protrusions are used to support the flexible circuit board passing through the hinge mechanism.

[0013] The hinge mechanism provided in the present application is designed to support the flexible circuit board (the first bending section) by using an outer support plate, and to support the flexible circuit board (the first bending section) by designing a plurality of support protrusions on the side surface of the outer support plate facing the flexible circuit board (the side surface facing away from the folding screen). By arranging the support protrusions on the side of the outer support plate close to the inner support plate, and each support protrusion is arranged in sequence along the width direction of the outer support plate, and the flexible circuit board is supported by the support protrusions, the redundant space of the flexible circuit board can be significantly increased without affecting the rigidity of the support plate assembly or the decorative plate, and the bending radius of the first bending section of the flexible circuit board can be increased, making the overall bending of the flexible circuit board smoother, preventing the flexible circuit board from delamination, thereby improving the reliability and service life of the flexible circuit board and improving the abnormal noise problem of the flexible circuit board during movement. In addition, by controlling the bending radius of the first bending section by combining multiple support protrusions, the bending requirements of flexible circuit boards with different redundant lengths can be met.

[0014] In a possible implementation, an end of the support protrusion away from the outer support plate has a protrusion vertex, and the protrusion vertex is used to support the flexible circuit board.

[0015] By extending the support protrusion toward one end of the decorative plate to form a raised apex, the support protrusion supports the flexible circuit board at this apex. This ensures the outer support plate precisely positions the flexible circuit board and accurately controls the bending radius of the first bending section of the flexible circuit board, preventing small-angle bending and improving the service life and reliability of the flexible circuit board. Furthermore, the support protrusion and the flexible circuit board form a point contact, resulting in a small contact area and low friction, which reduces any noise caused by the movement of the flexible circuit board.

[0016] In a possible implementation, an end surface of the supporting protrusion away from the outer support plate is a curved surface, and the vertex of the protrusion is the vertex of the curved surface.

[0017] By setting the top surface of the supporting protrusion to an ellipsoidal surface or a spherical surface, the top of the supporting protrusion forms a smooth curved surface protruding toward the decorative panel. In this way, the supporting protrusion can disperse the force acting on the top of the protrusion of the flexible circuit board, avoiding local damage or tearing of the flexible circuit board due to stress concentration, thereby ensuring the reliability of the flexible circuit board.

[0018] In one possible embodiment, the height of each supporting protrusion gradually increases in the direction away from the inner support plate; wherein the height of the supporting protrusion is the distance from the protrusion vertex to the reference plane of the outer support plate, and the reference plane is the plane where the straight section of the side surface of the outer support plate facing away from the folding screen is located, and when the hinge mechanism is in a folded state, the straight section is perpendicular to the width direction of the main axis.

[0019] By designing each supporting protrusion to gradually increase in height in the direction away from the inner supporting plate, the supporting protrusion can play a guiding role and support the flexible circuit board to bend toward the direction where the decorative plate is located, so that the flexible circuit board can transition from the first bending section to the second bending section.

[0020] In a possible embodiment, the apex of each supporting protrusion and the support point on the inner wall surface of the inner support plate for supporting the flexible circuit board are both located on a preset arc surface; wherein, the inner wall surface of the inner support plate is the side surface of the inner support plate facing away from the folding screen.

[0021] By making the apex of each supporting protrusion on the outer support plate and the supporting point on the inner wall surface of the inner support plate located on a preset arc surface, the preset arc surface can be a pre-designed arc with a reasonable bending radius, so as to accurately control the bending radius of the first bending section of the flexible circuit board and avoid small-angle bending of the flexible circuit board.

[0022] In a possible implementation, the difference between the radius of the preset arc surface and the thickness of the flexible circuit board is greater than 0.5 mm.

[0023] By designing the difference between the radius of the preset arc surface and the flexible circuit board to be greater than 0.5 mm, the flexible circuit board can be prevented from bending at a small angle, thereby ensuring the service life and reliability of the flexible circuit board.

[0024] In a possible embodiment, among the support protrusions, the support protrusion closest to the inner support plate is a proximal protrusion, the support protrusion farthest from the inner support plate is a distal protrusion, and at least one intermediate protrusion is provided between the proximal protrusion and the distal protrusion;

[0025] Among them, on the preset arc surface, the central angle corresponding to the arc between the proximal protrusion and the support point is the first central angle, and the angle of the first central angle is ≥45° and ≤65°; the central angle corresponding to the arc between the distal protrusion and the support point is the second central angle, and the angle of the second central angle is ≥80° and ≤100°.

[0026] By setting the first central angle of the proximal protrusion to ≥45° and ≤65°, the proximal protrusion maintains an appropriate distance from the support point, ensuring stable support for the flexible circuit board. This facilitates adjustment of the bending radius of the first bend section and facilitates the design of subsequent support protrusions. By setting the second central angle of the distal protrusion to ≥80° and ≤100°, the arc length between the distal and proximal protrusions is maintained, facilitating the placement of an intermediate protrusion between the two. The support protrusions can be matched according to the redundant length of the flexible circuit board.

[0027] In a possible implementation, the first central angle is 60°, and the second central angle is 90°.

[0028] In a possible embodiment, an intermediate protrusion is provided between the proximal protrusion and the distal protrusion, and the central angle corresponding to the arc between the intermediate protrusion and the support point is the third central angle, and the angle of the third central angle is greater than 65° and less than 80°.

[0029] By placing an intermediate protrusion between the proximal and distal protrusions, different combinations of the three supporting protrusions can meet the requirements of flexible circuit boards with different redundant lengths. Furthermore, by controlling the third central angle corresponding to the intermediate protrusion to be greater than 65° and less than 80°, the three supporting protrusions can stably support the flexible circuit board and precisely control the bending radius of the first bending section of the flexible circuit board.

[0030] In a possible implementation manner, the third central angle is 75°.

[0031] By setting the central angles corresponding to the proximal protrusion, the middle protrusion and the distal protrusion to 60°, 75° and 90° respectively, the width range covered by each support protrusion on the outer support plate and the spacing between adjacent support protrusions are appropriate, and the needs of flexible circuit boards with different redundant lengths can be met by matching the support protrusions.

[0032] In a possible implementation, when the redundancy factor of the flexible circuit board is within a first preset range, the proximal protrusion contacts the flexible circuit board;

[0033] When the redundancy factor of the flexible circuit board is within a second preset range, the proximal protrusion and at least a portion of the middle protrusion are in contact with the flexible circuit board;

[0034] When the redundancy factor of the flexible circuit board is within a third preset range, the proximal protrusion and the distal protrusion are in contact with the flexible circuit board;

[0035] The maximum value of the first preset range is less than the minimum value of the second preset range, the maximum value of the second preset range is less than the minimum value of the third preset range, and the redundancy factor of the flexible circuit board is the percentage of the redundant length of the flexible circuit board to the reference length of the flexible circuit board.

[0036] The coordination of the supporting protrusions on the outer support plate is controlled based on the redundancy factor of the flexible circuit board to accommodate flexible circuit boards of varying redundancy lengths. Regardless of the redundancy length of the flexible circuit board, the proximal protrusions can always contact the flexible circuit board. Furthermore, the greater the redundancy factor of the flexible circuit board, the larger the bending radius of the first bending section of the flexible circuit board should be.

[0037] In a possible implementation manner, the first preset range is >0 and ≤1, the second preset range is >1 and ≤2, and the third preset range is >2.

[0038] In a possible embodiment, the outer wall surface of the supporting protrusion is a smooth wall surface that smoothly extends from the protrusion vertex to the surface of the outer support plate.

[0039] In a possible embodiment, the width of the support protrusion gradually increases from the top of the protrusion to the end where the support protrusion is connected to the outer support plate;

[0040] Alternatively, from the apex of the protrusion to one end of the supporting protrusion connected to the outer supporting plate, the supporting protrusion includes a transition section and a straight rod section connected in sequence, the width of the transition section gradually increases, and the width of the straight rod section remains fixed.

[0041] In a possible embodiment, from the apex of the protrusion to one end of the support protrusion connected to the outer support plate, the support protrusion includes a head and a rod, and the connection portion between the head and the rod is a diameter-reducing portion.

[0042] In a possible embodiment, the width of the rod is fixed or gradually increases from the end of the rod connected to the head to the end of the rod connected to the outer support plate.

[0043] In a possible implementation, there is a gap between adjacent supporting protrusions, or adjacent supporting protrusions overlap with each other.

[0044] In a possible implementation, the method further includes:

[0045] The decorative plate is movably connected on both sides of the main shaft in the width direction, and is arranged on both sides of the main shaft in the thickness direction opposite to the inner support plate. The decorative plate, the inner support plate and the outer support plate together form a space for accommodating the flexible circuit board.

[0046] By flexibly connecting decorative panels to both sides of the main shaft in the width direction and positioning them on the opposite side of the main shaft in the thickness direction from the support plate assembly, the decorative panels serve to conceal the components connecting the main shaft and the support plate assembly, enhancing the appearance of the foldable electronic device. The space between the decorative panels and the support plate assembly accommodates the flexible circuit board that passes through the hinge mechanism.

[0047] In a possible implementation, the method further includes:

[0048] The fixing component is installed on the main shaft and is used to fix the flexible circuit board.

[0049] In a possible implementation, the fixing assembly includes a first magnetic member and a second magnetic member that are arranged opposite to each other, and the first magnetic member and the second magnetic member are used to clamp the flexible circuit board.

[0050] By providing the first magnetic component and the second magnetic component, the flexible circuit board is positioned by relying on magnetic attraction, so that the flexible circuit board can be positioned stably. Moreover, the flexible circuit board is not completely restricted. Under a large force, the flexible circuit board can overcome the magnetic attraction and produce a small displacement to protect the flexible circuit board from being torn or pulled.

[0051] On the other hand, the present application provides a foldable electronic device, including a first shell, a second shell and the hinge mechanism as described above, wherein the first shell and the second shell are respectively connected to two sides of the hinge mechanism.

[0052] The foldable electronic device provided in the present application includes a first housing, a second housing, and a hinge mechanism connected therebetween. The hinge mechanism supports the flexible circuit board (the first bending section) by designing a structural design of the support plate assembly, using an outer support plate to support the flexible circuit board. Multiple support protrusions are designed on the side of the outer support plate facing the flexible circuit board (the side facing away from the folding screen). The support protrusions are arranged on the side of the outer support plate close to the inner support plate, and each support protrusion is arranged in sequence along the width direction of the outer support plate. The flexible circuit board is supported by the support protrusions. This can significantly increase the redundant space of the flexible circuit board without affecting the rigidity of the support plate assembly or the decorative plate, increase the bending radius of the first bending section of the flexible circuit board, make the overall bending of the flexible circuit board smoother, prevent delamination of the flexible circuit board, thereby improving the reliability and service life of the flexible circuit board and improving the abnormal noise problem of the flexible circuit board during movement. In addition, by controlling the bending radius of the first bending section by combining multiple support protrusions, the bending requirements of flexible circuit boards with different redundant lengths can be met.

[0053] In one possible embodiment, the foldable electronic device further includes a foldable screen, which is mounted on the first housing and the second housing, and supported by the hinge mechanism;

[0054] When the foldable electronic device is in a folded state, the first shell and the second shell are relatively stacked, and the folding screen is surrounded by the first shell and the second shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 is a schematic structural diagram of a foldable electronic device in an unfolded state provided by an embodiment of the present application;

[0056] FIG2 is a schematic structural diagram of the foldable electronic device shown in FIG1 in a folded state;

[0057] FIG3 is a schematic diagram of the exploded structure of a foldable electronic device provided in an embodiment of the present application;

[0058] FIG4 is a schematic diagram of a partial structure of a foldable electronic device provided in an embodiment of the present application;

[0059] FIG5 is an enlarged structural diagram of the foldable electronic device in FIG4 ;

[0060] FIG6 is a schematic diagram of a flexible circuit board in a bent state in a related art;

[0061] FIG7 is a schematic diagram of another state of a flexible circuit board in the related art when it is in a bent state;

[0062] FIG8 is a schematic structural diagram of an outer support plate provided in an embodiment of the present application;

[0063] FIG9 is a partial enlarged structural diagram of point A in FIG8 ;

[0064] FIG10 is a partial cross-sectional view of FIG9;

[0065] FIG11 is a partial enlarged structural diagram of point A in FIG8 ;

[0066] FIG12 is a partial cross-sectional view of FIG11;

[0067] FIG13 is a schematic structural diagram of some shapes of support protrusions provided in an embodiment of the present application;

[0068] FIG14 is a schematic structural diagram of other shapes of support protrusions provided in an embodiment of the present application;

[0069] FIG15 is a schematic structural diagram of some other shapes of support protrusions provided in an embodiment of the present application;

[0070] FIG16 is a schematic diagram of a partial structure of the rotating shaft mechanism provided in an embodiment of the present application when in an expanded state;

[0071] FIG17 is a schematic diagram of a partial structure of the rotating shaft mechanism provided in an embodiment of the present application when in a folded state;

[0072] FIG18 is a schematic diagram of the design of each supporting protrusion on the outer support plate provided in an embodiment of the present application;

[0073] FIG19 is a schematic diagram showing a design of a reference length of a flexible circuit board provided in an embodiment of the present application;

[0074] FIG20 is a schematic diagram of a partial structure of a rotating shaft mechanism used in a simulation comparison example provided in an embodiment of the present application;

[0075] FIG21 is a comparison result of simulation using the rotating shaft mechanism in FIG20 .

[0076] Explanation of Reference Numerals: 1-foldable electronic device; 10-housing assembly; 20-foldable screen; 30-flexible circuit board; 40-fixing assembly; 50-positioning piece; 11-first housing; 12-second housing; 13-rotating shaft mechanism; 21-first area; 22-second area; 23-bendable area; 31-first bending section; 32-second bending section; 33-third bending section; 41-first magnetic member; 42-second magnetic member; 100-main shaft; 200-inner support plate; 300-outer support plate; 400-decorative plate; 210-guide portion; 310-support protrusion; 310a-proximal protrusion; 310b-distal protrusion; 310c-middle protrusion; 311-transition section; 312-straight rod section; 313-head; 314-rod portion; a-reference plane; b-horizontal plane; c-tangent plane; Q-support point. DETAILED DESCRIPTION

[0077] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0078] The present application provides a foldable electronic device, which may be a consumer electronic product. Exemplary foldable electronic devices include, but are not limited to, mobile phones, tablet computers (portable Android devices, PADs), notebook computers (NoteBook computers, abbreviated as NoteBooks), ultra-mobile personal computers (UMPCs), walkie-talkies, netbooks, POS (Point of Sales) machines, personal digital assistants (PDAs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, and the like.

[0079] Figure 1 is a schematic diagram of the structure of a foldable electronic device provided in an embodiment of the present application when in an unfolded state; Figure 2 is a schematic diagram of the structure of the foldable electronic device shown in Figure 1 when in a folded state. With reference to Figures 1 and 2, this embodiment is described using a foldable mobile phone as an example.

[0080] The foldable electronic device 1 can be used in different states in different usage scenarios. FIG. 1 shows the foldable electronic device 1 in an unfolded state, where the unfolding angle α of the foldable electronic device 1 is, for example, 180°. In this state, the foldable electronic device 1 can achieve a large screen display. FIG. 2 shows the foldable electronic device 1 in a folded state. In this state, the foldable electronic device 1 is compact and easy to carry.

[0081] It should be noted that the angles illustrated in this embodiment are all allowed to have slight deviations. For example, the unfolding angle α of the foldable electronic device 1 shown in Figure 1 is 180°, which means that the unfolding angle α can be 180° or approximately 180°, such as 170°, 175°, 185°, or 190°. The angles illustrated in the following examples should be understood in the same way.

[0082] In addition, the foldable electronic device 1 shown in Figures 1 and 2 is an electronic device that can be folded once. The electronic device includes two parts that can rotate relative to each other. When the two parts rotate to be coplanar, the foldable electronic device 1 is in an unfolded state (as shown in Figure 1). When the two parts rotate to overlap each other, the foldable electronic device 1 is in a folded state (as shown in Figure 2). In other embodiments, the foldable electronic device 1 can also be an electronic device that can be folded multiple times (more than twice). In this case, the foldable electronic device 1 can include multiple parts that are connected by sequential rotation. Two adjacent parts can be relatively separated to unfold to the unfolded state, and the two adjacent parts can also be relatively close to fold to the folded state.

[0083] Figure 3 is a schematic diagram of the exploded structure of a foldable electronic device provided in an embodiment of the present application. Referring to Figure 3, the foldable electronic device 1 includes a shell assembly 10 and a folding screen 20. The folding screen 20 is supported and connected to one side surface of the shell assembly 10. The side surface of the folding screen 20 facing away from the shell assembly 10 is its display surface (not shown in the figure). The display surface is used to display information and provide an interactive interface for the user. In this embodiment, the display surface of the folding screen 20 is defined as its front side, and the other side surface of the folding screen 20 opposite to the front side is defined as its back side. That is, the front side of the folding screen 20 is exposed outside the shell assembly 10, and the back side of the folding screen 20 faces the shell assembly 10 and is connected to the shell assembly 10. Accordingly, the side surface of the shell assembly 10 facing the folding screen 20 is defined as the front side of the shell assembly 10, and the side surface of the shell assembly 10 facing away from the folding screen 20 is defined as the back side of the shell assembly 10.

[0084] In this embodiment, the folding screen 20 can be, but is not limited to, an organic light-emitting diode (OLED) display, an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED) display, a mini organic light-emitting diode (MID) display, a micro organic light-emitting diode (MID) display, a micro organic light-emitting diode (MID) display, or a quantum dot light-emitting diode (QLED) display, etc.

[0085] The foldable screen 20 may include a first area 21, a second area 22, and a bendable area 23, with the bendable area 23 located between the first area 21 and the second area 22. During use of the foldable electronic device 1, the first area 21 and the second area 22 remain flat, while the bendable area 23 can bend to change the angle between the first area 21 and the second area 22, so that the foldable screen 20 folds or unfolds with the movement of the housing assembly 10, thereby enabling the foldable electronic device 1 to switch between the folded and unfolded states.

[0086] For example, in the foldable screen 20, at least the bendable area 23 is made of a flexible material to enable the bendable area 23 to be bendable. The first area 21 and the second area 22 can be made of a flexible material, a rigid material, or partially of a rigid material and partially of a flexible material, which is not limited in this embodiment.

[0087] Driven by the housing assembly 10, the foldable screen 20 can switch between an unfolded state and a folded state. As shown in Figures 1 and 3, when the foldable screen 20 is in the unfolded state, the first area 21 and the second area 22 are in a relatively distant unfolded state, the bendable area 23 is in a flattened state without bending, and the first area 21, the second area 22, and the bendable area 23 face the same direction and are coplanar. At this time, the angle between the first area 21 and the second area 22 is 180°, and the foldable screen 20 can achieve a large-screen display, providing users with richer information and a better user experience.

[0088] As shown in Figures 2 and 3 , when the foldable screen 20 is in the folded state, the first area 21 and the second area 22 are stacked relative to each other, and the bendable area 23 is bent. The bending angle of the bendable area 23 is, for example, 180°. In this state, the foldable electronic device 1 is compact and easy to carry and store.

[0089] It should be noted that the foldable electronic device 1 shown in the figure is an outward-folding electronic device. When in the folded state, the first area 21 and second area 22 of the foldable screen 20 face each other, and the housing assembly 10 is located between the first area 21 and the second area 22. The foldable screen 20 is enclosed outside the housing assembly 10 and is visible to the user. When an outward-folding electronic device is in the folded state, the foldable screen 20 is exposed and can be used to perform display functions. Therefore, there is no need to add an additional display screen on the back of the housing to realize the display function of the foldable electronic device 1 in the folded state.

[0090] In other examples, the foldable electronic device 1 may also be an inward-folding electronic device. When in the folded state, the first area 21 and the second area 22 of the foldable screen 20 are relatively close together, the bendable area 23 can be bent, and the housing assembly 10 protects the foldable screen 20 from being scratched by hard objects. If the inward-folding electronic device needs to provide a display function in the folded state, a display screen can be added to the back of the housing. The foldable electronic device 1 relies on this display screen to provide the display function when in the folded state.

[0091] In addition, in some embodiments, the foldable electronic device 1, particularly an inward-folding electronic device, can hover at an angle between the unfolded and folded states. For example, the hovering angle of the foldable electronic device 1 can be 120°, 130°, 140°, or 150°. The housing assembly 10 can rely on the damping force provided by the housing assembly 10 to cause the housing assembly 10 to hover in a semi-expanded state between the folded and unfolded states, with the foldable screen 20 remaining in the semi-expanded state along with the housing assembly 10. At this point, the bendable region 23 of the foldable screen 20 is also in a bent state, and the degree of bending of the bendable region 23 is less than that in the folded state. The first region 21 and the second region 22 of the foldable screen 20 are relatively inclined, with the angle between the first region 21 and the second region 22 being, for example, 120°, 130°, 140°, or 150°.

[0092] The housing assembly 10 is used to support and secure the foldable screen 20 and to switch the foldable screen 20 between the folded and unfolded states. Referring to Figure 3 , the housing assembly 10 includes a first housing 11, a second housing 12, and a hinge mechanism 13. The hinge mechanism 13 is connected between the first and second housings 11, 12. The first and second housings 11, 12 are rotatably connected via the hinge mechanism 13, thereby enabling relative rotation between the first and second housings 11, 12.

[0093] The first housing 11 supports and fixes the first area 21 of the foldable screen 20, and the second housing 12 supports and fixes the second area 22 of the foldable screen 20. In other words, the first area 21 of the foldable screen 20 is fixedly connected to the first housing 11, and the second area 22 of the foldable screen 20 is fixedly connected to the second housing 12. The bendable area 23 of the foldable screen 20 is arranged corresponding to the hinge mechanism 13. When the hinge mechanism 13 drives the first housing 11 and the second housing 12 to rotate relative to each other, the first area 21 and the second area 22 of the foldable screen 20 change their orientation accordingly, and the bendable area 23 of the foldable screen 20 bends or flattens as the orientation of the first area 21 and the second area 22 changes.

[0094] The hinge mechanism 13 drives the first housing 11 and the second housing 12 to rotate relative to each other, allowing the foldable electronic device 1 to switch between a folded state and an unfolded state. The first housing 11 and the second housing 12 can rotate away from each other until they are coplanar. In this case, the housing assembly 10 is in the unfolded state, and the foldable screen 20 is in the unfolded state as the housing assembly 10 unfolds, as shown in FIG1 . The first housing 11 and the second housing 12 can also rotate toward each other until they are relatively stacked. In this case, the housing assembly 10 is in the folded state, and the foldable screen 20 is in the folded state as the housing assembly 10 folds, as shown in FIG2 .

[0095] For example, the first housing 11 may have a support surface facing the first area 21 of the folding screen 20, and the first area 21 of the folding screen 20 is attached to the support surface of the first housing 11, for example, the first area 21 of the folding screen 20 is bonded to the support surface of the first housing 11. Similarly, the second housing 12 may have a support surface facing the second area 22 of the folding screen 20, and the second area 22 of the folding screen 20 is attached to the support surface of the second housing 12, for example, the second area 22 of the folding screen 20 is bonded to the support surface of the second housing 12.

[0096] The first shell 11 and the second shell 12 may both include a middle frame (not shown in the figure) and a back cover (not shown in the figure). The middle frame is connected between the folding screen 20 and the back cover. The side surface of the middle frame facing the folding screen 20 forms the above-mentioned support surface. The folding screen 20 can be mounted on this side surface of the middle frame. The back cover is connected to the side of the middle frame facing away from the folding screen 20. The middle frame and the back cover together enclose a accommodating space, and the accommodating space is used to install some functional devices of the foldable electronic device 1 (not shown in the figure).

[0097] The housing space of the housing assembly 10 is used to install some devices such as circuit boards, batteries, camera modules, microphones, speakers, etc. For example, circuit boards can be provided in the first housing 11 (in the housing space enclosed by the middle frame and the back cover of the first housing 11) and in the second housing 12 (in the housing space enclosed by the middle frame and the back cover of the second housing 12). The battery for powering the devices can be provided only in the first housing 11 or the second housing 12, or batteries can be provided in both the first housing 11 and the second housing 12. As for other devices such as camera modules, microphones, speakers, etc., they can be concentrated in the first housing 11 or the second housing 12, or some devices can be provided in the first housing 11 and some devices can be provided in the second housing 12.

[0098] As for the electrical connection between the circuit board in the first housing 11 and the circuit board in the second housing 12, the circuit board in the first housing 11 and the circuit board in the second housing 12 are typically electrically connected. Other components in the first housing 11 are connected to the circuit board in the first housing 11, and other components in the second housing 12 are connected to the circuit board in the second housing 12, thereby achieving electrical connection between the components. Typically, a flexible printed circuit (FPC) 30 is provided to connect between the circuit board in the first housing 11 and the circuit board in the second housing 12. The flexible printed circuit 30 extends through the hinge mechanism 13 into the first housing 11 and the second housing 12 to achieve connection between the circuit boards. For example, the two ends of the flexible printed circuit 30 can be connected to the circuit board in the first housing 11 and the circuit board in the second housing 12 via a BTB (Board to Board) connector.

[0099] Figure 4 is a schematic diagram of the partial structure of the foldable electronic device provided in an embodiment of the present application; Figure 5 is an enlarged structural diagram of the foldable electronic device in Figure 4.

[0100] This embodiment uses an outward-folding foldable electronic device 1 as an example for description. Referring to FIG4 , the figure shows the partial structure of the hinge mechanism 13 and foldable screen 20 of the foldable electronic device 1. The foldable screen 20 is supported on one side of the hinge mechanism 13 in the thickness direction (the Z direction shown in the figure). As previously described, the bendable region 23 of the foldable screen 20 corresponds to the hinge mechanism 13. As the hinge mechanism 13 is unfolded and folded, the bendable region 23 of the foldable screen 20 transitions between a flattened state and a bent state.

[0101] The first shell 11 and the second shell 12 are not shown in the figure. It should be understood that the first shell 11 and the second shell 12 are respectively connected to the two sides of the width direction of the hinge mechanism 13 (as shown in combination with Figure 3), and the first area 21 and the second area 22 of the folding screen 20 are respectively attached to the first shell 11 and the second shell 12. As the hinge mechanism 13 is unfolded and folded, the first shell 11 and the second shell 12 move relative to each other, driving the first area 21 and the second area 22 of the folding screen 20 to move relative to each other.

[0102] For an outward-folding electronic device, when the foldable electronic device 1 is in the folded state, the foldable screen 20 is disposed outside the hinge mechanism 13 (see FIG2 ). The bending radius of the bendable area 23 of the foldable screen 20 is larger, and the width of the bendable area 23 (the dimension in the X direction shown in FIG4 ) is also larger. Accordingly, the width of the hinge mechanism 13 supporting the bendable area 23 of the foldable screen 20 (the dimension in the X direction shown in FIG4 ) is typically also larger, and the hinge mechanism 13 typically requires more space for movement in its width direction to meet the bending requirements of the bendable area 23 of the foldable screen 20 and ensure stable support for the bendable area 23 of the foldable screen 20.

[0103] As shown in Figure 5, the hinge mechanism 13 generally includes a main shaft 100 and a support plate assembly. The main shaft 100 is located between the first shell 11 and the second shell 12 (as shown in Figure 3). The main shaft 100 can extend along the side edges of the opposite sides of the first shell 11 and the second shell 12 (the Y direction in the figure). The main shaft 100 serves as the main support structure of the hinge mechanism 13, which is equivalent to the rotation axis of the first shell 11 and the second shell 12. The first shell 11 and the second shell 12 rotate around the main shaft 100 (in the length direction). During the movement of the hinge mechanism 13, the main shaft 100 can be fixed and the area of ​​the bendable area 23 of the folding screen 20 corresponding to the main shaft 100 can be fixedly connected (for example, bonded) to the main shaft 100. The support plate assembly is movably connected to both sides of the main shaft 100 in the width direction (the X direction in the figure). The support plate assemblies located on both sides of the main shaft 100 can move relative to the main shaft 100 to realize the conversion of the hinge mechanism 13 between the unfolded state and the folded state.

[0104] The support plate assembly can be rotated in an angular direction relative to the main shaft 100, and the support plate assemblies on both sides of the main shaft 100 can move relative to each other with the main shaft 100 as the center. For example, the plate surfaces of the support plate assemblies on both sides of the main shaft 100 can be relatively far away so that the support plate assemblies are unfolded on both sides of the main shaft 100, and the support plate assemblies on both sides of the main shaft 100 are coplanar with the main shaft 100. At this time, the hinge mechanism 13 is in an unfolded state, and the foldable electronic device 1 is also in an unfolded state (see Figure 1); the plate surfaces of the support plate assemblies on both sides of the main shaft 100 can be close to each other so that the support plate assemblies on both sides of the main shaft 100 (in the width direction) are folded on one side of the main shaft 100 (in the thickness direction). At this time, the support plate assemblies on both sides of the main shaft 100 are nearly perpendicular to the main shaft 100 (in the plane direction) and are arranged relative to each other. At this time, the hinge mechanism 13 is in a folded state, and the foldable electronic device 1 is also in a folded state (see Figure 2).

[0105] 5 , in the case where the foldable electronic device 1 is an outward-folding electronic device, the support plate assembly generally includes an inner support plate 200 and an outer support plate 300. The inner support plate 200 and the outer support plate 300 are both located on both sides of the width direction of the main shaft 100, and the outer support plate 300 is located on the side of the inner support plate 200 on the corresponding side away from the main shaft 100. In other words, the inner support plate 200 is located between the main shaft 100 and the outer support plate 300. Both the inner support plate 200 and the outer support plate 300 can move relative to the main shaft 100 to realize the conversion of the hinge mechanism 13 between the unfolded state and the folded state. Exemplarily, the hinge mechanism 13 can be connected to the first shell 11 and the second shell 12 respectively through the outer support plates 300 on both sides. For example, the first shell 11 and the second shell 12 are locked together with the outer support plates 300 on the corresponding sides by screws, rivets, etc., so as to drive the first shell 11 and the second shell 12 to move relative to each other through the outer support plates 300 on both sides.

[0106] By arranging the inner support plate 200 and the outer support plate 300 to jointly support the bendable area 23 of the folding screen 20, on the one hand, the inner support plate 200 and the outer support plate 300 occupy a larger plane space, which can increase the size of the hinge mechanism 13 in its width direction, and the support plate assembly can support the bendable area 23 of the folding screen 20 stably to ensure the flatness of the bendable area 23 of the folding screen 20 in the flattened state, so that the bendable area 23 of the folding screen 20 can smoothly transition to the bent state; on the other hand, during the conversion of the hinge mechanism 13 between the unfolded state and the folded state, the inner support plate 200 and the outer support plate 300 change their postures in sequence, so that the posture of the support plate assembly is more flexible, meeting the requirement of a large bending radius of the bendable area 23 of the folding screen 20, especially in the folded state, the bendable area 23 of the folding screen 20 can be supported stably to improve the smoothness of the bendable area 23 of the folding screen 20 in the bent state.

[0107] During the transition of the hinge mechanism 13 from the unfolded state to the folded state, the surfaces of the outer support plates 300 on either side of the main shaft 100 approach each other until the outer support plates 300 on either side are substantially parallel to each other, thereby driving the folding screen 20 to transition to the folded state. At the same time, the outer support plates 300 on either side of the main shaft 100 translate in a planar direction toward the main shaft 100 to meet the spatial change requirement of the bendable area 23 of the folding screen 20 from flattening to bending. During the transition of the hinge mechanism 13 from the folded state to the unfolded state, the surfaces of the outer support plates 300 on either side of the main shaft 100 move away from each other until the outer support plates 300 on either side are substantially coplanar with the main shaft 100, thereby driving the folding screen 20 to transition to the flattened state. At the same time, the outer support plates 300 on either side of the main shaft 100 translate in a planar direction away from the main shaft 100 to meet the spatial change requirement of the bendable area 23 of the folding screen 20 from bending to flattening. As for the inner support plate 200 between the outer support plate 300 and the main shaft 100, the inner support plate 200 can have a larger free movement space and change its posture as the bending state of the corresponding area of ​​the bendable area 23 of the folding screen 20 changes, so as to support the corresponding area of ​​the bendable area 23 stably.

[0108] In order to achieve the movement of the support plate assembly relative to the main shaft 100, the rotating shaft mechanism 13 generally further includes a transmission swing arm (not shown in the figure), which is movably connected between the main shaft 100 and the support plate assembly. For example, one end of the transmission swing arm is movably connected to the main shaft 100 (rotation, sliding, rotation and sliding), and the other end of the transmission swing arm is movably connected to the outer support plate 300 (rotation, sliding, rotation and sliding). The inner support plate 200 is fixed by the transmission swing arm, and the inner support plate 200 flexibly changes its posture with the movement of the transmission swing arm. The transmission swing arm drives the support plate assembly to rotate and translate relative to the main shaft 100 to achieve the conversion of the rotating shaft mechanism 13 between the expanded state and the folded state, and further drives the shell assembly 10 to convert between the expanded state and the folded state.

[0109] In addition to the transmission swing arm, other components such as a synchronization assembly (not shown in the figure) and a damping assembly (not shown in the figure) are usually connected between the main shaft 100 and the support plate assemblies on both sides. The synchronization assembly is used to keep the support plate assemblies on both sides of the main shaft 100 in synchronous movement relative to the main shaft 100, so as to achieve synchronous movement of the first shell 11 and the second shell 12. The damping assembly is used to provide a damping force to ensure the stability of the shell assembly 10 in the expanded state, the folded state, and the transition between the two states. Exemplarily, both the synchronization assembly and the damping assembly can be connected between the main shaft 100 and the outer support plate 300.

[0110] Continuing with FIG5 , for an outward-folding electronic device, the hinge mechanism 13 may further include a decorative panel 400. The decorative panel 400 is also movably connected to both sides of the main shaft 100 in the width direction. Unlike the support plate assembly, the decorative panel 400 assembly can be connected to the other side of the main shaft 100 in the thickness direction (Z direction shown in the figure). The decorative panel 400 primarily serves to conceal the internal structure of the hinge mechanism 13. For example, the decorative panel 400 can cover components such as the transmission swing arm, synchronization assembly, and damping assembly connected between the main shaft 100 and the support plate assembly, thereby enhancing the appearance of the foldable electronic device 1 (especially when in the unfolded state).

[0111] The decorative panel 400 can be connected only to the main shaft 100, without being connected to the outer support plate 300, the first housing 11, or the second housing 12, so as to avoid restricting the movement of the housing assembly 10 driven by the rotating shaft mechanism 13. For example, the decorative panel 400 and the main shaft 100 can be connected by a hinge to meet the requirement that the decorative panels 400 on both sides of the main shaft 100 rotate relative to the main shaft 100.

[0112] Regarding the flexible circuit board 30 (not shown in Figures 4 and 5 ) that passes through the hinge mechanism 13, the flexible circuit board 30 passes through the main shaft 100. The portions of the flexible circuit board 30 located on either side of the main shaft 100 are accommodated within the space enclosed between the support plate assembly and the decorative panel 400. For example, the middle section of the flexible circuit board 30 corresponding to the main shaft 100 can be fixed to the main shaft 100 to position the flexible circuit board 30. The portions of the flexible circuit board 30 corresponding to the outer support plates 300 on either side can be fixed to the outer support plates 300 on the corresponding side, and the portions of the flexible circuit board 300 that extend from the outer support plates 300 to the corresponding side of the housing assembly 10 can be relatively fixed within the housing assembly 10. The section of the flexible support plate located between the outer support plates 300 and the main shaft 100 can change shape as the hinge mechanism 13 transitions between the unfolded and folded states. The space between the main shaft 100 and the outer support plates 300 defines the deformation range of the flexible circuit board 30.

[0113] The spindle 100 is provided with a fixing assembly 40, which fixes the flexible circuit board 30 so that the flexible circuit board 30 and the corresponding middle section of the spindle 100 are relatively fixed on the spindle 100 to position the flexible circuit board 30. Referring to FIG5 , as an example, the fixing assembly 40 may include a first magnetic member 41 and a second magnetic member 42. The first magnetic member 41 and the second magnetic member 42 may be arranged relative to each other along the thickness direction of the spindle 100 (the Z direction in the figure). The first magnetic member 41 and the second magnetic member 42 are fixed to the spindle 100. For example, the first magnetic member 41 and the second magnetic member 42 are bonded to the spindle 100. The flexible circuit board 30 is located between the first magnetic member 41 and the second magnetic member 42. The magnetic attraction between the first magnetic member 41 and the second magnetic member 42 allows the flexible circuit board 30 to be tightly fitted therebetween to fix the flexible circuit board 30.

[0114] By providing the first magnetic member 41 and the second magnetic member 42, the flexible circuit board 30 is positioned by magnetic attraction, which stabilizes the flexible circuit board 30. Furthermore, the flexible circuit board 30 is not completely restrained. Under a large force, the flexible circuit board 30 can overcome the magnetic attraction and slightly move, thereby protecting the flexible circuit board 30 from tearing or tearing. For example, along the thickness direction of the main shaft 100, at least a portion of the main shaft 100 can be composed of at least two parts, and the first magnetic member 41 and the second magnetic member 42 can be installed in different parts.

[0115] Of course, in addition to fixing the flexible circuit board 30 by magnetic attraction, in other examples, the flexible circuit board 30 can also be clamped in the main shaft 100 by pressure, or the flexible circuit board 30 can be directly bonded to the main shaft 100. As long as it is ensured that the flexible circuit board 30 will not be excessively pulled or torn during the long-term use of the foldable electronic device 1, this embodiment does not impose any specific restrictions on this.

[0116] As for the fixing of the portion of the flexible circuit board 300 corresponding to the outer support plate 300 to the outer support plate 300, as shown in Figure 5 , a positioning piece 50 can be used to press the flexible circuit board 300 into the outer support plate 300. The positioning piece 50 can be a thin metal sheet sandwiched within the outer support plate 300. For example, the outer support plate 300 can be composed of two parts arranged along its thickness direction, and the two parts can be locked by locking members such as screws and bolts. This arrangement facilitates the connection of components such as the transmission swing arm, synchronization assembly, and damping assembly to the outer support plate 300. The positioning piece 50 can be sandwiched between the two parts of the outer support plate 300, and the flexible circuit board 300 is pressed between the positioning piece 50 and any part of the outer support plate 300.

[0117] Of course, similar to the fixation of the flexible circuit board 30 on the main shaft 100, the flexible circuit board 30 can also be positioned on the outer support plate 300 through a magnetic structure, or the flexible circuit board 30 can be directly bonded to the outer support plate 300, which will not be repeated here.

[0118] As previously mentioned, during the transition between the unfolded and folded states of the hinge mechanism 13, the support plate assemblies on either side of the main shaft 100 not only need to be flattened or folded relative to the main shaft 100, but also need to move toward or away from the main shaft 100 to change the spacing between them and the main shaft 100, thereby meeting the spatial position requirements of the housing assembly 10 when transitioning between the unfolded and folded states. In this regard, for the flexible circuit board 30 passing through the hinge mechanism 13, the area of ​​the flexible circuit board 30 corresponding to the hinge mechanism 13 needs to move repeatedly between the unfolded and bent states, and a certain amount of redundancy must be reserved for the flexible circuit board 30 to prevent the flexible circuit board 30 from being pulled and affecting its service life and stability. For example, considering the fluctuations in the assembly tolerance of the flexible circuit board 30, the flexible circuit board 30 generally needs to add a redundancy of 0.3mm-0.5mm to the basic length required for the unfolded state.

[0119] However, with the trend of lightweight and thin development of foldable electronic devices 1, the hinge mechanism 13 is also thinned as the entire device becomes ultra-thin. The redundant space for accommodating the flexible circuit board 30 in the hinge mechanism 13 is getting smaller and smaller, which restricts the bending of the flexible circuit board 30. Especially for outward-folding electronic devices, it will significantly affect the shape of the flexible circuit board 30 in the bent state, and thus affect the service life of the flexible circuit board 30 and the performance of the foldable electronic device 1.

[0120] FIG6 is a schematic diagram of a flexible circuit board in a state of the related art when it is in a bent state; FIG7 is a schematic diagram of a flexible circuit board in another state of the related art when it is in a bent state.

[0121] 6 , the figure shows the bending structure of the flexible circuit board 30 in a taut state when the hinge mechanism 13 is in a folded state. Taking the deformation section of the flexible circuit board 30 between the two outer support plates 300 as an example, the so-called taut state flexible circuit board 30 can be understood as a flexible circuit board 30 with no additional redundancy and a length that just meets the required extension length between the two outer support plates 300 when the hinge mechanism 13 is in the unfolded state. In other words, as the name suggests, the taut state flexible circuit board 30 is in a taut state when the hinge mechanism 13 is in the unfolded state.

[0122] When the hinge mechanism 13 is in the folded state, from the single-sided structure of the flexible circuit board 30 (the deformation section between the position where the flexible circuit board 30 is fixedly connected to the main shaft 100 and the position where the flexible circuit board 30 is fixedly connected to the outer support plate 300 on one side), from the end where the flexible circuit board 30 is connected to the main shaft 100 to the end where the flexible circuit board 30 is connected to the outer support plate 300, the flexible circuit board 30 sequentially includes a first bending section 31, a second bending section 32 and a third bending section 33. The first bending section 31 is tangent to the inner support plate 200, the second bending section 32 is tangent to the decorative plate 400, and the third bending section 33 is a bending section that is inevitably formed when the second bending section 32 transitions to the position where the flexible circuit board 300 is fixedly connected.

[0123] The bending posture of the first bending section 31 of the flexible circuit board 30 determines the bending tendency of the second bending section 32 and the third bending section 33. In other words, the bending radius of the first bending section 31 determines the bending degree of the second bending section 32 and the third bending section 33. For example, to guide the bending of the flexible circuit board 30, a guide portion 210 is typically designed on the end of the inner support plate 200 facing the outer support plate 300. The guide portion 210 is a smooth arc-shaped protrusion facing the side where the decorative plate 400 is located to guide the routing of the first bending section 31 to the second bending section 32. The guide portion 210 can also limit the bending radius of the first bending section 31.

[0124] 7 , the figure shows the bending structure of the redundant flexible circuit board 30 when the hinge mechanism 13 is in the folded state. Continuing with the deformation section of the flexible circuit board 30 between the outer support plates 300 on both sides, the so-called redundant flexible circuit board 30 can be understood as a flexible circuit board 30 with increased redundancy and a length slightly greater than the required extension length between the outer support plates 300 on both sides when the hinge mechanism 13 is in the unfolded state. In other words, as the name suggests, the redundant flexible circuit board 30 is in a relaxed state when the hinge mechanism 13 is in the unfolded state.

[0125] When the hinge mechanism 13 is in the folded state, from the perspective of the single-sided structure of the flexible circuit board 30, since the length of the flexible circuit board 30 in the redundant state is slightly longer than that in the taut state, the second and third bending sections 32 and 33 occupy a longer overall length while the bending radius of the first bending section 31 remains unchanged, resulting in a smaller bending radius for the second and third bending sections 32 and 33.

[0126] Continuing with FIG. 7 , as foldable electronic devices 1 pursue the trend of becoming extremely lightweight and thin, the thickness of the hinge mechanism 13 has also become increasingly smaller. This has led to a narrower space between the outer support plate 300 and the decorative plate 400, resulting in less and less redundant space for the flexible circuit board 30. This can easily lead to small-angle bends (bending radius less than 0.5 mm) in the flexible circuit board 30, particularly in the second bend section 32 and the third bend section 33. During long-term use of the foldable electronic device 1, the flexible circuit board 30 will bend repeatedly, and small-angle bends may even develop into dead bends, which can affect the service life and reliability of the flexible circuit board 30.

[0127] Furthermore, for the commonly multi-layer (at least two-layer) flexible circuit board 30, due to the natural fit and presence of air gaps between the layers, as the bending radius decreases, the flexible circuit board 30 may delaminate when bent (as shown in the second bend section 32 in the figure). During the repeated flattening and bending process of the flexible circuit board 30, the posture of the flexible circuit board 30 switches back and forth between lamination and adhesion, causing abnormal noise in the flexible circuit board 30, which affects the performance of the foldable electronic device 1.

[0128] To increase the redundant space for the flexible circuit board 30, the related art typically reduces the thickness of the inner support plate 200 and the decorative plate 400, or even reduces the thickness of the outer support plate 300, thereby increasing the spacing between the inner support plate 200 (outer support plate 300) and the decorative plate 400. This increases the bending radius of the first bending section 31 and the bending radius of the second bending section 32 of the flexible circuit board 30. However, this approach reduces the rigidity of the inner support plate 200 and the decorative plate 400 (and the outer support plate 300), resulting in the risk of fracture of the support plate assembly (decorative plate 400) if the foldable electronic device 1 is colliding or falling.

[0129] In light of this, the present embodiment utilizes a structural design for the support plate assembly, utilizing the outer support plate 300 to support the flexible circuit board 30 (the first bend section 31). Multiple support protrusions are designed on the side of the outer support plate 300 facing the flexible circuit board 30 (the side facing away from the folding screen 20). These support protrusions are positioned on the side of the outer support plate 300 proximal to the inner support plate 200, and are arranged sequentially along the width of the outer support plate 300. This significantly increases the redundant space for the flexible circuit board 30, while also increasing the bending radius of the first bend section 31 of the flexible circuit board 30, without compromising the rigidity of the support plate assembly or the decorative panel 400. This results in a smoother overall bending of the flexible circuit board 30, thereby improving its reliability and service life. Furthermore, by controlling the bending radius of the first bend section 31 through the coordination of multiple support protrusions, the bending requirements of flexible circuit boards 30 with varying redundant lengths can be met.

[0130] Figure 8 is a structural schematic diagram of the outer support plate provided in an embodiment of the present application; Figure 9 is a local enlarged structural diagram of point A in Figure 8; Figure 10 is a local cross-sectional view of Figure 9; Figure 11 is a local enlarged structural diagram of point A in Figure 8; Figure 12 is a local cross-sectional view of Figure 11.

[0131] 8, 9 and 11, in this embodiment, a plurality of support protrusions 310 are provided on the outer support plate 300 of the support plate assembly. The support protrusions 310 are provided on the side surface of the outer support plate 300 facing away from the folding screen 20, that is, the support protrusions 310 are provided on the side surface of the outer support plate 300 facing the decorative plate 400, and the support protrusions 310 are provided on the outer support plate 300 corresponding to the area through which the flexible circuit board 30 passes, so as to support the flexible circuit board 30 by the support protrusions 310. Exemplarily, the support protrusions 310 can be an elongated strip structure, and along the length direction of the outer support plate 300, the support protrusions 310 at least cover the area where the flexible circuit board 30 is located, so as to support the flexible circuit board 30 stably by the support protrusions 310.

[0132] For example, the support protrusions 310 on the outer support plate 300 can be formed by a CNC (Computerized Numerical Control) processing process.

[0133] 9 and 10 (or 11 and 12 ), the support protrusions 310 are located on a side of the outer support plate 300 that is adjacent to the inner support plate 200, and the support protrusions 310 are sequentially arranged along the width of the outer support plate 300. In other words, the support protrusions 310 are sequentially arranged in a direction away from the inner support plate 200. Each support protrusion 310 is configured to support the flexible circuit board 30. Different combinations of the multiple support protrusions 310 can be used to meet the requirements of flexible circuit boards 30 with different redundant lengths. For example, in different application scenarios (supporting flexible circuit boards 30 with different redundant lengths), one of the multiple support protrusions 310 can support the flexible circuit board 30, two can support the flexible circuit board 30, or three or even all of the support protrusions 310 can support the flexible circuit board 30.

[0134] For the support protrusion 310 protruding from the outer support plate 300 toward the decorative plate 400, this embodiment defines the end of the support protrusion 310 connected to the outer support plate 300 as its root, and defines the end of the support protrusion 310 extending toward the decorative plate 400 as its top, that is, the root of the support protrusion 310 is connected to the outer support plate 300, and the top of the support protrusion 310 extends toward the decorative plate 400.

[0135] The support protrusions 310 have a raised vertex at the end away from the outer support plate 300. In other words, the top of the support protrusions 310 has a raised vertex. The support protrusions 310 use their raised vertex to support the flexible circuit board 30, so that the flexible circuit board 30 contacts their raised vertex. Because the position of each support protrusion 310 on the outer support plate 300 is fixed, and the height of each support protrusion 310 is also fixed, that is, the position of the raised vertex of each support protrusion 310 is fixed. By ensuring that the flexible circuit board 30 contacts the raised vertex of the support protrusion 310, the outer support plate 300 provides a precise positioning point for the flexible circuit board 30, providing more stable support for the flexible circuit board 30. It also allows for precise control of the bending radius of the first bending section 31 of the flexible circuit board 30, ensuring that the bending radius of the first bending section 31 of the flexible circuit board 30 is within a reasonable range, thereby preventing the flexible circuit board 30 from bending at a small angle and improving the service life and reliability of the flexible circuit board 30.

[0136] In addition, the support protrusion 310 uses its protruding apex to support the flexible circuit board 30. The flexible circuit board 30 and the support protrusion 310 are in point contact, and the contact area between the two is small, which can reduce the friction between the flexible circuit board 30 and the outer support plate 300, reduce the abnormal noise caused by friction, and improve the performance of the foldable electronic device 1.

[0137] As shown in FIG10 or FIG12 , in the case where the top of the support protrusion 310 forms a raised vertex, to avoid stress concentration caused by the support protrusion 310 on the flexible circuit board 30, in this embodiment, the top surface of the support protrusion 310 can be designed as a smooth arc surface, for example, an elliptical arc surface or a circular arc surface. The top of the support protrusion 310 forms a smooth arc surface that protrudes toward the decorative plate 400, thereby forming a raised vertex at the top of the support protrusion 310. In this way, when the flexible circuit board 30 contacts the raised vertex of the support protrusion 310, the support protrusion 310 can disperse the force acting on the flexible circuit board 30 at the raised vertex, thereby preventing local damage or tearing of the flexible circuit board 30 due to stress concentration and ensuring the reliability of the flexible circuit board 30.

[0138] As shown in FIG10 , in some embodiments, the top surface of the support protrusion 310 may be an elliptical arc surface, the cross-sectional shape of the top surface of the support protrusion 310 is an elliptical arc, and the protrusion vertex of the support protrusion 310 is the highest point of the elliptical arc surface. As shown in FIG12 , in other embodiments, the top surface of the support protrusion 310 may be a circular arc surface, the cross-sectional shape of the top surface of the support protrusion 310 is a circular arc, and the protrusion vertex of the support protrusion 310 is the highest point of the circular arc surface.

[0139] Continuing with reference to Figures 10 and 12, in this embodiment, among the support protrusions 310 on the outer support plate 300, the support protrusion 310 closest to the inner support plate 200 is defined as the proximal protrusion 310a, the support protrusion 310 farthest from the inner support plate 200 is defined as the distal protrusion 310b, and the support protrusion 310 between the proximal protrusion 310a and the distal protrusion 310b is defined as the intermediate protrusion 310c. At least three support protrusions 310 are provided on the outer support plate 300, that is, at least one intermediate protrusion 310c is provided between the proximal protrusion 310a and the distal protrusion 310b. In this way, different combinations of the support protrusions 310 on the outer support plate 300 can meet the requirements of flexible circuit boards 30 with different redundant lengths.

[0140] The figure shows an example of a support plate having three support protrusions 310, which are, in order, a proximal protrusion 310a, an intermediate protrusion 310c, and a distal protrusion 310b. Of course, in other examples, more than two intermediate protrusions 310c may be provided between the proximal protrusion 310a and the distal protrusion 310b. For example, two, three, or even more intermediate protrusions 310c may be provided between the proximal protrusion 310a and the distal protrusion 310b. This is not a limitation of the present embodiment.

[0141] Figure 13 is a schematic diagram of the structures of some supporting protrusion shapes provided in embodiments of the present application; Figure 14 is a schematic diagram of the structures of other supporting protrusion shapes provided in embodiments of the present application; and Figure 15 is a schematic diagram of the structures of other supporting protrusion shapes provided in embodiments of the present application. Referring to Figures 13 to 15 , in this embodiment, except for the top surface of supporting protrusion 310 being a smooth arc surface such as an elliptical arc or a circular arc, the shapes of other parts of supporting protrusion 310 are not limited in this embodiment.

[0142] 13 , as an example, the outer wall surface of the support protrusion 310 may form a smooth wall surface. In other words, the outer wall surface of the support protrusion 310 is a smoothly extended wall surface from the protrusion apex of the support protrusion 310 to the root of the support protrusion 310 .

[0143] For example, referring to (a) in Figure 13, from the protrusion apex of the support protrusion 310 to the root of the support protrusion 310, the width of the support protrusion 310 (the dimension of the support protrusion 310 extending along the width direction of the outer support plate 300) gradually increases, and the amplitude of the increase in the width of the support protrusion 310 gradually decreases, and the width of the support protrusion 310 gradually tends to be stable; referring to (b) in Figure 13, from the protrusion apex of the support protrusion 310 to the root of the support protrusion 310, the width of the support protrusion 310 gradually increases, and the amplitude of the increase in the width of the support protrusion 310 gradually increases, and the root of the support protrusion 310 is the place where its width is the largest; referring to (c) in Figure 13, from the protrusion apex of the support protrusion 310 to the root of the support protrusion 310, the support protrusion 310 may include a transition section 311 and a straight rod section 312 connected in sequence, the width of the transition section 311 gradually increases, and the width of the straight rod section 312 remains unchanged.

[0144] As shown in Figure 14, as another example, the outer wall surface of the support protrusion 310 may also have a diameter-changing portion. From the protrusion apex of the support protrusion 310 to the root of the support protrusion 310, the support protrusion 310 may include a head 313 and a rod 314, the protrusion apex is formed at the top of the head 313, and the connection portion between the head 313 and the rod 314 is the diameter-changing portion.

[0145] For example, referring to (a), (b) and (c) in Figure 14, in some examples, the width of the rod portion 314 can remain unchanged; wherein, (a) and (b) show that the width of the head portion 313 of the supporting protrusion 310 gradually increases and then gradually decreases from the protrusion vertex to the end connected to the rod portion 314, and the width of the head portion 313 of the supporting protrusion 310 at the maximum width is greater than the width of the rod portion 314, and the cross-sectional shape of the head portion 313 is, for example, a circular arc surface or an elliptical arc surface; (c) shows that the width of the head portion 313 of the supporting protrusion 310 gradually increases from the protrusion vertex to the end connected to the rod portion 314, and the increase in width becomes larger and larger, and the width of the head portion 313 reaches its maximum at the end connected to the rod portion 314. Referring to (d) in Figure 14, in other examples, the width of the head 313 of the supporting protrusion 310 can first gradually increase and then gradually decrease from the top of the protrusion to the end connected to the rod 314, and the width of the rod 314 can gradually increase from the end where the rod 314 is connected to the head 313 to the root of the supporting protrusion 310 (the end where the rod 314 is connected to the outer support plate 300).

[0146] 13 and 14 illustrate a situation where there are gaps between adjacent support protrusions 310 . Referring to FIG. 15 , in other examples, adjacent support protrusions 310 may overlap with each other while ensuring that the protrusion vertices are spaced apart from each other. For example, as shown in (a) in Figure 15, for the case where the outer wall surface of the support protrusion 310 forms a smooth wall surface (as shown in Figure 13), or the head 313 of the support protrusion 310 gradually increases in width from the protrusion apex to the end connected to the rod portion 314, and the increase in width becomes larger and larger, and the width of the rod portion 314 of the support protrusion 310 remains unchanged (as shown in (c) in Figure 14), adjacent support protrusions 310 can overlap with each other; for the case where the head 313 of the support protrusion 310 gradually increases in width and then gradually decreases from the protrusion apex to the end connected to the rod portion 314, and the width of the rod portion 314 gradually increases from the end connected to the head 313 to the root of the support protrusion 310 (as shown in (d) in Figure 14), adjacent support protrusions 310 can also overlap with each other.

[0147] In addition, for the multiple support protrusions 310 on the outer support plate 300, all the support protrusions 310 can maintain a substantially consistent outer profile, or the outer profiles of different support protrusions 310 can also be different, which is not limited in this embodiment.

[0148] Figure 16 is a schematic diagram of the partial structure of the hinge mechanism provided in an embodiment of the present application when in an unfolded state; Figure 17 is a schematic diagram of the partial structure of the hinge mechanism provided in an embodiment of the present application when in a folded state. Referring to Figures 16 and 17 , this embodiment provides a support protrusion 310 on the side of the outer support plate 300 near the inner support plate 200. The support protrusion 310 supports the flexible circuit board 30, replacing the original inner support plate 200 to control the bending of the first bending section 31 of the flexible circuit board 30. This increases the redundant space of the first bending section 31, increases the bending radius of the first bending section 31, and increases the length of the first bending section 31.

[0149] This reduces the overall length of the second and third bending sections 32, 33, resulting in a smoother transition between the first and second bending sections 31, 32, and between the second and third bending sections 32, 33. Consequently, the bending radius of the second and third bending sections 32, 33 can be increased accordingly, preventing the flexible circuit board 30 from bending at small angles, thereby increasing its service life and reliability. Furthermore, this prevents delamination of the flexible circuit board 30 and any unusual noises during use, thereby ensuring the performance of the foldable electronic device 1.

[0150] Continuing with FIG. 16 , in order to enable the support protrusions 310 on the outer support plate 300 to control the bending state of the flexible circuit board 30, in this embodiment, the height of the support protrusions 310 on the outer support plate 300 gradually increases as they move away from the inner support plate 200. This not only supports the flexible circuit board 30 but also guides the flexible circuit board 30. As shown in FIG. 17 , the gradually increasing heights of the support protrusions 310 cause the flexible circuit board 30 to bend toward the decorative plate 400, thereby transitioning the flexible circuit board 30 from the first bending section 31 to the second bending section 32.

[0151] As shown in Figure 16, for ease of explanation, this embodiment defines a reference plane a on the outer support plate 300. The reference plane a is the plane where the straight section of the side surface of the outer support plate 300 facing away from the folding screen 20 (the side surface facing the decorative plate 400) is located. When the hinge mechanism 13 is in the folded state, the straight section of the outer support plate 300 can be perpendicular to the width direction of the main shaft 100, that is, the straight section of the outer support plate 300 is perpendicular to the width direction of the hinge mechanism 13. Using the straight section of the outer support plate 300 as a reference position for the height of the support protrusion 310 facilitates the precise setting of the height of each support protrusion 310.

[0152] For example, the height of the proximal protrusion 310a on the outer support plate 300 is the distance between the protrusion vertex T1 of the proximal protrusion 310a and the reference plane a. Similarly, the height of the nth support protrusion 310 on the outer support plate 300 is the distance between the protrusion vertex Tn of the support protrusion 310 and the reference plane a. Where n is a positive integer ≥ 2.

[0153] In order to enable the supporting protrusions 310 on the outer support plate 300 to precisely control the bending radius of the first bending section 31 of the flexible circuit board 30, as shown in FIG17 , the apex of each supporting protrusion 310 on the outer support plate 300 and the support point Q on the inner wall surface of the inner support plate 200 (the surface of the inner support plate 200 facing away from the foldable screen 20) used to support the flexible screen can both be located on a predetermined arc surface. In other words, the apex of each supporting protrusion 310 on the outer support plate 300 and the support point Q on the inner wall surface of the inner support plate 200 are both located on the same arc. For example, the apex of each supporting protrusion 310 on the outer support plate 300 and the support point Q are both located on the same arc.

[0154] Exemplarily, the inner wall surface of the inner support plate 200 may have a groove (not shown in the figure), which is used to support the flexible circuit board 30. The support point Q on the inner support plate 200 may be within the groove. For example, the support point Q may be the intersection of the first bending section 31 of the flexible circuit board 30 and the groove.

[0155] In order to prevent the flexible circuit board 30 from bending at a small angle, the bending radius of the first bending section 31 of the flexible circuit board 30 can be designed in advance so that the bending radius of the first bending section 31 is within a reasonable range. The preset arc surface is a pre-designed arc with a reasonable bending radius.

[0156] In practical applications, when the bending radius of the flexible circuit board 30 is less than 0.5 mm, it can be considered that the flexible circuit board 30 has a small-angle bend. To address this issue, in this embodiment, the bending radius r of the first bending section 31 of the flexible circuit board 30 can be controlled to be greater than 0.5 mm. In other words, the difference between the radius R of the predetermined arc surface and the thickness of the flexible circuit board 30 should be greater than 0.5 mm. For example, the bending radius r of the first bending section 31 of the flexible circuit board 30 can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., and the corresponding difference between the radius R of the predetermined arc surface and the thickness of the flexible circuit board 30 can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.

[0157] Figure 18 is a schematic diagram of the design of each support protrusion on the outer support plate according to an embodiment of the present application. Referring to Figure 18 , in this embodiment, the radius R of the predetermined arc surface can be designed based on the required bending radius of the first bending section 31 of the flexible circuit board 30. The center angle of the arc between the vertex of each support protrusion 310 and the support point Q is designed based on the line OQ connecting the center O of the predetermined arc surface and the support point Q of the inner support plate 200. This determines the position and height of each support protrusion 310 on the outer support plate 300.

[0158] For ease of explanation, this embodiment defines the central angle ∠QOT1 corresponding to the arc between the protrusion vertex T1 of the proximal protrusion 310a on the outer support plate 300 and the support point Q as the first central angle. Taking the protrusion vertex Tn (n is a positive integer ≥3) of the distal protrusion 310b on the support plate as an example, the central angle ∠QOTn corresponding to the arc between the protrusion vertex Tn of the distal protrusion 310b and the support point Q is defined as the second central angle.

[0159] For example, when designing each supporting protrusion 310 on the outer support plate 300, the first central angle ∠QOT1 can be ≥45° and ≤65°. In this way, an appropriate distance can be maintained between the protrusion vertex T1 of the proximal protrusion 310a and the support point Q of the inner support plate 200. As the first bending section 31 of the flexible circuit board 30 is the closest supporting part after the support point Q, it can ensure that the flexible circuit board 30 is supported stably, is also conducive to adjusting the bending radius of the first bending section 31, and facilitates the design of each supporting protrusion 310 thereafter.

[0160] The second central angle ∠QOTn is ≥80° and ≤100°. This ensures that the arc length between the protrusion vertex Tn of the distal protrusion 310b and the protrusion vertex T1 of the proximal protrusion 310a is appropriate, facilitating the placement of the intermediate protrusion 310c therebetween and allowing for the matching of the support protrusions 310 based on the redundant length of the flexible circuit board 30. Furthermore, the second central angle is not excessively large, preventing the protrusion vertex Tn of the distal protrusion 310b from being too far from the protrusion vertex T1 of the proximal protrusion 310a. This prevents the distal protrusion 310b from restricting the bending of the flexible circuit board 30 toward the decorative panel 400, and ensures that each support protrusion 310 can precisely control the bending radius of the first bending section 31 of the flexible circuit board 30.

[0161] For example, the first central angle ∠QOT1 can be 60°, the second central angle ∠QOTn can be 90°, and the central angle corresponding to the arc between the protrusion vertex of the intermediate protrusion 310c and the support point Q can be greater than 60° and less than 90°. Taking an intermediate protrusion 310c provided between the proximal protrusion 310a and the distal protrusion 310b as an example, the central angle corresponding to the arc between the protrusion vertex T2 of the intermediate protrusion 310c and the support point Q on the inner support plate 200 is the third central angle. The third central angle ∠QOT2 can be greater than 65° and less than 80°. For example, the third central angle ∠QOT2 is 75°.

[0162] Determining the central angle corresponding to the arc between the apex of each support protrusion 310 on the outer support plate 300 and the support point Q on the inner support plate 200 is equivalent to determining the position of the apex of each support protrusion 310, based on which the height of each support protrusion 310 can be calculated.

[0163] Continuing with reference to Figure 18, during the design process, first determine the horizontal plane b that is tangent to the inner wall surface of the main shaft 100 (the wall surface on the side of the main shaft 100 facing away from the folding screen 20), and determine the tangent plane c that is tangent to the flexible circuit board 30 and the inner support plate 200. Combined with the reference plane a of the outer support plate 300, determine the position and height of each support protrusion 310.

[0164] First, the position of the center O of the preset arc surface is determined based on the radius R of the preset arc surface. A perpendicular line is drawn along the support point Q on the inner support plate 200 so that QO is perpendicular to the tangent surface c, and QO = R = the bending radius r of the first bending section 31 + the thickness of the flexible circuit board 30, thereby determining the position of the center O of the preset arc surface.

[0165] Taking the position and height of the proximal protrusion 310a as an example, a first central angle ∠QOT1 corresponding to the protrusion vertex T1 of the proximal protrusion 310a is drawn on a predetermined arc surface with center O and radius R, thereby determining the position of the protrusion vertex T1 of the proximal protrusion 310a. OB is drawn perpendicular to reference plane a, where point B is on reference plane a. Based on the structural dimensions of the hinge mechanism 13 in the folded state, the length of BO is determined. T1A1 is drawn perpendicular to reference plane a, where point A1 is on reference plane a. The height A1T1 of the proximal protrusion 310a can be calculated using the Pythagorean theorem.

[0166] Among them, A1T1=[BO / sin(180°-∠BOQ-∠QOT1)-R]sin(180°-∠BOQ-∠QOT1)=BO-R sin(180°-∠BOQ-∠QOT1).

[0167] Similarly, on a predetermined arc surface with center O and radius R, the central angles corresponding to the apex of other support protrusions 310 are determined. For example, for support protrusion 310 with apex Tn in the figure, the central angle ∠QOTn corresponding to apex Tn of support protrusion 310 is determined, and the position of apex Tn of support protrusion 310 is determined. TnAn is perpendicular to reference plane a, where An is on reference plane a. The height AnTn of support protrusion 310 can be calculated using the Pythagorean theorem.

[0168] Among them, AnTn=[BO / sin(180°-∠BOQ-∠QOTn)-R]sin(180°-∠BOQ-∠QOTn)=BO-R sin(180°-∠BOQ-∠QOTn).

[0169] Continuing with reference to Figure 18, taking the angle between the horizontal plane b and the tangent plane c as 45° as an example, the central angle corresponding to the arc between the preset arc surface and the support point Q is 45° as the reference central angle, and a certain angle is appropriately increased gradually to determine the first central angle ∠QOT1 corresponding to the protrusion vertex T1 of the proximal protrusion 310a, the central angle ∠QOT2 corresponding to the protrusion vertex T2 of the support protrusion 310 adjacent to the proximal protrusion 310a, and the central angle ∠QOTn corresponding to the protrusion vertex Tn (n is a positive integer ≥3) of each subsequent support protrusion 310, and then determine the height of each support protrusion 310, for example, determine A1T1, A2T2...AnTn.

[0170] Specifically, three supporting protrusions 310 are provided on the outer supporting plate 300, and the three supporting protrusions 310 are respectively a proximal protrusion 310a (the protrusion vertex is T1), an intermediate protrusion 310c (the protrusion vertex is T2), and a distal protrusion 310b (the protrusion vertex is Tn, n=3), and ∠QOT1=60°, ∠QOT2=75°, and ∠QOTn=90° are taken as an example, then: A1T1=BO-R sin(180°-∠BOQ-∠QOT1)=BO-R sin(180°-45°-60°)=BO-R sin75°, A2T2=BO-R sin(180°-∠BOQ-∠QOT2)=BO-R sin(180°-45°-75°)=BO-R sin60°, AnTn=BO-R sin(180°-∠BOQ-∠QOTn)=BO-R sin(180°-45°-90°)=BO-R sin45°.

[0171] As for how to meet the requirements of flexible circuit boards 30 with different redundant lengths by different combinations of the support protrusions 310 on the outer support plate 300, in some embodiments, the support protrusions 310 on the outer support plate 300 used to support the flexible circuit board 30 can be determined based on the redundant factor of the flexible circuit board 30. Specifically, regardless of the redundant length of the flexible circuit board 30, the proximal protrusions 310a of each support protrusion 310 on the outer support plate 300 can always contact the flexible circuit board 30, while the intermediate protrusions 310c and distal protrusions 310b can be configured in different combinations depending on the redundant length of the flexible circuit board 30.

[0172] In this embodiment, the redundancy factor of the flexible circuit board 30 is defined as the percentage of the redundant length of the flexible circuit board 30 to the required reference length. In other words, the redundancy factor of the flexible circuit board 30 = 100 * (actual length - reference length) / reference length. The length of the flexible circuit board 30 is determined based on its bending section. The bending section is the section of the flexible circuit board 30 fixedly connected between the outer support plates 300 on both sides and is subject to deformation with the movement of the hinge mechanism 13.

[0173] The reference length of the flexible circuit board 30 can be considered to be the length of the hinge mechanism 13 when it is in a taut state when in the extended state. In other words, the reference length of the flexible circuit board 30 exactly meets the requirements without any redundancy. Figure 19 is a schematic diagram of the design of the reference length of the flexible circuit board provided in an embodiment of the present application. Referring to Figure 19, the reference length of the flexible circuit board 30 can be determined based on the dimensions of the hinge mechanism 13 in the extended state. For example, when the hinge mechanism 13 is extended and the bent section of the flexible circuit board 30 is in a straight state, the reference length of the flexible circuit board 30 can be the sum of the lengths of sections A, B, C, and D shown in the figure. In other words, the reference length of the flexible circuit board 30 = A + B + C + D.

[0174] As the name implies, the actual length of the flexible circuit board 30 is the actual length of the bent section of the flexible circuit board 30 between the two outer support plates 300. For flexible circuit boards 30 with redundant length, the actual length of the flexible circuit board 30 is greater than the required reference length. The redundant length of the flexible circuit board 30 is the difference between the actual length and the reference length.

[0175] When the redundancy factor of the flexible circuit board 30 is within a first preset range, only the proximal protrusion 310a may be in contact with the flexible circuit board 30. When the redundancy factor of the flexible circuit board 30 is within a second preset range, the proximal protrusion 310a and at least a portion of the intermediate protrusion 310c may be in contact with the flexible circuit board 30. When the redundancy factor of the flexible circuit board 30 is within a third preset range, the proximal protrusion 310a and the distal protrusion 310b may be in contact with the flexible circuit board 30. The maximum value of the first preset range is less than the minimum value of the second preset range, and the maximum value of the second preset range is less than the minimum value of the third preset range.

[0176] Exemplarily, the first preset range of the redundancy factor of the flexible circuit board 30 can be between 0 and 1. That is, when 0 < redundancy factor ≤ 1, it indicates that the redundant length of the flexible circuit board 30 is very small. At this time, the bending radius of the first bending section 31 of the flexible circuit board 30 can be controlled to be smaller, and the first bending section 31 of the flexible circuit board 30 can only contact the proximal protrusion 310a. In other words, the flexible circuit board 30 is supported only by the proximal protrusion 310a.

[0177] The second preset range of the redundancy factor of the flexible circuit board 30 can be between 1 and 2. Specifically, when 1 < redundancy factor ≤ 2, the redundant length of the flexible circuit board 30 is moderate. In this case, the first bending radius of the flexible circuit board 30 can be slightly larger, allowing the first bending section 31 of the flexible circuit board 30 to contact the proximal protrusion 310a and at least a portion of the intermediate protrusion 310c. In other words, the proximal protrusion 310a and at least a portion of the intermediate protrusion 310c support the flexible circuit board 30. For example, if only the intermediate protrusion 310c is provided on the outer support plate 300, the flexible circuit board 30 can be supported by both the proximal protrusion 310a and the intermediate protrusion 310c.

[0178] The third preset range of the redundancy factor of the flexible circuit board 30 can be greater than 2. That is, when the redundancy factor is greater than 2, it indicates that the redundant length of the flexible circuit board 30 is longer. At this time, the first bending radius of the flexible circuit board 30 can be controlled to be larger, and the first bending section 31 of the flexible circuit board 30 can contact the proximal protrusion 310a and the distal protrusion 310b. In other words, the flexible circuit board 30 is supported by the proximal protrusion 310a and the distal protrusion 310b.

[0179] It should be noted that when the flexible circuit board 30 is supported by the proximal protrusions 310a and the distal protrusions 310b, the support provided by the intermediate protrusions 310c to the flexible circuit board 30 can be controlled based on the redundancy factor of the flexible circuit board 30. For example, when the redundancy factor of the flexible circuit board 30 is between 2 and 2.5, all support protrusions 310 on the outer support plate 300 can be used to support the flexible circuit board 30. In other words, the proximal protrusions 310a, the intermediate protrusions 310c, and the distal protrusions 310b jointly support the flexible circuit board 30. When the redundancy factor of the flexible circuit board 30 is greater than 2.5, the bending radius of the first bending section 31 of the flexible circuit board 30 can be increased, and in this case, the first bending section 31 of the flexible circuit board 30 is supported only by the proximal protrusions 310a and the distal protrusions 310b.

[0180] Figure 20 is a schematic diagram of the partial structure of the rotating shaft mechanism used in the simulation comparison example provided in an embodiment of the present application; Figure 21 is a comparison result of the simulation using the rotating shaft mechanism in Figure 20.

[0181] As shown in FIG20(a), the original solution uses an inner support plate 200 to control the bending radius of the first bending section 31 of the flexible circuit board 30, and the redundant space for the first bending section 31 in the width direction of the hinge mechanism 13 is 2 mm. As shown in FIG20(b), this embodiment uses an outer support plate 300 to control the bending radius of the first bending section 31 of the flexible circuit board 30, and the redundant space for the first bending section 31 in the width direction of the hinge mechanism 13 is 3.5 mm. Therefore, compared with the original solution that relies on the inner support plate 200 to control the first bending section 31 of the flexible circuit board 30, this embodiment relies on the outer support plate 300 to control the first bending section 31 of the flexible circuit board 30, which significantly increases the redundant space for the first bending section 31.

[0182] Specifically, in a simulation comparison example, a FPC 30 with a base length of 17 mm, a redundant length of 0.5 mm, and a corresponding redundant factor of 2.9 was used. In this embodiment, the proximal protrusions 310a and distal protrusions 310b on the outer support plate 300 were used to control the bending radius of the first bending section 31 of the FPC 30. The radius R of the predetermined arc surface at the vertex of each support protrusion 310 was calculated as: the bending radius of the first bending section 31 (0.9 mm) + the thickness of the FPC 30 (0.127 mm) (1.027 mm). Using the calculation formula for the position and height of the support protrusions 310, the first central angle ∠QOT1 corresponding to the proximal protrusion 310a was determined to be 60°, and the second central angle ∠QOTn corresponding to the distal protrusion 310b was determined to be 90°. A structural diagram of the support protrusions 310 of the outer support plate 300 was then drawn.

[0183] Table 1 Comparison of the bending radius and force simulation results of the first bending section of the flexible circuit board before and after optimization

[0184] Referring to (a) in Figure 21 and Table 1, in the original scheme, when the flexible circuit board 30 is in a bent state, the bending radius of the first bending section 31 of the flexible circuit board 30 is 0.739 mm, the flexible circuit board 30 is delaminated, and the pushing force of the inner support plate 200 on the flexible circuit board 30 (the pressure of the flexible circuit board 30 on the inner support plate 200) is 1.53 N; referring to (b) in Figure 21 and Table 1, in the scheme of this embodiment, when the flexible circuit board 30 is in a bent state, the bending radius of the first bending section 31 of the flexible circuit board 30 is 0.9 mm, the flexible circuit board 30 is not delaminated, and the pushing force of the inner support plate 200 on the flexible circuit board 30 is 0.75 N.

[0185] As can be seen, the solution of this embodiment significantly increases the redundant space of the first bending section 31 by using the outer support plate 300 to control the first bending section 31. Compared with the original solution, this embodiment increases the bending radius of the first bending section 31 of the flexible circuit board 30 by 22% and reduces the pushing force of the inner support plate 200 by 51%. The solution of this embodiment can make the overall bending of the flexible circuit board 30 more smooth, which can solve the delamination problem of the flexible circuit board 30. The contact area between the flexible circuit board 30 and the support plate assembly is reduced, and the pushing force of the flexible circuit board 30 on the inner support plate 200 is reduced, which can alleviate the abnormal noise problem caused by the movement of the flexible circuit board 30.

[0186] In the description of the embodiments of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to a fixed connection, an indirect connection via an intermediate medium, internal communication between two components, or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on specific circumstances.

[0187] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Claims

1. A hinge mechanism, applied to a foldable electronic device, having an unfolded state and a folded state, characterized in that: The rotating shaft mechanism comprises: Spindle; An inner support plate, movably connected to both sides of the main shaft in the width direction; An outer support plate, located on both sides of the main shaft in the width direction, and movably connected to a side of the inner support plate away from the main shaft; Among them, the surface of the outer support plate on one side facing away from the folding screen of the foldable electronic device has a plurality of support protrusions, and the plurality of support protrusions are located on the side of the outer support plate close to the inner support plate, and each of the support protrusions is arranged in sequence along the width direction of the outer support plate, and at least some of the support protrusions are used to support the flexible circuit board passing through the hinge mechanism.

2. The rotating shaft mechanism according to claim 1, characterized in that: One end of the supporting protrusion away from the outer supporting plate has a protrusion vertex, and the protrusion vertex is used to support the flexible circuit board.

3. The rotating shaft mechanism according to claim 2, characterized in that: The end surface of the supporting protrusion away from the outer supporting plate is a curved surface, and the vertex of the protrusion is the vertex of the curved surface.

4. The rotating shaft mechanism according to claim 3, characterized in that: Along the direction away from the inner support plate, the height of each support protrusion gradually increases; wherein, the height of the support protrusion is the distance from the top of the protrusion to the reference plane of the outer support plate, and the reference plane is the plane where the straight section of the side surface of the outer support plate facing away from the folding screen is located, and when the hinge mechanism is in the folded state, the straight section is perpendicular to the width direction of the main axis.

5. The rotating shaft mechanism according to claim 4, characterized in that: The protruding vertices of each supporting protrusion and the supporting points on the inner wall surface of the inner supporting plate for supporting the flexible circuit board are all located on a preset arc surface; wherein, the inner wall surface of the inner supporting plate is the side surface of the inner supporting plate facing away from the folding screen.

6. The rotating shaft mechanism according to claim 5, characterized in that: The difference between the radius of the preset arc surface and the thickness of the flexible circuit board is greater than 0.5 mm.

7. The rotating shaft mechanism according to claim 5, characterized in that: Among the supporting protrusions, the supporting protrusion closest to the inner supporting plate is a proximal protrusion, and the supporting protrusion farthest from the inner supporting plate is a distal protrusion, and at least one intermediate protrusion is provided between the proximal protrusion and the distal protrusion; Among them, on the preset arc surface, the central angle corresponding to the arc between the proximal protrusion and the support point is a first central angle, and the angle of the first central angle is ≥45° and ≤65°; the central angle corresponding to the arc between the distal protrusion and the support point is a second central angle, and the angle of the second central angle is ≥80° and ≤100°.

8. The rotating shaft mechanism according to claim 7, characterized in that: The first central angle is 60°, and the second central angle is 90°.

9. The rotating shaft mechanism according to claim 7, characterized in that: An intermediate protrusion is arranged between the proximal protrusion and the distal protrusion, and the central angle corresponding to the arc between the intermediate protrusion and the supporting point is a third central angle, and the angle of the third central angle is greater than 65° and less than 80°.

10. The rotating shaft mechanism according to claim 9, characterized in that: The angle of the third central angle is 75°.

11. The rotating shaft mechanism according to any one of claims 7 to 10, characterized in that: When the redundancy factor of the flexible circuit board is within a first preset range, the proximal protrusion contacts the flexible circuit board; When the redundancy factor of the flexible circuit board is within a second preset range, the proximal protrusion and at least a portion of the middle protrusion are in contact with the flexible circuit board; When the redundancy factor of the flexible circuit board is within a third preset range, the proximal protrusion and the distal protrusion are in contact with the flexible circuit board; Among them, the maximum value of the first preset range is less than the minimum value of the second preset range, the maximum value of the second preset range is less than the minimum value of the third preset range, and the redundancy factor of the flexible circuit board is the percentage of the redundant length of the flexible circuit board to the reference length of the flexible circuit board.

12. The rotating shaft mechanism according to claim 11, characterized in that: The first preset range is >0 and ≤1, the second preset range is >1 and ≤2, and the third preset range is >2.

13. The rotating shaft mechanism according to any one of claims 3 to 12, characterized in that: The outer wall surface of the supporting protrusion is a smooth wall surface smoothly extending from the top of the protrusion to the surface of the outer supporting plate.

14. The rotating shaft mechanism according to claim 13, characterized in that: From the apex of the protrusion to the end of the supporting protrusion connected to the outer supporting plate, the width of the supporting protrusion gradually increases; Alternatively, from the apex of the protrusion to the end where the supporting protrusion is connected to the outer supporting plate, the supporting protrusion includes a transition section and a straight rod section connected in sequence, the width of the transition section gradually increases, and the width of the straight rod section remains fixed.

15. The rotating shaft mechanism according to any one of claims 3 to 12, characterized in that: From the apex of the protrusion to one end of the supporting protrusion connected to the outer supporting plate, the supporting protrusion includes a head and a rod, and the connecting portion between the head and the rod is a diameter-changing portion.

16. The rotating shaft mechanism according to claim 15, characterized in that: From one end of the rod portion connected to the head portion to one end of the rod portion connected to the outer support plate, the width of the rod portion is fixed or gradually increases.

17. The rotating shaft mechanism according to any one of claims 13 to 16, characterized in that: There is a gap between adjacent supporting protrusions, or adjacent supporting protrusions overlap each other.

18. The rotating shaft mechanism according to any one of claims 1 to 17, characterized in that: Also includes: The decorative plate is movably connected on both sides of the main shaft in the width direction, and is arranged on both sides of the main shaft in the thickness direction opposite to the inner support plate. The decorative plate, the inner support plate and the outer support plate together enclose a space for accommodating the flexible circuit board.

19. The rotating shaft mechanism according to any one of claims 1 to 18, characterized in that: Also includes: A fixing assembly is installed on the main shaft and is used to fix the flexible circuit board.

20. The rotating shaft mechanism according to claim 19, characterized in that: The fixing assembly includes a first magnetic member and a second magnetic member that are arranged opposite to each other, and the first magnetic member and the second magnetic member are used to clamp the flexible circuit board.

21. A foldable electronic device, characterized in that: It comprises a first shell, a second shell and the rotating shaft mechanism according to any one of claims 1 to 20, wherein the first shell and the second shell are respectively connected to two sides of the rotating shaft mechanism.

22. The foldable electronic device according to claim 21, characterized in that: It also includes a folding screen, which is mounted on the first shell and the second shell, and is supported by the rotating shaft mechanism; Wherein, when the foldable electronic device is in a folded state, the first shell and the second shell are relatively stacked, and the folding screen is surrounded by the first shell and the second shell.

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