Patent Publication Number: US-2021173198-A1

Title: Driving device

Description:
TECHNICAL FIELD 
     The present invention relates to a driving device. 
     BACKGROUND ART 
     Conventionally, there has been proposed a magnetic force type driving device configured to rotate a movable plate by rotatably supporting the movable plate with respect to a frame with a pair of beams and by providing an end of a yoke in the vicinity of a permanent magnet fixed on a back side of the movable plate (refer for example to Patent Document 1). In the magnetic force type driving device described in Patent Document 1, a coil that generates magnetic poles at the ends of the yoke when applied with current is wound around the yoke at a position spaced apart from the movable plate in a plate thickness direction. 
     CITATION LIST 
     Patent Document 
     
         
         Patent Document 1: JP 2012-208395 A 
       
    
     SUMMARY OF THE INVENTION 
     Problem to be Solved 
     In the driving device described in Patent Document 1, since the coil is wound around the yoke at the position sufficiently separated from the movable plate in the plate thickness direction so as to prevent interference when the movable plate is rotated, there was a drawback that the size of the entire device is likely to increase in the plate thickness direction. 
     Therefore, an example of the problem to be solved by the present invention is to provide a driving device that can downsize the entire device. 
     Solution to Problem 
     In order to solve the problem and to achieve the object described above, a driving device of the present invention according to claim  1  includes a first driven part, a second driven part that rotatably supports the first driven part via a first shaft part, a base part that rotatably supports the second driven part via a second shaft part, a magnetic element provided on the second driven part, and a yoke part that includes a pair of ends and that is configured to rotate the first driven part via the second driven part by applying, to the magnetic element, a magnetic field generated at the ends, wherein the yoke part is arranged to sandwich, between the pair of ends, a reference plane on which the base part extends. Further, a driving device of the present invention according to claim  11  includes a movable part, a base part that rotatably supports the movable part via a shaft part, a magnetic element provided on the movable part, and a driving section that includes a coil part and that is configured to rotate the movable part by applying, to the magnetic element, a magnetic field generated by the coil part, wherein the coil part is formed by a wiring extending along the base part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a driving device according to a first example of the present invention; 
         FIG. 2  is a perspective view showing an upper face side of the driving device; 
         FIG. 3  is a perspective view showing a lower face side of the driving device; 
         FIG. 4  is a perspective view showing a yoke part and a magnetic element of the driving device; 
         FIG. 5  is a perspective view showing a driving device according to a second example of the present invention; 
         FIG. 6  is a perspective view showing a lower face side of the driving device; 
         FIG. 7  is a perspective view showing a main part of the driving device; 
         FIG. 8  is a perspective view showing a driving device according to a third example of the present invention; and 
         FIG. 9  is a perspective view showing a lower face side of the driving device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present invention will be described below. A driving device according to an embodiment of the present invention includes a first driven part, a second driven part that rotatably supports the first driven part via a first shaft part, a base part that rotatably supports the second driven part via a second shaft part, a magnetic element provided on the second driven part, and a yoke part including a pair of ends and configured to rotate the first driven part via the second driven part by applying the magnetic field generated at these ends to the magnetic element. The yoke part is configured such that the pair of ends thereof sandwiches a reference plane on which the base part extends. 
     Since the magnetic element is provided on the second driven part, the first driven part and the ends of the yoke part are prevented from interfering with each other, and, by disposing the magnetic element close to the ends of the yoke part, the entire device can be downsized. Further, the first driven part and the ends of the yoke part are prevented from interfering with each other even when the driving force is increased by disposing the magnetic element close to the ends of the yoke part and the swing angle of the first driven part is increased. In this instance, when a magnetic field having a frequency corresponding to the resonance frequency of the first driven part is generated at the ends of the yoke part, the swing angle of the first driven part can be increased while the swing angle of the second driven part can be reduced, thereby preventing the interference between the second driven part and the ends of the yoke part. In this way, it is possible to prevent the interference between the components while obtaining a large driving force, and the swing angle of the first driven part can be increased. 
     The magnetic element and the ends of the yoke part are arranged at positions corresponding to each other in the axis direction of the first shaft part (or the second shaft part). In order to obtain a large driving force, it is preferable that their positions in the axis direction correspond to each other; however, for convenience of arrangement of other components, for example, they may be positioned slightly displaced from each other in the axis direction. 
     It is preferable that the magnetic element is disposed on a closest part on the second driven part closest to the base part. This facilitates application of the magnetic field generated at the ends of the yoke part onto the magnetic element, thereby obtaining a large driving force. 
     It is preferable that the magnetic element is arranged at the central part of the second driven part in the axis direction of the second shaft part. This can prevent a movement such as twisting with respect to the rotation around the second shaft part as the axis direction during the driving of the second driven part. 
     The first driven part is formed in a circular plate shape or an elliptical plate shape, and the magnetic element is arranged on the second driven part at a position displaced in the axis direction of the first shaft part with respect to the closest part where the base part is closest to the first driven part. Consequently, the first driven part can be easily disposed close to the base part at the closest part, and the surface area of the first driven part can be increased. 
     Further, at a position corresponding to the closest part, the second driven part has a width in a facing direction in which the base part and the first driven part face each other that is smaller than that of rest of the second driven part. Consequently, in a case where the first driven part is a mirror, it is possible to prevent the light from being blocked by the second driven part at the closest part. 
     It is preferable that the magnetic elements are arranged on both sides of the second driven part in the intersecting direction intersecting the axis direction of the second shaft part. Consequently, a driving force can be applied to the second driven part from both sides in the intersecting direction. 
     It is preferable that the driving device further includes a coil part, and the wiring part forming the coil part includes an axially extending part that extends along the base part and extends in the axis direction of the second shaft part, and the yoke part is formed in an opened annular shape that surrounds the axially extending part from both sides of the reference plane and from a side opposite to the second driven part and that is opened on the second driven part side. Consequently, when a current flows through the axially extending part, the lines of magnetic force concentrate at the yoke part, and this can facilitate application of the magnetic field onto the magnetic element on the second driven part side where it is opened. 
     It is preferable that the first shaft part and the second shaft part are arranged coaxially. Consequently, the driving force applied to the second driven part can be easily transmitted to the first driven part. 
     It is preferable that the driving device further includes a coil part and a pedestal which is made of a non-magnetic material and to which the base part is joined, and that the coil part is disposed on the pedestal or in the pedestal. Consequently, by disposing the coil part on the pedestal or in the pedestal, the entire driving device can be downsized. 
     The driving device according to another embodiment of the present invention includes a driving device including a movable part, a base part that rotatably supports the movable part via a shaft part, a magnetic element provided on the movable part, and a driving section that includes a coil part and that is configured to rotate the movable part by applying, to the magnetic element, a magnetic field generated by the coil part. The coil part is formed by a wiring extending along the base part. 
     Since the coil part is constituted of the wiring that extends along the base part, the entire driving device can be downsized as compared with the configuration in which the coil part is arranged side by side with respect to the base part. 
     EXAMPLES 
     Each example of the present invention will be described in detail below. With respect to a second example and a third example, the same components and the components having the same function as those described in a first example are designated by the same reference signs as those in the first example, and the description thereof is omitted. 
     First Example 
     As shown in  FIGS. 1 to 3 , a driving device  1 A of this example is an optical deflector including a mirror  2  as a first driven part, a rotary frame  3  as a second driven part, a base part  4 , two magnetic elements  5 A,  5 B, a coil part  6 , two yoke parts  7 A,  7 B, a pedestal  8 , an inner torsion bar  20  as a first shaft part, and an outer torsion bar  30  as a second shaft part. The driving device  1 A is used, for example, for a detection device that is mounted on a vehicle to detect a distance from another vehicle, an installation or the like by transmitting and receiving light such as infrared rays. 
     In this example, the inner torsion bar  20  and the outer torsion bar  30  are arranged coaxially, wherein an extending direction (axis direction) thereof corresponds to an X direction, and a plate thickness direction of the mirror  2  corresponds to a Z direction. A direction orthogonal to both the X direction and the Z direction is a Y direction, that is, the mirror  2  extends along the XY plane. 
     The mirror  2  is formed in an elliptical plate shape with its longitudinal direction corresponding to the X direction, and a surface  21  thereof is a reflective face formed by mirror finishing. The inner torsion bars  20  are connected to both ends of the mirror  2  in the X direction. 
     The rotary frame  3  is formed in an elliptical annular shape when viewed from the Z direction with its longitudinal direction corresponding to the X direction, and it extends along the XY plane so as to surround the mirror  2 . The both ends of the rotary frame  3  in the X direction are provided with the inner torsion bars  20  connected to inner sides of said both ends and the outer torsion bars  30  connected to outer sides of said both ends. That is, the mirror  2  is rotatably supported by the rotary frame  3  via the inner torsion bars  20 . 
     The base part  4  is formed in a rectangular frame shape when viewed from the Z direction with its longitudinal direction corresponding to the X direction, and it extends along the XY plane so as to surround the rotary frame  3 . The outer torsion bars  30  are connected to an inner side of the base part  4  on both ends in the X direction and on central parts in the Y direction. That is, the rotary frame  3  is rotatably supported by the base part  4  via the outer torsion bars  30 . Herein, a plane on which the base part  4  extends is defined as a reference plane S 1 . The reference plane S 1  is arranged along the XY plane, and the mirror  2  and the rotary frame  3  also extend along the reference plane S 1 . 
     The mirror  2 , the rotary frame  3  and the inner torsion bars  20  as described above constitute a movable part, and the movable part is rotatably supported by the base part  4  via the outer torsion bars  30 . 
     The magnetic elements  5 A,  5 B are permanent magnets formed in a plate shape and are respectively arranged at central parts  31 ,  32  in the X direction on a lower face (i.e., a face opposite to the surface  21 ) of the rotary frame  3 . That is, the two magnetic elements  5 A,  5 B are arranged on both sides in the Y direction of the rotary frame  3 . The elliptical rotary frame  3  is closest to the base part  4  at the central parts  31 ,  32 , and thus the central parts  31 ,  32  are closest parts. As shown in  FIG. 4 , the magnetic elements  5 A,  5 B have magnetic poles (N pole and S pole) arranged in the Y direction. 
     The coil part  6  is formed by a wiring  61  extending along the base part  4 . That is, the wiring  61  is wound in a rectangular shape with its longitudinal direction corresponding to the X direction, thereby forming the coil part  6 . The number of turns of the wiring  61  wound along the base part  4  is appropriately set according to various conditions such as driving force to be applied to the second driven part, a space on the base part  4  and an allowable current for the wiring  61 . In this example, the coil part  6  is provided on the lower face  42  of the base part  4 , but it may be provided on the upper face  41 , or it may be provided on both of the upper face  41  and the lower face  42 . Herein, the upper face  41  of the base part  4  is a face that faces the same side as the surface (reflective face)  21  of the mirror  2 . 
     An appropriate power source is connected to both ends of the wiring  61  to supply electric power as needed. That is, a voltage having a frequency corresponding to the resonance frequency of the mirror  2  is applied to the both ends of the wiring  61  to generate a magnetic field. The wiring  61  includes axially extending parts  611 ,  612  extending along the X direction. 
     The yoke parts  7 A,  7 B are made of a ferromagnetic metal such as iron, and are arranged so as to surround the axially extending parts  611 ,  612 , respectively, so as to correspond to the magnetic elements  5 A,  5 B, respectively. That is, the yoke parts  7 A,  7 B are arranged so as to face the magnetic elements  5 A,  5 B, respectively, in the Y direction (i.e., so as to overlap with them when viewed from the Y direction). 
     Each of the yoke parts  7 A,  7 B includes a first extending part  71  extending along the XY plane on the upper side in the Z direction (i.e., the surface  21  side) of the axially extending part  611 ,  612 , a second extending part  72  extending along the XY plane on the lower side in the Z direction of the axially extending part  611 ,  612 , and a connecting part  73  extending along the ZX plane on the outside of the axially extending part  611 ,  612  (i.e., on the side opposite to the rotary frame  3 ) and connecting the first extending part  71  and the second extending part  72 . 
     That is, the yoke parts  7 A,  7 B are formed in an opened annular shape that is opened on the rotary frame  3  side and that surrounds the axially extending parts  611 ,  612  from both sides of the reference plane S 1  and from the side opposite to the rotary frame  3 . In this example, the base part  4  is also surrounded by the yoke parts  7 A,  7 B. Further, an inner end of the first extending part  71  and an inner end of the second extending part  72  correspond to a pair of ends  74 ,  75  of the yoke parts  7 A,  7 B. In the Z direction, the reference plane S 1  is sandwiched between the pair of ends  74 ,  75 . 
     The coil part  6  and the yoke parts  7 A,  7 B as described above function as a driving means configured to rotate the movable part by applying the magnetic field onto the magnetic elements  5 A,  5 B. 
     The pedestal  8  is configured such that the base part  4  is fixed thereto to support the base part  4 , and an upper face thereof (i.e., a face thereof on the base part  4  side) is provided with a recessed part (accommodating part) for accommodating the coil part  6 . That is, the coil part  6  is arranged inside the pedestal  8 . A recessed part (accommodating part) capable of accommodating the coil part  6  may be formed on the lower face (i.e., a face on the pedestal  8  side) of the base part  4 . 
     Now, the details of the driving force applied to the mirror  2  and the rotary frame  3  will be described. When a current flows through the coil part  6  and a magnetic field is generated, lines of magnetic force are to pass through the yoke parts  7 A,  7 B. Thus, the lines of magnetic force are to pass from one side toward the other side of the pair of ends  74 ,  75  (i.e., along the Z direction). Further, the magnetic poles of the magnetic elements  5 A,  5 B are arranged in the Y direction. 
     Due to these magnetic interactions, the rotary frame  3  provided with the magnetic elements  5 A,  5 B and supported by the outer torsion bars  30  arranged along the X direction is applied with the driving force that rotates the rotary frame  3  with respect to the X direction as the axis direction. The driving force generated at the magnetic element  5 A and the driving force generated at the magnetic element  5 B have the same direction of rotation. 
     Since the current flowing through the coil part  6  has a frequency corresponding to the resonance frequency of the mirror  2 , the rotary frame  3  does not rotate significantly even when the driving force is applied. It is preferable that the resonance frequency of the mirror  2  and the resonance frequency of the rotary frame  3  are different from each other, and it is more preferable that one of the resonance frequencies is not an integer multiple of the other one of the resonance frequencies. 
     When the rotation of the rotary frame  3  is transmitted to the mirror  2  via the inner torsion bars  20 , the mirror  2  rotates more than the rotary frame  3 , since the frequency of the rotation of the rotary frame  3  substantially corresponds with the resonance frequency of the mirror  2 . In this manner, the driving force applied to the rotary frame  3  is transmitted to the mirror  2 . 
     According to the above-described configuration, the magnetic elements  5 A,  5 B are provided on the rotary frame  3 , thus the mirror  2  and the ends  74 ,  75  of the yoke parts  7 A,  7 B are prevented from interfering with each other, and, by disposing the magnetic elements  5 A,  5 B close to the ends  74 ,  75 , the entire device can be downsized. 
     Further, since the magnetic elements  5 A,  5 B are provided on the rotary frame  3 , the mirror  2  and the ends  74 ,  75  are prevented from interfering with each other even when the driving force is increased and the swing angle of the mirror  2  is increased by disposing the magnetic elements  5 A,  5 B and the ends  74 ,  75  of the yoke parts  7 A,  7 B close to each other. In this instance, by generating, at the ends  74 ,  75 , the magnetic field having a frequency corresponding to the resonance frequency of the mirror  2 , the swing angle of the mirror  2  can be increased while the swing angle of the rotary frame  3  can be made smaller than the swing angle of the mirror  2 , thereby preventing the interference between the mirror  2  and the ends  74 ,  75 . In this way, the interference between the components can be prevented while obtaining a large driving force, and the swing angle of the mirror  2  can be increased. 
     Furthermore, the magnetic elements  5 A,  5 B are arranged at the central parts  31 ,  32  of the rotary frame  3  that are closest to the base part  4 , and this facilitates application of the magnetic field generated at the ends  74 ,  75  of the yoke parts  7 A,  7 B onto the magnetic elements  5 A,  5 B, thus a large driving force can be obtained and the swing angle of the mirror  2  can be increased. 
     Further, the magnetic elements  5 A,  5 B are arranged at the central parts  31 ,  32  in the X direction of the rotary frame  3 , thereby preventing a movement such as twisting with respect to the rotation around the outer torsion bars  30  as the axis direction during the driving of the rotary frame  3 . 
     Further, the two magnetic elements  5 A,  5 B are arranged on both sides in the Y direction of the rotary frame  3 , thus the rotary frame  3  can be driven from both sides in the Y direction. 
     Further, the yoke parts  7 A,  7 B are formed in an opened annular shape that is opened on the rotary frame  3  side and that surrounds the axially extending parts  611 ,  612  of the coil part  6 , thus the lines of magnetic force concentrate at the yoke parts  7 A,  7 B when a current flows through the axially extending parts  611 ,  612 , so this facilitates application of the magnetic field generated at the ends  74 ,  75  of the yoke parts  7 A,  7 B onto the magnetic elements  5 A,  5 B on the rotary frame  3  side where they are opened. 
     Further, since the inner torsion bars  20  and the outer torsion bars  30  are arranged coaxially, the driving force applied to the rotary frame  3  can be easily transmitted to the mirror  2 . 
     Further, since the coil part  6  is arranged on the pedestal  8 , the entire driving device  1 A can be downsized. 
     Further, since the coil part  6  is constituted of the wiring  61  extending along the base part  4 , the entire driving device  1 A can be downsized as compared with the configuration in which the coil part is arranged side by side with respect to the base part. 
     Second Example 
     As shown in  FIGS. 5 and 6 , a driving device  1 B of this example is an optical deflector including a mirror  2  as a first driven part, a rotary frame  3 B as a second driven part, a base part  4 B, four magnetic elements  5 C- 5 F, a coil part  6 B, four yoke parts  7 C- 7 F, a pedestal, an inner torsion bar  20  as a first shaft part, and an outer torsion bar  30  as a second shaft part. Although the pedestal is not shown in  FIGS. 5 and 6 , the pedestal of the driving device  1 B is the same as the pedestal  8  of the driving device  1 A of the first example. In this example also, the X direction, the Y direction and the Z direction are the same as those in the first example. 
     The rotary frame  3 B is formed in a hexagonal annular shape having vertices at both ends in the X direction when viewed from the Z direction, and it extends along the XY plane so as to surround the mirror  2 . That is, the rotary frame  3 B includes four inclined parts  33 - 36  extending so as to approach the mirror  2  in the X direction and approach the base part  4 B in the Y direction, and it also includes parallel parts  37 ,  38  extending along the X direction. 
     An intersection of the inclined part  33  and the inclined part  34  corresponds to one end of the rotary frame  3 B in the X direction, where the inner torsion bar  20  is connected to the inner side and the outer torsion bar  30  is connected to the outer side. Further, an intersection of the inclined part  35  and the inclined part  36  corresponds to the other end of the rotary frame  3 B in the X direction, where the inner torsion bar  20  is connected to the inner side and the outer torsion bar  30  is connected to the outer side. 
     The parallel part  37  extends so as to connect the inclined part  33  and the inclined part  35 , and the parallel part  38  extends so as to connect the inclined part  34  and the inclined part  36 . As shown in  FIG. 7 , the parallel parts  37 ,  38  include convex parts  371 ,  381  arranged toward outside in the Y direction (i.e., side opposite to the mirror  2 ) so as to recede from the respective closest parts  22 ,  23  of the mirror  2  located closest to the base part  4 B. 
     Further, the widths (dimensions in the Y direction) of the parallel parts  37 ,  38  are smaller than the widths of the inclined parts  33 - 36 . That is, the width of the rotary frame  3 B at the positions corresponding to the closest parts  22 ,  23  is smaller than the width at rest of the rotary frame  3 B. 
     The base part  4 B includes convex parts  43  corresponding to the convex parts  371 ,  381 , that is, the base part  4 B is formed so as to recede from the mirror  2  at the convex parts  43 . Further, the coil part  6 B is arranged along the base part  4 B and similarly includes convex parts. 
     The magnetic elements  5 C- 5 F are arranged at intersections  391 - 394  of the inclined parts  33 - 36  and the parallel parts  37 ,  38 , respectively. The intersections  391 - 394  are displaced in the X direction with respect to the closest parts  22 ,  23 . 
     The yoke parts  7 C- 7 F correspond to the magnetic elements  5 C- 5 F, respectively, and are arranged so as to avoid the convex parts  43  of the base part  4 B. The shape of the yoke parts  7 C- 7 F is the same as the shape of the yoke parts  7 A,  7 B in the first example. 
     According to the above-described configuration, as in the case of the first example, the magnetic elements  5 C- 5 F are provided on the rotary frame  3 B, thus the entire device can be downsized and the swing angle of the mirror  2  can be increased. In addition, the coil part  6 B is constituted of the wiring  61  extending along the base part  4 B, thus the entire driving device  1 B can be downsized. 
     Further, the magnetic elements  5 C- 5 F are arranged so as to be displaced in the X direction with respect to the closest parts  22 ,  23 , thus the mirror  2  can be easily disposed close to the base part  4 B at the closest parts  22 ,  23 , and the surface area of the mirror  2  can be increased. 
     Further, the rotary frame  3 B includes the convex parts  371 ,  381  that are facing opposite to the mirror  2 , and the widths of the parallel parts  37 ,  38  are smaller than the widths of the inclined parts  33 - 36 , thus it is possible to prevent the light L directed toward the mirror  2  from being blocked by the rotary frame  3 B at the closest parts  22 ,  23 . 
     Third Example 
     As shown in  FIGS. 8 and 9 , a driving device  1 C of this example is an optical deflector including a mirror  2 , a base part  4 , two magnetic elements  5 A,  5 B, a coil part  6 , two yoke parts  7 A,  7 B, a pedestal and a torsion bar  40 . That is, the driving device  1 C corresponds to the driving device  1 A of the first example except the rotary frame  3  and the inner torsion bars  20  are omitted and the mirror  2  is rotatably supported by the base part  4  via the torsion bars  40 . In addition, the magnetic elements  5 A,  5 B are arranged on the closest parts  22 ,  23  on the lower face of the mirror  2 . Although the pedestal is not shown in  FIGS. 8 and 9 , the pedestal of the driving device  1 C is the same as the pedestal  8  of the driving device  1 A of the first example. In this example also, the X direction, the Y direction and the Z direction are the same as those in the first example. 
     According to the above-described configuration, as in the case of the first example, the coil part  6  is constituted of the wiring  61  extending along the base part  4 , thus the entire driving device  1 C can be downsized. Further, the magnetic elements  5 A,  5 B are arranged at the closest parts  22 ,  23  of the mirror  2 , and this facilitates application of the magnetic field generated at the ends of the yoke parts  7 A,  7 B onto the magnetic elements  5 A,  5 B, thereby obtaining a large driving force and increasing the swing angle of the driven part. 
     The present invention is not limited to the examples described above, but includes other configurations and the like that can achieve the object of the present invention, and the following modifications and the like are also included in the present invention. 
     For example, in the first to third examples, the mirror  2  has an elliptical plate shape, but the mirror as the first driven part may have other shapes such as a circular plate shape or a polygonal plate shape, or may have any shape appropriate for its application. 
     Further, in the first to third examples described above, the yoke parts  7 A- 7 F have the opened annular shape that surrounds the axially extending part of the coil part and that is opened on the rotary frame side; however, the shape and the arrangement of the yoke parts are not limited to these as long as the yoke parts are configured so as to allow the magnetic flux to pass therethrough upon generation of the magnetic field by the coil part. 
     Further, in the first to third examples described above, the magnetic elements are arranged on both sides in the Y direction with respect to the mirror  2 ; however, the magnetic element may be arranged only on one side in the Y direction with respect to the mirror  2 . In this case, the yoke may also be arranged only on one side in the Y direction with respect to the mirror  2 . 
     Further, in the first example and the second example described above, the inner torsion bars  20  and the outer torsion bars  30  are arranged coaxially; however, the extending direction of the inner torsion bars  20  may intersect the extending direction of the outer torsion bars  30 . That is, the torsion bars may have other configurations as long as they allow to transmit the rotation of the rotary frame  3 ,  3 B to the mirror  2  when the rotary frame  3 ,  3 B is rotated. 
     Further, in the third example, the magnetic elements  5 A,  5 B are arranged at the closest parts  22 ,  23  of the mirror  2 ; however, the magnetic elements  5 A,  5 B may be arranged at positions displaced in the X direction with respect to the closest parts  22 ,  23  of the mirror  2 . 
     Although the preferred configurations and methods and such for carrying out the present invention have been described above, the present invention is not limited to these. That is, although the present invention is mainly illustrated and described with respect to specific examples, those skilled in the art can make modifications to the above-described examples regarding the shape, materials, quantities and other detailed configurations without departing from the scope of the technical idea and purpose of the present invention. Therefore, since the description limiting the shape, material, etc. disclosed above is merely an example for facilitating the understanding of the present invention and does not limit the present invention, the description of name of a member without a part or all of the limitation of the shape, materials, etc., is within the present invention. 
     REFERENCE SIGNS LIST 
     
         
           1 A- 1 C driving device 
           2  mirror (first driven part) 
           22 ,  23  closest part 
           3 ,  3 B rotary frame (second driven part) 
           31 ,  32  central part (closest part) 
           4 ,  4 B base part 
           5 A- 5 F magnetic element 
           6 ,  6 B coil part 
           61  wiring 
           611 ,  612  axially extending part 
           7 A- 7 F yoke part 
           8  pedestal 
           20  inner torsion bar (first shaft part) 
           30  outer torsion bar (second shaft part) 
           40  torsion bar (shaft part) 
         S 1  reference plane