Patent Publication Number: US-11653080-B2

Title: Optical member driving device, camera device and electronic apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Chinese patent application CN202010905485.4, filed on Sep. 1, 2020, 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 
     A camera device with a sensor shift OIS (Optical Image Stabilizer) function includes a fixed portion with a lens device and a movable portion with an image sensor, and drives the movable portion in a direction orthogonal to the optical axis of the lens device in the fixed portion or around the optical axis. 
       FIG.  9    is a diagram showing an example of a configuration of this type of conventional camera device. This camera device has an AF motor  810  which is a lens device, a case  820 , support plate springs  830 , a holder  840 , a plate  850 , magnets  860 , suspension wires  870 , a coil substrate  880 , an FPC  890 , an image sensor  900 , a sensor substrate  910 , a frame body  920 , and a bottom board  930 . The AF motor  810 , the case  820 , the holder  840 , the plate  850 , the magnets  860 , the frame body  920 , and the bottom board  930  constitute a fixed portion. The coil substrate  880 , the FPC  890 , the image sensor  900 , and the sensor substrate  910  constitute a movable portion. The support plate springs  830  and the suspension wires  870  support the movable portion with respect to the fixed portion. 
     In this camera device, the FPC  890  is attached on the rear side of the coil substrate  880 , and is bent to the front side to form a box shape. The movable portion moves in the X direction or the Y direction when current is supplied to coil of the coil substrate  880 . 
     However, in this type of conventional camera device, when the movable portion moves in the X direction or the Y direction, the circumferential portion of the coil substrate comes into contact with the FPC, and there is a problem that the smooth movement of the movable portion is hindered. 
     SUMMARY 
     One of objects of the present disclosure is to provide an optical member driving device with a movable portion capable of moving smoothly, a camera device and an electronic apparatus. 
     In accordance with a first aspect of the present disclosure, there is provided an optical member driving device including: a fixed portion with an accommodation space for accommodating a lens device; a movable portion which includes a holding portion for holding an image sensor and is supported by a suspension wire at a position on a rear side of the lens device. The fixed portion has a case surrounding a periphery of the movable portion, the movable portion has a coil substrate on which a coil is formed. The coil substrate has a main body portion and stopper portions projecting outward from a circumference of the main body portion, and the stopper portions are directly opposed to an inner surface of the case. 
     In accordance with a second aspect of the present disclosure, there is provided a camera device including the optical member driving device described above. 
     In accordance with a third aspect of the present disclosure, there is provided an electronic apparatus including the camera device described above. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a front view of a smartphone on which a camera device is mounted, the camera device including an optical member driving device according to an embodiment of the present disclosure; 
         FIG.  2    is a perspective view of the optical member driving device of  FIG.  1   ; 
         FIG.  3    is an exploded perspective view of the optical member driving device of  FIG.  2   ; 
         FIG.  4    is a perspective view in which the case and the bottom board are removed from  FIG.  2   ; 
         FIG.  5    is a cross-sectional perspective view of the optical member driving device of  FIG.  2   ; 
         FIG.  6    is a bottom view in which the bottom board is removed from the optical member driving device of  FIG.  2   ; 
         FIG.  7    is a cross-sectional perspective view in which only the coil substrate and the FPC are left from  FIG.  2   ; 
         FIG.  8    is a perspective view in which only the holder and the magnets are left from  FIG.  2   ; and 
         FIG.  9    is an exploded perspective view of a conventional camera device. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG.  1   , a camera device  101  including an optical member driving device  100  according to one embodiment of the present disclosure is accommodated in a housing of a smartphone  109 . The camera device  101  has an AF (Auto Focus) motor  102  as a lens device, an image sensor  107  as an optical member, and the optical member driving device  100 . The AF motor  102  has a lens body  110 , and an actuator driving the lens body  110  in a direction parallel to the optical axis of the lens body  110 . The image sensor  107  converts the light guided via the lens body  110  into an image signal and outputs the image signal. The optical member driving device  100  fixes the AF motor  102  and the image sensor  107 , and drives the image sensor  107  in a direction orthogonal to the optical axis of the lens body  110  of the AF motor  102  and in a direction rotating around the optical axis. As the lens device, it is not necessary to have an actuator that drives in a direction parallel to the optical axis of the lens body  110 . 
     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. A+Z side, which is the side of the subject viewed from the lens body  110 , may be referred to as a front side, and a−Z side, which is the opposite side (image sensor  107  side), may be referred to as a rear side. 
     As shown in  FIG.  3   , the optical member driving device  100  has a case  1 , four suspension wires  2 , four support plate springs  3 , a holder  4 , four magnets  5 , a coil substrate  6 , an FPC (Flexible printed circuits)  7 , four driver ICs  8 , and a bottom board  9 . Among these members, the case  1  and the bottom board  9  are combined as a housing, and the suspension wires  2 , the support plate springs  3 , the holder  4 , the magnets  5 , the coil substrate  6 , the FPC  7 , and the driver ICs  8  are accommodated in this housing. 
     The case  1 , the bottom board  9 , the holder  4 , and the magnets  5  constitute a fixed portion, and the coil substrate  6 , the FPC  7 , and the driver ICs  8  constitute a movable portion. The support plate springs  3  and the suspension wires  2  connect the fixed portion and the movable portion and support the movable portion. The AF motor  102  is accommodated and fixed in an accommodation space formed by a frame-shaped holder  4  constituting the fixed portion. The image sensor  107  is placed on a sensor substrate (not shown) and the sensor substrate is fixed to the rear surface of the FPC  7 . The rear surface of the FPC  7  corresponds to a holding portion that holds the image sensor  107 . 
     As shown in  FIG.  6   , the coil substrate  6  has a main body portion  600 , first stopper portions  610  and second stopper portions  620  that protrude outward from the circumference of the main body portion  600 . A rectangular through hole  69  is provided in the center of the main body portion  600  of the coil substrate  6 , and both the outer shape and the inner shape thereof have a quadrangular annular shape. Two coils  65  are provided on each side portion of the quadrangle of the main body portion  600 . The FPC  7  is formed by bending one point-symmetrical thin plate into a three-dimensional shape. The FPC  7  has a main body portion  70  and two connecting portions  71  arranged point-symmetrically. A rectangular through hole  79  is provided in the center of the main body portion  70  of the FPC  7 , and both the outer shape and the inner shape thereof have a quadrangular annular shape. The coil substrate  6  is fixed to the front surface of the main body portion  70 . 
     As shown in  FIG.  7   , in the two connecting portions  71  of the FPC  7 , the base end portions  73  rise to the front side from predetermined positions of the side portions on the +X side and the −X side of the main body portion  70 . The base end portion  73  where the connecting portion  71  of the FPC  7  rises is opposed to the side surface of the main body portion  600  of the coil substrate  6  and an adhesive is interposed therebetween. That is, the base end portion  73  is adhered and fixed to the coil substrate  6  with the adhesive. This adhesive may be squeezed out to the front side from the gap between the base end portion  73  of the FPC  7  and the circumference of the coil substrate  6 . This predetermined position is a position close to one corner portion of predetermined diagonal corners, and the predetermined diagonal corners are a corner portion on the +X+Y side and a corner portion on the −X−Y side. The connecting portion  71  extends along each side portion toward the side opposite to the predetermined diagonal corner, and when it reaches the corner portion with the adjacent side portion, it extends along this adjacent side portion and falls to the rear side at a predetermined position. This predetermined position is a position close to the other corner portion of the predetermined diagonal corners. The connecting portion  71  that fell to the rear side is bent toward the outside in the Y direction at the same height as the bottom board  9  and projects to the outside of the case  1  through the gap between the rear edge of the case  1  and the bottom board  9 . In this way, the FPC  7  covers the outside of the holder  4  except for the predetermined diagonal portions. As shown in  FIG.  4   , the rear edge of the portion extending along the two side portions of the connecting portion  71  is entirely in front of the coil substrate  6 . 
     The connecting portion  71  has a T-shaped tip end at a portion projecting to the outside of the case  1 , and a plurality of connecting terminals are provided on the rear surface of this T-shaped portion. Each side portion of the quadrangle of the main body portion  70  is provided with a driver IC  8 . The driver IC  8  is fixed to the rear surface of the FPC  7  at a position directly behind the coil  65  of each side portion closer to the predetermined diagonal corner of the quadrangle. Further, the sensor substrate to which the image sensor  107  is attached is attached to the rear surface of the main body portion  70 , and the light receiving surface of the image sensor  107  is exposed forward from the through hole  79 . The coil  65  and the image sensor  107  are electrically connected to the main body of the smartphone  109  via the FPC  7 . 
     As described above, the first stopper portions  610  and the second stopper portions  620  are provided so as to project outward from the circumference of each side portion of the main body portion  600  of the coil substrate  6 . Each of the first stopper portions  610  and the second stopper portions  620  is directly opposed to the inner surface of the case  1 . Conversely, the base end portions  73  of the connecting portions  71  of the FPC  7  and the portions where the connecting portions  71  fall are between the outer peripheral surface of the main body portion  600  of the coil substrate  6  and the inner surface of the case  1 . The two stopper portions  610 ,  620  project outward from positions where the FPC  7  does not exist on the outer periphery. The base end portions  73  are opposed to the side surface of the main body portion  600  of the coil substrate  6 , and are located inside the outside ends of the two stopper portions  610 ,  620 . The first stopper portion  610  is provided in an area between the other diagonal corner that is not the predetermined diagonal corner and the front side where the FPC  7  exists on the outer periphery, and the second stopper portion  620  is provided in an area between the predetermined diagonal corner and the front side where the FPC  7  exists on the outer periphery. When the movable portion moves in the XY direction and rotates around the Z axis, the first stopper portions  610  and the second stopper portions  620  abut the inner surface of the case  1  prior to any other portions of the movable portion. To ensure the movement, the first stopper portions  610  and the second stopper portions  620  are desirably provided in the vicinity of the corner portions. The functions of the first stopper portions  610  and the second stopper portions  620  as stoppers can be exerted by only one of them. However, by adopting a structure in which the base end portion  73  of the FPC  7  is sandwiched between the first stopper portions  610  and the second stopper portions  620 , it is possible to prevent the base end portion  73  from abutting against the inner surface of the case  1  prior to the first stopper portions  610  and the second stopper portions  620  during the movement. Further, an electrical connection portion  621  electrically connected to the main body portion  70  of the FPC  7  is provided on the rear surface of the second stopper portion  620 . 
     The holder  4  is a quadrangular frame-shape body when viewed in the Z direction and has two pairs of wall portions  41  opposed to each other in the X direction and the Y direction. There are notches  43  inwardly cut in a quarter arc shape on the outer surface of the corners where the wall portions  41  intersect. On the front surface of the wall portion  41 , there is provided a stand portion  480  protruding to the front side in two steps from the corner portion toward the center of the side portion. The stand portion  480  has a central foremost surface  481  and middle step surfaces  482  on both sides thereof. 
     A positioning protrusion  413  is provided in the center of the foremost surface  481  of the stand portion  480  of the wall portion  41  opposed to the X direction, and two protruding portions  414  are provided on both sides of the positioning protrusion  413  in the Y direction. The positioning protrusion  413  directly rises from a groove formed around it in an annular shape. The foremost surface  481  of the stand portion  480  of the wall portion  41  opposed to the Y direction is divided on both sides with a central recess  420  in between, and two protruding portions  414  are provided on both sides of the recess  420  in the X direction. Further, small protrusions  46  are provided on eight middle step surfaces  482  of the stand portions  480  of the wall portion  41 , respectively. 
     As shown in  FIG.  2   , the holder  4  is covered by the case  1 . The case  1  has a box shape, and has a quadrangular front board  10  when viewed from the Z direction and side boards  11  extending rearward from respective edges of the front board  10 . A rectangular through hole  19  is provided in the center of the front board  10  covering the front side of the holder  4  in the case  1 . The shape and size of the through hole  19  are substantially the same as the shape and size of the inner shape of the wall portion  41  of the holder  4 . When the AF motor  102  is accommodated in the holder  4 , the front side of the AF motor  102  is exposed from the through hole  19 . A recessed portion  180  recessed rearward at a position in the center of each side portion of the quadrangle is provided in the front board  10 . Each recessed portion  180  are provided with two through holes  14  along the side portion. The recessed portions  180  on the +X side and the −X side are each further provided with a positioning hole  13 , and the positioning hole  13  is located in the middle of the two through holes  14 . 
     The positioning protrusion  413  of the holder  4  is fitted into the positioning hole  13  of the front board  10  of the case  1 . At that time, the stand portion  480  and the rear surface of the recessed portion  180  abut against each other, and the rear surface of the recessed portion  180  is less likely to float with respect to the stand portion  480  due to the groove around the positioning protrusion  413 . The protruding portion  414  of the holder  4  is inserted into the through hole  14  of the front board  10  of the case  1 , and is fixed by thermal caulking. As shown in  FIG.  5   , since the width of the protruding portion  414  is wider than the width of the through hole  14  on the front side of the through hole  14  in the protruding portion  414 , the holder  4  is less likely to be separated from the case  1 . The wide width corresponds to the large diameter when the cross section after thermal caulking is circular. In addition, the front end of the protruding portion  414  is located behind the front board  10  of the portion adjacent to the recessed portion  180 . 
     As shown in  FIG.  4    and  FIG.  8   , an eaves portion  45  is provided on the inner surface of the wall portion  41  of the holder  4 . The eaves portion  45  projects inward from the rear end of the inner surface of the wall portion  41  and is provided with a first projecting portion that projects rearward from the inner end of the eaves portion  45 . The AF motor  102  is accommodated in a space surrounded by the inner surface of the wall portion  41  and the front surface of the eaves portion  45  in the holder  4 . The outer surface of the AF motor  102  is adhesively fixed to the inner surface of the wall portion  41 . 
     The rear surface of the wall portion  41  of the holder  4  adhesively fixes the front surface of the magnet  5 . The magnet  5  has an elongated rectangular parallelepiped shape and is provided along the wall portion  41 . There is a coil substrate  6  on the rear side of the magnet  5 . The magnet  5  and the coil  65  on the coil substrate  6  are opposed to each other at an interval. It is desirable that the outer surface of the wall portion  41 , which is also the outer surface of the holder  4 , and the outer surface of the magnet  5  are parallel and flush with each other. The corner between the rear surface of the holder  4  which is the adhesion surface adhered to the magnet  5 , and the outer surface is chamfered, and an inclined surface  453  is provided. In addition, the corner between the front surface which is the adhesion surface of the magnet  5  adhered to the holder  4 , and the outer surface is chamfered, and an inclined surface  52  is provided. The adhesive between the wall portion  41  and the magnet  5  on the contact surfaces is squeezed to these chamfered portions to form an adhesive accumulation. That is, a sufficient amount of adhesive is supplied between the rear surface of the holder  4  and the front surface of the magnet  5 , and the excess adhesive can be accommodated in the space formed by the two inclined surfaces  453  and  52 . However, the adhesive should not be squeezed out beyond the outer surfaces of the holder  4  and the magnet  5 . In addition, an adhesive is interposed between the surface facing the outside of the first projecting portion  451  and the inner surface of the magnet  5 , and the magnet  5  is also adhesively fixed by the first projecting portion  451 . In addition, the magnet  5  has two peripheral end surfaces  51  intersecting the front surface and the outer surface, and the holder  4  has two second projecting portions  452  projecting rearward from the rear surface and sandwiching the magnet  5 . An adhesive is interposed between each peripheral end surface  51  and the opposing surface of the second projecting portion  452  opposed to the peripheral end surface  51 , and the magnet  5  is also adhesively fixed by the second projecting portion  452 . In addition, as shown in  FIG.  5   , a recessed groove  454 , which is an adhesive receiving portion, recessed to the front side is provided at a position on the rear surface of the holder  4  where the magnet  5  is adhesively fixed. 
     The portion of the holder  4  excluding the corner portions on the +X+Y side and the −X−Y side is surrounded by the connecting portions  71  of the FPC  7 . The corner portions of the holder  4  on the +X+Y side and the −X−Y side are exposed to the outside without being surrounded by the connecting portions  71 . 
     As shown in  FIG.  3    and  FIG.  4   , the support plate spring  3  has an approximately L-shape. Round holes are provided in the base end portion of the support plate spring  3  and tip end portions of the tips divided at a right angle and extending from the base end portion. 
     The tip end portion of the support plate spring  3  is fixed on the middle step surface  482  of the stand portion  480  of the holder  4 . The small protrusion  46  of the middle step surface  482  of the stand portion  480  is fitted into the round hole of the tip end portion of the support plate spring  3 . The base end portion of the support plate spring  3  is in a state of floating on the front side of the notch  43  of the holder  4 . In the four corners of the coil substrate  6 , there are round holes at positions corresponding to the round holes of the tip end portions of the support plate springs  3 . 
     The suspension wire  2  passes through the notch  43  of the holder  4  and is suspended between the round hole of the base end portion of the support plate spring  3  and the round hole of the coil substrate  6 . That is, the front ends of the suspension wires  2  are inserted and soldered in the round holes of the base end portions of the support plate springs  3 , and the rear ends are inserted and soldered in the round holes of the four corners of the coil substrate  6 . In addition, at each of the corner portions on the +X+Y side and the −X−Y side, which are the predetermined diagonal corners exposed from the FPC  7 , the peripheral end surfaces  51  which are the side surfaces of the end portions of two magnets  5  facing the top of each corner portion constitute opposing surfaces opposed to each other at right angles. Each peripheral end surface  51  and the front surface, which is the surface facing the front side of the coil substrate  6  of the movable portion, are bridged by a resin having viscoelasticity. The resin with viscoelasticity used in this embodiment is, e.g., a so-called damper gel. The peripheral end surfaces  51  to be bridged include the peripheral end surface  51  of the magnet  5  on the +Y side facing the +X direction, the peripheral end surface  51  of the magnet  5  on the −Y side facing the −X direction, the peripheral end surface  51  of the magnet  5  on the +X side facing the +Y direction, and the peripheral end surface  51  of the magnet  5  on the −X side facing the −Y direction. Therefore, the damping effect can be obtained for both the X direction and the Y direction. 
     The details of the configuration of the present embodiment have been described above. The optical member driving device  100  in the present embodiment includes: a fixed portion having an accommodation space for accommodating the AF motor  102  which is a lens device; and a movable portion that has a holding portion for holding the image sensor  107  and is supported at a position on the rear side of the AF motor  102  by the suspension wires  2 . The fixed portion has a case  1  surrounding the periphery of the movable portion. The movable portion has a coil substrate  6  on which a coil  65  is formed. The coil substrate  6  has a main body portion  600  and stopper portions  610 ,  620  projecting outward from a circumference of the main body portion  600 . The stopper portions  610 ,  620  are directly opposed to an inner surface of the case  1 . Thus, since the stopper portions  610 ,  620  are directly opposed to the inner surface of the case  1  and there is nothing that hinders the movement of the movable portion, it is possible to provide an optical member driving device  100  in which the movable portion can move smoothly. 
     In addition, in the embodiment described above, the peripheral end surfaces  51  facing the corner portion on the +X−Y side and the corner portion on the −X−Y side and the front surface of the coil substrate  6  may not be bridged by the resin having viscoelasticity. In addition, it is not necessary that the peripheral end surfaces  51  are bridged, and for example, the surfaces of the second projecting portions  452  of the holder  4  facing the top of the corner portion may be bridged. In that case, the second projecting portions  452  may extend up to the rear side further than that shown in the figure. In addition, it is not necessary that the movable portion to be bridged is the coil substrate  6 , and for example, the FPC  7  may be provided on the front side of the coil substrate  6  to bridge the FPC  7 . 
     It is to be noted that, in the embodiment described above, it is not necessary to provide two protruding portions  414  of the holder  4  and two through holes  14  of the case  1  on each side portion of the through hole  19 , and the protruding portions  414  of the holder  4  and the through holes  14  of the case  1  may be provided only on two opposing side portions, and one or three or more protruding portions  414  of the holder  4  and one or three or more through holes  14  of the case  1  may be provided on each side portion. In addition, in one pair of opposing side portions, it is desirable that the number of the protruding portions  414  in each side portion is the same, but the number of the protruding portions  414  may be different between different opposing side portions. 
     In addition, in the embodiment described above, the caulking fixing of the protruding portions  414  of the holder  4  to the through holes  14  of the case  1  and the adhesive may be used in combination, and the case  1  and the holder  4  may be adhered to each other with the adhesive. In that case, the adhesive may be interposed between the front surface of the holder  4  and the rear surface of the front board  10  of the case  1 .