Patent Publication Number: US-2021176871-A1

Title: Electronic device

Description:
TECHNICAL FIELD 
     The present application relates to, without being limited to, the field of display technology, in particular, to an electronic device. 
     BACKGROUND 
     An electronic picture frame (picture screen) is a display device capable of continuously displaying the contents of paintings, and can truly simulate the appearance of paintings and be viewed as the paintings, thereby integrating artistic exhibition, appreciation, transmission and the like into a whole. 
     The electronic picture frame may include a display panel and a wooden frame outside the side surface of the display panel. With wood appearance, the electronic picture frame serves to simulate the painting frame and endows the picture within the electronic frame a more real painting look. 
     The existing display panel is connected with the wooden frame through screws arranged on the back surface, but the screw connection structure is complex, and the operations required for mounting and dismounting the screws are also complex. 
     SUMMARY 
     The present disclosure has been accomplished in order to at least partially solve the problems in the related art. The present disclosure provides an electronic device that can simplify the connection structure and operation while ensuring connection stability. 
     According to an aspect of the present disclosure, there is provided an electronic device including: 
     a frame; and 
     a display unit surrounded by the frame on a periphery thereof, 
     wherein the frame includes: 
     an inner frame having a front surface, a back surface opposite the front surface, and a side surface connected between the front surface and the back surface; and 
     an outer frame arranged around the side surface of the inner frame: 
     wherein the inner frame and outer frame are detachably engaged through at least one clamping structure. 
     In some embodiments, each of the at least one clamping structure includes a protrusion disposed on the side surface of the inner frame and a groove disposed at an inner side of the outer frame and configured to receive the protrusion. 
     In some embodiments, the at least one clamping structure includes an elastic clamping structure and an inelastic clamping structure, and 
     the elastic clamping structure enables the protrusion of the elastic clamping structure to enter into or be released from the corresponding groove through elastic deformation. 
     In some embodiments, the inner frame includes a middle frame located in an edge region of the front surface of the inner frame and a back case located on the back surface of the inner frame. 
     In some embodiments, the inelastic clamping structure includes a first clamping structure having: 
     a first protrusion disposed on the side surface of the inner frame, having a first side surface on the front surface side and a second side surface on the back surface side, the second side surface being parallel to the front surface, an angle between the first side surface and the second side surface being greater than 0 degree and less than 90 degrees; and 
     a first groove provided at the inner side of the outer frame and configured to receive the first protrusion, the first groove having a first face at the front surface side and a second face at the back surface side when assembled, the second face being parallel to and in surface contact with the second side surface when assembled. 
     In some embodiments, the angle between the first side surface and the second side surface is 30 to 60 degrees, and 
     the first face is parallel to the second face and has a gap with the first side surface when assembled. 
     In some embodiments, the back case includes side portions located on the side surfaces of the inner frame, and the first protrusions is disposed on a side of the side portion facing the outer frame when assembled. 
     In some embodiments, the outer frame includes a snap-fit portion that snaps into an upper surface of the middle frame when assembled. 
     In some embodiments, a first convex portion is provided on a lower surface of the snap-fit portion, and a first concave portion is provided in an upper surface of the middle frame, the first convex portion being received in the first concave portion when assembled, the first convex portion being elastically deformable. 
     In some embodiments, a second convex portion is provided on the second side surface, and a second concave portion is provided in the second face, the second convex portion being received in the second concave portion when assembled. 
     In some embodiments, the elastic clamping structure includes a second clamping structure located on the side surface of the inner frame, the second clamping structure including: 
     a first bent portion having a first end and a second end, the first end being connected to the middle frame: 
     a second protrusion that is disposed on a side, facing the outer frame, of the second end of the first bent portion when assembled, the second protrusion having a third side surface on the front surface side and a fourth side surface on the back surface side, an angle between the third side surface and the fourth side surface being 40 to 90 degrees, an angle between the fourth side surface and the front surface being 0 to 25 degrees; and 
     a second groove that is disposed at the inner side of the outer frame and configured to receive the second protrusion, the second groove having a third face on the front surface side and a fourth face on the back surface side when assembled, the third face being parallel to the third side surface when assembled, the fourth face being parallel to the fourth side surface when assembled. 
     In some embodiments, the first bent portion is elastically deformable and formed of a shape-memory material. 
     In some embodiments, the elastic clamping structure includes a third clamping structure located on the side surface of the inner frame, the third clamping structure including: 
     a second bent portion having a first end and a second end, the first end being connected to the middle frame 
     a third protrusion that is disposed on a side, facing the outer frame, of the second end of the second bent portion when assembled, the third protrusion having a fifth side surface on the front surface side and a sixth side surface on the back surface side, the sixth side surface being parallel to the front surface; and 
     a third groove that is disposed at the inner side of the outer frame and configured to receive the third protrusion, the third groove having a fifth face on the front surface side and a sixth face on the back surface side when assembled, the sixth face being parallel to and in surface contact with the sixth side surface when assembled, the fifth face having a gap with the fifth side surface when assembled. 
     In some embodiments, the second bent portion is elastically deformable and formed of a shape-memory material. 
     In some embodiments, a first opening is disposed at a portion of the back case corresponding to the second bent portion, and the second end of the second bent portion includes a protruding portion protruding from the sixth side surface toward the first opening. 
     In some embodiments, the frame further includes a closure member, the closure member being formed of an elastic material and including: 
     a base configured to close the first opening; 
     a major protrusion arranged on one side of the base, the major protrusion having an arrow structure disposed at an end away from the base, a dimension of the arrow structure in a direction perpendicular to a height direction of the major protrusion may be increased or reduced through elastic deformation; and 
     a minor protrusion arranged on the same side of the base as the major protrusion, the minor protrusion having a curved portion disposed at an end away from the base. 
     In some embodiments, the back case has a second opening into which the arrow structure of the major protrusion is inserted through elastic deformation, so that the back case is sandwiched between the curved portion of the minor protrusion and the base. 
     In some embodiments, the side edge of the inner frame includes a first side edge, two second side edges connected to two ends of the first side edge, respectively, and a third side edge connected between the two second side edges and disposed opposite the first side edge; wherein 
     the first clamping structure is disposed at the first side edge; 
     the second clamping structure is disposed at the second side edge; and 
     the third clamping structure is disposed at the third side edge. 
     In some embodiments, the inner frame is formed of a plastic or metal material. 
     In some embodiments, the outer frame is formed of wood or plastic. 
     In some embodiments, the edges of the display unit are fixed to the middle frame through a pressing piece. 
     In some embodiments, the middle frame is formed of a first middle frame and a second middle frame, the first middle frame being partially overlapping with the second middle frame, and one end portion of the second middle frame protrudes from one end portion of the first middle frame. 
     In some embodiments, the middle frame and the back case enclose a space having an opening, and the display unit is received in the space. 
     In some embodiments, the middle frame has a rectangular shape, a microphone is disposed on a short edge of the middle frame, and an infrared sensor and a light sensor are disposed on a long edge of the middle frame. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic structural view illustrating an electronic device according to an exemplary embodiment of the present disclosure; 
         FIG. 2 a    is a schematic structural view illustrating a partial cross-section cut along line A-A′ shown in  FIG. 1 ; 
         FIG. 2 b    is another schematic structural view illustrating a partial cross-section cut along line A-A′ shown in  FIG. 1 ; 
         FIG. 3  is a schematic structural view illustrating a partial cross-section of a frame according to an exemplary embodiment of the present disclosure where a first clamping structure is clamped: 
         FIG. 4  is a schematic view illustrating a partial structure of a first protrusion in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 5  is a schematic view illustrating a partial structure of a first groove in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 6  is a schematic structural diagram illustrating a partial cross-section cut along line B-B′ shown in  FIG. 1 : 
         FIG. 7  is a schematic structural view illustrating a partial cross-section of a second protrusion in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 8  is a schematic view illustrating a partial structure of a second protrusion in a frame according to an exemplary embodiment of the present disclosure: 
         FIG. 9  is a schematic view illustrating a partial structure of a second groove in a frame according to an exemplary embodiment of the present disclosure: 
         FIG. 10  is a schematic structural view illustrating a partial cross-section cut along line C-C′ shown in  FIG. 1 ; 
         FIG. 11  is a schematic view illustrating a partial structure of a third protrusion in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 12  is a schematic view illustrating a partial structure of a third groove in a frame according to an exemplary embodiment of the present disclosure: 
         FIG. 13  is a schematic view illustrating a partial structure of a first opening in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 14  is a schematic front view illustrating a structure of a closure member in a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 15  is a schematic side view illustrating a structure of a closure member in a frame according to an exemplary embodiment of the present disclosure: 
         FIG. 16  is a schematic structural view illustrating a frame according to an exemplary embodiment of the present disclosure in which the closure member is clamped at the first opening; and 
         FIG. 17  is a schematic structural view illustrating an inner frame of a frame according to an exemplary embodiment of the present disclosure; 
         FIG. 18  is a schematic view illustrating a structure of a display unit fixed on a middle frame according to an exemplary embodiment of the present disclosure; 
         FIG. 19  is a schematic structural view illustrating a display unit receiving space formed of a middle frame and a back case according to an exemplary embodiment of the present disclosure; and 
         FIG. 20  is a schematic structural view illustrating a microphone and a sensor disposed on a middle frame according to an exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     To make a person skilled in the art better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail in conjunction with the accompany drawings and embodiments. 
     According to an aspect of the present disclosure, referring to  FIGS. 1-17 , an exemplary embodiment of the present disclosure provides an electronic device, including: 
     a frame; and 
     a display unit  10  surrounded by the frame on a periphery thereof, 
     wherein the frame includes: an inner frame  4  having a front surface  49 , a back surface  48  opposite the front surface, and a side surface  47  connected between the front surface  49  and the back surface  49 , for fixing a target structure; 
     an outer frame  5  arranged around the side surface  47  of the inner frame  4 : 
     wherein the inner frame  4  and the outer frame  5  are detachably engaged by at least one clamping structure. 
     Referring to  FIG. 1  and  FIG. 2 a   , the frame provided by the exemplary embodiments of the present disclosure includes an inner frame  4  in which a target structure such as a display unit  10  may be fixed, and the inner frame  4  is clamped at an inner side of the outer frame  5 , in this way, the target structure is provided in the frame. Since the inner frame  4  and the outer frame  5  are connected by clamping, the structure is simple and the operation for assembly and disassembly is also simple and convenient. 
     In the mean time, structures such as screws are not seen from outside of the clamping structure, thus the mechanic sense of the product (electronic picture frame) would be attenuated, and an artistic and cultural favor would be advanced, promoting the artistic quality of the product. 
     Of course, the inner frame  4  (including the middle frame  41  and the back case  42  described hereinafter) may be formed of conventional plastic or metal material; while the outer frame  5  may be formed of wood (thus becoming a wooden frame), or may also be formed of plastic and the like. 
     Of course, the connection between the inner frame  4  and the target structure may be detached. That is, the target structure and the inner frame  4  are two relatively independent members. For example, they may be the display unit and the case of the display unit, respectively. When the two members are assembled, they may constitute a display member to perform display. 
     In an alternative embodiment, the inner frame  4  and the target structure may be fixedly connected in a non-detachable manner, so that the inner frame  4  and the target structure together constitute a relatively independent non-detachable member. 
     In an exemplary embodiment of the present disclosure, each of the at least clamping structure includes a protrusion provided on a side surface  47  of the inner frame  4 , and a groove provided at an inner side of the outer frame  5  for receiving the protrusion. 
     In an exemplary embodiment of the present disclosure, the clamping structure is divided into an elastic clamping structure and an inelastic clamping structure. The elastic clamping structure can enable the protrusion of the elastic clamping structure to enter into or be released from the corresponding groove through elastic deformation. 
     That is to say, each of the at least clamping structure may include a protrusion provided on a side surface  47  of the inner frame  4 , and a groove provided at an inner side of the outer frame  5  for the protrusion to enter, the protrusion and the groove are used cooperatively, that is, when the protrusion enters a corresponding groove, the inner frame  4  and the outer frame  5  are clamped together (assembled), whereas when the protrusion is released from the groove, the inner frame  4  is separated from the outer frame  5 . 
     As described above, the clamping structure is divided into two different types, i.e., elastic clamping structure and inelastic clamping structure. The elastic clamping structure can enable the protrusion thereof enter into or be released from a corresponding groove (or move close to or away from the outer frame  5 ) by elastic deformation. Whereas, the inelastic clamping structure cannot have distinct elastic deformation, thus the position of the protrusion is substantially fixed. 
     In an exemplary embodiment of the present disclosure, the inner frame includes a middle frame  41  located at least in an edge region of a front surface of the inner frame and a back case  42  located at least on a back surface of the inner frame. 
     Particularly, the inner frame  4  includes a back case  42  and a middle frame  41 , the middle frame  41  is disposed corresponding to the edge region of the front surface, and is of a structure similar to a shape like a Chinese character ‘ ’ with an opening provided in the center to expose a surface of a target structure; the back case  42  is located on the back surface of the inner frame, and is substantially a flat panel that seals the back surface of the inner frame, and has a protruding side portion  429  arranged at some positions of the edge thereof. 
     In an exemplary embodiment of the present disclosure, as shown in  FIGS. 2 b    to  5 , the inelastic clamping structure between the inner frame  4  and the outer frame  5  includes a first clamping structure, the first clamping structure including: 
     a first protrusion  11  provided on a side surface  47  of the inner frame  4  and having a first side surface  711  located at the front surface side and a second side surface  712  located at the back surface side, the second side surface  712  being parallel to a front surface  49 , and an angle between the first side surface  711  and the second side surface  712  being greater than 0 degree and less than 90 degrees; and 
     a first groove  51  provided at an inner side of the inner frame  5  for receiving the first protrusion  11 , the first groove  51  having a first face  721  at the front surface side and a second face  722  at the back surface side when assembled, the second face  722  being parallel to and in surface contact with the second side surface  712  when assembled. 
     In an exemplary embodiment of the present disclosure, the outer frame  5  includes a snap-fit portion  59  that is clamped on a front surface (i.e., upper surface) of the middle frame  41  when assembled. In a modification example provided by the present disclosure, as shown in  FIG. 2 b   , a first protrusion  591  disposed on a lower surface of the snap-fit portion  59 , a first groove  411  disposed on an upper surface of the middle frame  41 , the first protrusion  591  being received in the first groove  411  when assembled and being elastically deformable. Particularly, when the inner frame  4  and the outer frame  5  are assembled together, the first protrusion  591  on the lower surface of the snap-fit portion  59  is squeezed to elastically deform, and then is received in the first groove  411  on the upper surface of the middle frame  41 . By cooperation of the first groove  411  and the first protrusion  591 , the inner frame  4  and the outer frame  5  can be connected to each other firmly. 
     In an exemplary embodiment of the present disclosure, in a modification example provided by the present disclosure, as shown in  FIG. 2 b   , a second protrusion  7121  is disposed on the second side surface  712 , a second groove  7221  is disposed in the second face  722 , the second protrusion  7121  being received in the second groove  7221  when assembled. Particularly, when the inner frame  4  and the outer frame  5  are assembled together, that is, when the first protrusion  11  is inserted into the first groove  51 , the second protrusion  7121  on the second side surface  712  is engaged in the second groove  7221  in the second face  722 . By cooperation of the second groove  7221  and the second protrusion  7121 , the first protrusion  11  may be easily positioned in the first groove  51 , so that the assembling operation becomes simple and convenient. 
     In an exemplary embodiment of the present disclosure, the back case  42  has a side portion  429  located on a side surface of the inner frame, the first protrusion  11  is provided at a side of the side portion  429  facing toward the outer frame  5  when assembled. 
     Referring to  FIGS. 2 a    to  5 , a specific form of the inelastic clamping structure is a first clamping structure that includes a first protrusion  11  provided on a side surface of the inner frame. Wherein, the back case  42  has a side portion  429  provided on a side surface of the inner frame at a position corresponding to the first protrusion  11 , the first protrusion  11  may be provided outside of the side portion  429 , the reason that the first protrusion  11  is provided on the back case  42  is that the back case  42  has high strength and is not subject to elastic deformation. 
     In the mean time, a side at the back surface side of the first protrusion  11  is a second side surface  712  parallel to the front surface  49  (a lower side of the first protrusion  11  in  FIG. 2 a   ). Accordingly, in the first groove  51  for receiving the first protrusion  11  of the outer frame  5 , the second face  722  at the back surface side (the lower surface of the first groove  51  in  FIG. 2 a   ) is parallel to the second side surface  712 , so as to be able to keep surface contact (such as frictional contact) with the second side surface  712 , so that the inner frame is clamp-fixed between the second face  722  and the snap-fit portion  59  to ensure contact stability. By contrast, the first side surface  711  of the first protrusion  11  is inclined with respect to the second side surface  712  to facilitate assembly and disassembly. 
     In an exemplary embodiment of the present disclosure, an angle between the first side surface  711  and the second side surface  712  (angle a in  FIG. 3 ) is 30 to 60 degrees; the first face  721  is parallel to the second face  722 , and the first face  721  has a gap with the first side surface  711  when assembled. 
     That is to say, referring to  FIG. 2 a   , the first side surface  711  (the upper side of the first protrusion  11  in  FIG. 2 a   ) at the front surface side of the first protrusion  11  is disposed inclined at a designated angle with respect to the second side surface  712 , and the first face  721  (the upper surface of the first groove  51  in  FIG. 2 a   ) at the front surface side of the first groove  51  is parallel to the second face  722 , and the first face  721  has a gap with the first side surface  711 . The reason to employ the above structure is that the first clamping structure is inelastic, thus referring to  FIG. 3 , when the first protrusion needs to be snapped into or released from the first groove  51 , the inner frame needs to be inclined with respect to the outer frame  5 , whereas the first side surface  711  disposed inclined as described above would not touch the first face  721  during this process. 
     In an exemplary embodiment of the present disclosure, the first groove  51  has a larger depth, and in order to increase the strength of the outer frame  5 , the first groove  51  may only be disposed at the first protrusion  11  with reference to  FIG. 5 ; and when the outer frame  5  is formed of wood, the surface other than the first face  721  and the second face  722  may be a gradual slope surface to facilitate processing of wooden product, for example, the outer frame  5  is a wooden frame. 
     In an exemplary embodiment of the present disclosure, as shown in  FIGS. 6-9 , the elastic clamping structure between the inner frame  4  and the outer frame  5  includes a second clamping structure located at a side surface of the inner frame, the second clamping structure including: 
     a first bent portion  21  having a first end  211  and a second end  212 , the first end  211  being connected to the middle frame  41 ; 
     a second protrusion  12  provided at a side of a second end  212  of the first bent portion  21  facing toward the outer frame  51  when assembled, the second protrusion  12  having a third side surface  713  located at the front surface side and a fourth side surface  714  located at the back surface side, an angle between the third side surface  713  and the fourth side surface  714  being 40 to 90 degrees, an angle between the fourth side surface  714  and the front surface  49  being 0 to 25 degrees; and 
     a second groove  52  provided at an inner side of the outer frame  5  for receiving the second protrusion  12 , the second groove  52  having a third face  723  located at the front surface side and a fourth face  724  located at the back surface side when assembled, the third face  723  being parallel to the third side surface  713  when assembled, the fourth face  724  being parallel to the fourth side surface  714  when assembled. 
     By elastic deformation of the first bent portion  21 , the second protrusion  12  can enter into or be released from the second groove  52 . 
     In an exemplary embodiment of the present disclosure, the first bent portion  21  is formed of a shape-memory material. In this way, the first bent portion  21  is elastically deformable during assembling such that the second protrusion  12  can be engaged in the second groove  52 . After the assembling is accomplished, the first bent portion  21  can resume its original shape and last, thereby engaging the second protrusion  12  in the second groove  52  steadily, i.e., bringing the inner frame  4  and the outer frame  5  into secured connection with each other. 
     That is to say, referring to  FIGS. 6 to 9 , one form of the elastic clamping structure is a second clamping structure that includes a first bent portion  21  with a first end  211  thereof fixedly disposed (specifically, is connected to the middle frame  41  in the edge region on the front surface of the inner frame, the first bent portion  21  and the middle frame  41  may be an integrated structure), the second protrusion  12  is provided at a second end  212  of the first bent portion  21  (a lower end of a cantilever of the first bent portion  21  in  FIG. 6 ). The first bent portion  21  is formed of an elastic material such as plastic and has a small thickness, thereby being elastically deformable; and by elastic deformation of the first bent portion  21 , the second protrusion  12  of the second end  212  can move away from or approach the outer frame  5 , so that the second protrusion  12  enters or pops out of the second groove  52 . 
     In an exemplary embodiment of the present disclosure, the angle between the fourth side surface  714  at the back surface side of the second protrusion  12  (the lower side of the second protrusion in  FIG. 7 ) and the front surface  49  (angle b in  FIG. 7 ) and the angle between the third side surface  713  at the front surface side (the upper side of the second protrusion  12  in  FIG. 7 ) and the fourth side surface  714  of the second protrusion  12  both have particular ranges. Thus referring to  FIG. 6 , when viewed from the side, the second protrusion  12  has a triangular structure with an angle oriented toward the outer frame  5 , the shape of the second groove  52  at the inner side of the outer frame  5  matches with this angle of the triangle. Since the second groove  52  has a small depth, it is merely used to receive the end of the second protrusion  12  (i.e., the angle oriented toward the outer frame  5  of the triangle). In this way, when it is necessary to assemble the inner frame with the outer frame  5  or separate the inner frame from the outer frame  5 , the second protrusion  12  may snap into the second groove  52  naturally or pop out of the second groove  53  without separate operations. 
     In an exemplary embodiment of the present disclosure, a height of the second protrusion  12  should be greater than a predetermined gap between the back case  42  and the outer frame  5  plus a mounting tolerance to ensure that the end of the second protrusion  12  can enter the second groove  52 . 
     In an exemplary embodiment of the present disclosure, since the second groove  52  is very shallow, it has little influence on the structural strength, thus it may be a continuously extending groove as shown in  FIG. 9 . 
     In an exemplary embodiment of the present disclosure, as shown in  FIGS. 10 to 13 , the elastic clamping structure between the inner frame  4  and the outer frame  5  includes a third clamping structure located on a side surface of the inner frame, the third clamping structure including: 
     a second bent portion  22  having a first end  221  and a second end  222 , the first end  221  being connected to the middle frame  41 ; 
     a third protrusion  3  disposed at a side of the second end  222  of the second bent portion  22  facing toward the outer frame  51  when assembled, the third protrusion  13  having a fifth side surface  715  at the front surface side and a sixth side surface  716  at the back surface side, the sixth side surface  716  being parallel to the front surface  49 ; and 
     a third groove  53  disposed at the inner side of the outer frame  5  and configured to receive the third protrusion  13 , the third groove  53  having a fifth face  725  at the front surface side and a sixth face  726  at the back surface side when assembled, the sixth face  726  being parallel to and in surface contact with the sixth side surface  716  when assembled, the fifth face  725  has a gap with the fifth side surface  715  when assembled. 
     By elastic deformation of the second bent portion  22 , the third protrusion  13  can enter into or be released from the third groove  53 . 
     As shown in  FIG. 10 , a first opening  421  is provided at a portion of the back case  42  corresponding to the second bent portion  22  (i.e., a position right below the second bent portion  22 ). 
     In an exemplary embodiment of the present disclosure, the second bent portion  22  is formed of a shape-memory material. In this way, the second bent portion  22  is elastically deformable during assembly, such that the third protrusion  13  can be engaged in the third groove  53 . After the assembling is accomplished, the second bent portion  22  can resume its original shape and last, thereby engaging the third protrusion  13  in the third groove  53 , i.e., bringing the inner frame  4  and the outer frame  5  into secured connection with each other. 
     Referring to  FIGS. 10 to 13 , another form of the elastic clamping structure is a third clamping structure that includes a second bent portion  22 , with a first end  221  thereof fixedly disposed (specifically, is connected to the middle frame  41  in the edge region on the front surface of the inner frame, the second bent portion  22  and the middle frame  41  may be an integrated structure), the third protrusion  13  is provided outside a second end  222  of the second bent portion  22  (a lower end of a cantilever of the second bent portion  22  in  FIG. 10 ). The second bent portion  22  is formed of an elastic material such as plastic and has a small thickness, thereby being elastically deformable; and by elastic deformation of the second bent portion  22 , the third protrusion  13  of the second end  222  thereof can enter into or be released from the third groove  53  at an inner side of the outer frame  5 . 
     In an exemplary embodiment of the present disclosure, the sixth side surface  716  at the back surface side of the third protrusion  13  (the lower side of the third protrusion in  FIG. 10 ) and the sixth face  726  at the back surface side of the third groove  53  (the lower surface of the third groove  53  in  FIG. 10 ) are both parallel to the front surface  49  to form a stable surface contact therebetween and clamp the inner frame between the sixth face  726  and the snap-fit portion  59 ; and a gap exists between the fifth side surface  715  at the front surface side (the upper side of the third protrusion  13  in  FIG. 10 ) and the fifth face  725  at the front surface side of the third groove  53  (the upper surface of the third groove  53  in  FIG. 10 ) of the third protrusion to facilitate popping of the third protrusion  13  out of the third groove  53 . As can be seen, the specific form of the fifth face  725  is not limited, which may be, for example, an arc surface, or a flat surface, etc., as shown in  FIG. 10 . 
     In an exemplary embodiment of the present disclosure, referring to  FIG. 6  and  FIG. 10 , the middle frame  41  further has a portion extending longitudinally at the inner side of the first bent portion  21  and the second bent portion  22 , this portion is not a bent portion but a portion to form a semi-closed space with the back case  42  for providing a target structure (such as a display unit). 
     As shown in  FIG. 10 , a first opening  4211  is provided at a position corresponding to the third protrusion  13  on the back case  42  on the back surface of the inner frame. In this way, referring to  FIG. 10 , when it is necessary to separate the inner frame  4  from the outer frame  5 , the second end  222  of the second bent portion  22  may be toggled using a tool  9  through the first opening  421  (in order to facilitate drive of the second bent portion  22  by the tool  9 , a protruding portion  2221  protruding downwardly may be provided at the second end  222  of the second bent portion  22 , that is, the protruding portion  2221  protruding from the sixth side surface  716  toward the first opening  421 ), so that the third protrusion  13  pops out of the third groove  53 . It is to be understood that the size of the first opening  421  should be enough to allow insertion of the tool  9  therein. 
     In an exemplary embodiment of the present disclosure, the third groove  53  has a relatively large depth, in order to increase the strength of the outer frame  5 , the third groove  53  may only be provided at a position corresponding to the third protrusion  13  with reference to  FIG. 12 ; and when the outer frame  5  is formed of wood, the surface other than the fifth face  725  and the sixth face  726  may be a gradual slope surface to facilitate processing of a wooden product (for example, the outer frame  5  is a wooden frame). 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 14  and  FIG. 15 , the inner frame  4  further includes a closure member  6 , the closure member  6  being formed of an elastic material and including: 
     a base  61  for closing the first opening  421 ; 
     a major protrusion  62  disposed on one side of the base  62 , the major protrusion  62  having an arrow structure disposed at an end away from the base  61 , a dimension of the arrow structure in a direction perpendicular to a height direction of the major protrusion  62  may be increased or reduced through elastic deformation; and 
     a minor protrusion  63  disposed on the same side of the base  61  as the major protrusion  62 , the minor protrusion  63  having a curved portion disposed at an end away from the base  61 . 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 13 , the back case  42  has a second opening  422  into which the arrow structure of the major protrusion  62  is inserted through elastic deformation, the curved portion of the minor protrusion  63  being used to clamp the back case between the minor protrusion  63  and the base  61 . 
     In order to prevent the first opening  421  from affecting the overall appearance of the frame of the electronic device, a separate closure member  6  may be disposed to close the first opening  421 . When the inner frame needs to be separated from the outer frame  5 , the closure member  6  may be detached to expose the first opening, thereby allowing entry of the tool  9 . 
     Particularly, referring to  FIGS. 14 to 16 , the closure member  6  may be formed of an elastic material such as silica gel, the closure member  6  including: a base  61  for closing the first opening  421 , a major protrusion  62  (the number may be, for example, one) having an arrow structure at end portion thereof is disposed at one side of the base  61 ; and a minor protrusion  63  (the number may be, for example, two) having a hook structure (i.e., a bent portion) at an end portion thereof. Referring to  FIG. 16 , the arrow structure at the end portion of the major protrusion  62  may be contracted through elastic deformation, thereby being inserted into a second opening  422  on the back case  42  and then extended after insertion into the second opening  422 , a wall of the back case  42  on the edge of the first opening  421  may be clamped between the hook structure of the minor protrusion  63  and the base  61  to secure the closure member  6 , such that the base  61  blocks off the first opening  421 . Since the closure member  6  is formed of elastic material, it may be detached from the back case  62  through deformation of the arrow structure and the hook structure. 
     Of course, the closure member  6  may also employ other different forms as long as it can be detachably mounted on the inner frame  4  and block off the first opening  421 . 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 17 , a side edge of the inner frame  4  includes a first side edge  811  (the upper side of the inner frame  4  in  FIG. 17 ), two second side edges  812  (the left side and right side of the inner frame  4  in  FIG. 17 ) connected to the two ends of the first side edge  811 , respectively, and a third side edge  813  (the lower side of the inner frame  4  in  FIG. 17 ) connected between the two second side edges  812  and disposed opposite the first side edge  811 . The first clamping structure is disposed on the first side edge  811 ; the second clamping structure is disposed on the second side edge  812 ; the third clamping structure is disposed on the third side edge  813 . 
     That is to say, referring to  FIG. 17 , the first clamping structure and the third clamping structure may be disposed on two opposite side edges of the inner frame  4  (the first side edge  811  in an upper portion and the third side edge  813  in a lower portion), respectively, whereas the second clamping structure is disposed on the other two side edges of the inner frame  4  (the two second side edges  812  at the left and right sides). Of course, a plurality of clamping structures of the same type may be disposed on each side edge of the inner frame  4 . In an exemplary embodiment of the present disclosure, the first clamping structure is inelastic, thus the inner frame  4  needs to be tilted with respect to the outer frame  5  in a particular manner to facilitate snap-in and release, thus all first clamping structures should be disposed on the same side edge; whereas the third clamping structure needs to be released by toggle of the tool  9 , thus for easy operation, the third clamping structure should be disposed on a side edge opposite to the first clamping structure; since the second protrusion  112  of the second clamping structure is snapped into the second groove  52  by a small depth, it can be easily snapped in or released upon a force, thus the second clamping structure should be disposed on a side edge different from the first clamping structure and the third clamping structure. 
     Of course, it should be understood that the middle frame  41  and the back case  42  may be connected to each other by adhesion or clamping, for example, when the target structure is a display unit, the middle frame  41  and the back case  42  may be two portions of the outer case of the display unit, and fix the display unit therein after being engaged together. 
     Of course, it should be understood that it is suitable that the snap-fit portion  59  is disposed at a position on the edge of the front surface of the middle frame  41 , but it is preferably disposed at least at a position corresponding to the first protrusion  11 , the first protrusion  13 , and more preferably referring to  FIG. 1 , the snap-fit portion  59  is formed as a closed “loop” to ensure stability of the snap-fitting. 
     Of course, it should be understood that for convenient demolding and increased strength, a person skilled in the art may dispose structures such as transitional circular corners, recesses and reinforcing ribs in the protrusions, grooves and bent portions, and such structures may result in throughholes and recesses and the like in the first side surface  711  to the sixth side surface  716 , as shown in  FIG. 4 ,  FIG. 8 . 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 18 , the edge of the display unit  10  may be fixed on the middle frame  41  via a pressing piece  43 . Particularly, after the middle frame  41  is put in place, the display unit  10  is placed on the middle frame  41 , at this time, the edge of the display unit  10  and the edge of the middle frame  41  abut against each other, an end of the pressing piece  43  is placed on a non-display side of the display unit, and the other end of the pressing piece  43  is fixed on the middle frame  41  via a fastener or a magnetic member, such that the display unit  10  is reliably fixed on the middle frame  41 . It is to be understood that the number and position of the pressing piece  43  may be arbitrarily set as desired. 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 19 , the middle frame  41  may be formed of a first middle frame  412  and a second middle frame  413 , the first middle frame  412  and the second middle frame  413  being partially overlapping with each other, and an end of the middle frame  413  protrudes out of an end of the first middle frame  412 . Particularly, the middle frame  41  has a dual-layer construction, with one layer being the first middle frame  412 , and the other being the second middle frame  413 . The first middle frame  412  has a substantially L-shape, and the second middle frame  413  has a flat-plate shape, as shown in  FIG. 19 , a horizontal portion of the L-shaped first middle frame  412  and an end portion of the second middle frame  413  partially overlap with each other, and the other end portion of the middle frame  413  protrudes from the horizontal portion of the first middle frame to be exposed. The first middle frame  412  may be formed of a material different from the second middle frame  413 , so that better protection can be provided for the display unit while ensuring certain rigidity. 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 19 , the middle frame  41  and the back case  42  may enclose a space  45  having an opening  44  and in which the display unit  10  is received. Particularly, the space  45  receiving the display unit  10  is enclosed by the walls of the middle frame  41  and the back case  42 , and a display surface of the display unit  10  is exposed from the middle frame  4  that is formed of the middle frame  41  and the back case  42 . 
     In an exemplary embodiment of the present disclosure, as shown in  FIG. 1  (the front view) and  FIG. 20  (the back view), the middle frame  41  has a rectangular shape, a microphone  01  may be disposed on a short edge of the middle frame  41 , and an infrared sensor  02  and an light sensor  03  are disposed on a long edge of the middle frame  41 . Particularly, as shown in  FIG. 20 , a microphone  01  is disposed on a vertical edge of the rectangular middle frame  41 , and an infrared sensor  02  and a light sensor  03  are disposed on a horizontal edge of the rectangular middle frame  41 . Particularly, a groove is disposed on a vertical edge of the rectangular middle frame  41 , the microphone  01  is received in the groove, so that the periphery of the microphone  01  is protected by the middle frame  41 , and by means of the microphone  01  a sound of the electronic device may be output. On or more grooves are disposed on the horizontal edge of the rectangular middle frame  41 , the infrared sensor  02  and the light sensor  03  are respectively received in the grooves, so that the periphery of the infrared sensor  02  and the light sensor  03  are protected by the middle frame  41 , and by means of the infrared sensor  02  an external control signal may be received, and by means of the light sensor  03  the electronic device may easily sense external environment data, so that the electronic device becomes more intelligent, for example, the intensity of illumination, contrast and the like may be adjusted based on the external environment data sensed by the light sensor  03 . 
     In an exemplary embodiment of the present disclosure, the electronic device may be any product with a display function, including mobile phone, tablet computer, TV set, displayer, laptop computer, digital photo frame and navigator, It should be understood that above embodiments are just examples for illustrating the principle of the invention, however, the invention is not limited thereto. Various modifications and variations can be made by a person skilled in the art without departing from the spirit and the scope of the present invention. These modifications and variations should be considered to be within protection scope of the present invention.