Patent Publication Number: US-2022240400-A1

Title: Electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2020/120377, filed on Oct. 12, 2020, which claims priorities to Chinese Patent Application No. 201910976196.0, filed on Oct. 15, 2019, and Chinese Patent Application No. 202010756865.6, filed on Jul. 31, 2020. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties. 
    
    
     FIELD 
     The present disclosure relates to the technical field of electronic products, and particularly, to an electronic device. 
     BACKGROUND 
     Generally, a display screen of an electronic device, such as a smart phone and a tablet computer, has a relatively fixed size. The electronic device adopting a large-size display screen has a poor portability, while the electronic device employing a small-size display screen has relatively poor use experience. It is difficult to balance the portability and the use experience of the electronic devices. 
     SUMMARY 
     In this regard, it is urgent to provide an electronic device. 
     An electronic device includes a housing assembly, a tension assembly connected to the housing assembly, and a flexible screen module. The housing assembly includes a first housing, and a second housing connected to the first housing. The first housing has a first supporting surface, the second housing has a second supporting surface, and the first supporting surface is flush with the second supporting surface. The flexible screen module includes a fixed end, and a free end opposite to the fixed end. The fixed end is connected to the first housing and supported by the first supporting surface, the free end bypasses an end of the second housing facing away from the first housing and extends into the housing assembly, and the free end is connected to the tension assembly. The first housing is movable relative to the second housing to enable at least a part of the flexible screen module to unfold on the second supporting surface or to retract into the housing assembly. 
     An electronic device includes a housing assembly, a guide member, and a flexible screen module. The housing assembly includes a first housing, and a second housing connected to the first housing. The second housing has a first protrusion provided at an end thereof. The guide member is connected to the second housing, a groove is defined in the guide member, and the first protrusion extends into the groove. A part of the flexible screen module is connected to the first housing, and the other part of the flexible screen module bypasses the guide member and extends into the housing assembly. The second housing is movable relative to the first housing to drive the flexible screen module located in the housing assembly to unfold on the second housing along the guide member and the first protrusion, or to drive the flexible screen module unfolded on the second housing to retract into the housing assembly along the first protrusion and the guide member. 
     An electronic device includes a housing assembly, a guide member, and a flexible screen module. The housing assembly includes a first housing, and a second housing connected to the first housing. The second housing has a first protrusion provided on an end thereof. The guide member is connected to the second housing. A groove is defined in the guide member, and the first protrusion extends into the groove. The flexible screen module includes a first screen body, and a second screen body connected to the first screen body. A position of the first screen body and a position of the first housing are relatively fixed. The second housing is movable relative to the first housing into a first position and a second position, and the second housing is configured to drive the second screen body to move along the guide member and the first protrusion. At the first position, the first screen body is exposed to a side of the first housing, the second screen body bypasses the guide member and is received in the housing assembly. At the second position, at least a part of the second screen body unfolds and is exposed to a side where the first screen body is located. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to clearly explain technical solutions of embodiments of the present disclosure or technical solutions in the prior art, drawings used in the embodiments or in prior art are briefly described below. Obviously, the drawings described below merely illustrate some embodiments of the present disclosure. Based on these drawings, drawings of other embodiments can be obtained by those skilled in the art without paying creative efforts. 
         FIG. 1  is a front view of an electronic device according to an embodiment. 
         FIG. 2  is a bottom view of the electronic device illustrated in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the electronic device illustrated in  FIG. 1  in a state. 
         FIG. 4  is a cross-sectional view of the electronic device illustrated in  FIG. 1  in another state. 
         FIG. 5  is an exploded view of the electronic device illustrated in  FIG. 4 . 
         FIG. 6  is a schematic diagram of the electronic device illustrated in  FIG. 4  after part of the structure is removed. 
         FIG. 7  is a schematic diagram of the electronic device illustrated in  FIG. 3  after part of the structure is removed. 
         FIG. 8  is a schematic diagram of the electronic device illustrated in  FIG. 7  from another perspective. 
         FIG. 9  is a schematic diagram of the electronic device illustrated in  FIG. 8  in another state. 
         FIG. 10  is an exploded view of the electronic device illustrated in  FIG. 1 . 
         FIG. 11  is an exploded view of a second housing of the electronic device illustrated in  FIG. 10 . 
         FIG. 12  is a cross-sectional view of the electronic device illustrated in  FIG. 9 . 
         FIG. 13  is an enlarged schematic diagram of portion A of the electronic device illustrated in  FIG. 12 . 
         FIG. 14  is an exploded view of a first housing of the electronic device illustrated in  FIG. 10 . 
         FIG. 15  is an enlarged schematic view of portion B of the first housing of the electronic device illustrated in  FIG. 14 . 
         FIG. 16  is an enlarged schematic diagram of portion C of the second housing of the electronic device illustrated in  FIG. 11 . 
         FIG. 17  is a schematic diagram of a flexible screen module according to an embodiment. 
         FIG. 18  is an exploded view of the flexible screen module of the electronic device illustrated in  FIG. 17 . 
         FIG. 19  is an enlarged schematic diagram of portion D of the flexible screen module of the electronic device illustrated in  FIG. 17 . 
         FIG. 20  is a cross-sectional view of the electronic device illustrated in  FIG. 7 . 
         FIG. 21  is a cross-sectional view of the electronic device illustrated in  FIG. 9 . 
         FIG. 22  is an exploded view of a tension assembly, a support plate, and a cover plate of the electronic device illustrated in  FIG. 10 . 
         FIG. 23  is an exploded view of the tension assembly, the support plate and the cover plate of the electronic device illustrated in  FIG. 22  from another perspective. 
         FIG. 24  is a cross-sectional view of an electronic device according to another embodiment. 
         FIG. 25  is a schematic diagram of an electronic device according to yet another embodiment. 
         FIG. 26  is an exploded view of the electronic device illustrated in  FIG. 25 . 
     
    
    
     REFERENCE SIGNS 
     
         
         
           
               100 . electronic device;  10 . housing assembly;  12 . first housing 
               12   a . first supporting surface;  12   b . first pushing portion;  121 . first bracket 
               121   a . sliding groove;  122 . back cover;  123 . first support member 
               123   a . limit groove;  123   b . bump;  123   c . guide groove 
               124 . decoration member;  125 . slot;  14 . second housing 
               14   a . second supporting surface;  14   b . first channel;  14   c . second slideway 
               14   d . second channel;  14   e . guide recess;  14   f  end surface 
               141 . second bracket;  142 . end cover;  143 . second support member 
               143   a . first protrusion;  143   b . connection portion;  143   c . limit portion 
               143   d . guide protrusion bar a 1 . arc surface;  144 . side cover 
               145 . positioning protrusion;  146 . PVC film;  147 . rotation shaft 
               148 . support plate;  148   a . second protrusion;  149 . cover plate 
               16 . receiving space;  20 . flexible screen module;  20   a . fixed end 
               20   b . free end;  20   c . second pushing portion;  21 . flexible display 
               21   a . first screen body;  21   b . second screen body;  23 . reinforcement layer 
               25 . support plate;  251 . first plate;  253 . second plate 
               253   a . strip plate;  27 . slide rail;  27   a . first slideway 
               30 . guide member;  30   a . groove;  40 . circuit board 
               50 . battery;  60 . tension assembly;  61 . elastic member 
               63 . movable member;  63   a . limit column;  65 . pin 
               67 . transmission body;  71 . pressing plate;  73 . double-sided adhesive DESCRIPTION OF EMBODIMENTS 
           
         
       
    
     In order to facilitate the understanding of the present disclosure, the present disclosure will be described in detail below with reference to the relevant drawings. The preferred embodiments of the present disclosure are illustrated in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to explain the present disclosure thoroughly and comprehensively. 
     As used herein, “terminal device” refers to, but is not limited to, an apparatus capable of receiving and/or transmitting communication signals and being connected via any one or several of the following connection methods. 
     (1) Connection via wired lines, such as a public switched telephone network (PSTN), a digital subscriber line (DSL), a digital cable, and a direct cable connection. 
     (2) Connection via a wireless interface, such as a cellular network, a wireless local area network (WLAN), a digital TV network such as a DVB-H network, a satellite network, an AM-FM broadcast transmitter. 
     A terminal device configured to communicate through a wireless interface may be referred to as a “mobile terminal”. Examples of the mobile terminal include, but are not limited to, the following electronic devices:
         (1) a satellite phone or a cellular phone;   (2) a personal communication system (PCS) terminal combining a cellular radio phone with data processing, fax, and data communication functions;   (3) a radio phone, a pager, Internet/Intranet access, a Web browser, a notebook, a calendar, a personal digital assistant (PDA) equipped with a global positioning system (GPS) receiver;   (4) a conventional laptop and/or palmtop receiver; and   (5) a conventional laptop and/or palmtop radio telephone transceiver, etc.       

     Referring to  FIG. 1 ,  FIG. 2 , and  FIG. 3 , an electronic device  100  according to an embodiment includes a housing assembly  10 , a flexible screen module  20 , a guide member  30 , a circuit board  40 , and a battery  50 . The housing assembly  10  has a hollow structure. The flexible screen module  20 , the guide member  30 , the circuit board  40 , the battery  50 , etc. can all be disposed in the housing assembly  10 . The circuit board  40  is in communication connection with the flexible screen module  20 , and the battery  50  can supply power to the flexible screen module  20  and electronic elements on the circuit board  40 . Of course, the electronic device  100  may further include a camera module (not shown), the camera module is in communication connection with the circuit board  40 , and the battery  50  can supply power to the camera module. It can be appreciated that the electronic device  100  in the embodiment of the present disclosure is, but not limited to, a mobile terminal such as a mobile phone and a tablet computer, or other portable electronic device. In the embodiments of the present disclosure, as an example for description, the electronic device  100  is a mobile phone. 
     With reference to  FIG. 4  and  FIG. 5 , in this embodiment of the present disclosure, the housing assembly  10  includes a first housing  12  and a second housing  14 , and the second housing  14  and the first housing  12  are movable relative to each other. Specifically, in this embodiment, the second housing  14  and the first housing  12  are slidably connected to each other. In other words, the first housing  12  is slidable relative to the second housing  14 . For example, the first housing  12  is slidable relative to the second housing  14  into a first position and a second position. With reference to  FIG. 3 , when the first housing  12  is at the first position, the electronic device  100  has a relatively small size to be portable. With reference to  FIG. 4 , when the first housing  12  is at the second position, the electronic device  100  can have a relatively large display area to improve the use experience of the electronic device  100 . In this embodiment, an overall length of the electronic device  100  when the first housing  12  is at the second position is greater than that when the first housing  12  is at the first position. In this way, the exposed flexible screen module  20  can have a variable length. In other words, the electronic device  100  has a variable size in the length direction. In this embodiment, an external interface of the electronic device  100 , such as a data cable socket, a charging cable socket, or an earphone socket, may be disposed at an end in the length direction. In other embodiments, an overall width of the electronic device  100  when the first housing  12  is at the second position may be greater than that when the first housing  12  is at the first position, so that the exposed flexible screen module  20  has a variable width. In other words, the electronic device  100  has a variable width in the width direction. In this embodiment, the external interface of the electronic device  100 , such as a data cable socket, a charging cable socket, or an earphone socket, may be disposed at an end in the width direction. 
     Specifically, referring to  FIG. 4  and  FIG. 5 , a receiving space  16  can be defined by the first housing  12  and the second housing  14 . The receiving space  16  can be used to receive the guide member  30 , the circuit board  40 , the battery  50 , and the like. The flexible screen module  20  includes a fixed end  20   a , and a free end  20   b  opposite to the fixed end. The fixed end  20   a  is disposed on the first housing  12 . At the first position, the flexible screen module  20  bypasses the guide member  30 , and the free end  20   b  of the flexible screen module  20  is received in the housing assembly  10 , such that a part of the flexible screen module  20  is hidden in the housing assembly  10  and may not be used for displaying. The first housing  12  may include a back cover  122 , and a light-transmitting area may be disposed on a side where the back cover  122  is located. The part of the display module  20 , which is received in the housing assembly  10  when the first housing  12  is at the first position, may also be used for displaying to expand the application scenarios of the electronic device  100 . The light-transmitting area may be formed by transparent glass or an opening defined in the back cover  122 . Once the first housing  12  slides into the second position relative to the second housing  14 , at least the part of the flexible screen module  20  received in the housing assembly  10  is exposed. The exposed flexible screen module  20  can be used for displaying, enabling the electronic device  100  to have a relatively large display area, thereby improving the user experience. 
     The guide member  30  is disposed on the second housing  14 . In a process of the first housing  12  sliding into the second position relative to the second housing  14 , the guide member  30  can guide the flexible screen module  20  to be deformed and unfolded on the second housing  14 . Specifically, the guide member  30  may be a rotating shaft structure with teeth, and the flexible screen module  20  is linked with the guide member  30  by means of engaging or the like. When the first housing  12  slides relative to the second housing  14 , a part of the flexible screen module  20  engaging with the guide member  30  is driven by the guide member  30  to move and to be unfolded from or to retract into the housing assembly  10 . 
     It can be understood that the guide member  30  may also be a round shaft without teeth. In the process of switching the first housing  12  from the first position to the second position, the part of the flexible screen module  20  attached to the guide member  30  is expanded by the guide member  30 , allowing more part of the flexible screen modules  20  to be exposed to outside of the housing assembly  10  and to be in an unfolded and flat state. In some embodiments, the guide member  30  is rotatably disposed on the second housing  14 . In the process of the flexible screen module  20  gradually unfolding, the guide member  30  can rotate with the movement of the flexible screen module  20 . In other embodiments, the guide member  30  may be fixed on the second housing  14 , and the guide member  30  has a smooth surface; and in the process of the flexible screen module  20  unfolding, the guide member  30  can slidably contact the flexible screen module  20  with its smooth surface. In other words, in such embodiments, the guide member  30  and the second housing  14  can be formed into one piece or welded, the guide member  30  can be regarded as a part of the second housing  14 , and the free end  20   b  of the flexible screen module  20  bypasses an end of the second housing  14  facing away from the first housing  12  and extends into the housing assembly  10 . 
     When the first housing  12  switches from the second position to the first position, the flexible screen module  20  can be driven by the guide member  30  to be retracted. Of course, referring to  FIG. 6  and  FIG. 7 , the electronic device  100  may further include a tension assembly  60 . The free end  20   b  of the flexible screen module  20  is linked with the tension assembly  60 . In the process of the second housing  14  switching from the second position to the first position, the flexible screen module  20  is driven by the tension assembly  60  to restore, allowing the part of the flexible screen module  20  to retract into the housing assembly  10 . After the flexible screen module  20  is retracted into the housing assembly  10 , the electronic device  100  can have a relatively small size of appearance, thereby improving the portability of the electronic device  100 . 
     In some embodiments, the electronic device  100  may further include a driving mechanism (not shown), the driving mechanism may be disposed in the housing assembly  10 , the driving mechanism may be linked with the second housing  14  or the first housing  12  and configured to drive the first housing  12  to move relative to the second housing  14 , so as to drive the flexible screen module  20  to be unfolded or retracted. It can be understood that the driving mechanism  40  may be omitted, and the user may directly and manually drive the relative movement between the first housing  12  and the second housing  14 . 
     With reference to  FIG. 8  and  FIG. 9 , the first housing  12  of the electronic device  100  has a first supporting surface  12   a , and the second housing  14  has a second supporting surface  14   a . In the process of the first housing  12  moving relative to the second housing  14 , the first supporting surface  12   a  and the second supporting surface  14   a  are kept flush for supporting the flexible screen module  20 , so that the flexible screen module  20  can be unfolded to be flat or retracted into the housing assembly  10 . A first channel  14   b  (referring to  FIG. 4 ) is defined by the guide member  30  and the second housing  14  and in communication with the receiving space  16 , a part of the flexible screen module  20  is attached to the first supporting surface  12   a  and connected to the first housing  12 , the other part of the flexible screen module  20  is attached to the guide member  30 , passes through the first channel  14   b , and extends into the housing assembly  10 . During the movement of the first housing  12  relative to the second housing  14 , the first supporting surface  12   a  moves relative to the second supporting surface  14   a  and drives the flexible screen module  20  located in the housing assembly  10  to enter or exit from the housing assembly  10  through the first channel  14   b , and the flexible screen module  20  stretching out of the first channel  14   b  can be supported by the second supporting surface  14   a . In the embodiments of the present disclosure, “flush” can be simply construed as two planes being disposed coplanar. Of course, considering engineering errors, “flush” should be understood as that the surfaces of the parts meet a predetermined flatness requirement and a predetermined parallelism requirement, rather than two planes being strictly coplanar. 
     Specifically, the flexible screen module  20  includes a flexible display screen  21  for displaying. The flexible display screen  21  includes a first screen body  21   a , and a second screen body  21   b  connected to the first screen body  21   a . In the present embodiment, the first screen body  21   a  and the second screen body  21   b  are an integrated structure. With reference to  FIG. 3  and  FIG. 4 , the first screen body  21   a  and the second screen body  21   b  can be simply distinguished from each other in the following way: when the first housing  12  is at the first position, the first screen body  21   a  is a part of the flexible screen module  20  exposed to a side where the first supporting surface  12   a  is located, and the second screen body  21   b  is a part of the flexible screen module  20  received in the housing assembly  10 . 
     A position of the first screen body  21   a  and a position of the first housing  12  are relatively fixed. For example, the first screen body  21   a  can be fixedly connected to the first housing  12  by means of bonding or threads. Of course, the first screen body  21   a  can be fixedly connected to the first housing  12  via other intermediate support structure, so as to more reliably position the first screen body  21   a  on the first housing  12 . With reference to  FIG. 5 , the first housing  12  is movable relative to the second housing  14  between the first position and the second position and drives the second supporting surface  14   a  to move relative to the first supporting surface  12   a . At the first position, the screen body  21   a  is exposed and the first screen body  21   a  is supported by the first supporting surface  12   a , and the second screen body  21   b  passes through the first channel  14   b  and extends into the housing assembly  10  to be approximately parallel to the first screen body  21   a , as illustrated in  FIG. 3 . Of course, when the first housing  12  is at the first position, the second supporting surface  14   a  and the first supporting surface  12   a  can jointly support the first screen body  21   a . With reference to  FIG. 4  and  FIG. 5 , at the second position, at least a part of the second screen body  21   b  extends out of the first channel  14   b  and is supported by the second supporting surface  14   a  to expand a display area of the electronic device  100 . It can be understood that other intermediate structural members may exist between the first supporting surface  12   a  and the first screen body  21   a  or between the second supporting surface  14   a  and the second screen body  21   b , so that the first supporting surface  12   a  can support the first screen body  21   a  through the intermediate structural member, or the second supporting surface  14   a  can support the second screen body  21   b  through the intermediate structural member. 
     Referring to  FIG. 10  and  FIG. 11 , the first housing  12  may include a first bracket  121 , and a first support member  123  connected to the first bracket  121 . The first support member  123  has an approximate plate shape, and the first supporting surface  12   a  is located on the first support member  123 . The back cover  122  is connected to the first bracket  121 . In this embodiment, the first support member  123  is connected to the first bracket  121  by means of threaded fasteners. In other embodiments, the first support member  123  and the first bracket  121  may be formed into one piece. For example, the first support member  123  and the first bracket  121  may be formed by die casting. The second housing  14  may include a second bracket  141 , and a second support member  143  connected to the second bracket  141 . The second bracket  141  has substantially a U shape, the second support member  143  has an approximate plate shape, the second supporting surface  14   a  is located on the second support member  143 , and the guide member  30  is connected to the second bracket  141 . In this embodiment, the second support member  143  is connected to the second bracket  141  by means of threaded fasteners. In other embodiments, the second support member  143  and the second bracket  141  may be formed into one piece, for example, the second support member  143  and the second bracket  141  may be formed by die casting. 
     Furthermore, with reference to  FIG. 9  and  FIG. 10 , in the embodiment of the present disclosure, sliding grooves  121   a  are defined on both sides of the first bracket  121 , and the second bracket  141  is slidably disposed in the sliding grooves  121   a , allowing the second housing  14  to slide smoothly on the first housing  12 . Further, referring to  FIG. 12  and  FIG. 13 , one of the second housing  14  and the first housing  12  has a positioning protrusion  145  provided thereon, and the other one of the first housing  12  and the second housing  14  has a slot defined therein. In the process of the first housing  12  moving relative to the second housing  14 , the positioning protrusion  145  engages into the slot  125  to fix the first housing  12  to the second housing  14 . In the embodiment of the present disclosure, the positioning protrusion  145  is formed by a bolt, the slot  125  is formed through a thin elastic sheet. The slot  125  is defined by fixedly connecting one of the second bracket  141  and the first bracket  121  to the elastic sheet, and the positioning protrusion  145  is defined by fixedly connecting the other one of the second bracket  141  and the first bracket  121  to the bolt. In the process of the first housing  12  moving relative to the second housing  14  to a specific position, the positioning protrusion  145  can enter the slot  125  to exert the positioning function, so as to maintain the flexible screen module  20  in an unfolded state. In some embodiments, one slot is provided and a position of the slot  125  corresponds to a state of the first housing  12  being at the second position, so as to more reliably position the first housing  12  with respect to the second housing  14 , thereby maintaining the stable unfolded state of the flexible screen module  20 . In other embodiments, more than two slots are provided, and the slots  125  are spaced apart from each other along a movement direction of the first housing  12  relative to the second housing  14 , so as to maintain the stable unfolded state of the flexible screen module  20  at multiple specific positions, thereby expanding the application scenarios of the electronic device  100 . For example, a plurality of intermediate positions may exist between the first position and the second position. In different intermediate positions, the flexible screen module  20  has different expanded areas, and the display area of the electronic device  100  has different sizes. In other embodiments, the positioning protrusion  145  and the slot  125  may be disposed in other positions, and the positioning protrusion  145  may adopt other structural forms such as an elastic column or an elastic thimble. 
     Furthermore, at the first position, the back cover  122  can better shield the second bracket  141  to prevent dust or liquid from entering the electronic device  100 , thereby improving the waterproof and dustproof performance of the electronic device  100 . Furthermore, in this embodiment, the battery  50  and the circuit board  40  are disposed on the first bracket  121  and covered by the back cover  122 . Further, referring to  FIG. 10 , the electronic device  100  may include a pressing plate  71 . The circuit board  40  is connected to a side of the first bracket  121  facing away from the first supporting surface  12   a , and the pressing plate  71  is stacked on the circuit board  40  and detachably connected to the first bracket  121  through threaded fasteners. In this way, the pressing plate  71  is pressed against the circuit board  40  to reliably fix the circuit board  40  on the first bracket  121 . The battery  50  can be fixedly connected to a side of the pressing plate  71  facing away from the circuit board  40  through a double-sided adhesive  73 . Further, the first housing  12  may include a decorative member  124 , and the decorative member  124  is fixedly connected to the back cover  122  through glue or threaded fasteners. In the embodiment of the present disclosure, the decorative member  124  is located at an end of the back cover  122  and is used to interact with an external interface structure, such as a data cable socket, an earphone socket, and the like, defined in the back cover  122 . 
     Furthermore, the second housing  14  may include an end cover  142 , and the end cover  142  may be fixedly connected to the second bracket  141  through a structure such as a threaded fastener or a buckle, and the first channel  14   b  is defined by the cover  142  together with the guide member  30 . In the embodiment of the present disclosure, a position of the end cover  142  is opposite to a position of the decorative member  124 , i.e., the end cover  142  is located at an end of the electronic device  100 , and the decorative member  124  is located at the other end of the electronic device  100 . Of course, the end cover  142  can be assembled with the guide member  30  as a component having the first channel  14   b , which is then connected to the second bracket  141 . 
     With reference to  FIG. 11 , the second housing  14  may further include a side cover  144  and a polyvinyl chloride (PVC) film  146 . Two side covers  144  may be provided and both are fixedly connected to the second bracket  141  by means of screws. The two side covers  144  are respectively disposed on both sides of the second bracket  141  and cover a part of the second bracket  141  slidably engaging with a sliding groove  121   a  of the first bracket  121 . Two PVC films  146  may be provided and correspond to the two side covers  144  in one-to-one correspondence. The PVC film  146  may be adhered to the side cover  144  and cover holes defined in the side cover  144  for threading screws and cover the screws disposed in and penetrating through the holes. In this way, the second housing  14  has a better appearance and integrity and prevents liquid or dust from entering the electronic device  100  from the second housing  14 . After the end cover  142 , the side cover  144 , and the second bracket  141  are assembled and fixed, the side cover  144  can pass through the back cover  122  and enter and exit from the back cover  122  in the process of the first housing  12  moving relative to the second housing  14 . 
     Referring to  FIG. 10 , in this embodiment, the guide member  30  is rotatably disposed on the second bracket  141 . Specifically, the second housing  14  may include a rotation shaft  147  connected to the second bracket  141 , and the cylindrical guide member  30  is sleeved on the rotation shaft  147  and rotatably fits with the rotation shaft  147 . In some embodiments, the rotation shaft  147  is fixedly connected to the second bracket  141  by means of threaded fasteners. In other embodiments, the rotation shaft  147  may be welded to the second bracket  141  or formed into one piece with the second bracket  141 . In a process of the flexible screen module  20  entering and exiting the housing assembly  10 , the guide member  30  is attached to the flexible screen module  20  and can be driven by the flexible screen module  20 , so as to guide the flexible screen module  20  to be bent and deformed. The cylindrical guide member  30  may have a relatively large outer diameter in order to satisfy the requirement of a limit bending radius of the flexible screen module  20 . In combination with the structural configuration of the first channel  14   b , the cylindrical guide member  30  can support and protect a bending part of the second screen body  21   b , so as prevent the bending part of the second screen body  21   b  from being damaged, thereby prolonging the fatigue life of the flexible screen module  20 . The rotatable guide member  30  may also reduce the frictional resistance in the process of the flexible screen module  20  entering and exiting from the first channel  14   b , and reduce the abrasion on a surface of the flexible screen module  20  and on a surface of the guide member  30 , thereby prolonging the service life of the electronic device  100 . 
     It can be understood that the end cover  142  and the first channel  14   b  are not essential. When the end cover  142  and the first channel  14   b  are omitted, at the first position, the part of the flexible screen module  20  attached to the guide member  30  can be exposed and used for displaying, so as to expand the application scenarios of the electronic device  100 . 
     Further, referring to  FIG. 8 , grooves  30   a  surrounding the guide member  30  are defined on the surface of the guide member  30 , and the second support member  143  has first protrusions  143   a  provided at an end thereof close to the guide member  30 . The first protrusions  143   a  extend into the grooves  30   a , the first protrusions  143   a  may not contact groove walls of the grooves  30   a  to avoid interference with rotation of the guide member  30 . Further, the first protrusion  143   a  may have an arc surface al tangent to the second supporting surface  14   a , the arc surface al and the second supporting surface  14   a  are located on a same side of the second supporting member  143 , and the arc surface al extends into the groove  30   a . In a process of retracting the second screen body  21   b  into the housing assembly  10 , the above-mentioned structure enable the second screen body  21   b  to move smoothly from the second supporting surface  14   a  to the guide member  30 , thereby preventing the second screen body  21   b  from being bent and causing a jam at a gap between the second supporting member  143  and the guide member  30 . Of course, the first protrusions  143   a  can guide the flexible screen module  20  in the process of the second screen body  21   b  entering and exiting the housing assembly  10 , thereby enabling the flexible screen module  20  to be unfolded to be flat or to be smoothly retracted into the housing assembly  10 . It can be understood that, by providing the first protrusions  143   a , the requirements on the gap between the second support member  143  and the guide member  30  can be appropriately reduced, and accordingly, the requirements on assembly accuracy can be reduced and the assembly efficiency can be improved. It can be understood that the arc surface al of the first protrusion  143   a  is not essential. For example, a surface of the first protrusion  143   a , which is on the same side as the second supporting surface  14   a , may be located on the same plane as the second supporting surface  14   a , and this plane can be tangent to a cylindrical surface of the guide member  30 , thereby allowing the flexible screen module  20  to be better attached to the surface of the guide member  30  and deformed through the guiding of the guide member  30 . 
     In the embodiment of the present disclosure, at least two grooves  30   a  are provided and the grooves  30   a  are spaced apart from each other along an axial direction of the guide member  30 , and at least two first protrusions  143   a  are provided and correspond to the at least two grooves  30   a  in one-to-one correspondence. By providing the plurality of first protrusions  143   a , the flexible screen module  20  can be relatively stable in the process of entering and exiting from the first channel  14   b , and prevent being stuck. 
     Referring to  FIG. 14 ,  FIG. 15  and  FIG. 16 , a plurality of limit grooves  123   a  spaced apart from each other is defined in the first support member  123 ; the second support member  143  is substantially comb-shaped, and the second support member  143  includes a connection portion  143   b  and a plurality of limit portions  143   c  extending from the connection portion  143   b . The plurality of limit portions  143   c  has at least a part of the second supporting surface  14   a . In other words, the plurality of limit portions  143   c  may have all the second supporting surface  14   a , that is, the plurality of limit portions  143   c  is used to support the flexible screen module  20 . The plurality of limit portions  143   c  may have a part of the second supporting surface  14   a , and the connection portion  143   b  has the other part of the second supporting surface  14   a , that is, a part of a surface of the connection portion  143   b  and a part of a surface of the plurality of limit portions  143   c  are configured to support the second supporting surface  14   a  of the flexible screen module  20 . The limit portions  143   c  are disposed on an end of the connection portion  143   b  facing away from the first protrusions  143   a , that is, the limit portions  143   c  are disposed on an end of the connection portion  143   b  close to the fixed end  20   a . The limit portions  143   c  correspond to the limit grooves  123   a  in one-to-one correspondence, and in the process of the first housing  12  moving relative to the second housing  14 , the limit portion  143   c  moves in a corresponding one limit groove  123   a.    
     Due to the presence of the sliding grooves  121   a  defined on both sides of the first bracket  121  and slidable fitting with the second bracket  141 , in the process of the first housing  12  moving relative to the second housing  14 , the limit portions  143   c  and groove walls of the limit grooves  123   a  may not be in contact to reduce the frictional resistance between the second support member  143  and the first support member  123 . Of course, the limit portion  143   c  can slidably fit in the limit groove  123   a , and thus the groove wall of the limit groove  123   a  can be used to limit and guide the movement of the limit portion  143   c , and to guide and limit the sliding of the first housing  12  relative to the second housing  14 ; and in this embodiment, the first bracket  121  can slidably fit with the second bracket  141  without providing the sliding grooves  121   a  on both sides of the first bracket  121 . 
     Further, referring to  FIG. 16 , each limit portion  143   c  may have a guide protrusion bar  143   d  provided at an edge thereof and extending along a moving direction of the first housing  12 . The guide protrusion  143   d  has an end surface  14   f  at the same side as the second supporting surface  14   a , and a height difference exists between the end surface  14   f  and the second supporting surface  14   a . In other words, the guide protrusion bar  143   d  and the limit portion  143   c  form a stepped structure. With reference to  FIG. 15 , the limit groove  123   a  is a sinking groove and extends along a moving direction of the second housing  14 . The limit groove  123   a  has a lug  123   b  provided at a side wall thereof and spaced apart from a bottom of the limit groove, so as to define a guide groove  123   c  between the lug  123   b  and the bottom of the limit groove  123   a . The guide protrusion bar  143   d  is disposed in and penetrates through the guide groove  123   c . The position of the second support member  143  and the first support member  123  can be limited in a thickness direction of the electronic device  100  by means of the engagement between the guide protrusion bar  143   d  and the guide groove  123   c , thereby preventing the second support member  143  from moving out of the limit groove  123   a , enabling the second supporting surface  14   a  and the first supporting surface  12   a  to stably support the flexible screen module  20 . 
     Referring to  FIG. 17  and  FIG. 18 , in the embodiment of the present disclosure, the flexible screen module  20  further includes a reinforcement layer  23  and a support plate  25 , and the flexible display screen  21 , the reinforcement layer  23  and the support plate  25  are sequentially stacked. A high-viscosity adhesive can be disposed between the flexible display screen  21  and the reinforcement layer  23  as well as between the reinforcement layer  23  and the support plate  25 , to reliably fix the flexible display screen  21 , the reinforcement layer  23 , and the support plate  25 . A part of the support plate  25  is attached to the first supporting surface  12   a  and connected to the first housing  12 , and the other part of the support plate  25  is attached to the guide member  30 , passes through the first channel  14   b , and extends into the housing assembly  10 . Further, the support plate  25  includes a first plate  251  and a second plate  253 . The first plate  251  is stacked on the reinforcement layer  23  and corresponds to a position of the first screen body  21   a , and the second plate  253  is stacked on the reinforcement layer  23  and corresponds to a position of the second screen body  21   b . The second screen body  21   b  and the first screen body  21   a  constitute part or all of the flexible display screen  21 . 
     The reinforcement layer  23  may be a polyimide film (PI film), and the reinforcement layer  23  covers the second screen body  21   b  and the first screen body  21   a . The reinforcement layer  23  has excellent high-temperature resistance and low-temperature resistance, electrical insulation, cohesiveness and radiation resistance, and thus the reinforcement layer  23  can guide the deformation of the flexible display screen  21  and play a better role in protecting and supporting the flexible display screen  21 . In other embodiments, the reinforcement layer  23  is made of other relatively flexible materials, such as polyester or polyfluoride, so as to utilize the flexibility of the reinforcement layer  23  to guide the deformation of the flexible display screen  21  and to play a better role in protecting and supporting the flexible display  21 . 
     Further, the first plate  251  may have higher rigidity, and the shape of the first plate  251  remains unchanged along the movement of the first housing  12  relative to the second housing  14 . Further, the first plate  251  may be fixedly connected to the first housing  12 . For example, the first plate  251  may be connected to the first support member  123  or the first bracket  121  by bonding or by means of threaded fasteners. The second plate  253  may include a plurality of strip plates  253   a  space apart from each other, and a longitudinal extension direction of the strip plates  253   a  is parallel to an axial direction of the guide member  30 . In the process of the second screen body  21   b  entering and exiting the housing assembly  10 , the strip plates  253   a  can be well attached to the surface of the guide member  30 , so as to guide the deformation of the flexible screen module  20  and provide the flexible screen module  20  with appropriate structural rigidity. The second plate  253  may have a relatively small thickness, and accordingly, the thickness of the flexible screen module  20  corresponding to the second screen body  21   b  and the volume of the part of the flexible screen module  20  can be reduced, thereby reducing the bending radius of the flexible screen module  20  corresponding to the second screen body  21   b . By appropriately setting a width of the strip plates  253   a  and the interval between two adjacent strip plates  253   a , the bending radius of the flexible screen module  20  corresponding to the second screen body  21   b  can be further reduced, so as to reduce the outer diameter of the guide member  30 , allowing the structure of the electronic device  100  to be more compact and achieving the thin and light design of the electronic device  100 . In some embodiments, the second plate  253  and the first plate  251  are both thin steel sheets. In other embodiments, the second plate  253  and the first plate  251  may be plastic sheets or the like. 
     Referring to  FIG. 19 , the flexible screen module  20  may further include a sliding rail  27  connected to an end of the second screen body  21   b  facing away from the first screen body  21   a , and the sliding rail  27  has a first slideway  27   a . With reference to  FIG. 20  and  FIG. 21 , in the embodiment of the present disclosure, in the process of the flexible screen module  20  entering and exiting the housing assembly  10 , the tension assembly  60  can apply a tension force on the flexible screen module  20  through the slide rail  27  to unfold the part of the flexible screen module  20  exposed on the second support member  143 , or to stably retract the part of the flexible screen module  20  unfolded on the second support member  143  into the housing assembly  10 . 
     Referring to  FIG. 20  and  FIG. 21 , in one embodiment, the tension assembly  60  is disposed in the housing assembly  10  and connected to the free end  20   b  of the flexible screen module  20 . The tension assembly  60  includes an elastic member  61  and a movable member  63 . The elastic member  61  and the movable member  63  are both connected to the second housing  14  and located in the housing assembly  10 . A second slideway  14   c  is defined in the second housing  14 , and an end of the movable member  63  is rotatably connected to the second housing  14 . With reference to  FIG. 22  and  FIG. 23 , the movable member  63  has a limit column  63   a  provided at the other end thereof, and the limit column  63   a  penetrates through the first slideway  27   a  and the second slideway  14   c . In the process of switching the first housing  12  between the first position and the second position, the movable member  63  swings relative to the second housing  14  to apply the tension force on the flexible screen module  20 . 
     Further, in the embodiment of the present disclosure, the elastic member  61  is a torsion spring, a free end of the torsion spring is connected to the second housing  14 , and the other free end of the torsion spring is connected to the movable member  63 . In the process of the first housing  12  switching between the first position and the second position, a torsional deformation of the torsion spring allows the movable member  63  to apply the tension force to the flexible screen module  20 . Further, in the embodiment of the present disclosure, the movable member  63  is rotatably connected to the second housing  14  through a pin  65 , and the torsion spring is sleeved on the pin  65  and generates the torsional deformation during the swing of the movable member  63 . 
     In the process of the flexible screen module  20  stretching out of the housing assembly  10 , i.e., in the process of switching the first housing  12  from the first position to the second position, the flexible screen module  20  drive the limit column  63   a  to swing through the slide rail  27 , the torsion spring generates the torsional deformation and accumulates elastic potential energy, and the tension force, as resistance, is applied by the movable member  63  on the flexible screen module  20  through the slide rail  27 , thereby enabling the flexible screen module  20  to be unfolded smoothly. In the process of the flexible screen module  20  retracting into the housing assembly  10 , i.e., in the process of the first housing  12  switching from the second position to the first position, the torsion spring releases the elastic potential energy, and the tension force, as driving force, is applied by the movable member  63  on the flexible screen module  20  through the slide rail  27 , thereby enabling the flexible screen module  20  to retract into the housing assembly  10  smoothly. That is, in the process of the flexible screen module  20  retracting into the housing assembly  10 , the movable member  63  can be driven by the torsion spring to restore. 
     In some embodiments, a moving direction of the second housing  14  relative to the first housing  12  is perpendicular to the longitudinal extension direction of the first slideway  27   a , and the second slideway  14   c  has an arc groove shape. The limit column  63   a  on the movable member  63  swings along the second slideway  14   c  having the arc groove shape, and the limit column  63   a  also slides in the first slideway  27   a  and pulls the slide rail  27 , so as to tension the flexible screen module  20  through the interaction of the movable member  63  and the slide rail  27 . In this embodiment, a swing angle of the movable member  63  is about 80 degrees. Referring to  FIG. 20 , as an example, a position of the movable member  63  when the first housing  12  is at the first position is regarded at an angle of zero point, the longitudinal extension direction of the first slideway  27   a  can be arranged in parallel to the movable member  63 , that is, the longitudinal extension direction of the movable member  63  is arranged in parallel to the axial direction of the guide member  30 . Referring to  FIG. 21 , compared to the first position, the movable member  63  swings about 80 degrees when the first housing is at the second position, and at this moment, the longitudinal extension direction of the movable member  63  is inclined with respect to the axial direction of the guide member  30 . At this moment, the part of the flexible screen module  20  stretching out of the housing assembly  10  reaches the limit position, that is, the part of the second screen body  21   b  stretching out of the second housing  14  reaches the limit position. 
     Of course, in other embodiments, the swing angle of the movable member  63  may be greater than or equal to 90 degrees. At the second position, the longitudinal extension direction of the movable member  63  can be arranged perpendicular to the axial direction of the guide member  30 , and at the first position, the movable member  63  can be arranged at an acute angle with respect to the axial direction of the guide member  30 . In this embodiment, the retracting stroke of the second screen body  21   b , i.e., the movement stroke of the slide rail  27 , is greater than or equal to a distance between a center of the rotation shaft of the movable member  63  and a center of the limit column  63   a.    
     In other embodiments, the tension assembly  60  may be connected to the first housing  12  and apply the tension force to the flexible screen module  20  in the process of the flexible screen module  20  entering and exiting from the channel. The tension assembly  60  may have other structural forms. For example, the movable member  63 , the first slideway  27   a , and the second slideway  14   c  can be omitted, and the tension assembly  60  includes an elastic rope connected to the second housing  14  or the first housing  12 , and the elastic rope is configured to apply the tension force to the flexible screen module  20  along with the movement of the second housing  14  relative to the first housing  12 . 
     Further referring to  FIG. 22  and  FIG. 23 , the second housing  14  may include a bearing plate  148 , and the bearing plate  148  and the second support member  143  are respectively located on opposite sides of the second bracket  141  (referring to  FIG. 10 ). The bearing plate  148  can be detachably connected to the second bracket  141  by means of threaded fasteners, and the second slideway  14   c  is defined in the bearing plate  148 . Of course, in other embodiments, the bearing plate  148  may be welded to the second bracket  141 , or the bearing plate  148  may be formed into one piece with the second bracket  141 . The bearing plate  148  has a second protrusion  148   a  provided at an end thereof close to the guide member  30 . With reference to  FIG. 20 , the first protrusion  143   a  extends into the groove  30   a . At least two second protrusions  148   a  can be provided and correspond to the grooves  30   a  on the guide member  30  in one-to-one correspondence. The structure of the second protrusion  148   a  can refer to the first protrusion  143   a . For example, the second protrusion  148   a  can also have an arc surface al which will not be repeated here. The above structure can enable the flexible screen module  20  to move smoothly between the guide member  30  and the bearing plate  148 , and prevent the flexible screen module  20  from bending and causing a jam at the gap between the bearing plate  148  and the guide member  30 . Of course, the second protrusion  148   a  can also guide the flexible screen module  20  in the process of the flexible screen module  20  entering and exiting the housing assembly  10 , allowing the flexible screen module  20  to be unfolded to be flat or smoothly retracted into the housing assembly  10 . It can be understood that, by providing the second protrusion  148   a , the requirement on the gap between the bearing plate  148  and the guide member  30  can be appropriately reduced, thereby reducing the requirement for assembly accuracy and improving assembly efficiency. 
     Further, referring to  FIG. 22  and  FIG. 23 , the second housing  14  may include a cover plate  149  configured to cover a side of the bearing plate  148  facing away from the second supporting surface  14   a , a second channel  14   d  is defined by the cover plate  149  and the bearing plate  148  (referring to  FIG. 4 ), and the free end  20   b  of the flexible screen module  20  is movably received in the second channel  14   d . In the process of the flexible screen module  20  entering and exiting the housing assembly  10 , a rod-shaped body of the movable member  63  can swing in the second channel  14   d . The cover plate  149  can shield and decorate the first screen body  21   a  of the flexible screen module  20 , and can also limit the movement of the movable member  63  and the first screen body  21   a  within the second channel  14   d.    
     It is understood that the cover plate  149  can be transparent or an opening, so as to form a light-transmitting area, and the first housing  12  can be located at one or several specific positions between the first position and the second position through the interaction between the positioning protrusion  145  and the slot  125 , and the first screen body  21   a  exposed to the light-transmitting area is used for displaying. In this embodiment, the electronic device  100  may only be provided with a rear camera, and the first screen body  21   a  in the light-transmitting area can be used to exert functions such as selfie and video call, so as to save the cost of components of the electronic device  100  and save the internal housing assembly  10  of the electronic device  100 . 
     Of course, the back cover  122  of the electronic device  100  may have a light-transmitting area. When the first housing  12  is at the first position, the light-transmitting area of the cover plate  149  corresponds to the light-transmitting area of the back cover  122 , and thus the first screen body  21   a  exposed to the light-transmitting areas can be used for displaying. In this embodiment, the electronic device  100  may only be provided with a rear camera, and the first screen body  21   a  of the light-transmitting area and the other light-transmitting area is used to realize functions such as selfie and video call, so as to save the cost of the electronic device  100  and save the internal housing assembly  10  of the electronic device  100 . In this embodiment, the first screen body  21   a  can be used for displaying when the first housing  12  is at the first position, thereby improving the convenience ofuse of the electronic device  100  and broadening the application scenarios of the electronic device  100 . 
     In other embodiments, the tension assembly  60  may have other structural forms. Referring to  FIG. 24 , in another embodiment, the movable member  63  is rotatably connected to the second housing  14 . In the process of the flexible screen module  20  stretching out of the housing assembly  10 , the movable member  63  is driven by the flexible screen module  20  to rotate relative to the second housing  14  to release the flexible screen module  20  wound around the movable member  63 , and the elastic member  61  (not shown) accumulates elastic potential energy. In the process of the flexible screen module  20  retracting into the housing assembly  10 , the elastic member  61  releases the elastic potential energy and the movable member  63  is driven to restore, so that the free end  20   b  is wound around the movable member  63 . In this embodiment, the elastic member  61  may be a torsion spring sleeved on the movable member  63 . 
     Referring to  FIG. 25  and  FIG. 26 , in another embodiment, the tension assembly  60  may include a plurality of transmission bodies  67 , a guide recess  14   e  is defined in the second housing  14 , the plurality of transmission bodies  67  are arranged sequentially along an extension direction of the guide recess  14   e , the free end  20   b  of the flexible screen module  20  is provided at one end of the tension assembly  60 , and the first housing  12  is disposed at the other end of the tension assembly  60 . In the process of the flexible screen module  20  stretching out of the housing assembly  10 , the plurality of transmission bodies  67  is pushed by the free end  20   b  to abut against each other sequentially and moves along the guide recess  14   e . In the process of the flexible screen module  20  retracting into the housing assembly  10 , the plurality of transmission bodies  67  is pushed by the first housing  12  to abut against each other sequentially and moves along the guide recess  14   e . Specifically, in the embodiment illustrated in  FIG. 26 , the guide recess  14   e  is defined on each of the two sides of the moving direction of the first housing  12  relative to the second housing  14 , and each guide recess  14   e  is correspondingly provided with the tension assembly  60 . Further, the transmission body  67  is a cylinder or a ball, and the transmission body  67  is slidable or rollable in the guide recess  14   e.    
     The guide recess  14   e  is substantially in a U-shape, and the first housing  12  has a first pushing portion  12   b  provided at one end thereof. The first pushing portion  12   b  is a part of the first housing  12  disposed in and penetrating through the guide recess  14   e . The flexible screen module  20  has a second pushing portion  20   c  provided at the free end  20   b  thereof. The second pushing portion  20   c  is a part of the flexible screen module  20  disposed in and penetrating through the guide recess  14   e . In the process of the flexible screen module  20  stretching out of the housing assembly  10 , the opposite ends of the first housing  12  and the second housing  14  depart from each other, the second pushing portion  20   c  of the free end  20   b  pushes the transmission bodies  67  at one end of the tension assembly  60  to abut against each other in sequence and move along the guide recess  14   e , while the transmission bodies  67  located at the other end of the tension assembly  60  generate a pushing force on the first pushing portion  12   b . In other words, in the process of the flexible screen module  20  stretching out of the housing assembly  10 , the two ends of the tension assembly  60  generate the pushing forces on the first pushing portion  12   b  and the second pushing portion  20   c , respectively, and the free end  20   b  and the fixed end  20   a  of the flexible screen module  20  tend to depart from each other. That is, the tension assembly  60  generates tension force exerting on the flexible screen module  20 , so as to keep the flexible screen module  20  in an unfolded and flat state. Similarly, in the process of the flexible screen module  20  retracting into the housing assembly  10 , the opposite ends of the first housing  12  and the second housing  14  approach to each other, and the first pushing portion  12   b  of the first housing  12  pushes the transmission body  67  at one end of the tension assembly  60  to enable the plurality of transmission bodies  67  to abut against each other in sequence and move along the guide recess  14   e , while the transmission bodies  67  located at the other end of the tension assembly  60  generate a pushing force on the second pushing portion  20   c . In other words, in the process of the flexible screen module  20  retracting into the housing assembly  10 , the two ends of the tension assembly  60  generate the pushing forces on the first pushing portion  12   b  and the second pushing portion  20   c , respectively, and the free end  20   b  and the fixed end  20   a  of the flexible screen module  20  tend to depart from each other. That is, the tension assembly  60  generates the tension force exerting on the flexible screen module  20  to keep the flexible screen module  20  in the unfolded and flat state. 
     Of course, the tension assembly  60  may be implemented in other forms. For example, in an implementation where the electronic device  100  includes a driving mechanism, the driving mechanism may be connected to the free end of the flexible screen module  20 . In the process of the flexible screen module  20  stretching out of the housing assembly  10 , the driving mechanism gradually releases the flexible screen module  20  and applies a tension force to the flexible screen module  20 , so that the flexible screen module  20  can be flatly unfolded on the second housing  14 . In the process of the flexible screen module  20  retracting into the housing assembly  10 , the driving mechanism drives the free end of the flexible screen module  20  to gradually wind on the shaft, so as to steadily retract the flexible screen module  20  into the housing assembly  10 . In such an implementation, the driving mechanism may be a motor, or a combination of a motor and a gear set. 
     The technical features of the above-mentioned embodiments can be combined arbitrarily. The possible combinations of the various technical features in the above-mentioned embodiments are not described individually for the purpose of concise description. However, any combinations of these technical features should be considered to fall within the scope of the present disclosure, unless they are contradictory to each other. 
     The above-mentioned embodiments are merely several embodiments of the present disclosure, and the description thereof is relatively specific and detailed. However, the above-mentioned embodiments should not be understood as limitations on the scope of the present disclosure. It should be pointed out that, for those of ordinary skill in the art can make various modifications and improvements without departing from the concept of the present disclosure, and all these modifications and improvements shall fall within the protection scope of the present disclosure. The protection scope of the present disclosure should be determined by the appended claims.