Patent Publication Number: US-2021181456-A1

Title: Lens driving device, camera device, and electronic apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/151,386, filed on Oct. 4, 2018, entitled “LENS DRIVING DEVICE, CAMERA DEVICE, AND ELECTRONIC APPARATUS”, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a lens driving device, a camera device, and an electronic apparatus. 
     BACKGROUND ART 
     A small-sized camera is mounted on an electronic apparatus, e.g., a mobile phone or a smart phone. As this type of small-sized camera, for example, as disclosed in US 2015/049209, there is known a small-sized camera having an image stabilization function. 
     SUMMARY 
     In US 2015/049209, the camera includes a lens support configured to support a lens, and a frame member surrounding a periphery of the lens support. In order to support the lens support so as to be freely movable in a direction orthogonal to an optical axis direction of the lens relative to the frame member, a plurality of balls are used. Further, the related-art lens driving device includes a magnet and a magnetic member provided so as to be opposed to the magnet. An attraction force generated between the magnet and the magnetic member causes the balls to be sandwiched between the lens support and the frame member. 
     However when a force larger than the attraction force between the magnet and the magnetic member is applied due to, for example, falling, the lens support may be separated from the balls, and then the lens support may hit the balls again. The frame member that is brought into point contact with the balls receives the impact, and thus there have been problems in that a dent or a crack may occur in a ball hitting part and smooth movement of the lens support may not be ensured. 
     The present invention has been nude to solve the above-mentioned problems in the related art, and has an object to provide a lens driving device, a camera device, and an electronic apparatus, which are capable of ensuring smooth movement of a lens support. 
     In one aspect of the prevent invention is a lens driving device. The lens driving device includes: a lens support configured to support a lens; a first moving member plate and a second moving member plate that surround around a periphery of the lens support, wherein the first moving member plate is supported so as to be freely movable relative to the second moving member plate by a first support mechanism that includes a first support protrusion and a first guide recess into which the first support protrusion is fitted, the lens support is supported so as to be freely movable relative to the first moving member plate by a second support mechanism that includes a second support protrusion and a second guide recess into which the second support protrusion is fitted, no guide recesses are formed on the first moving member plate while both the first support protrusion of the first support mechanism and the second support protrusion of the second support mechanism are formed on the first moving member plate so that the first support protrusion protrudes from the first moving member plate towards one side of an optical axis direction of the lens and that the second support protrusion protrudes from the first moving member plate towards another side of the optical axis direction, the first guide recess of the first support mechanism is formed on the second moving member plate so as to be recessed toward the one side of the optical axis direction, and the first guide recess has two side surfaces expanding along the optical axis direction so as to oppose to each other, and a bottom surface that connects the two side surfaces, the second guide recess of the second support mechanism is formed on the lens support so as to be recessed toward another side of the optical axis direction, and the second guide recess has two side surfaces expanding along the optical axis direction so as to oppose to each other, and an upper surface that connects the two side surfaces. 
     Preferably, the first support protrusion and the first guide recess are in contact each other at an ends thereof in the optical axis direction, and the second support protrusion and the second guide recess are in contact each other at an ends thereof in the optical axis direction. 
     Preferably, the first moving member plate and the second moving member plate are in contact only at the first support protrusion and the first guide recess. 
     Preferably, the lens support and the first moving member plate are in contact only at the second support protrusion and the second guide recess. 
     Preferably, the lens support is provided with a magnet that generates a driving force for movement, the second moving member plate is provided with a magnetic member so as to generate an attraction force between the magnet and the magnetic member along the optical axis direction through intermediation of the second moving member plate. 
     Preferably, the second moving member plate has a rectangular bottom plate having four corners, a protrusion that protrudes toward the optical axis direction is provided on each four corner of the rectangular bottom plate, a cover is fixed to a distal end of the protrusion, and a gap is formed between the cover and the lens support in the optical axis direction. 
     Preferably, the first support mechanism and the second support mechanism are provided on each corner of rectangular outer profiles of the lens support, the first moving member plate, and the second moving member plate when viewing from the optical axis direction, and the first support mechanism and the second support mechanism are overlaid each other at each corner of the rectangular outer profiles. 
     Preferably, the first support protrusion is in contact with the two side surfaces and the bottom surface of the first guide recess, and the second support protrusion is in contact with the side surfaces of the upper surface of the second guide recess. 
     Another aspect of the present invention is a camera device. The camera device includes: the lens driving device of the above aspects; and a lens supported by the lens support. 
     Another aspect of the present invention is an electronic apparatus. The electronic apparatus includes the camera device of the above aspect. 
     According to the present invention, the first and the second support protrusion and the first and the second guide recess extend in the direction orthogonal to the optical axis direction of the lens, and the first and the second support protrusion are in contact with the first and the second guide recess respectively at least at two points in the cross section in the optical axis direction of the lens. Therefore, the lens support or the frame member receives less impact in the optical axis direction of the lens, and the smooth movement of the lens support can be ensured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view for illustrating a camera device according to a first embodiment of the present invention as viewed obliquely from above. 
         FIG. 2  is an exploded perspective view for illustrating a moving member used in the camera device according to the first embodiment of the present invention as viewed obliquely from above. 
         FIG. 3  is an exploded perspective view for illustrating the moving member used in the camera device according to the first embodiment of the present invention as viewed obliquely from below. 
         FIG. 4  is an exploded perspective view for illustrating a part of a fixed member used in the camera device according to the first embodiment of the present invention as viewed obliquely from above. 
         FIG. 5  is a perspective view for illustrating a flexible printed board used in the camera device according to the first embodiment of the present invention. 
         FIG. 6  is an X-direction sectional view for illustrating the moving member used in the camera device according to the first embodiment of the present invention. 
         FIG. 7  is a Y-direction sectional view for illustrating the moving member used in the camera device according to the first embodiment of the present invention. 
         FIG. 8  is a sectional view for illustrating the camera device according to the first embodiment of the present invention. 
         FIG. 9  is a sectional view for illustrating the camera device according to the first embodiment of the present invention, which is taken along the line A-A of  FIG. 8 . 
         FIG. 10  is a sectional view for illustrating the camera device according to the first embodiment of the present invention, which is taken along the line B-B of  FIG. 8 . 
         FIG. 11  is a sectional view for illustrating a periphery of a first support mechanism in a camera device according to a second embodiment of the present invention. 
         FIG. 12  is a sectional view for illustrating a periphery of a second support mechanism in the camera device according to the second embodiment of the present invention. 
         FIG. 13  is a sectional view for illustrating a periphery of a first support mechanism in a camera device according to a third embodiment of the present invention. 
         FIG. 14  is a sectional view for illustrating a periphery of a second support mechanism in the camera device according to the third embodiment of the present invention. 
         FIG. 15  is an XY-direction sectional view for illustrating a first support mechanism in a camera device according to a fourth embodiment of the present invention. 
         FIG. 16  is an XY-direction sectional view for illustrating a first support mechanism in a camera device according to a fifth embodiment of the present invention. 
     
    
    
     EXEMPLARY EMBODIMENT OF THE PRESENT INVENTION 
     Embodiments of the present invention are described with reference to the drawings. 
       FIG. 1  to  FIG. 10  are illustrations of a first embodiment of the present invention. 
       FIG. 1  is an illustration of a camera device  10  according to the first embodiment of the present invention. The camera device  10  includes a lens driving device  12  and a lens  14  mounted to the lens driving device  12 . 
     The lens driving device  12  includes a fixed member  16  and a moving member  18  supported so as to be freely movable relative to the fixed member  16 . As illustrated in  FIG. 2  and  FIG. 3 , the moving member  18  includes a lens support  20  and a first frame member  22  surrounding the lens support  20 . The lens support  20  and the first frame member  22  each have a substantially quadrangular outer shape as viewed from above. 
     For the sake of convenience, an optical axis direction of the lens  14  is herein referred to as “Z direction”, a direction orthogonal to the optical axis direction is referred to as “X direction”, and a direction orthogonal to the Z direction and the X direction is referred to as “Y direction”. Further, an object side of an optical axis is referred to as “upper side”, and a side which is opposite to the upper side and on which an image sensor (not shown) is to be arranged is referred to as “lower side”. 
     The lens support  20  has a lens mounting hole  24 . The lens mounting hole  24  has a circular shape as viewed from the direction and is formed on the inner side of the lens support  20 . The lens  14  is mounted to the lens mounting hole  24 . 
     The first frame member  22  includes a first moving member plate  26 , a second moving member plate  28 , and a first cover  30 . The lens support  20 , the first moving member plate  26 , and the second moving member plate  28  are each made of engineering plastics such as liquid crystal polymer (LCP), polyacetal, polyamide, polycarbonate, modified polyphenylene ether, and polybutylene terephthalate. Further, the first cover  30  is made of, for example, a metal. The first moving member plate  26 , the second moving member plate  28 , and the first cover  30  have openings  32 ,  34 , and  36 , respectively, for allowing passage of light therethrough. The openings  32 ,  34 ,  36  are each formed in a substantially circular shape. 
     The first frame member  22  supports the lens support  20  so as to be freely movable in the Y direction and the X direction. That is, the first frame member  22  includes an orthogonal-direction support mechanism  38 , and is configured so that the lens support  20  is freely movable in XY directions via the orthogonal-direction support mechanism  38 . 
     The orthogonal-direction support mechanism  38  includes a first support mechanism  40  and a second support mechanism  42  that are provided away from each other in the Z direction. The first support mechanism  40  is provided on the lower side in the Z direction, and as illustrated in  FIG. 6  and  FIG. 7 , includes a first support portion  44  formed so as to protrude on a lower surface of the first moving member plate  26  and a first guiding portion  46  formed so as to be recessed in an upper surface of the second moving member plate  28 . The first support portion  44  is fitted to the first guiding portion  46 . The first support portion  44  and the first guiding portion  46  extend in the X direction, and are formed in the vicinity of each of four corner portions of the first moving member plate  26  and the second moving member plate  28 . The first support portion  44  and the first guiding portion  46  extending in the X direction are fitted to each other so as to regulate movement in the Y direction, and hence the first moving member plate  26  is freely movable only in the X direction relative to the second moving member plate  28 . The first support portion  44  and the first guiding portion  46  are surrounded by three orthogonal lines in a cross section (see  FIG. 7 ) taken along the Z direction in the Y direction, and are brought into surface contact with each other in three planes (opposed side surfaces and lower surface) in the X direction. 
     The second support mechanism  42  is provided on the upper side in the Z direction, and as illustrated in  FIG. 6  and  FIG. 7 , includes a second support portion  48  formed so as to protrude on an upper surface of the first moving member plate  26  and a second guiding portion  50  formed so as to be recessed in a lower surface of the lens support  20 . The second support portion  48  is fitted to the second guiding portion  50 . The second support portion  48  and the second guiding portion  50  extend in the Y direction, and are formed in the vicinity of each of four corner portions of the lens support  20  and the first moving member plate  26 . The second support portion  48  and the second guiding portion  50  extending in the Y direction are fitted to each other so as to regulate movement in the X direction, and hence the lens support  20  is freely movable only in the Y direction relative to the first moving member plate  26 . The second support portion  48  and the second guiding portion  50  ate surrounded by three orthogonal lines in a cross section (see  FIG. 6 ) taken along the Z direction in the X direction, and are brought into surface contact with each other in three planes (opposed side surfaces and upper surface) in the X direction. 
     At each of four corners of the first cover  30 , a mounting portion  52  is provided so as to extend downward in the Z direction. The mounting portion  52  has a quadrangular mounting hole  54 . Further, at each of four corners of the second moving member plate  28 , a mounted portion  56  is formed so as to laterally protrude. The mounted portion  56  is fitted to the mounting hole  54 , so that the first cover  30  is fixed to the second moving member plate  28 . Between a lower surface of the first cover  30  and the upper surface of the lens support  20 , as illustrated in  FIG. 6  and  FIG. 7 , there is ensured a necessity minimum gap including an error caused bye a tolerance or the like so as to regulate movement of the lens support  20  or the first moving member plate  26  in the Z direction relative to the second moving member plate  28 . 
     On the outer side of the lens support  20 , first magnets  58  are fixed on two surfaces in the X direction and one surface in the Y direction. Each of the first magnets  58  and  58  on the two surfaces in the X direction has an S pole and an N pole formed in the X direction. Further, the first magnet  58  on the one surface in the Y direction has an S pole and an N pole formed in the direction. 
     Further, on two surfaces in the X direction in a lower surface of the second moving member plate  28 , first magnetic members  60  and  60  made of a magnetic substance are provided. The first magnetic members  60  and  60  are opposed in the Z direction to the first magnets  58  and  58  on the two surfaces in the X direction through intermediation of the second moving member plate  28 . An attraction force is generated between the first magnetic members  60  and  60  and the first magnets  58  and  58 . Therefore, the lens support  20  and the first moving member plate  26  are attracted through intermediation of the second moving member plate  28 , and Z-direction contact is maintained between the first support portion  44  and the first guiding portion  46  and between the second support portion  48  and the second guiding portion  50 . 
     Further, on the second moving member plate  28 , a second magnet  62  is fixed on an outer surface on the opposite side of the surface on which the first magnet  58  is provided in the Y direction. The second magnet  62  is divided into two pieces in the Z direction. Each of the two pieces has an S pole and an N pole formed in the Y direction, and opposite polarities are provided in the vertical direction. 
     Next, a relationship between the fixed member  16  and the moving member  18  is described. 
     Referring back to  FIG. 1 , the fixed member  16  includes a second frame member  64 . The second frame member  64  surrounds the periphery of the first frame member  22  of the moving member  18 . The second frame member  64  includes a base  66  and a second cover  68 . Each of the base  66  and the second cover  68  is made of a resin or a non-magnetic metal, and has a square shape as viewed from above. The second cover  68  is fitted to the outer side of the base  66  to form the second frame member  64 . Further, the base  66  and the second cover  68  have through holes  70  and  72 , respectively, for allowing passage of light or insertion of the lens  14  therethrough. 
     Further, as illustrated in  FIG. 4 , an opening portion  74  is formed through each of four side surfaces of the base  66 . A flexible printed board  76  is arranged so as to surround the outer side of the base  66  and surround the opening portions  74 . That is, as illustrated in  FIG. 4  and  FIG. 5 , the flexible printed board  76  is bent into a quadrangular shape so as to surround the outer shape of the base  66 , and at a lower portion of the flexible printed board  76 , a first terminal portion  78  and a second terminal portion  80  are formed. The second terminal portion  80  is opposed to the first terminal portion  78  in the Y direction. Energization to a first coil  82  to be described later is controlled is the first terminal portion  78 , and energization to a second coil  84  to be described later is controlled via the second terminal portion  80 , but the present invention is not limited thereto. 
     On the inner side of the flexible printed board  76 , the first coils  82  are fixed on two surfaces in the X direction and one surface in the Y direction. Further, the second coil  84  is fixed on another surface in the Y direction on the inner side of the flexible printed board  76 . Further, on the inner side of the flexible printed board  76 , an X-direction position detecting element  86  is arranged inside one first coil  82  in the X direction, a Y-direction position detecting element  88  is arranged inside the first coil  82  in the Y direction, and a Z-direction position detecting element  90  is arranged on the lateral side of the second coil  84 . 
     The first coils  82  and  82  provided on the two surfaces in the X direction are electrically connected to each other in series. 
     The first coils  82 , the X-direction position detecting element  86 , and the Y-direction position detecting element  88  face the inner side of the base  66  through the opening portions  74 , and are opposed to the first magnets  58 . Similarly, the second coil  84  and the Z-direction position detecting element  90  face the inner side of the base  66  through the opening portion  74 , and are opposed to the second magnet  62 . 
     Further, as illustrated in  FIG. 1 , on the outer side of the flexible printed board  76 , a second magnetic member  92  made of a magnetic substance is provided. The second magnetic member  92  is opposed to the second magnet  62  through intermediation of the flexible printed board  76  and the second coil  84 . Magnetic fluxes from the second magnet  62  flow through the second magnetic member  92  so that an attraction force is generated between the second magnet  62  and the second magnetic member  92 . Therefore, in the moving member  18 , an attraction force acts in the Y direction of the fixed member  16 . 
     As illustrated in  FIG. 1  and  FIG. 8  to  FIG. 10 , the moving member  18  is supported by an optical axis-direction support mechanism  94  so as to be freely movable relative to the fixed member  16  in the Z direction. The optical axis-direction support mechanism  94  includes a third support portion  96  and a fourth support portion  98  provided in the second frame member  64 , and a third guiding portion  100  and a fourth guiding portion  102  formed in the moving member  18 . The third support portion  96  and the third guiding portion  100  are combined with each other, and the fourth support portion  98  and the fourth guiding portion  102  are combined with each other. 
     Each of the third support portion  96  and the fourth support portion  98  is made of, for example, a ceramic, a metal, or a resin, and in the first embodiment, is formed as a column extending in the Z direction. Further, the third support portion  96  and the fourth support portion  98  are provided away from each other in the X direction in the vicinity of corner portions of the base  20  on a side-surface inner side on the second magnet  62  side of the base  66 . 
     Each of the third support portion  96  and the fourth support portion  98  has a circular shape in an XY-direction cross section, but may have a shape of a part of a circle, or an oval or polygonal shape other than the circular shape. 
     That is, as illustrated in  FIG. 1  and  FIG. 8  to  FIG. 10 , a bottom surface portion  104  is formed around the through hole  70  of the base  60 , and lower fixing portions  106  and  106  are formed on both sides on the inner side of the bottom surface portion  104  as cylindrical grooves. Lower ends of the third support portion  96  and the fourth support portion  98  are inserted and fixed to the lower fixing portions  106  and  106 . Further, upper ends of the above-mentioned second magnetic member  92  at both ends in the X direction are bent in the Y direction to form upper fixing portions  108  and  108 . Upper ends of the third support portion  96  and the fourth support portion  98  are inserted and fixed to insertion holes  110  and  110  formed in the upper fixing portions  108  and  108  so that the third support portion  96  and the fourth support portion  98  are fixed to the second frame member  64 . In the first embodiment, the second magnetic member  92  also has a support function for the third support portion  96  and the fourth support portion  98 , and thus the number of components can be reduced as compared to a case in which components for support are separately provided. Further, the third support portion  96  and the fourth support portion  98  can be stably supported. 
     As illustrated in  FIG. 8  and  FIG. 9 , the third guide portion  100  includes a first contact portion  112  and a second contact portion  114  formed away from each other in the Z direction. In the first embodiment, the first contact portion  112  and the second contact portion  114  are formed as circular holes, and are brought into contact with an outer surface of the third support portion  96  in a 360-degree circumferential direction in the XY-direction cross section of the third support portion  96 . 
     As illustrated in  FIG. 8  and  FIG. 10 , in the XY-direction cross section, the fourth guide portion  102  is formed of two wall surfaces opposed to each other in the Y direction. Both the wall surfaces of the fourth guide portion  102  protrude as a curve toward the fourth support portion  98  to form protruding portions  116  and  116 . Middles of the protruding portions  116  and  116  correspond to a third contact portion  118  that is brought into contact with the fourth support portion  98 . The third contact portion  118  is brought into contact with the fourth support portion  98  at two points in the Y direction to reduce a frictional resistance. 
     In the above-mentioned configuration, with energization to the first coils  82  and  82  opposed to the first magnets  58  and  58  on the two surfaces in the X direction in which magnetic fluxes in the Z direction are interposed, currents flow through the first coils  82  and  82  in the Y direction, and a Lorentz force acts on the first coils  82  and  82  in the X direction by the Fleming&#39;s left hand rule. The first coils  82  and  82  are fixed to the base  66 , and hence the lens support  20  and the first moving member plate  26  move in the X direction while being supported by the first support mechanism  40  with a reaction force acting on the first magnets  58  and  58  serving as a drive force for the lens support  20  and the first moving member plate  26 . 
     In this case, as illustrated in  FIG. 7 , when the drive force in the X direction is represented by F x , the following expression may be satisfied to drive the lens support  20  and the second moving member plate  28  in the X direction: 
         F   x &gt;μ x1 ( N   x1   +W   x1 )+μ x2 ( N   x2   +W   x2 ).
 
     In the expression, μ x1  and μ x2  each represent a friction coefficient between the first support portion  44  and the first guiding portion  46 , W x1  and W x2  each represent a load to be applied to the first support portion  44 , and N x1  and N x2  each represent a force to be applied to the first support portion  44  due to the attraction force between the first magnets  58  and  58  and the first magnetic members  60  and  60 . Further, the following expression may be satisfied: 
         N+W   x =( N   x1   +W   x1 )+( N   x2   −W   x2 ), 
     and F x  can be represented as follows: 
         F   x =μ x ( N+W   x ),
 
     provided that μ x  is an average value of μ x1  and μ x2 . 
     Further, with energization to the first coil  82  opposed to the first magnet  58  in the Y direction in which magnetic fluxes in the Z direction are interposed, currents flow through the first coil  82  in the X direction, and a Lorentz force acts on the first coil  82  in the Y direction by the Fleming&#39;s left hand rule. The first coil  82  it fixed to the base  66 , and hence the lens support  20  moves in the Y direction while being supported by the second support mechanism  42  with a reaction force acting on the first magnet  58  serving as a drive force for the lens support  20 . 
     In this case, as illustrated in  FIG. 6 , when the drive force in the X direction is represented by F y , the following expression may be satisfied to drive the lens support  20  in the Y direction: 
         F   y &gt;μ y1 ( N   y1   +W   y1 )+μ y2 ( N   y2   +W   y2 ).
 
     In the expression, μ y1  and μ y2  each represent a friction coefficient between the second support portion  48  and the second guiding portion  50 , W y1  and W y2  each represent a load to be applied to the second support portion  48 , and N y1  and N y2  each represent a force to be applied to the second support portion  48  due to the attraction force between the first magnets  58  and  58  and the first magnetic members  60  and  60 . Further, the following expression may be satisfied: 
         N+W   y =( N   y1   +W   y1 )+( N   y2   −W   y2 ), 
     and F y  can be represented as follows: 
         F   y =μ y ( N+W   y ).
 
     provided that μ y  an average value of μ y1  and μ y2 . 
     When the energization to the first coil  82  is canceled after the lens support  20  is moved in any one of the X direction and the Y direction, the lens support  20  stops at a position at which the energization is slopped due to the attraction force between the first magnets  58  and  58  and the first magnetic members  60  and  60 , the friction between the first support portion  44  and the first guiding portion  46 , and the friction between the second support portion  48  and the second guiding portion  50 . 
     In this case, it is assumed that the camera device  10  receives, for example, impact in a −Y direction. When the camera device  10  receives the impact in the −Y direction, the lens support  20  and the first moving member plate  26  are caused to move in a +Y direction against the attraction force between the first magnets  58  and  58  and the first magnetic members  60  and  60 . However, the lens support  20  and the first moving member plate  26  are not separated and hardly move even when receiving impact from the outride because the lens support  20  and the first moving member plate  26  are supported by the first support mechanism  40  so as to regulate the movement in the Y direction. After receiving the impact, the lens support  20  and the first moving member plate  26  are applied with a force of returning the lens support  20  and the first moving member plate  26  in the −Y direction due to the attraction force between the first magnets  58  and  58  and the first magnetic members  60  and  60 . Also in this case, the lens support  20  and the first moving member plate  26  hardly move even when receiving impact from the outside because the first support portion  44  and the first guiding portion  46  maintain the contact. With respect to the impact in the X direction, while the contact between the first support portion  44  and the first guiding portion  46  is maintained, only the lens support  20  is guided by the first support mechanism  40  to be moved relative to the first moving member plate  26 . Further, also with respect to the impact in the Z direction, the contact between the first support portion  44  and the first guiding portion  46  is easily maintained, but even when the first support portion  44  and the first guiding portion  46  are separated from each other, the impact is received with a surface at the time of return. Therefore, the damage is small, and smooth movement of the lens support  20  can be ensured. The second support mechanism  42  also acts similarly. 
     Further, in the first support mechanism  40  and the second support mechanism  42 , the first support portion  44  and the first guiding portion  46  are fitted to each other in the X direction, and the second support portion  48  and the second guiding portion  50  are fitted to each other in the Y direction, thereby forming independent support mechanisms. Therefore, a force in the rotation direction does not act even with a simultaneous drive in the XY directions, and the lens support  20  can be prevented from being vibrated in the rotation direction. 
     Next, with energization to the second coil  84  arranged between the second magnet  62  and the second magnetic member  92  in which magnetic fluxes in the Y direction are interposed, currents flow through the second coil  84  in the X direction, and a Lorentz force acts on the second coil  84  in the Z direction by the Fleming&#39;s left hand rule. The second coil  84  is fixed to the base  66 , and hence the moving member  18  moves in the Z direction while being supported by the optical axis-direction support mechanism  94  with a reaction force acting on the second magnet  62  serving as a drive force for the moving member  18 . 
     In this case, when the drive force in the Z direction is represented by F x , the drive force F z  may satisfy the following expression to drive the moving member  18  in the Z direction: 
         F   z &gt;(μ z3   ×N   z3   +μ   z4   ×N   z4 )+ W.  
 
     In the expression, N z  represents an attraction force generated by the second magnet  62  (N z =N z3 +N z4 ), μ z3  represents a friction coefficient between the third support portion  96  and the third guiding portion  100 , μ z4  represents a friction coefficient between the fourth support portion  98  and the fourth guiding portion  102 , and W represents a total weight of the moving member  18 . 
     When the energization to the second coil  84  is canceled after the moving member  18  is moved in the Z direction, the moving member  18  stops at a position at which the energization is stopped due to the attraction force between the second magnet  62  and the second magnetic member  92 , the friction between the thud support portion  96  and the third guiding portion  100 , and the friction between the fourth support portion  98  and the fourth guiding portion  102 . 
     In this case, it is assumed that the camera dev ice  10  receives, for example, impact in the −Y direction. When the camera device  10  receives the impact in the −Y direction, the moving member  18  is caused to move in the +Y direction against the attraction force between the second magnet  62  and the second magnetic member  92 . However, the moving member  18  hardly moves even when receiving impact from the outside because Y-direction contact between the third guiding portion  100  and the third support portion  96  and between the fourth guiding portion  102  and the fourth support portion  98  is maintained. After receiving the impact, the moving member  18  is applied with a force of returning the moving member  18  in the −Y direction due to the attraction force between the second magnet  62  and the second magnetic member  92 . Also in this case, the moving member  18  hardly moves even when receiving impact from the outside because Y-direction contact between the third guiding portion  100  and the third support portion  96  and between the fourth guiding portion  102  and the fourth support portion  98  is maintained. 
     In this case, even when the third guiding portion  100  or the fourth guiding portion  102  is slightly deformed, the third support portion  96  and the fourth support portion  98  have a shape extending in the Z direction, and hence a force that is not local but successive acts along the Z direction on the third support portion  96  and the fourth support portion  98 . Therefore, abrupt motion change does not occur due to a reciprocating motion of the moving member  18  or the like. Therefore, the smooth movement of the lens support  20  can be ensured. 
     The moving member  18  is supported by the optical axis-direction support mechanism  94  provided on the Y direction side, and further the moving member  18  is heavy because the first magnets  58  and the like are provided. Therefore, a moment of hanging downward in the Z direction is generated. However, the optical axis-direction support mechanism  94  is supported by the third support portion  96  and the fourth support portion  98  extending in the Z direction, and hence as compared to a case in which balls are used for support as in the related art, the above-mentioned hanging downward can be reduced. 
       FIG. 11  and  FIG. 12  are illustrations of a second embodiment of the present invention. 
     As compared to the above-mentioned first embodiment, the second embodiment differs in the structures of the first support mechanism  40  and the second support mechanism  42 . 
     That is, in the first support mechanism  40 , the first support portion  44  is formed so that its lower surface side protrudes in an arc shape. Therefore, in the Z-direction cross section illustrated in  FIG. 11 , side surfaces of the first support portion  44  and the first guiding portion  46  are brought into line contact with each other, and bottom surfaces thereof are brought into point contact with each other. In the X direction, the side surfaces are brought into surface contact with each other, and the bottom surfaces are brought into line contact with each other. Further, the second support portion  48  is formed so that its upper surface side protrudes in an arc shape. Therefore, in the Z-direction cross section illustrated in  FIG. 12 , side surfaces of the second support portion  48  and the second guiding portion  50  are brought into line contact with each other, and bottom surfaces thereof are brought into point contact with each other. In the X direction, the side surfaces are brought into surface contact with each other, and the bottom surfaces are brought into line contact with each other. 
     As described above, in the first support mechanism  40  and the second support mechanism  42 , the first support portion  44  and the first guiding portion  46  are brought into surface or line contact with each other in the X direction, and the second support portion  48  and the second guiding portion  50  are brought into surface or line contact with each other in the X direction. Therefore, the friction three can be reduced as compared to that in the first embodiment. 
     Parts similar to those in the first embodiment are denoted by the same reference symbols, and description thereof is omitted. 
       FIG. 13  and  FIG. 14  are illustrations of a third embodiment of the present invention. 
     As compared to the above-mentioned first embodiment, the third embodiment differs in the structures of the first support mechanism  40  and the second support mechanism  42 . 
     That is, in the first support mechanism  40 , the first support portion  44  is formed so that its lower surface side protrudes in an arc shape, Therefore, in the Z-direction cross section illustrated in  FIG. 13 , side surfaces and bottoms surfaces of the first support portion  44  and the first guiding portion  46  are brought into point contact with each other. In the X direction, line contact is achieved at three points of the side surfaces and the bottom surface. Further, the second support portion  48  is formed so that its upper surface and side surface sides protrude in an arc shape. Therefore, in the Z-direction cross section illustrated in  FIG. 14 , the side surfaces and the bottom surfaces of the second support portion  48  and the second guiding portion  50  are brought into point contact with each other. In the X direction, line contact is achieved at three points of the side surfaces and the bottom surface. In the third embodiment, in the Z-direction cross section, point contact is achieved in both side surfaces, but point contact may be achieved only in one side surface. 
     As described above, in the first support mechanism  40  and the second support mechanism  42 , the first support portion  44  and the first guiding portion  46  are brought into contact with each other at three points in the X direction, and the second support portion  48  and the second guiding portion  50  are brought into contact with each other at three points in the X direction. Therefore, the friction force can be further reduced as compared to that in the second embodiment. 
     Parts similar to those in the first and second embodiments are denoted by the same reference symbols, and description thereof is omitted. 
       FIG. 15  is an illustration of a fourth embodiment of the present invention. 
     In the fourth embodiment, the first support portion  44  has a linear side surface, but the first guiding portion  46  has a shape of protruding in a curved shape. Therefore, the first support portion  44  and the first guiding portion  46  are brought into point contact with each other in the XY-direction cross section. 
       FIG. 16  is an illustration of a fifth embodiment of the present invention. 
     In the fifth embodiment, the first guiding portion  46  has a linear side surface, but the first support portion  44  has a shape of protruding in a curved shape. Therefore, the first support portion  44  and the first guiding portion  46  are brought into point contact with each other in the XY-direction cross section. 
     In the description above of the embodiments, a part formed into a protruding shape is referred to as the support portion, and a part formed into a recessed shape is referred to as the guiding portion, but the protruding part may be referred to as the guiding portion, and the recessed part may be referred to as the support portion. Further, the configurations of the first to fifth embodiments may be combined as appropriate. 
     The first magnet  58  and the first coil  82 , and the second magnet  62  and the second coil  84  may be arranged at interchanged positions. In this case, other members are optimally rearranged as appropriate. Further, the lens driving device  12  has a focus adjusting function and an image stabilization function, but may further have a zoom function, for example. The lens driving device  12  to be used in the camera device  10  is described herein, but the present invention is also applicable to other devices.