JP6030287B2 - Lens driving device and method of manufacturing lens driving device - Google Patents

Description

  The present invention relates to a lens driving device mounted on a relatively small camera used in a mobile phone or the like, and a method for manufacturing the lens driving device.

  Conventionally, as a lens driving device for driving a photographing lens of a camera mounted on a mobile phone or the like, a holder that holds the lens and moves in the optical axis direction, a driving coil that drives the holder in the optical axis direction, and driving A lens driving device including a magnet is known (see, for example, Patent Document 1). The lens driving device described in Patent Document 1 is formed so that the shape when viewed from the optical axis direction is a square shape. The lens driving device includes eight driving magnets formed in a plate shape, and the driving magnets are arranged at each of the four corners of the lens driving device and at each of the four sides of the lens driving device. In this lens driving device, the driving coil is fixed to the holder. This driving coil is wound so that the shape when viewed from the optical axis direction is an octagonal shape, and each side of the driving coil wound in the octagonal shape is the diameter of the lens driving device. It faces each of the eight drive magnets inside in the direction.

  The lens driving device also includes a yoke that covers the outer periphery of the driving coil and the driving magnet. The yoke is arranged on the inner peripheral side of the drive coil in the radial direction of the lens driving device and the octagonal cylindrical outer yoke piece covering the outer surface of the eight driving magnets in the radial direction of the lens driving device. Individual inner yoke pieces. The four inner yoke pieces are arranged to face the inner side surfaces of the driving magnets arranged at the four corners of the lens driving device via the driving coils. In this lens driving device, the inner yoke piece is formed in a curved plate shape having an arc shape when viewed from the optical axis direction.

  Further, the lens driving device includes an upper leaf spring for holding the holder so as to be movable in the optical axis direction. The upper leaf spring includes an outer ring portion fixed to the yoke or the like, an inner ring portion fixed to the holder, and a bridge portion that connects the outer ring portion and the inner ring portion. Since the outer yoke piece and the inner yoke piece are integrally formed in the yoke of this lens driving device, it is inside the yoke (that is, between the outer yoke piece and the inner yoke piece in the radial direction of the lens driving device). When the outer ring portion is disposed, the bridge portion must be formed so as to avoid the inner yoke piece, and the shape of the bridge portion becomes complicated. Therefore, the upper leaf spring is disposed outside the yoke (subject side with respect to the yoke). Further, in this lens driving device, since the upper leaf spring is disposed outside the yoke, a cover for protecting the upper leaf spring is provided.

JP 2008-191332 A

  In the lens driving device described in Patent Document 1, the outer surfaces of the eight driving magnets are covered with the outer yoke pieces, and the driving magnets are arranged on the inner surfaces of the driving magnets arranged at the four corners of the lens driving device. Since the inner yoke pieces are arranged to face each other, it is possible to increase the density of magnetic flux generated by the driving magnet and passing through the driving coil. However, in this lens driving device, since the yoke includes the inner yoke piece, the upper leaf spring is disposed outside the yoke so that the shape of the upper leaf spring is not complicated. As a result, this lens driving device requires a separate cover for protecting the upper leaf spring, which complicates the configuration of the lens driving device.

  Therefore, the object of the present invention is to increase the density of magnetic flux generated by the driving magnet and passing through the driving coil, and the leaf spring connecting the movable body and the fixed body does not have to have a complicated shape. An object of the present invention is to provide a lens driving device capable of simplifying the configuration while protecting the leaf spring. Moreover, the subject of this invention is providing the manufacturing method of this lens drive device.

In order to solve the above problems, a lens driving device of the present invention includes a movable body that holds a lens and is movable in the optical axis direction of the lens, a fixed body that holds the movable body so as to be movable in the optical axis direction, and a movable body. a drive mechanism for driving the body in the optical axis direction, and a leaf spring for connecting the fixed body and the movable body, a lens driving shapes Ru is formed in a substantially rectangular shape when viewed in the optical axis direction an apparatus, the drive mechanism includes a drive coil which is fixed to the movable body, is fixed to the fixed body, and a driving magnet which is opposed to the drive coil in the radial direction of the outer lens Rutotomoni, As the driving magnets, there are provided first driving magnets disposed at the four corners of the lens driving device, and the fixed body is made of a magnetic material and covers one end surface of the driving magnet in the optical axis direction. And arranged inside the drive coil in the radial direction A yoke member having an inner yoke portion; and a cover member formed separately from the yoke member and made of a magnetic material, and covering the outer peripheral side of the movable body, the drive mechanism, and the leaf spring. A subject-side end surface portion constituting the subject-side end surface of the driving device is provided, and the outer peripheral side of the yoke member is completely covered, and a gap is provided between the yoke member and the cover member in a direction perpendicular to the optical axis direction. The end plate portion is formed in a substantially frame shape, is connected to the subject side end of the inner yoke portion, and overlaps the subject side end surface portion when viewed from the optical axis direction. A gap is formed between the lens and the subject-side end surface, and the driving coil is formed by being wound so that the shape when viewed from the optical axis direction is a substantially octagonal shape, and is formed in a substantially octagonal shape. Eight of drive coils Are substantially parallel to each of the four side surfaces of the lens driving device, the remaining four sides of the eight sides of the driving coil are arranged at the four corners of the lens driving device, and the inner yoke portion is The plate is formed in a plate shape that rises in the optical axis direction from the inner peripheral end surface of the end plate portion, and is disposed to face the first drive magnet via the drive coil, and is connected to the drive coil of the first drive magnet. The opposing surface is formed in a planar shape .

  In the lens driving device according to the present invention, a cover member in which the inner yoke portion is disposed inside the driving coil in the radial direction of the lens and the outer peripheral side of the driving mechanism having the driving coil and the driving magnet is formed of a magnetic material. Covered with Therefore, in the present invention, it is possible to increase the density of magnetic flux generated by the driving magnet and passing through the driving coil.

  In the present invention, the cover member that covers the outer peripheral side of the movable body, the drive mechanism, and the leaf spring is formed separately from the yoke member having the inner yoke portion. Therefore, it is possible to dispose the leaf spring at a position avoiding the inner yoke portion and inside the cover member. Therefore, even if the shape of the leaf spring is not complicated, the leaf spring can be disposed inside the cover member and can be protected by the cover member. In addition to the cover member functioning as a yoke, There is no need to provide a separate member for protecting the leaf spring. As a result, in the present invention, it is possible to simplify the configuration of the lens driving device while protecting the leaf spring without making the leaf spring in a complicated shape.

  In the present invention, since the outer peripheral side of the movable body, the drive mechanism, and the leaf spring is covered by the cover member, the cover member can prevent foreign matter from entering the lens drive device. In the lens driving device described in Patent Document 1, an opening for preventing interference with the outer yoke piece is formed on the side surface of the cover and the side surface of the base fixed to the cover. In the apparatus, it is difficult to prevent foreign matter from entering the lens driving device unless a case for covering the cover and the base is separately provided.

Further, in the present invention, the end plate portion is formed in a substantially frame shape, the inner yoke portion, which is formed in a flat plate shape which rises from the inner peripheral end surface of the end plate portion in the optical axis direction, bending the inner yoke portion It can be formed by processing. Therefore, the thickness of the inner yoke portion can be made equal to the thickness of the end plate portion, and magnetic saturation at the inner yoke portion can be suppressed. In addition, when the inner yoke portion is formed in a curved plate shape like the inner yoke piece described in Patent Document 1, the inner yoke portion is formed by drawing, so that the thickness thereof is the end plate portion. As a result, magnetic saturation is likely to occur in the inner yoke portion.

In the present invention , the lens driving device is formed so as to have a substantially square shape when viewed from the optical axis direction, and the driving mechanism is disposed at each of the four corners of the lens driving device as a driving magnet. that first comprises a drive magnet, the drive coil, the shape when viewed in the optical axis direction is formed by winding in a substantially octagonal shape, the driving coil is formed in a substantially octagonal eight four sides of the edges, substantially are parallel to Tsu name as each of the four sides of the lens driving device, the remaining four sides of the octagonal drive coils are arranged in the four corners of the lens drive device, the inner The yoke portion is disposed to face the first driving magnet via the driving coil, and the surface of the first driving magnet facing the driving coil is formed in a flat shape . For this reason, the distance between the facing surface of the first driving magnet facing the driving coil and the inner yoke portion is kept equal, and the facing of the inner yoke portion facing the facing surface of the first driving magnet facing the driving coil. The area can be increased. Therefore, it is possible to effectively increase the density of the magnetic flux generated by the driving magnet and passing through the driving coil.

  In this invention, it is preferable that a drive mechanism is provided with the 2nd drive magnet arrange | positioned along each of the four side surfaces of a lens drive device as a drive magnet. If comprised in this way, it will become possible to raise the drive force of a drive mechanism.

In the present invention, the first outer drive magnet is formed in a columnar shape when viewed in the optical axis direction becomes substantially trapezoidal shape, yaw click member, which covers the first drive magnet from the outside in the radial direction It is preferable to provide a yoke part. If comprised in this way, an outer yoke part can be arrange | positioned using the four corners of the lens drive device which becomes a dead space easily. Therefore, it is possible to effectively increase the density of the magnetic flux generated by the driving magnet and passing through the driving coil without increasing the size of the lens driving device.

In the present invention, the lens driving device of the yoke member with respect to the shooting side end face, provided with a positioning member for positioning in the optical axis direction, the positioning member is preferably formed in the yoke member and the other member . If comprised in this way, it will become possible to position a yoke member accurately in an optical axis direction.

  The lens driving device according to the present invention includes, for example, a manufacturing method of a lens driving device including an assembly process in which a positioning member, a leaf spring, a yoke member, and a driving magnet are sequentially stacked in this order on the surface of the subject-side end surface opposite to the subject. Manufactured by. In the lens driving device of the present invention, since the yoke member and the cover member are formed separately, the positioning member, the leaf spring, the yoke member, and the driving magnet are stacked in this order in the cover member, so that the light Positioning of these members in the axial direction and fixing of these members can be easily performed. Therefore, the lens driving device can be easily assembled.

  As described above, in the lens driving device of the present invention, it is possible to increase the density of the magnetic flux generated by the driving magnet and passing through the driving coil, and the leaf spring connecting the movable body and the fixed body is complicated. Even without the shape, the configuration can be simplified while protecting the leaf spring. Moreover, according to the manufacturing method of the lens driving device of the present invention, the lens driving device can be easily assembled.

It is a perspective view of the lens drive device concerning an embodiment of the invention. It is sectional drawing of the EE cross section of FIG. It is a disassembled perspective view of the lens drive device shown in FIG. It is a perspective view of the state which removed the cover member and the spacer from the lens drive device shown in FIG. FIG. 3 is a bottom view showing the drive mechanism and the yoke member shown in FIG. 2 from the non-subject side. It is sectional drawing for demonstrating the structure of the yoke member concerning other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Schematic configuration of lens driving device)
FIG. 1 is a perspective view of a lens driving device 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line EE of FIG. FIG. 3 is an exploded perspective view of the lens driving device 1 shown in FIG. In the following description, as shown in FIG. 1 and the like, the three directions orthogonal to each other are defined as the X direction, the Y direction, and the Z direction, the X direction is the left-right direction, the Y direction is the front-rear direction, and the Z direction is the up-down direction. And Further, the Z1 direction side in FIG. 1 and the like is the “upper” side, and the Z2 direction side is the “lower” side.

  The lens driving device 1 of this embodiment is mounted on a relatively small camera used in a mobile phone, a drive recorder, a surveillance camera system, or the like. As shown in FIG. Is formed. Specifically, the lens driving device 1 is formed so that the shape of the lens for photographing when viewed from the direction of the optical axis L (optical axis direction) is a substantially square shape. The four side surfaces of the lens driving device 1 are substantially parallel to the left-right direction or the front-rear direction.

  In this embodiment, the Z direction (vertical direction) is substantially coincident with the optical axis direction. In addition, in a camera equipped with the lens driving device 1 of the present embodiment, an imaging element (not shown) is arranged on the lower side, and a subject arranged on the upper side is photographed. That is, in this embodiment, the upper side (Z1 direction side) is the subject side (object side), and the lower side (Z2 direction side) is the anti-subject side (imaging element side, image side).

  As shown in FIGS. 1 and 2, the lens driving device 1 includes a movable body 2 that holds a photographing lens and is movable in the optical axis direction, and a fixed body that holds the movable body 2 so as to be movable in the optical axis direction. 3 and a drive mechanism 4 for driving the movable body 2 in the optical axis direction. In addition, the lens driving device 1 includes leaf springs 5 and 6 (see FIG. 2) that connect the movable body 2 and the fixed body 3. That is, the movable body 2 is movably held by the fixed body 3 via the leaf springs 5 and 6. In this embodiment, the leaf spring 5 is disposed on the upper end side of the movable body 2, and the leaf spring 6 is disposed on the lower end side of the movable body 2. In addition, illustration of the leaf | plate springs 5 and 6 is abbreviate | omitted in FIG.

  The movable body 2 includes a sleeve 8 that holds a lens holder 7 to which a plurality of lenses are fixed. The fixed body 3 includes a cover member 10 constituting a side surface of the lens driving device 1, a base member 11 constituting an end surface of the lens driving device 1 on the side opposite to the subject, and a spacer 12 to which a part of the leaf spring 5 is fixed. The yoke member 13 is formed separately from the cover member 10 and made of a magnetic material. In FIGS. 2 and 3, the lens holder 7 is not shown.

  The lens holder 7 is formed in a substantially cylindrical shape. A plurality of lenses having a circular shape when viewed from the optical axis direction are fixed to the inner peripheral side of the lens holder 7. Hereinafter, the radial direction of this lens is referred to as “radial direction”.

  The sleeve 8 is formed of, for example, a resin material and has a substantially cylindrical shape. As shown in FIG. 3, the inner peripheral surface of the sleeve 8 is formed so that the shape when viewed from the optical axis direction is substantially circular. The outer peripheral surface on the upper end side of the sleeve 8 is formed so that the shape when viewed from the optical axis direction is substantially circular. The outer peripheral surface on the lower end side of the sleeve 8 is formed so that the shape when viewed from the optical axis direction is a substantially octagonal shape. Four of the eight side surfaces constituting the outer peripheral surface on the lower end side of the sleeve 8 are arranged so as to be substantially parallel to each of the four side surfaces of the lens driving device 1, and the outer peripheral surface on the lower end side of the sleeve 8. The remaining four side surfaces of the eight side surfaces constituting the lens are arranged at the four corners of the lens driving device 1 in a state inclined by approximately 45 ° with respect to the front-rear direction and the left-right direction. Further, a substantially octagonal flange portion 8 a that extends outward in the radial direction is formed at the lower end portion of the sleeve 8. The outer peripheral surface of the lens holder 7 is fixed to the inner peripheral surface of the sleeve 8.

  The cover member 10 is made of a magnetic material. Moreover, the cover member 10 is formed in the substantially square cylinder shape with the bottom which has the bottom part 10a and the cylinder part 10b. The bottom portion 10 a arranged on the upper side constitutes an end surface on the subject side of the lens driving device 1. That is, the bottom portion 10 a of the present embodiment is a subject side end surface portion that constitutes a subject side end surface of the lens driving device 1. A through hole 10c is formed at the center of the bottom 10a. The cover member 10 covers the outer peripheral side of the movable body 2, the drive mechanism 4, and the leaf springs 5 and 6. In this embodiment, the cover member 10 almost completely covers the outer peripheral side of the movable body 2, the drive mechanism 4, and the leaf springs 5 and 6. In this embodiment, the cover member 10 completely covers the outer peripheral sides of the spacer 12 and the yoke member 13.

  The base member 11 is made of, for example, a resin material. The base member 11 is formed in a block shape having a substantially square shape when viewed from the optical axis direction. The base member 11 is attached to the lower end side of the cover member 10. A through hole 11 a is formed at the center of the base member 11.

  The spacer 12 is formed of, for example, a resin material and is formed in a substantially square flat block shape. In addition, a through-hole 12a having a substantially octagonal shape when viewed from the optical axis direction is formed at the center of the spacer 12, and the spacer 12 is formed in a frame shape. The spacer 12 is fixed to the lower surface of the bottom 10 a of the cover member 10.

  The leaf spring 5 includes an annular movable body fixing portion fixed to the upper end side of the sleeve 8, a fixed body fixing portion fixed between the spacer 12 and the yoke member 13, and the movable body fixing portion and the fixed body fixing. And a plurality of arm parts connecting the parts. The leaf spring 5 is fixed to the sleeve 8, the spacer 12, and the yoke member 13 so that the thickness direction and the optical axis direction substantially coincide. The leaf spring 6 includes a movable body fixing portion that is fixed to the lower end side of the sleeve 8, a fixed body fixing portion that is fixed to the base member 11, and an arm portion that connects the movable body fixing portion and the fixed body fixing portion. ing. The leaf spring 6 is fixed to the sleeve 8 and the base member 11 so that the thickness direction and the optical axis direction substantially coincide with each other. The leaf spring 6 is electrically divided into two spring pieces, and also has a function of a power feeding terminal to a driving coil 15 (to be described later) constituting the driving mechanism 4.

(Configuration of drive mechanism and yoke member)
FIG. 4 is a perspective view of the lens driving device 1 shown in FIG. 1 with the cover member 10 and the spacer 12 removed. FIG. 5 is a bottom view showing the drive mechanism 4 and the yoke member 13 shown in FIG. 2 from the non-subject side.

  The drive mechanism 4 includes a drive coil 15 fixed to the outer peripheral side of the sleeve 8, a drive magnet 17 as a first drive magnet disposed at each of the four corners of the lens drive device 1, and the lens drive device 1. And a drive magnet 18 as a second drive magnet disposed along each of the four side surfaces.

  The driving coil 15 is formed by being wound so that the shape when viewed from the optical axis direction is a substantially octagonal shape. As shown in FIG. 3, the driving coil 15 is fixed to the upper surface of the flange portion 8 a of the sleeve 8. Specifically, the drive coil 15 is formed with four long side portions 15a arranged substantially parallel to the front-rear direction or the left-right direction, and shorter than the long side portions 15a, and is formed with respect to the front-rear direction and the left-right direction. The short side portion 15b is arranged in a state inclined at about 45 °, the long side portion 15a is substantially parallel to each of the four side surfaces of the lens driving device 1, and the short side portion The driving coil 15 is fixed to the upper surface of the flange portion 8a so that 15b is arranged at the four corners of the lens driving device 1. That is, each of the four sides of the eight sides of the drive coil 15 formed in a substantially octagonal shape is substantially parallel to each of the four side surfaces of the lens driving device 1, and among the eight sides of the drive coil 15 The driving coil 15 is fixed to the upper surface of the flange portion 8a so that the remaining four sides of the lens are disposed at the four corners of the lens driving device 1, respectively.

  The inner side surface of the long side portion 15 a is in contact with the four side surfaces on the lower end side of the sleeve 8 disposed substantially parallel to each of the four side surfaces of the lens driving device 1. A gap S is formed between the inner side surface of the short side portion 15b and the four side surfaces on the lower end side of the sleeve 8 disposed at the four corners of the lens driving device 1 (see FIG. 3).

  The drive magnet 17 is formed in a columnar shape having a substantially isosceles trapezoidal shape when viewed from the optical axis direction, and as shown in FIG. 5, two parallel planes 17a that are substantially parallel to each other. , 17b and two flat inclined surfaces 17c inclined with respect to the parallel surfaces 17a, 17b. The parallel surface 17a is formed to have a larger area than the parallel surface 17b. The driving magnet 17 is fixed to the inner surface of the four corners of the cylindrical portion 10b of the cover member 10 so that the outer surface of the short side portion 15b of the driving coil 15 and the parallel surface 17a face each other. The magnet 17 is disposed opposite to the driving coil 15 on the outer side in the radial direction. The parallel surface 17a of this embodiment is a surface facing the driving coil 15 of the driving magnet 17.

  The drive magnet 18 is formed in a substantially rectangular plate shape. Specifically, the drive magnet 18 is formed in a substantially rectangular plate shape whose shape when viewed from the optical axis direction is a flat rectangular shape. The driving magnet 18 is fixed to the inner side surface of the cylindrical portion 10b of the cover member 10 so as to face the outer surface of the long side portion 15a of the driving coil 15, and the driving magnet 18 is arranged in the radial direction. The drive coil 15 is arranged on the outer side. The length of the drive magnet 18 in the optical axis direction is substantially equal to the length of the drive magnet 17 in the optical axis direction.

  The yoke member 13 includes an end plate portion 13a disposed so as to cover the upper end surfaces of the drive magnets 17 and 18, and an inner yoke portion 13b disposed on the inner side of the drive coil 15 in the radial direction. The yoke member 13 is formed by pressing a metal plate made of a magnetic material. Specifically, the yoke member 13 is formed by punching with a press and bending with a press.

  The end plate portion 13a is formed in a flat plate shape that is substantially orthogonal to the optical axis direction. Moreover, the end plate part 13a is formed in a substantially frame shape. Specifically, the end plate portion 13a is formed in a substantially frame shape in which the shape of the outer peripheral end surface is a substantially square shape and the shape of the inner peripheral end surface is a substantially octagonal shape. Of the eight sides of the inner peripheral end face of the end plate portion 13a formed in a substantially octagonal shape, each of the four sides is arranged substantially parallel to each of the four side surfaces of the lens driving device 1, and the inner circumference of the end plate portion 13a. Each of the remaining four sides of the eight sides of the end face is disposed at each of the four corners of the lens driving device 1 in an inclined state of approximately 45 ° with respect to the front-rear direction and the left-right direction. The upper end surfaces of the drive magnets 17 and 18 are in contact with the lower surface of the end plate portion 13a. The four corners of the outer peripheral end surface of the end plate portion 13a are chamfered.

  The inner yoke portion 13b is formed in a substantially rectangular or substantially square flat plate shape. The inner yoke member 13b is formed so as to rise in the optical axis direction from the inner peripheral end face of the end plate portion 13a. Specifically, the inner yoke member 13b is formed to rise downward from each of the four sides of the inner peripheral end surface of the end plate portion 13a disposed at the four corners of the lens driving device 1. The inner yoke portion 13b is formed in a gap S formed between the four side surfaces on the lower end side of the sleeve 8 arranged at the four corners of the lens driving device 1 and the inner side surface of the short side portion 15b of the driving coil 15. Are arranged. That is, the inner yoke portion 13b is disposed on the inner side of the short side portion 15b in the radial direction, and is disposed to face the driving magnet 17 through the short side portion 15b. The length of the inner yoke portion 13b in the optical axis direction is shorter than the length of the driving magnet 17 in the optical axis direction.

  The upper surface of the yoke member 13 is fixed to the lower surface of the spacer 12. Further, the upper surface of the yoke member 13 is in contact with the lower surface of the fixed body fixing portion of the leaf spring 5. The upper surface of the fixed body fixing portion of the leaf spring 5 is in contact with the lower surface of the spacer 12. In this embodiment, the spacer 12 has a function of positioning the yoke member 13 with respect to the bottom portion 10a of the cover member 10 in the optical axis direction. The spacer 12 in this embodiment has the light of the yoke member 13 with respect to the bottom portion 10a. This is a positioning member for positioning in the axial direction. In this embodiment, the cover member 10 and the yoke member 13 function as a yoke for forming the magnetic circuit of the drive mechanism 4.

(Lens driving device manufacturing method)
At the time of manufacturing the lens driving device 1 configured as described above, with the cover member 10 turned upside down, the spacer 12, the leaf spring 5, and the like are disposed on the bottom 10 a of the cover member 10 from the opposite side of the cover member 10. The yoke member 13 and the drive magnets 17 and 18 are sequentially stacked and assembled in this order (assembly process). Thereafter, the sleeve 8, the leaf spring 6 and the base member 11 are attached.

(Main effects of this form)
As described above, in this embodiment, the inner yoke portion 13b is disposed inside the driving coil 15 in the radial direction, and the outer peripheral sides of the driving coil 15 and the driving magnets 17 and 18 are covered with the cover member 10. ing. Therefore, in this embodiment, the density of magnetic flux generated by the driving magnet 17 and passing through the driving coil 15 can be increased.

  In this embodiment, the cover member 10 and the yoke member 13 are formed separately. Therefore, the leaf spring 5 can be disposed at a position avoiding the inner yoke portion 13 b (specifically, above the yoke member 13) and inside the cover member 10. Therefore, even if the shape of the arm portion of the leaf spring 5 is not complicated, the leaf spring 5 can be disposed inside the cover member 10 and can be protected by the cover member 10, and the yoke can be protected. In addition to the cover member 10 functioning as a member, there is no need to separately provide a member for protecting the leaf spring 5. As a result, in this embodiment, the configuration of the lens driving device 1 can be simplified while protecting the leaf spring 5 without making the leaf spring 5 complicated.

  Further, in this embodiment, since the cover member 10 and the yoke member 13 are formed separately, as described above, the spacer 12 and the plate are formed on the bottom 10a of the cover member 10 from the side opposite to the subject of the cover member 10. By sequentially stacking the spring 5, the yoke member 13, and the driving magnets 17 and 18 in this order, it is possible to easily position these members in the optical axis direction and to fix these members together. Therefore, in this embodiment, assembly of the lens driving device 1 is facilitated.

  In this embodiment, the cover member 10 covers the outer peripheral side of the movable body 2, the drive mechanism 4, the leaf springs 5 and 6, the spacer 12, and the yoke member 13. Therefore, the cover member 10 can prevent foreign matter from entering the lens driving device 1.

  In this embodiment, the inner yoke portion 13b formed so as to rise from the inner peripheral end face of the end plate portion 13a is formed in a flat plate shape. Therefore, the inner yoke portion 13b can be formed by bending. Therefore, in this embodiment, the thickness of the inner yoke portion 13b can be made the same as the thickness of the end plate portion 13a, and magnetic saturation in the inner yoke portion 13b can be suppressed. In addition, when the inner yoke portion 13b is formed in a curved plate shape like the inner yoke piece described in Patent Document 1, the inner yoke portion 13b is formed by drawing, so that the thickness thereof is the end. It becomes thinner than the thickness of the plate portion 13a, and as a result, magnetic saturation is likely to occur in the inner yoke portion 13b.

  In this embodiment, the inner yoke portion 13b is formed in a flat plate shape, and the parallel surface 17a of the driving magnet 17 disposed to face the inner yoke portion 13b via the driving coil 15 is formed in a flat shape. ing. Therefore, it is possible to increase the facing area of the inner yoke portion 13b facing the parallel surface 17a while keeping the distance between the parallel surface 17a and the inner yoke portion 13b uniform. Therefore, in this embodiment, the density of magnetic flux generated by the driving magnet 17 and passing through the driving coil 15 can be effectively increased.

  In this embodiment, the spacer 12 that functions to position the yoke member 13 with respect to the bottom 10a of the cover member 10 in the optical axis direction is formed separately from the yoke member 13b. Therefore, in this embodiment, the yoke member 13 can be accurately positioned in the optical axis direction.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited to this, and various modifications can be made without departing from the scope of the present invention.

  In the embodiment described above, the yoke member 13 includes the inner yoke portion 13b disposed inside the drive coil 15 in the radial direction. In addition, for example, as shown in FIG. 6, the yoke member 13 may include an outer yoke portion 13 c that covers the parallel surface 17 b of the driving magnet 17 from the radially outer side in addition to the inner yoke portion 13 b. . In this case, since the outer yoke portion 13c can be disposed by using the four corners of the lens driving device 1 that is likely to become a dead space, it is generated by the driving magnet 17 without increasing the size of the lens driving device 1. It is possible to effectively increase the density of the magnetic flux passing through the drive coil 15.

  In the embodiment described above, the yoke member 13 includes the inner yoke portion 13 b that is disposed to face the drive magnet 17. In addition to this, for example, the yoke member 13 is disposed inside the driving coil 15 in the radial direction in addition to the inner yoke portion 13b or in place of the inner yoke portion 13b, and is disposed opposite to the driving magnet 18. An inner yoke portion may be provided.

  In the embodiment described above, the inner yoke portion 13b is formed in a flat plate shape, but the inner yoke portion 13b may be formed in a curved plate shape. In this case, for example, the parallel surface 17a of the drive magnet 17 may be formed in a curved shape, and the portion facing the parallel surface 17a of the drive coil 15 may be formed in a curved shape.

  In the embodiment described above, the drive mechanism 4 includes one drive coil 15, but the drive mechanism 4 may include two drive coils 15. In this case, the facing surface of the driving magnet 17 facing the driving coil 15 and the facing surface of the driving magnet 18 facing the driving coil 15 are magnetized in two poles. Moreover, in the form mentioned above, although the lens drive device 1 is formed so that the shape when seen from the optical axis direction is a substantially square shape, the lens drive device 1 is when seen from the optical axis direction. You may form so that a shape may become a substantially rectangular shape.

DESCRIPTION OF SYMBOLS 1 Lens drive device 2 Movable body 3 Fixed body 4 Drive mechanism 5 Leaf spring 10 Cover member 10a Bottom part (object side end surface part)
12 Spacer (positioning member)
13 Yoke member 13a End plate part 13b Inner yoke part 13c Outer yoke part 15 Driving coil 17 Driving magnet (first driving magnet)
17a Parallel surface (opposite surface with drive coil)
18 Driving magnet (second driving magnet)
L Optical axis Z Optical axis direction

Claims (5)

A movable body that holds a lens and is movable in the optical axis direction of the lens, a fixed body that holds the movable body so as to be movable in the optical axis direction, and a drive for driving the movable body in the optical axis direction mechanism and comprises a plate spring which connects the movable member and said fixed member, a lens driving device shape Ru is formed in a substantially square shape when viewed from the optical axis direction,
The drive mechanism includes a drive coil which is fixed to the movable body, is fixed to the fixed body, Rutotomoni and a drive magnet disposed opposite to said driving coil at outer side in the radial direction of the lens, As the driving magnet, the first driving magnet disposed at each of the four corners of the lens driving device,
The fixed body is made of a magnetic material, and has an end plate portion that covers one end face of the driving magnet in the optical axis direction, and an inner yoke portion that is disposed inside the driving coil in the radial direction. A yoke member, and a cover member formed separately from the yoke member and formed of a magnetic material, and covering the outer peripheral side of the movable body, the drive mechanism, and the leaf spring;
The cover member includes a subject-side end surface portion that constitutes a subject-side end surface of the lens driving device, and completely covers the outer peripheral side of the yoke member,
A gap is formed between the yoke member and the cover member in a direction orthogonal to the optical axis direction,
The end plate portion is formed in a substantially frame shape and is connected to the subject side end of the inner yoke portion, and overlaps the subject side end surface portion when viewed from the optical axis direction,
In the optical axis direction, a gap is formed between the end plate portion and the subject side end surface portion ,
The driving coil is formed by being wound so that the shape when viewed from the optical axis direction is a substantially octagonal shape,
Four sides of the eight sides of the driving coil formed in a substantially octagonal shape are substantially parallel to each of the four side surfaces of the lens driving device, and the remaining of the eight sides of the driving coil. The four sides are arranged at the four corners of the lens driving device,
The inner yoke portion is formed in a flat plate shape that rises from the inner peripheral end surface of the end plate portion in the optical axis direction, and is disposed to face the first driving magnet via the driving coil.
The lens driving device characterized in that a surface of the first driving magnet facing the driving coil is formed in a flat shape . The drive mechanism is, as the driving magnet, the lens driving apparatus according to claim 1, characterized in that it comprises four second drive magnet disposed along each side of the lens driving device. It said first drive magnet, the shape when viewed from the optical axis direction is formed in a columnar shape as a substantially trapezoidal shape,
The yoke member, a lens driving apparatus according to claim 1 or 2 wherein, characterized in that it comprises an outer yoke portion from the outside of the radial direction to cover the first drive magnet. A positioning member for positioning the yoke member with respect to the subject side end surface portion in the optical axis direction;
The positioning member is a lens driving device according to any one of claims 1 to 3, characterized in that it is formed by the yoke member and the other member. It is a manufacturing method of the lens drive device according to claim 4 ,
A method for manufacturing a lens driving device, comprising: an assembly step of sequentially stacking the positioning member, the leaf spring, the yoke member, and the driving magnet in this order on a surface of the subject-side end surface portion opposite to the subject. .

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