CN108303777A - Lens driver and the photographic means and electronic equipment for having it - Google Patents

Abstract

The lens driver of Miniaturizable is provided, and has its photographic means and electronic equipment.In the lens driver, moving parts has the lens mount for fixing lens, fixing member supports moving parts is moved freely along the radial direction of lens, and magnetite is fixed on the component in moving parts and fixed component, and displacement is fixed on coil on another component；Magnetite has positioned at the yoke of center and around the yoke, the polylith magnetite pieces that are fixed in the yoke；Polylith magnetite pieces be respectively provided with the first magnetic pole strength being fixed in yoke and with its second magnetic pole strength towards opposite direction；The magnetic pole that polylith magnetite pieces are magnetized to all first magnetic pole strengths is identical, and the second magnetic pole strength is opposite with its magnetic pole；Polylith magnetite pieces are fixed in yoke, and the radial direction of the direction of magnetization and lens intersects vertically；Displacement coil is radially axial Circular Winding with lens；The inner peripheral surface of displacement coil windings is at least part of to penetrate the second magnetic pole strength of gap face.

Description

Lens driving device, photographic device and electronic equipment equipped with it

【Technical field】

The present invention relates to a lens driving device used in electronic equipment such as mobile phones and smart phones, and a camera and electronic equipment equipped with the lens driving device.

【Background technique】

Considering the application on equipment such as camera equipment, the conventional lens driving device may have an anti-shake device. A conventional electromagnetic anti-shake device includes a magnet and a displacement coil, and compensates for vibration by moving a lens member in a direction perpendicular to the optical axis by the magnet and the displacement coil (Patent Document 1).

【Existing technical literature】

【Patent Literature】

[Patent Document 1] Patent Publication No. 2011-65140

【Content of invention】

【Problems to be solved by the invention】

The lens driving device in Patent Document 1 includes a lens holder, a focusing coil, a magnet, and a displacement coil. In the lens drive device, the focusing coil is wound on the lens frame and mounted on the inner side of the magnetic pole surface of the magnet through a gap. In a certain example, the coil for displacement is wound facing the outer magnetic pole surface of the magnet. The displacement coils in other examples are wound axially in the direction of the optical axis. Therefore, the radial dimension of the lens driving device becomes large.

The object of the present invention is to provide a miniaturized lens driving device, and a photographic device and electronic equipment equipped with the lens driving device.

【way of solving the problem】

A lens driving device, characterized in that it comprises a moving part, a fixed part, a magnet and a coil for displacement,

The moving part is equipped with a lens holder for fixing the lens, the fixed part supports the moving part to move freely along the radial direction of the lens, and the magnet is fixed to one of the moving part and the fixed part. On the component, the displacement is fixed on another component with a coil;

The magnet has a yoke at the center and a plurality of magnet pieces around the yoke and fixed on the yoke;

The plurality of magnet pieces respectively have a first magnetic pole surface fixed on the yoke and a second magnetic pole surface facing in the opposite direction to the first magnetic pole surface;

The plurality of magnet pieces are magnetized such that the magnetic poles of all the first magnetic pole surfaces are the same, and the magnetic poles of the second magnetic pole surface are opposite to those of the first magnetic pole surface;

The plurality of magnet pieces are fixed on the yoke, and the magnetization direction is perpendicular to the radial direction of the lens;

The coil for displacement is an annular winding with the radial direction of the lens as the axial direction;

At least a part of the inner peripheral surface of the displacement coil winding faces the second magnetic pole surface through a gap.

【Invention effect】

The present invention can provide a miniaturizable lens driving device, and a photographic device and electronic equipment equipped with the lens driving device.

【Description of drawings】

Fig. 1a and Fig. 1b are a diagram illustrating the first embodiment of the lens driving device according to the present invention, wherein Fig. 1a is a perspective view and Fig. 1b is a cross-sectional view.

FIG. 2 is an exploded perspective view of the lens driving device shown in FIG. 1a.

FIG. 3 is a perspective view showing a partially assembled state of the lens driving device shown in FIG. 1a.

Figure 4a is a schematic representation of the plurality of magnetite pieces making up the magnetite.

Figure 4b is a schematic representation of the yoke portion making up the magnet.

Figure 4c is an illustration of a magnet.

Fig. 4d is a cross-sectional view showing the positional relationship between the magnet and the displacement coil.

Fig. 5a, Fig. 5b, Fig. 5c and Fig. 5d are respectively other illustrations of magnets.

Fig. 6a and Fig. 6b are diagrams showing the second embodiment of the lens driving device according to the present invention. Figure 6a is a perspective view, and Figure 6b is a cross-sectional view.

FIG. 7 is an exploded perspective view of the lens driving device shown in FIG. 6a.

FIG. 8 is a perspective view showing a partially assembled state of the lens driving device shown in FIG. 6a.

【Number Description】

1 Lens driver

2 front frame

2a Peripheral sidewall

2b front side wall

2c Through hole

3 front side shrapnel

3a inner peripheral side

3b Peripheral side

3c wrist

3d jack

4 magnets

5(5a,···,5h) magnet sheet

6 Yoke

7a First magnetic pole face

7b Second pole face

8a First yoke face

8b Second yoke face

8c Third yoke face

9 magnet holder

9a Cylindrical wall

9b Magnet placement part

9c hole

10 lens holder

10a Lens holder

10b Peripheral surface

10c cylindrical wall

10d protrusion

11 Coil for focusing

12 rear side shrapnel

12a inner peripheral side

12b Peripheral side

12c wrist

13 Coil for displacement

13a Inner peripheral surface

14 Printed Substrates

15 wire spring

16 Rear frame

16a Through hole

16b Cylindrical wall

16c Magnet Arrangement Department

16d Anterior protrusion

16e Rear protrusion

17 moving parts

18 Fixed parts

【Detailed ways】

The embodiments of the present invention will be illustrated below in conjunction with the drawings.

This embodiment is a lens driving device applied to a camera used in electronic devices such as mobile phones and smart phones.

[Structure of the Lens Driving Device of the First Embodiment]

In the description, take the up and down direction in Figure 1b and Figure 6b as the direction of the optical axis of the lens, the upper side in Figure 1b and Figure 6b as the front side of the optical axis direction, and the lower side in Figure 1b and Figure 6b as the rear side of the optical axis direction side. The front side is the subject (not shown) side, and the rear side is the imaging element (not shown) side.

First, the structure of the lens driving device 1 of the first embodiment will be described with reference to FIGS. 1a to 4d.

As shown in FIGS. 1 a to 3 , the lens driving device 1 includes a moving member 17 , a fixing member 18 , a magnet 4 , and a coil 13 for displacement. The moving part 17 includes a front leaf spring 3 , a magnet holder 9 , a lens (not shown) holder 10 , a focusing coil 11 , and a rear leaf spring 12 . The fixed part 18 includes a front side frame body 2 and a rear side frame body 16, which can support the magnet frame 9, one of the components of the moving part 17, to move freely along the radial direction of the lens. The magnet 4 is fixed to the moving member 17 , and the coil 13 for displacement is fixed to the fixed member 18 .

The device is equipped with a plurality of magnets 4, such as four in this example. Each magnet 4 is fixed on the magnet frame 9, and faces the outer peripheral surface 10b of the lens frame 10 through a gap in the radial direction of the lens, and is arranged at intervals of 90 degrees in the circumferential direction.

As shown in FIGS. 4 a to 4 d , each magnet 4 has a yoke 6 at the center and a plurality of magnet pieces 5 a , 5 b , 5 c , 5 d located around the yoke 6 and fixed on the yoke 6 . Hereinafter, "magnet pieces 5" are sometimes collectively referred to as a plurality of magnet pieces 5a, 5b, 5c, and 5d. The magnet pieces 5 each include a first magnetic pole surface 7 a and a second magnetic pole surface 7 b. The first magnetic pole face 7 a is fixed to the yoke 6 . The second magnetic pole face 7b faces in the opposite direction to the first magnetic pole face 7a. The magnet pieces 5 are magnetized so that the first magnetic pole surfaces 7a have the same magnetic poles, for example, both are N poles, and the second magnetic pole surfaces 7b and the first magnetic pole surfaces 7a have opposite magnetic poles, for example, both are S poles. The magnet pieces 5 are fixed to the yoke 6 respectively, and the magnetization direction is perpendicular to the radial direction of the lens.

The yoke 6 has a first yoke surface 8a, a second yoke surface 8b, and a third yoke surface 8c. The first yoke surface 8 a faces the inner diameter direction in the lens radial direction and is opposed to the outer peripheral surface 10 b of the lens holder 10 . The second yoke face 8b faces in the outer diameter direction opposite to the first yoke face 8a. The third yoke surfaces 8 c face in a direction perpendicular to the radial direction of the lens, some faces in the direction of the optical axis, and some faces in a direction perpendicular to the aforementioned surface facing in the direction of the optical axis. The first pole faces 7 a of the magnet pieces 5 are all fixed around the third yoke face 8 c of the yoke 6 .

The magnetic flux emitted by the first magnetic pole surface 7a of each magnet piece 5a, 5b, 5c, 5d magnetized to the N pole is gathered into the yoke 6 from the third yoke surface 8c, and the magnetic flux from the first yoke surface 8a and the second magnetic flux The yoke surface 8b projects radially towards the lens. In this way, a larger magnetic flux density can be obtained.

In addition, magnetic flux enters the second magnetic pole surface 7b magnetized to the S pole of each magnet piece 5a, 5b, 5c, 5d from a direction substantially perpendicular to the lens radial direction.

As shown in FIGS. 1 a to 3 , the number of coils 13 for displacement is the same as that of magnets 4 . Each displacement coil 13 is an annular winding whose axis is the radial direction of the lens. At least a part of the inner peripheral surface 13a of the winding of each displacement coil 13 faces the second magnetic pole surface 7b of the magnet piece 5 through the gap.

The lens radial outer surface of the displacement coil 13 is fixed to the lens radial inner surface of the printed circuit board 14 . The printed circuit board 14 is a square plate-shaped body with four sides viewed from the radial direction of the lens, and the displacement coil 13 is fixed on each of the sides. Each surface of the printed circuit board 14 is attached to the inner surface of each outer peripheral side wall 2 a of the front side housing 2 . Therefore, the coils 13 for displacement are arranged at a certain distance along the circumferential direction of the lens, and are fixed to the fixing member 18 . The displacement coil 13 is energized through the printed circuit board 14 .

The lens holder 10 is a cylindrical body, and the lens support part 10a is formed in the inner peripheral side of this cylindrical body. The lens is placed at the lens support portion 10a.

The focusing coil 11 is a circular winding whose axis is the optical axis, and is fixed on the outer peripheral surface 10 b of the lens holder 10 . The outer peripheral surface of the focusing coil 11 faces the first yoke surface 8 a of the yoke 6 through a gap.

The magnet holder 9 is a cylindrical body. The function of the magnet frame 9 is to fix the magnet 4 and support the lens frame 10 to move freely in the direction of the optical axis. The magnet holder 9 is installed from the outer periphery of the lens holder 10 along the lens radial direction with a gap.

The magnet holder 9 is square when viewed from the optical axis direction, and has a cylindrical wall 9a that is square when viewed in the radial direction of the lens. Each cylindrical wall 9a is provided with a magnet accommodating portion 9b. The magnet accommodating part 9b has holes 9c, and the holes 9c are respectively square when viewed from the radial direction of the lens. The outer peripheral edge of the hole 9c other than the front side protrudes outward in the lens radial direction from the cylindrical wall 9a.

Each magnet 4 is fixed to the magnet mounting part 9b. Therefore, the magnets 4 are arranged at a certain distance along the circumferential direction of the lens, and are fixed on the moving part 17 .

The front elastic sheet 3 is made of conductive material and is divided into four parts. Each front elastic piece 3 has an inner peripheral side part 3a and an outer peripheral side part 3b. The outer peripheral side portion 3b is located further outside in the lens radial direction than the inner peripheral side portion 3a. The inner peripheral side part 3a is elastically connected to the outer peripheral side part 3b through the wrist part 3c. The inner peripheral side portion 3 a is fixed to the front side of the lens holder 10 . The outer peripheral side portions 3b are fixed to four corners on the front side of the magnet holder 9 .

The inner peripheral portion 3 a of the front elastic piece 3 is electrically connected to the focusing coil 11 . An insertion hole 3d for inserting the wire spring 15 is provided on the outer peripheral side portion 3b located on the radially outer side of the lens than the position fixed on the corner of the magnet holder 9 for fixing one end of the wire spring 15 and electrically connecting it. The focusing coil 11 is energized through the wire spring 15 and the front elastic piece 3 .

The rear elastic piece 12 is made of conductive material and is divided into four parts. Each rear elastic piece 12 has an inner peripheral side part 12a and an outer peripheral side part 12b. The outer peripheral side portion 12b is located further outside in the lens radial direction than the inner peripheral side portion 12a. The inner peripheral side part 12a is elastically connected to the outer peripheral side part 12b through the arm part 12c. The inner peripheral side portion 12 a is fixed to the rear side of the lens holder 10 . The outer peripheral side portions 12b are fixed to the four corners on the rear side of the magnet holder 9 .

The front elastic piece 3 and the rear elastic piece 12 can support the lens holder 10 to move along the optical axis direction against the magnet holder 9 .

The rear frame body 16 is a square plate-shaped body viewed from the optical axis direction. A through hole 16 is provided at the center of the rear frame body 16 through which the light passing through the lens can pass. The four corners of the rear frame body 16 respectively have wire springs 15 extending toward the front side in the direction of the optical axis.

Viewed from the direction of the optical axis, the front frame body 2 is a square box structure with an outer peripheral side wall 2a and a front side wall 2b. A through hole 2c is provided at the center of the front side wall 2b through which the light directed toward the lens can pass. The rear end of the outer peripheral side wall 2 a of the front frame body 2 is mounted on the outer edge of the rear frame body 16 .

Steel wire spring 15 is 4 conductive steel wires, and one end is fixed on the front side shrapnel 3 that is contained on the magnet frame 9, and the other end is fixed on the rear side frame body 16. The wire spring 15 can support the magnet frame 9, that is, the moving part 17, facing the rear frame body 16, that is, the fixed part 18, and freely move along the radial direction of the lens.

In the lens driving device 1 of the first embodiment, the displacement coil 13 is an annular winding with the radial direction of the lens as the axial direction, and the inner peripheral surface 13a of the winding of the displacement coil 13 faces the second end of the magnet piece 5 through a gap. Two magnetic pole faces 7b.

Therefore, compared with the coil structure for displacement wound opposite to the outer magnetic pole surface of the magnet and the coil structure for displacement wound with the optical axis as the axial direction, this design can miniaturize the radial dimension of the lens.

As will be described later, the inner peripheral surface 13a of the winding of the displacement coil 13 faces the second magnetic pole surface 7b of the magnet 5 through a gap so that the displacement coil 13 generates an electromagnetic force. Therefore, in terms of the structure in which the inner peripheral surface 13a of the winding of the displacement coil 13 faces the second magnetic pole surface 7b of the magnet 5 through the gap, as shown in FIG. The second magnetic pole surface 7b of the magnet piece 5 is enough.

When the displacement coil 13 of the lens driving device 1 has a current passing along the direction of the arrow 19 shown in Figure 4d, the magnetic flux linked by the current to the second magnetic pole surface 7b of each magnet piece 5 can make the displacement coil 13 generates an electromagnetic force directed toward the radially outer side of the lens. The reaction force of this electromagnetic force can cause the magnet 4 to generate a force toward the radially inner side of the lens, so that the moving part 17 and the magnet 4 can move along the direction of the force generated by the magnet.

When the current in the coil 13 for displacement passes along the direction of the arrow 20 shown in FIG. 4 d , the moving part 17 moves in the direction opposite to that of the arrow 19 .

When a current flows in the coil 13 for displacement, the moving member 17 moves together with the magnet 4 along the radial direction of the lens toward the fixed member 18 for fixing the coil 13 for displacement. That is, the lens frame 10 and the lens fixed on the frame move toward the front side frame body 2 and the rear side frame body 16 along the lens radial direction. In this way, the anti-shake function can be realized.

When a current passes through the focusing coil 11 along the direction of the arrow 21 shown in FIG. side electromagnetic force, so that the lens holder 10 and the lens fixed on the holder move to the front side of the optical axis direction.

When the current in the focusing coil 11 passes along the direction of the arrow 22 shown in FIG. 3 , the lens holder 10 and the lens fixed on the holder move to the rear side in the direction of the optical axis.

Therefore, when a current flows through the focusing coil 11 , the lens holder 10 and the lens fixed on the holder will move along the optical axis. The lens will move to the position where the restoration force and the thrust (electromagnetic force) of the front side elastic piece 3 and the rear side elastic piece 12 are balanced to realize actions such as focusing. Current can flow in only one direction.

The deformation of the magnet 4 is illustrated below with reference to FIGS. 5 a to 5 d.

The magnet 4 shown in FIG. 5 a has a plate-shaped yoke 6 in the shape of a cuboid and four magnet pieces 5 with trapezoidal cross-sections. The length of the first magnetic pole surface 7a of the magnet piece 5 is shorter than the length of the second magnetic pole surface 7b. The first pole faces 7 a of each magnet piece 5 are fixed around the third yoke face 8 c of the yoke 6 . And the second magnetic pole surface 7b of the magnet piece 5 is connected with the second magnetic pole surface 7b of other adjacent magnet pieces 5 . Therefore, since the outer peripheral surface of the magnet 5 is all the second magnetic pole surface 7b, the magnetic flux interlinked with the displacement coil 13 is less uneven.

The magnet 4 shown in FIG. 5 b has a plate-shaped magnetic yoke 6 in the shape of a cuboid and two plate-shaped magnet pieces 5 in the shape of a rectangular parallelepiped. The magnet pieces 5 clamp the yoke 6 back and forth along the optical axis. That is, two surfaces of the third yoke surface 8c of the yoke 6 face the optical axis direction, and the first magnetic pole surfaces 7a of the magnet pieces 5a, 5b are respectively fixed on the two third yoke surfaces 8c. Therefore, the lens driving device 1 can be easily manufactured.

The magnet piece 5e of the magnet 4 shown in FIG. 5c is fixed on the second yoke surface 8b of the magnet 4 shown in FIG. c5a. The first magnetic pole surface 7 a of the magnet piece 5 e is also magnetized to the same magnetic pole as the first magnetic pole surface 7 a of the other magnet piece 5 . Therefore, the magnetic flux of each magnet piece 5a, 5b, 5c, 5d, 5e is emitted only from the first yoke surface 8a, so the magnetic flux density is larger than that of the magnet shown in Fig. 5a.

The magnet 4 shown in FIG. 5 d has a disk-shaped magnetic yoke 6 and three fan-shaped plate-shaped magnet pieces 5 . The third yoke face 8c faces a direction perpendicular to the radial direction of the lens. The first magnetic pole surfaces 7a of the respective magnet pieces 5f, 5g, and 5h are fixed around the entire circumference of the third yoke surface 8c. Since the magnetization direction can be controlled according to the shape of the magnet piece 5, it is easy to manufacture.

[Structure of Lens Driving Device of Second Embodiment]

First, the structure of the lens driving device 1 according to the second embodiment will be described with reference to FIGS. 6a to 8 . In the illustrated lens driving device 1 , the magnet 4 is fixed to the fixed member 18 , and the displacement coil 13 is fixed to the movable member 17 . Except that the structures of the moving part 17 and the fixed part 18 are changed, the others are the same as the first embodiment, so the description thereof can be cited.

The moving part 17 includes the lens holder 10 and the focusing coil 11 . And the fixing part 18 includes the front side frame body 2 and the rear side frame body 16, without the magnet frame 9 and the wire spring 15 and the like. The front elastic piece 3 and the rear elastic piece 12 connect the fixed part 18 and the moving part 17, and support the moving part 17 to move freely along the optical axis direction of the lens and the radial direction of the lens.

The lens holder 10 is equipped with the cylindrical wall 10c, and the cylindrical wall 10c is square when viewed from the lens radial direction. The focusing coil 11 is fixed on the outer peripheral surface of the cylindrical wall 10c. The front and rear ends of the respective surfaces of the cylindrical wall 10c are formed with protrusions 10d protruding outward. On the outer peripheral side of the focusing coil 11, the displacement coil 13 is sandwiched between the two protrusions 10d, 10d at the front and rear ends.

The inner peripheral side portion 3 a of the front elastic piece 3 is fixed to the front side of the lens holder 10 . The inner peripheral side portion 12 a of the rear elastic piece 12 is fixed to the rear side of the lens holder 10 . The focusing coil 11 and the displacement coil 13 are electrically connected to the front elastic piece 3 and/or the rear elastic piece 12 .

The rear housing 16 is cylindrical when viewed from the optical axis direction, and has a cylindrical wall 16b extending from the square outer peripheral edge to the front side in the optical axis direction. Notches are formed on each surface of the cylindrical wall 16b from the front edge to the center of the cylindrical wall 16b to form a magnet arrangement portion 16c. The magnet 4 is attached to each magnet arrangement part 16c. Therefore, the magnets 4 are arranged at a certain distance along the circumferential direction of the lens and fixed on the fixing member 18 .

In addition, front protrusions 16 d are respectively provided at four corners of the front edge of the rear frame 16 . The front protrusion 16d fits into the insertion hole 3d of the front elastic piece 3, and the outer peripheral side portion 3b of the front elastic piece 3 is fixed to the front edge of the cylindrical wall 16b.

The four corners of the bottom of the rear frame body 16 are respectively provided with rear protrusions 16e. The rear protrusion 16e fits into the insertion hole 12d of the rear elastic piece 12, and the outer peripheral side portion 12b of the rear elastic piece 12 is fixed to the bottom of the cylindrical wall 16b.

The front side frame body 2 is made of a magnetic material, and it is also acceptable to abut against the radially outer side of the magnet 4 .

When current flows through the coil 13 for displacement, the moving part 17 moves toward the fixed part 18 used for fixing the magnet 4 along the lens radial direction. That is, the lens frame 10 and the lens fixed on the frame move toward the front side frame body 2 and the rear side frame body 16 along the lens radial direction. In this way, the anti-shake function can be realized.

However, when current flows through the focusing coil 11 , the lens holder 10 and the lenses fixed on the holder will move along the optical axis. The lens will move to the position where the restoration force and the thrust (electromagnetic force) of the front side elastic piece 3 and the rear side elastic piece 12 are balanced to realize actions such as focusing.

In the lens driving device 1 of the second embodiment, the same as the lens driving device 1 of the first embodiment, the displacement coil 13 is an annular winding with the radial direction of the lens as the axial direction, and the inner peripheral surface of the winding is 13a, as shown in FIG. 6b, at least a part of it faces the second magnetic pole faces 7b of the plurality of magnet pieces 5 through the gap. Therefore, the lens driving device 1 according to the second embodiment can also reduce the radial size of the lens compared with the conventional structure of the lens driving device.

Furthermore, in this example, four magnets 4 and four coils for displacement 13 are respectively provided in the circumferential direction, but two each may be provided. At this time, it is preferable to arrange the combination of the two magnets 4 and the displacement coil 13 at intervals of 90 degrees. In addition, a combination of three sets of magnets 4 and coils 13 for displacement may be provided. In this case, the intervals are preferably equidistant in the circumferential direction.

In addition, the magnet sheet 5 is not limited to the division method shown in FIG. 4a to FIG. 4d and FIG. 5a to FIG. 5d , for example, it can be divided into two parts, or can be divided into more parts.

In addition, the first yoke surface 8a and the radial inner surface of the magnet piece 5 are drawn on the same horizontal plane on the drawings, but it is not limited to this in actual application. The first yoke surface 8a faces the diameter of the magnet piece 5. It may protrude toward the inner side or be recessed. In addition, the 1st yoke surface 8a may be made into a curved surface.

[Embodiment of Camera Device and Electronic Equipment]

The lens driving device 1 described above can reduce the size of the lens in the radial direction. Therefore, electronic devices such as camera devices, mobile phones, and smart phones using the lens driving device 1 of this embodiment can also reduce the radial size of the lens.

The most ideal embodiment of the present invention has been described above with reference to the appended drawings, but the present invention is not limited to the above embodiment, and various changes can be made within the technical scope grasped according to the description of the patent application scope.

Claims (12)

1. A lens driving device, characterized in that, possesses a moving part, a fixed part, a magnet and a displacement coil, The moving part is provided with a lens holder for fixing the lens, the fixing part supports the moving part to move freely along the radial direction of the lens, and the magnet is fixed to one of the moving part and the fixed part On, the displacement is fixed on another part with a coil; The magnet has a yoke at the center and a plurality of magnet pieces around the yoke and fixed on the yoke; The plurality of magnet pieces respectively have a first magnetic pole surface fixed on the yoke and a second magnetic pole surface facing in the opposite direction to the first magnetic pole surface; The plurality of magnet pieces are magnetized such that the magnetic poles of all the first magnetic pole surfaces are the same, and the magnetic poles of the second magnetic pole surface are opposite to those of the first magnetic pole surface; The plurality of magnet pieces are fixed on the yoke, and the magnetization direction is perpendicular to the radial direction of the lens; The coil for displacement is an annular winding with the radial direction of the lens as the axial direction; At least a part of the inner peripheral surface of the displacement coil winding faces the second magnetic pole surface through a gap. 2. The lens driving device according to claim 1, wherein a plurality of the magnets and the displacement coils are arranged at a certain distance along the circumferential direction of the lens. 3. The lens driving device according to claim 1, wherein the yoke has a first yoke surface, a second yoke surface and a third yoke surface, and the first yoke surface is along the The lens is radially opposite to the outer peripheral surface of the lens holder, the second yoke surface faces in the opposite direction to the first yoke surface, and the third yoke surface faces in a direction perpendicular to the lens radial direction, The first pole surface of the magnet piece is fixed on the third yoke surface. 4 . The lens driving device according to claim 3 , wherein the magnet pieces are arranged along the third yoke surface in the entire circumferential direction of the yoke. 5. The lens driving device according to claim 4, wherein the third yoke surface has a surface facing the optical axis direction of the lens and a surface facing a direction perpendicular to the surface facing the optical axis direction . 6. The lens driving device according to claim 3, characterized in that: the third yoke surface has two surfaces facing the optical axis direction of the lens, and the magnet pieces are respectively fixed on the two surfaces . 7. The lens driving device according to claim 3, characterized in that: the lens driving device further comprises other magnet pieces, and the first magnetic pole surface of the other magnet pieces is fixed on the second magnetic yoke surface . 8. The lens driving device according to claim 1, characterized in that: the lens driving device also has a focusing coil, and the focusing coil is an annular winding with the optical axis direction of the lens as the axial direction, and is fixed The yoke has a surface facing the outer peripheral surface of the focusing coil on the outer peripheral surface of the lens holder. 9. The lens driving device according to claim 8, further comprising a magnet holder for fixing the magnet, and the magnet holder fixes the magnet and supports the lens holder toward the Free movement in the direction of the optical axis, The moving member includes the lens holder and a magnet holder for fixing the magnet, and the fixing member fixes the displacement coil. 10. The lens driving device according to claim 8, wherein the moving member includes the lens holder for fixing the displacement coil, and the fixing member fixes the magnet. 11. A photographic device comprising the lens driving device according to any one of claims 1 to 10. 12. An electronic device comprising the lens drive device according to any one of claims 1 to 10.