Rotating shaft device and folding screen equipment

Abstract

A rotating shaft device (13) and a folding screen device are applied to the field of electronic devices. The rotating shaft device (13) comprises a rotating shaft cover (103) and a limiting structure (401). The rotating shaft cover (103) and the limiting structure (401) form a limiting cavity, one or more flexible material layers (501) pass through the limiting cavity, and the fixing positions of the two ends of each flexible material layer (501) are located on the two sides of the limiting cavity respectively; the limiting cavity is used for limiting the movement direction of the one or more flexible material layers (501) in the limiting cavity when the fixed positions at the two ends of the flexible material layers (501) move relatively. Thus, the limiting cavity limits the movement direction of the shaft-penetrating flexible material layer (501) at the rotating shaft (108), so that the bending form of the flexible material layer (501) at the rotating shaft (108) is consistent. Besides, the shaft-penetrating flexible material layer (501) is limited in the limiting cavity, so that the shaft-penetrating flexible material layer (501) can be prevented from jacking up the inner screen (107) of the folding screen equipment, the inner screen (107) at the rotating shaft (108) can be prevented from generating light and shadow, and the user experience is prevented from being influenced.

Description

A rotating shaft device and folding screen device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on March 24, 2023, with application number 202310305432.2 and invention name “A hinge device and folding screen device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of folding screen devices, and in particular to a hinge device and a folding screen device. Background Art

[0003] A foldable screen device refers to a device that achieves a foldable screen display form through bendable components such as hinges and flexible screens. Among them, the hardware systems corresponding to different flexible screens are usually connected using a through-axis FPC (Flexible Printed Circuit) to achieve signal and power transmission. The through-axis here means that the FPC passes through the rotating shaft so that the two ends of the FPC are located in the middle frame corresponding to different flexible screens. In addition, foldable screen devices usually enhance thermal conductivity by adding a through-axis graphene layer to avoid the problem of abnormal local display of the foldable screen due to large temperature differences between different flexible screens.

[0004] In the existing solution, the through-axis FPC and the graphene layer share the hinge position and overlap and stack. Since the through-axis FPC and graphene are both flexible materials, and the basic mechanical properties such as hardness, modulus, and tensile coefficient of the two flexible materials are very different, when the folding screen device is in the unfolded state, the through-axis FPC and graphene at the hinge each present different shapes. Inconsistent shapes will cause the through-axis FPC and graphene to interfere with each other during the bending process, thereby reducing the bending life of the through-axis FPC layer and the graphene layer. In addition, inconsistent shapes will also cause the through-axis FPC and graphene at the hinge to lift up the inner screen of the folding screen device, causing the inner screen at the hinge to produce screen light and shadow, affecting the user experience.

[0005] Summary of the Invention

[0006] The purpose of this application is to provide a hinge device and a folding screen device that prevents the flexible material layers from interfering with each other during the bending process. It also prevents the flexible material layer passing through the hinge from lifting the inner screen of the folding screen device, causing light and shadow on the inner screen at the hinge, affecting the user experience.

[0007] In a first aspect, the present application provides a hinge device, which is applied to a foldable screen device, comprising:

[0008] The rotating shaft cover and the limiting structure form a limiting cavity, through which one or more flexible material layers pass, with the fixed positions at both ends of each flexible material layer located on either side of the limiting cavity. The limiting cavity is used to limit the movement direction of the one or more flexible material layers within the limiting cavity when the fixed positions at both ends of the flexible material layer move relative to each other.

[0009] For example, two flexible material layers, the through-axis FPC layer and the graphene layer, pass through a limiting cavity. When the fixed positions at both ends of the through-axis FPC layer and the graphene layer undergo relative movement, such as relative movement away from each other, the through-axis FPC layer and the graphene layer at the rotating shaft move within the limiting cavity. In this way, the limiting cavity can limit the movement direction of the through-axis flexible material layer at the rotating shaft, so that the bending shape of the flexible material layer at the rotating shaft is consistent. In addition, confining the through-axis flexible material layer within the limiting cavity can prevent the flexible material layer from bending in the rotating shaft area and lifting up the inner screen of the folding screen, thereby preventing the screen from generating screen light and shadow, affecting the user experience.

[0010] In one possible implementation, the side of the limiting structure away from the limiting cavity includes a groove, such as a "J"-shaped profiling structure. The groove is used to accommodate part of the screen of the folding screen device when the fixed positions at both ends of the flexible material layer are closest to each other. That is, when the flexible material layer is in a closed state (the flexible screens at both ends are at an angle of 0°), the folding screen will produce a water drop angle. The groove will accommodate the water drop angle, which is conducive to the lightness and thinness of the whole machine and the improvement of the inner screen crease.

[0011] In one possible implementation, when the fixed positions at both ends of the flexible material layer are farthest apart (the flexible screens at both ends are at an angle of 180°), the maximum width of the groove is greater than the maximum height of the groove. The maximum width of the groove is parallel to the folding screen of the folding screen device; the maximum height of the groove is perpendicular to the folding screen of the folding screen device. At this time, the arc surface interface where the limiting structure contacts the through-axis flexible material layer is a quasi-parabola with a width greater than the height. Using this quasi-parabola to provide contoured support for the through-axis flexible material layer can avoid contact between the through-axis FPC layer and the outer screen, thereby avoiding light and shadow caused by the through-axis FPC layer and the inner screen, affecting the user experience.

[0012] In one possible implementation, multiple layers of flexible material, specifically a thermally conductive material layer and a flexible printed circuit board (FPC), are passed through the limiting cavity. The thermally conductive material layer can be a graphene layer, which is used to facilitate heat transfer between the flexible screens on different sides. The flexible printed circuit board, also known as a through-axis FPC layer, is used to facilitate signal and power transfer between the different flexible screens.

[0013] In a possible implementation, the heat-conducting material layer has a corrugated surface. Compared with other heat-conducting material layers with flat surfaces, the heat-conducting material layer with a corrugated surface can increase the bending life of the heat-conducting material layer.

[0014] In one possible implementation, the thermally conductive material layer is thicker at the bend than at the non-bend portion. For example, increasing the thickness of a graphene layer at the bend increases its modulus. When the modulus of the graphene layer increases to match that of the through-axis FPC layer, the through-axis FPC layer and the graphene layer achieve better morphological consistency.

[0015] In one possible implementation, the bend is located within the limiting cavity. Thickening the limited bend area ensures the morphological consistency of each flexible material layer. Specifically, when the through-axis FPC layer and the graphene layer have good morphological consistency at the rotating shaft, the morphological consistency of the through-axis FPC layer and the graphene layer can also be maintained in other areas due to minimal redundancy. Therefore, thickening the bend within the limiting cavity can reduce the cost of thickening while ensuring the consistency of each flexible material layer.

[0016] In one possible implementation, the flexible printed circuit board is equipped with positioning slots connected to the thermally conductive material layer, with a width of 2 to 3 mm. In the hinge area, the through-axis FPC is connected to the thermally conductive material layer, such as a graphene layer, via the positioning slots, which increases the support strength of the through-axis FPC layer. Otherwise, directly attaching the graphene layer to the through-axis FPC layer would cause the copper traces on the through-axis FPC layer to deviate from the bend-neutral layer, reducing the flex life index and failing to meet flex life requirements.

[0017] The positioning slot can be connected to the thermal conductive material layer by adhesive.

[0018] In one possible implementation, the two sides of the positioning slot are empty, for example, the thermal conductive material layer and the through-axis FPC layer are connected by an air-gap. This ensures that the copper traces in the through-axis FPC are located on the bend neutral layer.

[0019] The hinge device provided in the embodiment of the present application can be used on the inner screen of a folding screen device, and can also be used on the outer screen of a folding screen device.

[0020] In a second aspect, the present application provides a folding screen device, comprising: a main frame, a sub-frame, a hinge door panel, and a hinge device;

[0021] The main frame is connected to the sub-frame through the hinge device and the hinge door plate, and the hinge door plate limits the relative movement direction of the folding screen of the folding screen device; the hinge is transformed into the hinge device described in any one of the first aspects.

[0022] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution or beneficial effect is included in at least one embodiment. Therefore, the description of a technical feature, technical solution or beneficial effect in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in the present embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that the embodiment can be implemented without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in specific embodiments that do not embody all embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a folding screen provided by an embodiment of the present application;

[0024] FIG2 is a perspective view of a folding screen device provided by an embodiment of the present application in a fully unfolded state, viewed from a top angle;

[0025] FIG3 is a schematic diagram of a connection between a through-axis FPC and graphene in a closed state of the whole device provided by an existing solution;

[0026] FIG4 is a schematic diagram of a folding screen device in an unfolded state provided by an embodiment of the present application;

[0027] FIG5 is a schematic structural diagram of a rotating shaft device provided in an embodiment of the present application;

[0028] FIG6 is a schematic diagram of an unfolded state of a folding screen device provided in an embodiment of the present application;

[0029] FIG7 is a schematic diagram of a folding screen structure formed by a rotating shaft device provided in an embodiment of the present application;

[0030] FIG8 is a schematic diagram of a screen with a corrugated surface in a fully unfolded state provided by an embodiment of the present application;

[0031] FIG9 is a schematic diagram of a corrugated surface provided in an embodiment of the present application;

[0032] FIG10 is a schematic diagram of an inner screen provided in an embodiment of the present application, wherein the thickness at the bending portion is greater than the thickness at the non-bending portion. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The term "and / or" in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0035] In the description and claims of the embodiments of this application, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order of objects. For example, the terms "first target object" and "second target object" are used to distinguish different objects, rather than to describe a specific order of objects.

[0036] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0037] In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. For example, "multiple processing units" means two or more processing units; "multiple systems" means two or more systems.

[0038] In order to enable those skilled in the art to better understand the present invention, the embodiments of the present application are described below in conjunction with the accompanying drawings.

[0039] In a foldable screen device, users can use flexible components such as hinges (also called hinge devices) and flexible screens to achieve foldable screen display forms, thereby increasing the screen size while maintaining the convenience of one-handed operation and portability. The foldable screen device can be a device composed of a whole flexible screen, and the hinge device divides the flexible screen into two parts. When folding, the two parts of the flexible screen can be folded along the hinge device. In addition, the foldable screen device can also be a device composed of two flexible screens, which use different display logics and are connected by a hinge device to achieve the superposition and unfolding of the foldable screen device. In addition, the foldable screen device can also be a device that is folded by two hinge devices to form a three-layer flexible screen, etc.

[0040] In these folding screen devices, a through-axis flexible material layer is generally provided at the rotating shaft, and the two ends of the through-axis flexible material layer are respectively provided in different flexible screen middle frames, so as to realize signal transmission, power transmission and heat transfer between different flexible screens. The flexible material layer is composed of flexible material. Flexible material is used to indicate a material that can be extruded and deformed, and has better deformation ability than rigid material. For example, graphene is a commonly used flexible material with thermal conductivity. In the embodiment of the present application, the flexible material layer can be a through-axis FPC layer and / or a graphene layer, or it can be other flexible material layers that can realize signal transmission, power transmission and heat transfer.

[0041] In the prior art, the above-mentioned through-axis flexible material layer includes two layers, namely the through-axis FPC layer and the graphene layer, and the FPC layer and the graphene layer share a common rotating shaft and overlap and stack. Due to the large differences in the basic mechanical properties of the through-axis FPC and graphene, such as hardness, modulus, and tensile coefficient, the through-axis FPC layer and the graphene layer will have different shapes at the rotating shaft when the folding screen device is in the unfolded state. Inconsistent shape will cause the through-axis FPC layer and the graphene layer to interfere with each other during the stacking process, thereby reducing the bending life of the through-axis FPC layer and the graphene layer. In addition, the inconsistent shape will cause the through-axis FPC layer and the graphene layer at the rotating shaft to lift up the inner screen of the folding screen device, resulting in screen light and shadow on the inner screen at the rotating shaft, affecting the user experience.

[0042] Exemplary description: Figure 1 shows a folding screen mobile phone provided in an embodiment of the present application.

[0043] When the user is using a foldable screen mobile phone, the flexible screen 11 and the flexible screen 12 can be overlapped or unfolded through the hinge device 13. Among them, the flexible screen 11 and the flexible screen 12 can be two flexible screens with different display logics, or they can be two parts of a whole flexible screen. Exemplarily, when the angle between the flexible screen 11 and the flexible screen 12 is the largest, the foldable screen mobile phone is fully unfolded. When the angle between the flexible screen 11 and the flexible screen 12 is the smallest, the foldable screen mobile phone is completely closed. At this time, the inner screen of the foldable screen device may not display and is in an off state, and the outer screen is used for display. The outer screen can be on the other side opposite to the flexible screen 11 or the flexible screen 12.

[0044] In order to better illustrate the through-shaft flexible material layer provided at the rotating shaft, a detailed description will be given below with reference to FIG. 2 to FIG. 4 .

[0045] Figure 2 is a perspective view from a top-down angle of the folding screen device shown in Figure 1 when it is in a fully unfolded state.

[0046] The hardware system 102 of the main frame 101 corresponding to the flexible screen 11 is connected to the hardware system 106 of the sub-frame 105 corresponding to the flexible screen 12 via the through-axis FPC layer 104 to achieve signal and power transmission. The main frame 101 side is equipped with a motherboard system-on-chip (SoC) and an internal display driver IC (DDIC).

[0047] The starting point of the through-axis FPC layer 104 is at a fixed position of the main frame 101 , and the end point of the through-axis FPC layer 104 is at a fixed position of the sub-frame 105 . The middle part passes through the main frame 101 , the rotating shaft 108 and the sub-frame 105 in sequence.

[0048] The hinge 108 is also provided with a hinge cover 103 to prevent the components at the hinge 108 from being exposed to the outside, thus protecting it from dust and water. The screen 107 is folded and unfolded based on the main frame 101, hinge 108, and sub-frame 105. The screen 107 indicates that the flexible screen 11 and the flexible screen 12 constitute a single screen.

[0049] The reason for adding through-axis graphene to the through-axis FPC is that, as foldable phones become increasingly thin and light, the heat dissipation capacity of the entire device is poor, and the heat is concentrated in the main frame, causing the main frame to heat up faster than the sub-frame. In addition, there are a large number of small parts on the hinge, which have poor thermal conductivity, resulting in a large temperature difference between the main and sub-frames. Due to the large temperature difference between the main and sub-frames, the screen will display abnormally in some areas. Adding through-axis graphene is equivalent to adding a heat conduction channel between the main and sub-frames. See Figure 3, which is a schematic diagram of the connection between the through-axis FPC and graphene in a fully closed state provided by the existing solution. Among them, the angle between the main frame and the sub-frame is the smallest when fully closed.

[0050] The through-axis FPC layer 104 and the through-axis graphene layer 201 share the same pivot axis and perforations on the main and sub-frames, overlapping and stacking. The through-axis FPC layer is secured to the main and sub-frames via fixing points on the main board and fixing points on the sub-board 106. Furthermore, the through-axis graphene layer is secured to the pivot door panels 202 and 203 via fixing points near the main board and fixing points near the sub-board 106. The fixing points of the through-axis graphene layer do not overlap with those of the through-axis FPC layer. The through-axis FPC layer and the graphene layer are not secured at the pivot axis.

[0051] There are two pivot door panels as described in Figure 3, and the two pivot door panels are symmetrical along the perpendicular bisector of the line segment formed by the farthest two endpoints of the pivot cover 103. For the two pivot door panels, when the mobile phone is fully closed, the angle between the pivot door panel 202 and the pivot door panel 203 is the smallest, and the screen forms a water drop-shaped corner 301. When the mobile phone is fully unfolded, the angle between the pivot door panel 202 and the pivot door panel 203 is the largest. The main frame 101 is connected to the sub-frame 105 through the pivot door panels and the pivot device, and is used to limit the relative movement direction of the folding screen of the folding screen device. For example, the pivot door panels described in Figure 3 limit the relative movement direction of the folding screen of the folding screen device to the horizontal inward folding direction.

[0052] The folding screen device described in Figure 3 is fully unfolded to obtain the unfolded diagram shown in Figure 4. At this time, the angle between the rotating shaft door panel 202 and the rotating shaft door panel 203 is at its minimum. At the rotating shaft, there is redundant length between the through-axis FPC layer 104 and the graphene layer 201, and the through-axis FPC layer 104 and the graphene layer 201 bend at the rotating shaft. Among them, the degree of bending of the through-axis FPC layer is less than that of the graphene layer 201. On the one hand, the bending of the through-axis FPC layer and the graphene layer 201 easily lifts up the screen 107, causing light and shadow on the screen. On the other hand, the bending morphologies of the through-axis FPC layer 104 and the graphene layer 201 are inconsistent, resulting in mutual interference between the through-axis FPC layer and the graphene layer during the bending process, thereby reducing the bending life of the through-axis FPC layer and the graphene layer. Through analysis, it was found that due to the large differences in basic mechanical parameters such as hardness, modulus and tensile coefficient between the through-axis FPC and graphene, the flexible material bends in different shapes when the whole machine is unfolded.

[0053] Based on this, the present invention provides a hinge device that adds a limiting structure to an existing hinge device. The flexible material layer passing through the hinge forms a limiting cavity through the limiting structure and the hinge cover, restricting its bending shape, ensuring that the bending shape of the flexible material layer at the hinge is consistent. In addition, confining the flexible material layer passing through the hinge within the limiting cavity can prevent the flexible material layer from bending in the hinge area, which could push up the screen of the folding screen device, thereby preventing screen light and shadow from appearing on the hinge, affecting the user experience.

[0054] Next, we will take the folding screen device as the folding screen type shown in Figures 3 and 4 as an example, and combine the accompanying drawings to introduce the hinge device provided by this application in detail. It should be noted that the above folding screen is an inner screen.

[0055] Example 1

[0056] Refer to Figure 5, which is a schematic diagram of the structure of a rotating shaft device provided in an embodiment of the present application. The device includes a limiting structure 401 and a rotating shaft cover 103. The limiting structure 401 is used to define the shape of the through-shaft flexible material layer 501 at the rotating shaft. Specifically, the limiting structure 401 and the rotating shaft cover form a limiting cavity, through which the through-shaft flexible material layer 501 passes, with its ends fixedly positioned on either side of the limiting cavity.

[0057] When the fixed positions at both ends of the flexible material layer move relative to each other, the movement direction of each through-shaft flexible material layer 501 in the limiting cavity is the same or substantially the same, thus ensuring that the shapes of different flexible material layers at the rotating shaft are consistent.

[0058] Exemplary explanation: Assuming the two fixed positions are approaching each other, the inner screen is gradually closing. When the two fixed positions are closest to each other, the inner screen is in a completely closed state. At this time, there is no redundancy in each layer of the through-shaft flexible material layer 501 at the rotating shaft, and each layer of the through-shaft flexible material layer 501 moves in the same or substantially the same direction.

[0059] Assuming the two fixed positions are moving away from each other, the inner screen is gradually unfolding. When the two fixed positions are farthest apart, the inner screen is in the unfolded state. At this point, the limiting cavity at the axis restricts the movement direction of each flexible material layer 501, ensuring that each flexible material layer 501 moves in the same or substantially the same manner at the axis.

[0060] In the embodiment of the present application, the embodiment of the present application does not limit the cavity shape and cavity size of the limiting cavity. It can be a cavity shape with a convexity as shown in Figure 5, or it can be other cavity shapes, such as a concave cavity shape.

[0061] For example, a limiting structure 401 is added to the folding screen device shown in Figure 4 at the rotating shaft to form a schematic diagram of the unfolded state of the folding screen device as shown in Figure 6. Among them, the flexible material layer 501 is a through-axis FPC layer 104 and a thermal conductive material layer (such as the graphene layer 201 shown in the figure). The through-axis FPC layer 104 and the graphene layer 201 pass through a limiting cavity composed of a limiting structure and a rotating shaft cover. When the fixed positions at both ends of the through-axis FPC layer 104 and the graphene layer 201 (the through-axis FPC layer 104 and the graphene layer 201 are fixed respectively) send relative motion, relative to that shown in Figure 4, the morphological consistency of the through-axis FPC layer 104 and the graphene layer 201 at the rotating shaft is high.

[0062] For non-rotating axis locations, such as the main frame and sub-frame locations, the bending probability of the through-axis FPC layer 104 and the graphene layer 201 is low. Therefore, the through-axis FPC layer and the graphene layer at the non-rotating axis locations do not need to be processed for morphological consistency.

[0063] In addition, regarding the shape of the limiting structure, a groove is included on the side away from the limiting cavity, that is, the side close to the folding screen is the groove. The groove is used to accommodate part of the inner screen of the folding screen device in the closed state. Continuing to refer to FIG. 3, when the screen is folded to form a water-drop-shaped fold angle 301, the groove can partially accommodate the water-drop-shaped fold angle 301, that is, provide a certain space for the water-drop-shaped fold angle 301 to avoid the water-drop-shaped fold angle 301 directly contacting the solid plane.

[0064] Exemplary illustration: Taking the rotating shaft device shown in FIG. 5, its limiting structure can be a "ji" - shaped profiling structure (the structure shown in FIG. 5). Among them, the upper "one" of the limiting structure and the rotating shaft cover 103 form a limiting cavity, and the other side is close to the inner screen. The "ji" - shaped profiling structure has a relatively larger cross-sectional area of the supporting part compared to the structure with a dot on the upper side, such as a triangular structure (the fixed point and the rotating shaft cover 103 form a limiting cavity). In this way, more through-shaft FPC layers and graphene layers can cover the bracket, improving the morphological consistency of the through-shaft FPC layers and graphene layers at the rotating shaft.

[0065] In addition, the groove part on the lower side of the "ji" - shaped profiling structure can increase the space for accommodating the water-drop-shaped fold angle 301 when the folding screen mobile phone is completely closed.

[0066] In addition, the limiting structure can also be regarded as a "U" - shaped profiling structure, a horseshoe-shaped profiling structure, etc. The specific structural form of the limiting structure can be adjusted by those skilled in the art according to needs.

[0067] Considering that the relationship between the height and width of the groove will affect the contact situation between the through-shaft flexible material layer 501 and the inner screen 107, specifically the contact situation between the through-shaft FPC layer and the inner screen 107. When the through-shaft FPC layer contacts the inner screen 107, light and shadow will be generated on the inner screen, affecting the user experience. In this application, the maximum width and maximum height of the groove are limited. The maximum width of the groove is greater than the maximum height of the groove. The width direction of the groove is parallel to the inner screen direction of the folding screen mobile phone, and the height direction is perpendicular to the inner screen direction of the folding screen mobile phone.

[0068] When the maximum width of the groove is greater than the maximum height of the groove, the arc surface interface where the limiting structure contacts the through-shaft flexible material layer is a parabola-like shape with a width greater than the height. Referring to the parabola-like shape 502 shown in FIG. 5, at this time, the symmetry axis of the parabola-like shape is the symmetry axis of the "ji" - shaped profiling structure. Using this parabola-like shape to profile and support the through-shaft flexible material layer can avoid the contact between the through-shaft FPC layer and the outer screen.

[0069] Exemplary illustration: As shown in Figure 5, the reference plane is inner screen 107. The dimension of the "J"-shaped profiling structure parallel to inner screen 107 is the width, and the dimension of the "J"-shaped profiling structure perpendicular to inner screen 107 is the height. To avoid light and shadow caused by contact between the through-axis FPC layer and inner screen 107, the maximum width value A is greater than the maximum height value B.

[0070] Specifically, the size of A is related to the thickness of the entire device. For example, if the device is 14.3mm thick, A is between 2.0 and 4.0mm. For example, A is 3mm. Where B > A, and considering assembly requirements, the current solution generally chooses a B size of 1.5A. That is, when A is 3mm, B is 4.5mm.

[0071] It is worth noting that due to the limited cavity between the shaft cover and the limiting structure, the existing perforated assembly solution cannot be used. During the shaft assembly process, the through-shaft FPC layer and the graphene layer must be assembled separately to the shaft area before the shaft is assembled. The existing perforated assembly solution is: after the shaft is assembled, the through-shaft FPC and graphene layers are assembled separately through the shaft cavity.

[0072] The materials used for the retaining structure include, but are not limited to, metals such as steel and titanium alloys, as well as composite materials containing fiber materials such as glass fiber, carbon fiber, and aramid fiber. For example, the "J"-shaped profiling bracket is a metal sheet, wherein the steel is an iron-carbon alloy with a carbon content of between 0.02% and 2.11% by mass. These materials have superior structural strength, which helps reduce the thickness of the profiling bracket while ensuring its support strength, thereby facilitating the thinning and weight reduction of the folding screen.

[0073] The hinge device provided in the embodiments of the present application is applied to a foldable screen device, limiting the movement direction of the through-shaft flexible material layer at the hinge, ensuring that the bending shape of the flexible material layer at the hinge is consistent. Furthermore, confining the through-shaft flexible material layer within the limiting cavity prevents the through-shaft flexible material layer from lifting the inner screen of the foldable screen device, which could cause light and shadow on the inner screen at the hinge and affect the user experience.

[0074] Example 2

[0075] This embodiment of the present application also provides another hinge device. Based on the first embodiment, each flexible material layer is connected by an empty slot. By adding a transition layer between the through-axis FPC layer and the adjacent flexible material layer, the copper traces of the through-axis FPC layer are prevented from straying into other flexible material layers. For example, the graphene layer and the through-axis FPC layer are connected by an empty slot. The empty slot can be an air gap.

[0076] In addition, when the through-axis FPC layer is in direct contact with other flexible material layers, such as a graphene layer, the copper traces in the through-axis FPC layer will deviate to the graphene layer, resulting in the risk of fatigue breakage of the through-axis FPC layer. A positioning slot is provided in the through-axis FPC layer in the hinge area, and the adjacent flexible material layers are connected to the through-axis FPC layer through the positioning slot. There are empty slots on both sides of the positioning slot, that is, in the non-hinge area, the through-axis FPC layer is connected to the adjacent flexible material layer through the empty slot. The positioning slot defines the position of other adjacent flexible material layers in the hinge area, avoiding direct connection with the through-axis FPC layer, thereby preventing the copper traces of the through-axis FPC layer from deviating to the adjacent flexible material layer, thereby reducing the risk of fatigue breakage of the through-axis FPC layer.

[0077] In order to better illustrate the rotating shaft device provided in the embodiment of the present application, a detailed description is given below with reference to FIG7 .

[0078] See Figure 7, which shows a schematic diagram of a folding screen structure formed by a hinge assembly according to an embodiment of the present application. The hinge assembly's selected limiting structure is a "J"-shaped profiling structure 401. The maximum width B of the "J"-shaped profiling structure is 1.5 times its maximum height A (the definitions of the width and height directions are as in Example 1 and will not be discussed here).

[0079] In the structure shown in Figure 7, in the non-rotating axis area, the through-axis FPC layer 104 and the graphene layer 201 are connected by an air-gap 701. The thickness of the air-gap 701 layer cannot be too small, otherwise it will not achieve the purpose of preventing the copper traces of the through-axis FPC layer from deviating to other flexible material layers. The thickness of the air-gap 701 layer cannot be too large, otherwise it will not be conducive to the thinning of the foldable screen mobile phone. In the embodiment of the present application, the thickness of the air-gap 701 layer is selected to be 46μm.

[0080] It is worth noting that in actual use, the graphene layer should be as thin as possible while meeting the thermal conductivity requirements. The embodiment of the present application selects a graphene layer thickness of 40 μm. In addition, the graphene layer needs to be thermally insulated to prevent the graphene layer from affecting the temperature of other devices when transferring heat, thereby affecting the life of other devices. The surface of the graphene layer 201 is covered with a 10 μm thick PET (Polyethylene terephthalate, polyester resin) layer and a 16 μm thick PTFE (Poly tetra fluoroethylene, polytetrafluoroethylene) layer. Among them, the graphene layer and the PTFE layer are connected by a 5 μm thick mesh double-sided adhesive layer.

[0081] In the hinge area, the through-axis FPC layer 104 is connected to the graphene layer 201 through the positioning slot 502. Since the graphene layer is directly pasted onto the through-axis FPC layer, the copper trace position of the through-axis FPC layer will deviate from the bending neutral layer, the bending life index will decrease, and the bending life requirement cannot be met. In one possible implementation method, the positioning slot can be a reinforcement plate made of materials such as PI (polyimide), PET (high-temperature resistant polyester film) and FR4. Among them, the main components of the FR4 material reinforcement plate are glass fiber cloth and epoxy resin glue. The through-axis FPC layer 104 is connected to the graphene layer 201 through the reinforcement plate to avoid contact between the through-axis FPC layer and the graphene layer, thereby improving the bending life of the through-axis FPC layer.

[0082] In the hinge area, the thickness of the positioning slot layer is set to 2-3mm to prevent contact between the FPC layer and the graphene layer. To prevent adhesive leakage, the adhesive layer width is required to be less than the width of the positioning slot layer (the definition of the width direction is the same as that of the width direction in Example 1 and is not repeated here).

[0083] In addition, the graphene layer 201 can also be connected to the positioning slot through an adhesive foot (also called adhesive backing), and then connected to the through-axis FPC layer 104 through the positioning slot. The adhesive backing material can be hot melt adhesive, thermal conductive silicone, silicone adhesive, etc. This application does not limit the adhesive material.

[0084] In the embodiment of the present application, the thickness of the adhesive must meet the following conditions: the width of the adhesive between the graphene and the positioning slot is 0.2mm-0.5mm smaller than the width of the positioning slot. This can prevent direct contact between the through-axis FPC layer 104 and the graphene layer 201, thereby improving the bending life of the through-axis FPC layer.

[0085] In addition, the hinge cover 103 of the foldable screen device is adhered to the through-axis FPC layer with adhesive. The through-axis FPC layer is adhered to the main board on the main frame 101 and the sub-board on the sub-frame 105 through adhesive at different positions. The graphene layer 201 is adhered to the hinge door panels 202 and 203 with adhesive at different positions.

[0086] CT analysis of the solution described in Figure 7 demonstrates good consistency in the motion of the through-axis graphene layer and the through-axis FPC layer. Furthermore, multiple dynamic bending tests (≥200,000 cycles) of the entire device confirmed that neither the graphene layer nor the through-axis FPC layer exhibited any bending.

[0087] The hinge device provided in the embodiment of the present application can ensure that the copper traces in the through-axis FPC do not deviate to the adjacent flexible material layer on the basis of ensuring the consistency of the shapes of different flexible material layers in the hinge area, and can avoid the risk of fatigue breakage of the through-axis FPC layer.

[0088] Example 3

[0089] In one possible implementation, in order to further improve the bending life of the thermally conductive material layer, such as the graphene layer, a corrugated surface is used on the thermally conductive material layer. To better illustrate this embodiment of the application, a detailed description is given in conjunction with FIG8 .

[0090] Refer to Figure 8, which is a schematic diagram of a fully unfolded state of a screen with a corrugated surface provided in an embodiment of the present application. Among them, (a) is the rotating shaft device shown in Figure 7. For a detailed introduction, please refer to Example 2 and will not be discussed here. For the bending area 601, the bending radius of the graphene layer 201 is 0.543mm, and the strain value of the bending here is 4.35%. However, the strain threshold for the fracture of the graphene layer is 2.25%, and the strain value of the bending in the bending area is greater than the strain threshold for the fracture of the graphene, and there is a risk of fracture. Among them, the bending radius refers to the radius of the inscribed circle inscribed in the bending area.

[0091] Since the corrugated surface can change the modulus of the graphene layer relative to the non-corrugated surface in (a), the threshold of graphene strain can be increased. Therefore, the bending area 601 can be processed to generate a corrugated surface. Among them, (b) is the result diagram when the screen is fully unfolded after the bending area 601 is processed to generate a corrugated surface. The bending radius of the bending area 601 is 0.584, and the bending strain value is 5.07%. At this time, the strain threshold of the fracture of the broken graphene layer exceeds 10%. Since the bending strain value is less than the strain threshold of the graphene fracture, the risk of fracture of the graphene layer can be reduced compared to (a).

[0092] As shown in Figure 9, a graphene layer with a total thickness of 0.04 mm has a corrugated surface of 0.01 mm. To achieve this corrugated surface structure, in one possible implementation, partial die-cutting can be used to create a 0.01 mm corrugated surface. Partial die-cutting refers to cutting the die only in a specified area.

[0093] In actual applications, not all locations require a corrugated surface. Considering die-cutting costs, a radius threshold for the bend radius can be set. When the bend radius exceeds the radius threshold, a partial die-cut is performed on the bend area to obtain a graphene layer with a corrugated surface.

[0094] The embodiment of the present application does not limit the local die-cutting method. The graphene layer can be die-cut by a die-cutting proofing machine, or local die-cutting can be performed by laser die-cutting or other methods.

[0095] Exemplary description: The bending radius of each part of the graphene layer is analyzed with the help of simulation software. When the bending radius is greater than a radius threshold, the graphene layer at that part is die-cut to form a corrugated surface.

[0096] The radius threshold should be set according to the bending radius corresponding to the fracture threshold. Assuming the bending radius corresponding to the fracture threshold is 0.5, the radius threshold can be set to 0.5.

[0097] It should be noted that FIG8 is merely an example, and the parameter values ​​therein are set only for the purpose of illustrating that the corrugated surface of the thermally conductive material layer helps reduce the risk of fracture. In actual use, those skilled in the art may adjust the above-mentioned parameter values.

[0098] Example 4

[0099] In the embodiment of the present application, the thickness of the bent portion can be made greater than that of the non-bent portion by locally thickening the bent portion, thereby improving the morphological consistency of each flexible material layer.

[0100] See Figure 10, which is a schematic diagram of a fully unfolded screen, wherein the thickness of the bent portion is greater than the thickness of the non-bent portion, provided in an embodiment of the present application. (a) is the hinge assembly shown in Figure 7, which is described in detail in Example 2 and will not be discussed here. Regarding bending region 801, its bending radius is 0.543, where the specific definition of the bending radius is as described in Example 3 and will not be discussed here.

[0101] Since the modulus of the graphene layer is inconsistent with that of the through-axis FPC layer, the modulus of the graphene layer is lower than that of the through-axis FPC layer, resulting in the bending radius of the graphene layer in (a) being smaller than that of the through-axis FPC layer, and the two having inconsistent morphologies. As mentioned above, the through-axis FPC layer and the graphene layer have inconsistent morphologies, and interfere with each other during the bending process, which will reduce the bending life of the through-axis FPC layer and the graphene layer. Therefore, the bending region 801 is locally thickened so that the thickness at the bending region 801 exceeds that of other regions. For the graphene layer, when the thickness at the bending portion increases, the modulus of the graphene layer will also increase. When the modulus of the graphene layer increases to be consistent with that of the through-axis FPC layer, the through-axis FPC layer and the graphene layer can have better morphological consistency. Specifically, at the thickened portion, the absolute value of the difference between the bending radius of the graphene layer and the bending radius of the through-axis FPC layer is within a preset difference range or the bending radius of the two are the same.

[0102] Among them, (b) is the bending shape of the graphene layer and the through-axis FPC layer obtained after thickening in the bending area 801. By comparing the bending shapes of (a) and (b), it can be found that the graphene layer and the through-axis FPC layer in (b) have good morphological consistency in the bending area.

[0103] In one possible implementation, to locally thicken the graphene layer, at least one graphene layer may be added at the location where thickening is required. The embodiment of the present application may also achieve thickening in other ways, which are not limited here.

[0104] Regarding the graphene layer thickening method, it can be thickened at all bends, while leaving non-bends unthickened, so that the FPC layer and the graphene layer at the bends have good morphological consistency. However, in actual use, considering the cost of thickening, a threshold range of thickening radius is generally set, and the thickening process is performed on the bend areas of the graphene layer whose bending radius falls within the threshold range. This is because areas with larger bending radii require more graphene material, which is too costly.

[0105] For example, assuming that the thickening radius threshold range is greater than or equal to 0.1 and less than or equal to 0.3, when the bending radius of the graphene layer obtained by the simulation software is 0.2, the bending radius of the graphene falls within the thickening radius threshold range, and the graphene layer here is thickened.

[0106] Regarding the specific thickening radius threshold range, those skilled in the art can adjust it as needed, and this application does not specifically limit the thickening radius threshold range.

[0107] In addition, in the embodiment of the present application, the thickened area at the bend can be confined within the limiting cavity. In this way, the morphological consistency of the through-axis FPC layer and the graphene layer is improved through the limiting effect of the limiting cavity and the thickening of the graphene layer at the bend of the limiting cavity.

[0108] In addition, by thickening the bending area in the limiting cavity where the bending radius is within the thickening radius threshold range, the thickening cost can be further reduced, and the morphological consistency of the through-axis FPC layer and the graphene layer can be ensured.

[0109] In summary, when the flexible material layer is used, the morphological consistency of each flexible material layer can be improved by locally thickening the bent portion so that the thickness of the bent portion is greater than that of the non-bent portion.

[0110] The hinge device provided in the embodiment of the present application can be applied to the inner screen of a folding screen device, and can also be used on the outer screen of a folding screen device. The specific implementation method of the hinge device on the outer screen is the same as that of the inner screen, and will not be discussed here.

[0111] The hinge device provided in the embodiments of this application can be used in foldable screen mobile phones, other foldable screen personal computers (PCs), or other devices with foldable screens. For example, it can be used in foldable screen tablets. The hardware structure of the device is described in detail below.

[0112] An embodiment of the present application provides a hardware structure of a folding screen device, and the specific device includes a folding screen, etc.

[0113] It is understood that the structures illustrated in the embodiments of the present invention do not constitute specific limitations on the device. In other embodiments of the present application, the device may include more or fewer components than shown, or combine or separate certain components, or arrange the components differently. The components shown in the diagram may be implemented in hardware, software, or a combination of software and hardware.

[0114] The foldable screen is used to display images, videos, etc. The foldable screen includes a display panel. The display panel can use a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a MiniLED, a MicroLed, a Micro-oLed, a quantum dot light-emitting diode (QLED), etc. In some embodiments, the device 100 may include one or N display screens 194, where N is a positive integer greater than one.

[0115] The folding screen of the folding screen device adopts a main frame, a sub-frame, a hinge door panel and the above-mentioned device. The main frame is connected to the sub-frame through a hinge device and a hinge door panel. The hinge door panel limits the relative movement direction of the folding screen. The hinge device includes a hinge cover and a limiting structure. The hinge cover and the limiting structure form a limiting cavity. One or more flexible material layers pass through the limiting cavity, and the fixed positions at both ends of each flexible material layer are respectively located on both sides of the limiting cavity. The limiting cavity is also used to limit the movement direction of one or more flexible material layers in the limiting cavity when the fixed positions at both ends of the flexible material layer undergo relative movement.

[0116] It should be noted that the above devices are merely illustrative, and the embodiments of the present application can also be applied to other devices with foldable screens. This will not be further described here.

[0117] The descriptions of the processes or structures corresponding to the above figures have different emphases. For parts that are not described in detail in a certain process or structure, please refer to the relevant descriptions of other processes or structures.

[0118] The above is only a specific embodiment of the present application, but the scope of protection of this application is not limited to this. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A rotating shaft device, It is characterized in that Applied to folding screen equipment, the device comprises: a rotating shaft cover and a limiting structure; The rotating shaft cover and the limiting structure form a limiting cavity; One or more flexible material layers are passed through the limiting cavity, and the fixed positions at both ends of each flexible material layer are respectively located on two sides of the limiting cavity; The limiting cavity is used to limit the movement direction of the one or more flexible material layers in the limiting cavity when the fixed positions at both ends of the flexible material layer move relative to each other.

2. The device according to claim 1, It is characterized in that The limiting structure includes a groove on one side away from the limiting cavity; the groove is used to accommodate part of the screen of the folding screen device when the fixed positions at both ends of the flexible material layer are closest to each other.

3. The device according to claim 2, It is characterized in that When the fixed positions at both ends of the flexible material layer are farthest apart, the maximum width of the groove is greater than the maximum height of the groove; the maximum width of the groove is parallel to the screen of the folding screen device; and the maximum height of the groove is perpendicular to the screen of the folding screen device.

4. The device according to claim 1, It is characterized in that The limiting cavity is filled with multiple flexible material layers, which include: a heat-conducting material layer and a flexible circuit board.

5. The device according to claim 4, It is characterized in that The heat conductive material layer has a corrugated surface.

6. The device according to claim 4, It is characterized in that The material thickness of the thermal conductive material layer at the bending portion is greater than the material thickness at the non-bending portion.

7. The device according to claim 6, It is characterized in that The bending part is located inside the limiting cavity.

8. The device according to claim 4, It is characterized in that The flexible circuit board is provided with a positioning slot, and the positioning slot is connected to the thermal conductive material layer; the width of the positioning slot is 2 to 3 mm.

9. The device according to claim 8, It is characterized in that The positioning slot is connected to the thermal conductive material layer by adhesive.

10. The device according to claim 8, It is characterized in that Both sides of the positioning slot are empty slots.

11. The device according to claim 1, It is characterized in that The device is applied to the inner screen of the folding screen device.

12. The device according to claim 1, It is characterized in that The device is applied to the outer screen of the folding screen device.

13. A folding screen device, It is characterized in that The device comprises a main frame, a sub-frame, a rotating shaft door panel and a rotating shaft device; The main frame is connected to the sub-frame through the pivot device and the pivot door plate, and the pivot door plate limits the relative movement direction of the folding screen of the folding screen device; the pivot is transposed to the device as described in claims 1-12.

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