Patent Publication Number: US-2021165240-A1

Title: Optical Member Driving Device, Camera Device and Electronic Apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Chinese Utility Model application CN 201922087122.X, filed on Nov. 28, 2019, the contents of which are incorporated by reference herein. 
     TECHNICAL FIELD 
     The present disclosure relates to an optical member driving device used in electronic apparatus such as smartphones, a camera device, and an electronic apparatus. 
     BACKGROUND 
     There is a Patent Document of Chinese utility model CN209044147U (hereinafter referred to as “Patent Document 1”) which discloses a technique related to camera devices installed in electronic apparatus such as smartphones. The vibration suppression structure for voice coil motor according to Patent Document 1 has a carrier for holding a lens, and a base to support the carrier. In this vibration suppression structure, coating expansion portions projecting outward are formed at the four corners of the carrier, and viscoelastic resin is provided between the coating expansion portions and the columns rising from the four corners of the base. The viscoelastic resin provides a vibration suppression effect when the carrier is driven. 
     However, in case of the technique in Patent Document 1, there is a problem that it is necessary to make the carrier into a shape with coating expansion portions at four corners, so that the processing of the carrier takes time. 
     SUMMARY 
     In view of such problem, an object of the present disclosure is to provide an optical member driving device, a camera device and an electronic apparatus, which can exhibit stable vibration suppression effect and are easily manufactured. 
     In order to solve the above problem, according to a first aspect of the present disclosure, there is provided an optical member supporting device including: a carrier provided with a through hole for mounting an optical member and having a rectangular shape; a housing having two opposite plates sandwiching the carrier and a plurality of column portions rising from one plate of the two plates toward the other plate of the two plates; and springs arranged between the carrier and the housing. Chamfered corner surfaces are provided at four corners of the carrier, and viscoelastic resin is provided between the corner surfaces and opposite surfaces of the column portions facing the corner surfaces. 
     According to a second aspect of the present disclosure, there is provided a camera device including the optical member supporting device described above. 
     According to a third aspect of the present disclosure, there is provided an electronic apparatus including the camera device described above. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of a smartphone mounted with a camera device including an optical member driving device according to an embodiment of the present invention; 
         FIG. 2  is a perspective view of the optical member driving device shown in  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of the optical member driving device shown in  FIG. 2 ; 
         FIG. 4  is an exploded perspective view of the optical member driving device shown in  FIG. 2 ; 
         FIG. 5  is a diagram showing a configuration in a case of the optical member driving device shown in  FIG. 2 ; 
         FIG. 6  is a diagram showing a portion in which viscoelastic resin is arranged in the optical member driving device of  FIG. 2 ; and 
         FIG. 7  is a diagram showing a portion in which the viscoelastic resin is arranged in the optical member driving device of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present invention are explained with reference to drawings. As shown in  FIG. 1 , a camera device  15  including an optical member driving device  1  according to one embodiment of the present invention is embedded in a housing of a smartphone  19 . 
     The camera device  15  includes: a lens body  11  which is an optical member; an image sensor  12  to convert light incident via the lens body  11  into an image signal; and an optical member driving device  1  to drive a lens body  11  while holding the lens body  11  and the image sensor  12 . Hereinafter, an optical axis direction of lens body  11  is appropriately referred to as a Z-direction, one direction orthogonal to the Z direction is appropriately referred to as an X-direction, and a direction orthogonal to both the Z-direction and the X-direction is appropriately referred to as a Y-direction. Further, the side of the subject viewed from the lens body  11  may be referred to as the front side, and the opposite side (the image sensor  12  side) may be referred to as the rear side. The front side corresponds to the +Z side, and the rear side corresponds to the -Z side. 
     As shown in  FIG. 2 ,  FIG. 3  and  FIG. 4 , the optical member driving device  1  includes a carrier  4 , a front side spring  5 , two rear side springs  6 , two magnets  7 , two coils  8 , and a FPC (Flexible printed circuits)  9  accommodated in a housing  10  obtained by combining a base  3  and a case  2 . Of these portions, the housing  10 , the magnets  7 , and the FPC9 form a fixed portion, and the carrier  4  and the coils  8  form a movable portion moving relative to the fixed portion. 
     The details of the configuration of each portion will be described below. The case  2  includes a quadrangular front plate  20 , a side plate  22  extending from the −Y side edge of the front plate  20  to the −Z side, and three side plates  21  extending from the other three edges to the −Z side. The side plate  22  on the −Y side of the case  2  has a concave portion  29  notched on the +Z side. Convex portions  26  are provided at the end edge of the side plate  21  on the −Z side. A through hole  25  is bored in the center of the front plate  20 . Positioning protrusions of the front side spring  5  are provided at four corners of the rear surface of the front plate  20  of the case  2 . Two pairs of convex pieces  27   a  and  27   b  separated in the Y-direction are provided on the inner side of the side plate  21  on the +X side and the inner side the side plate  21  on the −X side of the case  2 , respectively. A magnet  7  is accommodated and fixed between each pair of the convex pieces  27   a  on the side plate  21 . A coil  8  is accommodated with a gap between each pair of the convex pieces  27   b  on the side away from the side plate  21 . 
     The base  3  includes: a quadrangular rear plate  30  corresponding to the quadrangle of the front plate  20 ; two column portions  33   a  rising from two corners on the +Y side of the rear plate  30  toward the +Z side; two column portions  33   b  rising from two corners on the -Y side of the rear plate  30  toward the +Z side; and a side plate  39  rising from an end edge of the rear plate  30  on the −Y side toward the +Z side. The side plate  39  is provided corresponding to the shape of the concave portion  29 . A through hole  35  is bored in the center of the rear plate  30 . Concave portions  36  recessed toward the side of the through hole  35  are provided at positions corresponding to the convex portions  26  of the case  2  at the end edge of the rear plate  30 . 
     Of the column portions  33   a  and  33   b  at the four corners of the rear plate  30 , the two column portions  33   b  on the −Y side are divided into an inner column piece  33   b   1  on the side of the through hole  35  and an outer column piece  33   b   2  on the side of the vertex of the corner. A gap  38  is provided between the inner column piece  33   b   1  and the outer column piece  33   b   2 . Positioning protrusions of the rear side spring  6  are provided at positions slightly separated on a predetermined side of each of the column portions  33   a  and  33   b  at the four corners of the rear plate  30 . A groove  336  is formed in the side surface on the +Y side of the column portion  33   a.  A plurality of rectangular holes are bored in the side plate  39 . 
     The column portions  33   a  and  33   b  have opposing surfaces  31  on the inner peripheral side. The opposing surfaces  31  are opposed to the corner surfaces  43  of the carrier  4  to be described later. The opposing surfaces  31  are plane surfaces formed on the front halves of the column portions  33   a  and  33   b,  and are provided at 90-degree intervals facing the center of the through holes  35 . 
     The FPC9 has a plate shape in which four corners of a rectangle are cut off. A plurality of components such as Hall elements  92  or lands  96  are provided on the surface of the FPC9 on the +Y side. A plurality of terminals (not shown) are provided on the surface of the FPC9 on the −Y side. The FPC9 is fixed to the side plate  39  in such a manner that the components on the surface on the +Y side thereof are accommodated in the rectangular holes of the side plate  39  of the base  3 . 
     An adhesive is applied to the concave portions  36  and grooves  336  of the base  3 , and the base  3  and the case  2  are joined by the adhesive. The convex portions  26  of the case  2  are fitted into the concave portions  36  of the base  3 . The portion of the FPC9 on the +Z side is fitted into the concave portion  29  of the side plate  22  of the case  2 , and the surface of the FPC9 on the −Y side is exposed to the outside of the case  2 . Terminals of the FPC9 are connected to the substrate on which the image sensor  12  is mounted. 
     The carrier  4  is provided with a through hole  45  for attaching the lens body  11  as an optical member, and has a rectangular outer shape when viewed from the Z direction. The carrier  4  has two pairs of side surfaces  41  and side surfaces  42  facing each other in the Y-direction and the X-direction, and corner surfaces  43  chamfered at four corners. A convex portion  48  protruding outward in the X-direction is provided on the side surface  42 . A coil  8  is wound around the convex portion  48 . The coil  8  together with the magnet  7  generates the driving force of the movable portion. 
     The corner surfaces  43  are regulated by the side surfaces  41  and the side surfaces  42  in the circumferential direction, and regulated by the recess portions  431  described later on the front side and on the rear side. The corner surfaces  43  are provided at 90-degree intervals toward the side opposite to the center of the through hole  35 . The corner surface  43  and the opposing surface  31  have approximately the same dimension in the Z direction thereof, but the opposing surface  31  is larger in the circumferential direction thereof, and they face each other in parallel. 
     As shown in  FIG. 6  and  FIG. 7 , the corner portions of the peripheral edge portion  46  of the through hole  45  on the +Z side and the −Z side are recessed toward the −Z side and the +Z side, respectively, as recess portions  431 . By allowing an arm portion  54  of a front side spring  5  and arm portions  64   a,    64   b  of rear side springs  6  described later to pass therethrough, the recess portions  431  act as escapes for the arm portion  54  and the arm portions  64   a,    64   b  when the carrier  4  moves in the optical axis direction. Further, the dimensions of the corner surfaces  43  in the Z direction are regulated. Four convex portions  461  protruding toward the +Z side and the −Z side are formed on the front surface of the peripheral edge portion  46  on the +Z side and the rear surface of the peripheral edge portion  46  on the −Z side, respectively. Each of the convex portions  461  on the +Z side and the −Z side has a shape in which the hypotenuse of a right triangle is rounded inward in accordance with the peripheral edge portion  46 . The convex portion  461  acts as a stopper in the optical axis direction of the carrier  4 . Further, positioning protrusions of the front side spring  5  and the rear side springs  6  are provided on the front surface of the peripheral edge portion  46  on the +Z side and the rear surface of the peripheral edge portion  46  on the −Z side. 
     The front side spring  5  has one inner portion  56 , four outer portions  53 , and four arm portions  54  interposed between them. The inner portion  56  is provided with a bent portion  58  bent in a U-shape on the outer side. The outer portion  53  is formed in a rectangular shape. The outer portion  53  is bored with a positioning hole. The arm portion  54  has a zigzag shape. The arm portion  54  is connected to the inner portion  56  and the outer portion  53 . 
     The inner portion  56  of the front side spring  5  is fixed to the peripheral edge portion  46  on the +Z side by fitting the positioning protrusion of the peripheral edge portion  46  on the +Z side of the carrier  4  into the bent portion  58  of the inner portion  56 . The outer portion  53  of the front side spring  5  is fixed to the front plate  20  by fitting the positioning protrusion of the front plate  20  of the case  2  into the positioning hole of the outer portion  53 . 
     The two rear side springs  6  are separated from each other on the +X side and the −X side to form a quadrangle as a whole. The two rear side springs  6  are electrically insulated from each other. Each of the two rear side springs  6  includes one inner portion  66 , two outer portions  63   a  and  63   b,  an arm portion  64   a  interposed between the inner portion  66  and the outer portion  63   a,  and an arm portion  64   b  interposed between the inner portion  66  and the outer portion  63   b.    
     The inner portion  66  is provided along the peripheral edge portion  46  of the carrier  4  and is bored with a positioning hole. In addition, it has an electrical connection portion electrically connected to the coil  8 . 
     The outer portion  63   a  is located on the +Y side, and has a shape such that one apex angle of a triangle is cut. The outer portion  63   b  is located on the −Y side, and has an outer portion piece  63   b   1  and an extension piece  63   b   2 . The outer portion  63   a  has a pentagonal shape. Positioning holes are bored in the outer portion  63   a  and the outer portion piece  63   b   1 . 
     The extension piece  63   b   2  is fitted into the gap  38  of the base  3 , extends from the base end connected to the outer portion piece  63   b   1  to the −Y side along the gap  38 , and is connected to the land  96  of the FPC9. 
     The arm portions  64   a  and  64   b  have a zigzag shape. The arm portion  64   a  is connected to the inner portion  66  and the outer portion  63   a,  and the arm portion  64   b  is connected to the inner portion  66  and the outer portion  63   b.    
     The inner portion  66  of the rear side spring  6  is fixed to the peripheral edge portion  46  on the −Z side by fitting the positioning protrusion of the peripheral edge portion  46  on the −Z side of the carrier  4  into the positioning hole of the inner portion  66 . The outer portion  63  of the rear side spring  6  is fixed to the rear plate  30  by fitting the positioning protrusion of the rear plate  30  of the base  3  into the positioning hole of the outer portion  63   a.  The extension piece  63   b   2  is fitted into the gap  38 . 
     The two coils  8  are formed by one coil wire, respectively, and both ends are electrically connected to the electrical connection portions of the rear side spring  6 , respectively. The tip ends of the two extension pieces  63   b   2  of the rear side spring  6  are electrically connected to the lands  96  of the FPC9, respectively. Thereby, an electric current path of the external power source→the terminal of the FPC9→the land  96  of the FPC9 on the +X side→the rear side spring  6  on the +X side→the coil  8  on the +X side→the coil  8  on the −X side→the rear side spring  6  on the −X side→the land  96  of the FPC9 on the −X side→the terminal of the FPC9→the external power source is formed, and electric current is supplied to the coil  8 . 
     As shown in  FIG. 6  and  FIG. 7 , the corner surfaces  43  of the carrier  4  and the opposing surfaces  31  of the column portions  33   a  and  33   b  facing the corner surfaces  43  confront with each other in parallel, and viscoelastic resin  100  is provided between the corner surfaces  43  and the opposing surfaces  31 . The viscoelastic resin  100  is a so-called damper gel. With the damper gel, vibration generated in the carrier  4  supported by the housing  10  via the front side spring  5  and the rear side spring  6  is quickly converged. 
     The above is the details of the configuration of the present embodiment. The optical member driving device  1  according to the present embodiment includes: a carrier  4  provided with a through hole  45  for mounting an optical member and having a rectangular outer shape; a housing  10  having a front plate  20  and a rear plate  30  opposite each other with the carrier  4  sandwiched therebetween, and a plurality of column portions  33   a  and  33   b  rising from the rear plate  30  toward the front plate  20 ; and a front side spring  5  and a rear side spring  6  arranged between the carrier  4  and the housing  10 . Chamfered corner surfaces  43  are provided at four corners of the carrier  4 , and viscoelastic resin  100  is provided between the corner surfaces  43  and the opposing surfaces  31  of the column portions  33   a  and  33   b  facing the corner surfaces  43 . Vibration suppression effect is exhibited by the viscoelastic resin  100  between the corner surfaces  43  and the opposing surfaces  31 . Further, since the shape of the carrier  4  is obtained by chamfering the four corners of the rectangle only, the carrier  4  is relatively easily manufactured. Therefore, it is possible to provide an optical member driving device  1 , a camera device  15  and an electronic apparatus, which can exhibit stable vibration suppression effect and are easily manufactured. 
     It is to be noted that at least one of the corner surfaces  43  and the opposing surfaces  31  may be a curved surface instead of a plane surface. In addition, the surface may be rough. It is not necessary to provide the viscoelastic resin  100  all between each of the corner surfaces  43  and the opposing surfaces  31 , and may be provided so as to obtain an appropriate vibration suppression effect. Further, the size of the corner surfaces  43  and the opposing surfaces  31  and the distance therebetween may be appropriately designed.