JP2019003150A - Lens drive device, camera module using lens drive device, and manufacturing method of lens drive device - Google Patents

Abstract

To provide a lens drive device capable of stably holding a lens holding member with an upper plate spring and a lower plate spring, a camera module using the lens drive device, and a manufacturing method of the lens drive device.SOLUTION: A lens holding member 10 including a coil 60 mounted thereon is supported by an upper plate spring 30 and lower plate springs 20A, 20B. In an initial state where the coil 60 is not energized, the lens holding member 10 abuts against a support base 40. Spring constant of a lower elastic arm part of the lower plate springs 20A, 20B is set to be smaller than spring constant of an upper elastic arm part of the upper plate spring 30, to thereby stabilize the attitude of the lens holding member 10.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lens driving device in which a lens holding member is supported by an upper leaf spring and a lower leaf spring, a camera module using the lens driving device, and a method of manufacturing the lens driving device.

Patent Document 1 describes an invention related to a lens driving device.
The lens driving device includes a base member and a yoke that covers the base member. A spacer member is fixed inside the ceiling of the yoke, and an upper leaf spring is fixed to the lower surface of the spacer member. A metal plate member is embedded in the base member, a part of the metal plate member serves as a connection terminal, and a part of the plate surface of the metal plate member is exposed on the upper surface of the base member to form a connection portion. ing. One end of the lower leaf spring is fixed to the fixing surface of the surface of the base member, and the other end of the lower leaf spring is fixed in contact with the connecting portion exposed on the surface of the base member. Yes. As a result, the coil can be energized through the lower leaf spring from the connection terminal.

  A lens holding member having a coil is housed inside the yoke, and the lens holding member is supported by an upper plate spring and a lower plate spring so as to be movable in the optical axis direction of the lens. A magnet is fixed inside the yoke, and the magnet faces the outside of the coil.

  As described in paragraph “0042” of Patent Document 1, in the lens driving device, when the coil is in a non-energized state, the lens holding member is urged toward the base member by the lower leaf spring. The lens holding member is in contact with the buffer portion protruding from the upper surface of the base member. When a drive current is applied to the coil through the pair of lower leaf springs, the lens holding member has an optical axis within the range in which the lower leaf spring can be elastically deformed by the drive current flowing in the coil and the magnetic field from the magnet facing the coil. Move in the direction. By this operation, the image is focused on the image sensor.

Utility Model Registration No. 3182605

  In the lens driving device described in Patent Document 1, when the coil is in a non-energized state, the lens holding member is urged toward the base member by the urging force of the lower leaf spring. However, since the lens holding member is also supported by the upper leaf spring, if the balance between the elastic biasing force by the upper leaf spring and the elastic biasing force by the lower leaf spring is not properly set, the lens holding member is stably It becomes difficult to contact the base member.

  In the lens driving device described in Patent Document 1, the lower leaf spring is provided on both the fixed surface formed on the upper surface of the base member and the connection portion that is a part of the metal plate member exposed on the upper surface of the base member. It is fixed. Therefore, if the tolerance of the relative position in the optical axis direction becomes large between the fixed surface of the base member and the connecting portion that is a part of the metal plate member, the flatness accuracy of the lower leaf spring cannot be maintained. It becomes difficult to bring the lens holding member into contact with the base member without tilting.

  The present invention solves the above-described conventional problems, and in an initial state where the coil is not energized, the lens holding member can be urged in a balanced manner toward the support base, and the lens holding member is stably supported. It is an object of the present invention to provide a lens driving device that can be supported by a base, a camera module using the lens driving device, and a method of manufacturing the lens driving device.

The present invention provides a support base, a case covering the support base, a lens holding member on which at least a part is located inside the case and on which a lens body can be mounted, and the lens holding member of the lens body. An upper leaf spring and a lower leaf spring that are movably supported in the optical axis direction; a coil mounted on the lens holding member; and a magnet that is provided inside the case and faces the coil.
The upper leaf spring is integrally formed with an upper fixed side support portion and an upper movable side support portion, and an upper elastic arm portion that connects the upper fixed side support portion and the upper movable side support portion. The leaf spring is integrally formed with a lower fixed side support portion and a lower movable side support portion, and a lower elastic arm portion connecting the lower fixed side support portion and the lower movable side support portion,
The upper fixed side support portion of the upper leaf spring is fixed to the case side, the upper movable side support portion is fixed to the upper portion of the lens holding member, and the lower fixed side support portion of the lower leaf spring is the support. It is fixed to the base side, the lower movable side support part is fixed to the lower part of the lens holding member,
In an initial state in which the coil is not energized, the lens holding member is in contact with the support base directly or via another member.
In the initial state, the lower elastic arm portion applies the lens holding member toward the support base, rather than the urging force that the upper elastic arm portion urges the lens holding member toward the support base. The urging force to be applied is smaller.

In the lens driving device of the present invention, it is preferable that the spring constant of the lower elastic arm portion is smaller than the spring constant of the upper elastic arm portion.
For example, the cross-sectional area of the lower elastic arm portion is smaller than the cross-sectional area of the upper elastic arm portion.

  In the lens driving device of the present invention, in the initial state, the lower fixed side support portion and the lower movable side support portion of the lower leaf spring are preferably located on the same plane perpendicular to the optical axis.

  In the lens driving device of the present invention, for example, a stopper protrusion that abuts the lower part of the lens holding member and the support base in the initial state on either the lower part of the lens holding member or the support base. It is formed, and at least a part of the stopper protrusions can be configured as being positioned between the lower fixed side support portion and the lower movable side support portion.

In the lens driving device of the present invention, spring fixing surfaces are formed at a plurality of locations on the upper surface of the support base,
A pair of the lower leaf springs are provided, and the lower fixed side support portions of the lower leaf springs are supported on the spring fixing surfaces,
A conductive plate is stacked on the lower fixed side support portion of each of the lower plate springs, and a connection terminal is formed on the conductive plate.

  For example, the lower fixed side support portion and the conductive plate are welded, and the lower fixed side support portion of the lower leaf spring is bonded to the support base.

  The camera module of the present invention includes any one of the lens driving devices, a lens body held by the lens holding member of the lens driving device, and an imaging element facing the lens body. Is.

Next, the present invention provides a support base, a case that covers the support base, a lens holding member on which at least a part is located inside the case and on which a lens body can be mounted, and the lens holding member An upper leaf spring and a lower leaf spring that are movably supported in the optical axis direction of the lens body; a coil mounted on the lens holding member; and a magnet provided inside the case and facing the coil. ,
The upper leaf spring is integrally formed with an upper fixed side support portion and an upper movable side support portion, and an upper elastic arm portion that connects the upper fixed side support portion and the upper movable side support portion. The leaf spring is integrally formed with a lower fixed side support portion and a lower movable side support portion, and a lower elastic arm portion connecting the lower fixed side support portion and the lower movable side support portion,
The upper fixed side support portion of the upper leaf spring is fixed to the case side, the upper movable side support portion is fixed to the upper portion of the lens holding member, and the lower fixed side support portion of the lower leaf spring is the support. It is fixed to the base side, the lower movable side support part is fixed to the lower part of the lens holding member,
In the manufacturing method of the lens driving device in which the lens holding member is in contact with the support base directly or through another member in an initial state where the coil is not energized,
(A) using a pair of conductive plates having a connection terminal and a pair of lower leaf springs, and stacking the lower stationary side support portions of the lower leaf springs and the conductive plates;
(B) The lower fixed side stacked in the step (a) on the support base so that the lower fixed side support portion is disposed between the support base and the conductive plate. Arranging and fixing the support part and the conductive plate respectively;
Have
In the initial state, the lower elastic arm portion applies the lens holding member toward the support base rather than the urging force that the upper elastic arm portion urges the lens holding member toward the support base. The urging force to be applied is set to be smaller.

  The manufacturing method of the lens driving device of the present invention includes a welding step of welding the lower fixed side support portion of the lower leaf spring and the conductive plate, which are overlapped in the step (a), The step (b) is performed.

In the manufacturing method of the lens driving device of the present invention, the plate thickness of the conductive plate is larger than the plate thickness of the lower leaf spring,
In the welding step, a laser is irradiated from the side of the lower fixed side support portion to the overlapping portion of the lower fixed side support portion and the conductive plate to weld the lower fixed side support portion and the conductive plate. It is preferable.

In the method for manufacturing a lens driving device according to the present invention, it is preferable that a spring constant of the lower elastic arm portion is smaller than a spring constant of the upper elastic arm portion.
For example, the cross-sectional area of the lower elastic arm portion is smaller than the cross-sectional area of the upper elastic arm portion.

  In the manufacturing method of the lens driving device of the present invention, in the initial state, the lower fixed side support portion and the lower movable side support portion of the lower leaf spring are located on the same plane perpendicular to the optical axis. It is preferable.

  In the manufacturing method of the lens driving device of the present invention, the lower part of the lens holding member and the support base are brought into contact with either the lower part of the lens holding member or the support base in the initial state. Preferably, a stopper protrusion is formed, and at least a part of the stopper protrusion is positioned between the lower fixed side support part and the lower movable side support part.

  In the lens driving device in which the lens holding member is in contact with the support base directly or through another member in an initial state where the coil is not energized, the upper elastic arm portion of the upper leaf spring is The lens holding member is biased to the support base with a biasing force larger than that of the lower elastic arm portion of the lower leaf spring. Therefore, in the initial state, the lens holding member can be stably supported on the support base.

  In addition, the lower fixed side support part of the lower leaf spring is installed on the base, and the conductive plate having the connection terminals is installed on the lower fixed side support part, so that the lower fixed side support member can have a dimensional accuracy. The upper surface of the support base that can be well molded can be assembled as a reference. Thereby, the flatness of the lower lower spring can be maintained high, and in the initial state, the lens holding member can be installed while suppressing the inclination with reference to the support base.

The perspective view which shows the external appearance of the lens drive device of embodiment of this invention, FIG. 2 is an exploded perspective view showing components of the lens driving device shown in FIG. FIG. 2 is an exploded perspective view showing an assembly of a support base, a lower leaf spring, and a lens holding member provided at a lower portion of the lens driving device shown in FIG. FIG. 3 is a bottom view of the assembly in which the components shown in FIG. 3 are assembled, as viewed from below with the support base removed; Sectional drawing which cut | disconnected the lens drive device shown in FIG. Sectional drawing which looked at what cut | disconnected the lens drive device by the VI-VI line of FIG. Sectional drawing which removed the lens holding member and the magnet from the sectional view shown in FIG. An exploded perspective view showing a support member, a part of the upper leaf spring and a magnet; An exploded perspective view showing a lower leaf spring, a lens holding member and an upper leaf spring; An exploded perspective view showing a process of attaching the lower leaf spring and the conductive plate to the support base,

  1, 2, and 5 show the overall structure of the lens driving device 1 according to the embodiment of the present invention. FIG. 3 shows a support base, a lower leaf spring, a lens holding member, The assembly 70 is shown.

  The lens driving device 1 has a lens holding member 10. The lens holding member 10 is formed by injection molding with a synthetic resin material. As shown in FIG. 3, the lens holding member 10 has a cylindrical portion 13. The cylindrical portion 13 is a relatively thin cylindrical body and has a center hole 13a continuous in the Z1-Z2 direction. A lens body (lens barrel or lens barrel) is attached to the center hole 13a of the cylindrical portion 13. The lens body includes a lens set obtained by combining one lens or a plurality of lenses, and a lens holder that holds the lens or the lens set. For example, an internal thread portion is formed in the center hole 13a, an external thread portion is formed on the outer peripheral surface of the lens holder, and the external thread portion is screwed to the internal thread portion, so that the lens body is mounted inside the cylindrical portion 13. Mounted. Alternatively, the lens body is inserted into the center hole 13a, and the lens body and the inner surface of the cylindrical portion 13 are fixed with an adhesive.

  A Z1-Z2 direction shown in each figure is a vertical direction, which is a direction (optical axis direction) parallel to the optical axis O of the lens body. A lens driving device 1 whose entire structure is shown in FIGS. 1, 2 and 5 is mounted on a portable electronic device such as a cellular phone. An imaging element such as a CCD is disposed on the Z2 side of the lens driving device 1. The lens driving device 1, the lens body, and the image sensor are combined to form a camera module. In the camera module, when the lens holding member 10 and the lens body mounted on the lens holding member 10 move in the Z1-Z2 direction, automatic focusing of an image formed on the image sensor is performed.

  As shown in FIGS. 1, 2, and 3, the lens driving device 1 is provided with a support base 40 and a case 3. The support base 40 and the case 3 are combined to form a housing having a storage space inside. In the storage space, the lens holding member 10 having the coil 60, the upper leaf spring 30 that supports the upper portion of the lens holding member 10, and the support member 50 that is positioned between the ceiling 3 a of the case 3 and the upper leaf spring 30. The lower plate springs 20A and 20B that support the lower portion of the lens holding member 10 and the four magnets M facing the coil 60 are provided.

  As shown in FIGS. 1 and 2, the case 3 is formed of a magnetic steel plate (steel plate made of ordinary steel) or the like and functions as a magnetic yoke. The case 3 has a quadrangular shape (rectangular shape) in a plan view as viewed from the optical axis direction. As the outer wall portion, there are four side wall portions 3d and a square wall portion 3e that connects the side wall portions 3d. Is provided. The case 3 has a ceiling 3a, and an opening 3b is formed in the ceiling 3a. As shown in FIG. 3, an opening 44 is formed in the center of the support base 40, and the opening 44 of the support base 40 faces the center hole 13a of the lens holding member 10 from below, The opening 3b of the ceiling 3a faces the center hole 13a from above. The planar shape of the opening 3b of the case 3 is a quadrangular shape, and as shown in FIG. 2, the opposing yoke 3c bent in the Z2 direction is integrally formed from the four corners of the inner edge of the opening 3b. Is formed. As shown in FIGS. 6 and 7, the opposing yoke portion 3c faces the inner surface of each square wall portion 3e from the inside of the case.

  As shown in FIGS. 2 and 5, inside the case 3, a support member (spring fixing member) 50 is provided on the inner side (inner surface side) which is the Z <b> 2 side of the ceiling portion 3 a. The support member 50 is made of a nonmagnetic material such as a synthetic resin material. The support member 50 has a rectangular frame shape, and includes four side support portions 51 and corner support portions 52 positioned at four corner portions. The side portion support portion 51 faces the inner surface of the side wall portion 3 d of the case 3, and the corner portion support portion 52 faces the inner surface of the corner wall portion 3 e of the case 3. Case contact portions 53 are formed in each of the four corner support portions 52. The case contact portion 53 is formed to protrude in the Z1 direction from the upper surface of the side support portion 51 of the support member 50.

  As shown in FIGS. 5 and 8, a spring fixing surface 55 is provided on the lower surface of the side support portion 51 formed on the support member 50 in the Z2 direction. The spring fixing surface 55 is formed so as to protrude from the lower surface of the side support portion 51 to the Z2 side, and the surface (lower surface) is a flat surface parallel to the XY plane. The spring fixing surfaces 55 are provided at both end portions of the respective side support portions 51.

  As shown in FIG. 7 and FIG. 8, support ridges 56 that protrude (project) toward the lower side (Z2 direction) are integrally formed on the four corner support portions 52 of the support member 50. Yes. The support raised portion 56 has a trapezoidal shape when viewed from the Z2 side. Magnet contact portions 57 projecting in the Z2 direction are formed at two locations on the surface of the support ridge 56 facing downward. The surface of the magnet contact portion 57 facing the Z2 direction is a magnet contact surface parallel to the XY plane.

  As shown in FIGS. 2, 5, and 7, the upper leaf spring 30 is fixed to the lower surface of the support member 50 facing the Z2 direction. The upper leaf spring 30 includes a rectangular frame-shaped upper fixed side support portion 31, a pair of upper movable side support portions 32 positioned on the Y1 side and the Y2 side inside, and an upper fixed side support portion 31. The upper elastic arm portion 33 for connecting the upper movable side support portion 32 is integrally formed of a leaf spring metal material. The upper leaf spring 30 is formed by etching. The upper leaf spring 30 is disposed such that the thickness direction is the optical axis direction when the lens driving device 1 is assembled.

  As shown in FIG. 8 and FIG. 9, the upper fixed side support portion 31 of the upper leaf spring 30 has a strip-shaped side facing portion 31 a that linearly extends in the X direction and the Y direction, and is positioned at four corners. The corner facing portion 31b is formed continuously and integrally. The side facing portion 31 a is a portion that faces the inner surface of the side wall portion 3 d of the case 3, and the corner surface facing portion 31 b is a portion that faces the inner surface of the corner wall portion 3 e of the case 3. The side wall portion 3d of the case 3 is a flat portion of the lateral outer wall portion of the case 3, and the square wall portion 3e is located between the adjacent side wall portions 3d and is located on the side of the case 3. The outer wall portion on the side is a curved surface.

  The two upper elastic arm portions 33 located on the Y1 side connect the side facing portion 31a formed on the Y1 side in the upper fixed side support portion 31 and the upper movable side support portion 32 located on the Y1 side. . The two upper elastic arm portions 33 located on the Y2 side connect the side facing portion 31a formed on the Y2 side in the upper fixed side support portion 31 and the upper movable side support portion 32 located on the Y2 side. .

  As shown in FIGS. 7 and 8, the side facing portion 31 a of the upper fixed side support portion 31 of the upper leaf spring 30 is abutted against the spring fixing surface 55 formed on the side support portion 51 of the support member 50. At this time, a trapezoidal support raised portion 56 formed in the support member 50 enters between the square face facing portion 31 b of the upper plate spring 30 and the upper elastic arm portion 33, so that the support member 50 and the upper plate spring 30. Are positioned with respect to each other. Also, the support member 50 can be positioned in the optical axis O direction inside the case 3 by abutting the case contact portion 53 against the inner surface of the ceiling portion 3a (the lower surface facing the Z2 side).

  In a state where the support member 50 and the upper fixed side support portion 31 of the upper leaf spring 30 are installed inside the ceiling portion 3a of the case 3, the side facing portion 31a and the corner facing portion 31b of the upper fixed side support portion 31 A thermosetting adhesive having fluidity is supplied to the boundary portion. The adhesive penetrates the abutting portion between the inner surface of the ceiling portion 3 a of the case 3 and the case contact portion 53 of the support member 50 due to a capillary phenomenon, and the spring fixing surface 55 of the support member 50 and the upper leaf spring 30. It penetrates into the joint with the side facing portion 31a.

  As shown in FIGS. 2 and 6, the lens driving device 1 is provided with four magnets M. The four magnets M are formed independently. Each magnet M has an outer surface Ma directed outward in the radial direction around the optical axis O and a magnetized surface Mg facing the optical axis O. Between the outer side surface Ma and the magnetized surface Mg, an adhesive surface Mb that is inclined and opposed to each other is formed. Each magnet M has a flat upper surface Mc facing the Z1 direction. Each magnet M is magnetized such that the magnetized surface Mg and the outer surface Ma have different polarities. Further, the magnetized surfaces Mg of all the magnets M are magnetized so as to have the same polarity.

  As shown in FIGS. 5 and 6, the four magnets M are disposed inside the case 3 and inside the square wall portion 3 e, respectively. A fluid thermosetting adhesive is applied to the inner surfaces of the side wall portions 3d located on both sides of the case 3 with the square wall portion 3e in between, and the bonding surface Mb of the magnet M is opposed at an angle of 90 degrees. Magnetically attracted to the inner surface of the side wall 3d. With the adhesive interposed between the magnet M and the case 3, each magnet M is moved in the Z1 direction, and the upper surface Mc facing the Z1 direction is formed on the corner support portion 52 of the support member 50. The magnet is brought into contact with the magnet contact portion 57. As a result, each magnet M is positioned so as to be fixed at the same position in the direction of the optical axis O in a state where the magnetized surface Mg is directed to the optical axis O.

  With the support member 50, the upper leaf spring 30, and the magnet M incorporated in the case 3, the process proceeds to the heating step. In this heating step, an adhesive interposed between the inner surface of the ceiling portion 3a of the case 3 and the support member 50, an adhesive interposed between the spring fixing surface 55 and the side facing portion 31a, and the inner surface of the case 3 And the adhesive interposed between the magnet M and the magnet M are simultaneously cured.

After the support member 50, the upper leaf spring 30 and the magnet M are assembled in the case 3, the assembly 70 shown in FIG. 2 is assembled in the case 3. An exploded perspective view of the assembly 70 is shown in FIG.
The assembly 70 shown in FIG. 3 is provided with a pair of lower leaf springs 20A and 20B separated from each other between the support base 40 and the lens holding member 10 positioned thereon. The lower leaf spring located on the Y1 side is denoted by reference numeral 20A, and the lower leaf spring located on the Y2 side is denoted by reference numeral 20B. Each of the lower leaf springs 20A and 20B includes a lower fixed side support portion 21, a lower movable side support portion 22, and a lower elastic arm portion 23 that connects the lower fixed side support portion 21 and the lower movable side support portion 22. It is integrally formed of a conductive leaf spring metal material. For example, the lower leaf springs 20A and 20B are formed of a springy stainless steel plate or phosphor bronze plate. The lower leaf springs 20A and 20B are formed by etching. The lower leaf springs 20A and 20B are arranged such that the thickness direction is the optical axis direction when the lens driving device 1 is assembled.

  As shown in FIG. 3, an attachment portion 21a located on the X2 side and an attachment portion 21b located on the X1 side are formed on the lower fixed side support portion 21 of the lower leaf spring 20A located on the Y1 side. The lower fixed side support portion 21 of the lower leaf spring 20B located on the Y2 side is also formed with an attachment portion 21a located on the X2 side and an attachment portion 21b located on the X1 side. The lower leaf springs 20A and 20B each have a mounting hole 24a formed in the mounting portion 21a located on the X2 side, and a mounting hole 24b formed in the mounting portion 21b located on the X1 side.

  As shown in FIGS. 2 and 3, the conductive plate 25A is overlaid on the upper side (Z1 side) of the X2 side mounting portion 21a of the lower leaf spring 20A located on the Y1 side, and the lower leaf spring 20B located on the Y2 side. The conductive plate 25B is superimposed on the upper side (Z1 side) of the attachment portion 21a on the X2 side. The conductive plates 25A and 25B are formed of a conductive metal plate, and are formed of, for example, a rolled steel plate whose surface is gold-plated, brass or another copper alloy plate. The conductive plates 25A and 25B have a support plate portion 26 parallel to the XY plane, and a connection terminal 27 bent from the support plate portion 26 to the lower side Z2. A hole 28 is formed in the support plate portion 26.

  With the mounting portion 21a of the lower leaf spring 20A and the support plate portion 26 of the conductive plate 25A positioned and overlapped, the mounting portion 21a and the support plate portion 26 are welded. This welding is performed by laser spot welding. The attachment portion 21a of the lower leaf spring 20B on the Y2 side and the support plate portion 26 of the conductive plate 25B are also welded in the same manner. The lower plate springs 20A and 20B are thinner than the conductive plates 25A and 25B, and laser spot welding is performed by irradiating a laser from the lower plate springs 20A and 20B side (Z2 side).

  As shown in FIG. 3, the support base 40 has a quadrangular planar shape and is formed of a synthetic resin material that is a nonmagnetic material. On the four corners of the support base 40, spring fixing surfaces 41A and 41B are formed. Two spring fixing surfaces located on the X2 side are denoted by reference numeral 41A, and two spring fixing surfaces located on the X1 side are denoted by reference numeral 41B. Positioning protrusions 42a are integrally formed on the two spring fixing surfaces 41A located on the X2 side, and positioning protrusions 42b are integrally formed on the two spring fixing surfaces 41B located on the X1 side. The positioning protrusions 42a and 42b protrude in the Z1 direction. The positioning protrusions 42a and the positioning protrusions 42b are cylindrical bodies each having a constant radius.

  As shown in FIG. 3, the support base 40 has a through hole 43 at a position adjacent to the spring fixing surface 41A formed on the X2 side. The through hole 43 is formed between the side 40c facing the X2 side of the support base 40 and each spring fixing surface 41A. The through hole 43 is formed through the support base 40 in the vertical direction (Z1-Z2 direction).

  In the state where the support plate portion 26 of each conductive plate 25A, 25B is overlapped and welded to the X2 side attachment portion 21a of the lower leaf springs 20A, 20B, the attachment holes 24a formed in the respective attachment portions 21a, respectively, The positioning projections 42 a provided on the two spring fixing surfaces 41 </ b> A of the support base 40 are inserted into the holes 28 formed in the support plate portion 26. Thereby, each attachment part 21a and the support plate part 26 are overlapped and positioned on the spring fixing surface 41A. Further, positioning protrusions 42b provided on the two spring fixing surfaces 41B are inserted into the respective mounting holes 24b formed in the X1 side mounting portions 21b of the lower leaf springs 20A and 20B, and the respective mounting portions are mounted. 21b is positioned and installed on the spring fixing surface 41B.

  Adhesive is applied to the positioning protrusions 42a and 42b provided on the support base 40, and the mounting portions 21a of the support base 40 and the lower leaf springs 20A and 20B are obtained by thermal curing or UV curing of the adhesive. , 21b are bonded and fixed. The attachment portions 21a of the lower leaf springs 20A and 20B and the conductive plates 25A and 25B are also bonded to each other. The tip portions of the four positioning projections 42a and 42b are hot-pressed to form caulking deformation portions at the tip portions of the positioning projections 42a and 42b, and the lower leaf springs 20A and 20B on the support base 40. The conductive plates 25A and 25B may be fixed by caulking.

  When the conductive plates 25A and 25B are fixed on the support base 40, the connection terminals 27 integral with the conductive plates 25A and 25B are inserted into the through holes 43 formed in the support base 40, and connected. The tip of the terminal 27 on the Z2 side is exposed further below the lower surface of the support base 40. At this time, by filling the inside of the through-hole 43 with an adhesive, the conductive plates 25A and 25B can be firmly fixed to the support base 40, and the through-hole 43 is closed with an adhesive and supported. It becomes easy to prevent liquid or the like from entering the inside of the case 3 from the lower side of the base 40 through the through hole 43.

  As shown in FIG. 3, attachment holes 22a are formed in the lower movable side support portions 22 of the lower leaf springs 20A and 20B on the X1 side and the X2 side, respectively. As shown in the bottom view of FIG. 4, on the lower surface of the lens holding member 10 facing in the Z2 direction, spring fixing surfaces 10b are provided on the X1 side and the X2 side. In each spring fixing surface 10b, a protrusion 10c protruding in the Z2 direction is integrally formed on the Y1 side, and a protrusion 10d protruding in the Z2 direction is integrally formed on the Y2 side. The mounting holes 22a formed at both ends of the lower movable side support portion 22 of the lower leaf spring 20A on the Y1 side are fitted into the projections 10c, and the respective lower projections 10c are heat caulked to move the lower movable portion of the lower leaf spring 20A. The side support portions 22 are fixed to the two spring fixing surfaces 10 b on the lower surface of the lens holding member 10. Similarly, the mounting holes 22a formed at both ends of the lower plate spring 20B on the Y2 side are fitted to the projections 10d and heat caulked, so that the lower movable side support portion 22 of the lower plate spring 20B has two. It is fixed to the spring fixing surface 10b of the place.

  Since the support base 40 is injection-molded with a synthetic resin material, the flatness of the four spring fixing surfaces 41A and 41B is maintained high. By fixing the lower fixed side support portion 21 of the lower leaf springs 20A and 20B in contact with the spring fixing surfaces 41A and 41B, the lower leaf springs 20A and 20B can be fixed while maintaining high flatness. . Thereby, the inclination of the lens holding member 10 supported by the lower movable side support portion 22 of the lower leaf springs 20A and 20B can be suppressed, and the lens holding member 10 is moved along the spring fixing surfaces 41A and 41B of the optical axis O. It can be installed in a state where the perpendicularity to the plane (XY plane) is kept high. In the present embodiment, the four spring fixing surfaces 41A and 41B protrude upward (Z1 side) from the upper surface of the support base 40 and are located on the same plane, but the spring fixing surfaces 41A 41B may not protrude from the upper surface of the support base 40.

  As shown in FIG. 3, a flange portion 11 is formed on the Z2 side and a plurality of regulating protrusions 12 are formed on the Z1 side on the outer side of the cylindrical portion 13 of the lens holding member 10. The flange portion 11 may have a bowl shape extending substantially continuously in the circumferential direction around the optical axis O, or may be formed intermittently in the circumferential direction. The restricting protrusions 12 are formed at intervals in the circumferential direction. The flange portion 11 and the plurality of regulating protrusions 12 face each other in the optical axis direction (Z1-Z2 direction).

  As shown in the bottom view of FIG. 4, projections 19a and 19b are integrally formed at two locations on the bottom surface of the lens holding member 10 facing the Z2 direction. The protrusions 19a and 19b protrude in the Z2 direction. The protrusion 19a located on the Y1 side is a winding protrusion for fixing the winding start end 61a of the conducting wire forming the coil 60, and the protrusion 19b located on the Y2 side is a winding protrusion for fixing the winding end 61b of the conducting wire. The conducting wire for forming the coil 60 is a coated conducting wire, and has a copper wire that is a conductive metal wire and an insulating coating layer that covers the copper wire. The covering layer has a two-layer structure of an insulating layer such as a polyurethane resin covering the copper wire and a fusion layer such as a polyamide resin on the surface thereof.

  The coating layer is removed at the winding start end 61a of the conducting wire, and the winding start end 61a is wound around the protrusion 19a on the Y1 side shown in FIG. The conducting wire extending from the protrusion 19 a is wound between the flange portion 11 and the restriction protrusion 12 on the outer side portion of the cylindrical portion 13 of the lens holding member 10. In the winding process, the conductive wire is heated by applying hot air or the like, and the insulating layers are fusion-bonded together by melting the fusion layer to form the coil 60. The winding end 61b of the conducting wire that has finished winding the coil 60 is drawn out to the lower surface of the lens holding member 10, the coating layer is removed, and the winding end 61b is wound around the Y2 projection 19b shown in FIG.

  As shown in FIG. 4, when the lower movable side support portion 22 of the lower leaf springs 20A and 20B is fixed to the spring fixing surfaces 10b and 10b on the lower surface of the lens holding member 10, it is wound around the protrusion 19a on the Y1 side. The winding start end 61a of the conducting wire is adjacent to the lower movable side support portion 22 of the lower leaf spring 20A on the Y1 side, and the winding start end 61a and the lower movable side support portion 22 are soldered. The winding end 61b of the conducting wire wound around the Y2 side projection 19b and the lower movable side support portion 22 of the Y2 side lower leaf spring 20B are also soldered in a state adjacent to each other. As a result, the lower leaf spring 20A is conducted to the winding start end 61a of the conducting wire, and the lower leaf spring 20B is conducted to the winding end 61b.

  As shown in FIG. 3, the conductive plate 25A is overlapped and joined (welded) to the attachment portion 21a of the lower leaf spring 20A, and the conductive plate 25B is overlapped and joined (welded) to the attachment portion 21a of the lower leaf spring 20B. Therefore, the connection terminal 27 of the conductive plate 25A is electrically connected to the winding start end 61a of the coil 60 via the lower plate spring 20A, and the connection terminal 27 of the conductive plate 25B is wound of the coil 60 via the lower plate spring 20B. It conducts to the terminal end 61b.

  As shown in FIGS. 2 and 3, a spring fixing surface 10 a is provided on the upper surface of the cylindrical portion 13 of the lens holding member 10 facing the Z1 direction. After the support member 50, the upper leaf spring 30, and the magnet M are fixed inside the case 3, the lens holding member 10, the lower leaf springs 20A and 20B, the conductive plates 25A and 25B, and the support base around which the coil 60 is wound. The assembly 70 assembled with 40 is inserted into the case 3 from below. The spring fixing surface 10a of the lens holding member 10 is abutted on the lower side of the upper movable side support portion 32 of the upper leaf spring 30 inside the case 3, and the spring fixing surface 10a and the upper movable side support portion 32 are bonded. It is fixed with an agent. The support base 40 and the case 3 are also fixed to each other with an adhesive.

  As shown in FIGS. 2 and 3, there is a gap between the outer surface of the cylindrical portion 13 of the lens holding member 10 and the coil 60 at a portion where the regulating protrusion 12 on the outer side of the lens holding member 10 does not exist. (S) is formed. The gaps (S) are formed at four locations on the outer side of the lens holding member 10. When the lens holding member 10 is housed inside the case 3 and the upper end portion of the lens holding member 10 and the upper movable side support portion 32 of the upper leaf spring 30 are fixed, 4 around the opening 3b of the case 3 is fixed. The opposing yoke portion 3c bent downward from the place enters the gap (S). Therefore, the magnetized surface Mg of the magnet M faces the outside of the coil 60, and the facing yoke portion 3 c faces the inside of the coil 60.

  As shown in FIG. 3, the lower elastic arms 23 provided on the lower leaf springs 20A and 20B are formed in a thin curved shape, that is, a meandering shape, and are provided on the upper leaf spring 30 as shown in FIG. The upper elastic arm portion 33 is also formed into a thin curved shape, that is, a meandering shape. The lower leaf springs 20A and 20B and the upper leaf spring 30 have substantially the same thickness, but as shown in FIG. 9, the lower leaf springs 20A and 20B are lower than the width of the upper elastic arm portion 33 provided on the upper leaf spring 30. The width dimension of the lower elastic arm portion 23 provided on the leaf springs 20A and 20B is reduced. That is, the cross-sectional area of the lower elastic arm portion 23 is smaller than the cross-sectional area of the upper elastic arm portion 33. Therefore, the spring constant of the lower elastic arm portion 23 is smaller than the spring constant of the upper elastic arm portion 33. The upper elastic arm portion 33 and the lower elastic arm portion 23 have different lengths, or the upper leaf spring 30 and the lower leaf springs 20A and 20B have different plate thicknesses, so that the upper elastic arm portion 33 has a different thickness. The spring constant of the lower elastic arm portion 23 may be set smaller than the spring constant.

  FIG. 5 shows a cross section of the lens driving device 1 in an initial state where the coil 60 is not energized. The upper surface of the lens holding member 10 is located above the lower surface of the support member 50 (Z1 direction) inside the frame-shaped support member 50. Therefore, the upper leaf spring 30 is fixed to the upper spring fixing surface 10a on the upper surface of the lens holding member 10 rather than the upper fixing side support portion 31 bonded to the lower spring fixing surface 55 of the supporting member 50. The side support portion 32 moves (displaces) by a distance H in the Z1 direction, which is a direction away from the support base 40. Therefore, the upper elastic arm portion 33 is bent, and the lens holding member 10 is urged toward the support base 40 in the Z2 direction by the elastic force of the upper elastic arm portion 33 of the upper leaf spring 30. .

  As shown in FIG. 3, stopper protrusions 45a and 45b are integrally formed on the upper surface of the support base 40 facing the Z1 direction. Each of the two stopper projections 45a is located in a space 29 between the lower fixed side support portion 21 and the lower movable side support portion 22 of the lower leaf springs 20A and 20B, as shown in FIG. The upper surface of the stopper projection 45a is substantially flush with the upper surfaces of the lower leaf springs 20A and 20B. One stopper protrusion 45b is located between the two lower leaf springs 20A and 20B, and the upper surface of the stopper protrusion 45b is also located substantially flush with the upper surfaces of the lower leaf springs 20A and 20B. .

  In the initial state shown in FIG. 5, the lower surface of the lens holding member 10 abuts against the stopper protrusions 45a and 45b by the urging force of the upper leaf spring 30, but the lower leaf springs 20A and 20B are supported on the lower fixed side. The part 21 and the lower movable side support part 22 are located on the same plane parallel to the plane (XY plane) perpendicular to the optical axis O. Therefore, in the initial state, the lower elastic arm portion 23 hardly bends. That is, in the initial state where the coil 60 is not energized, the lower elastic arm portion 23 urges the lens holding member 10 toward the support base 40, and the upper elastic arm portion 33 supports the lens holding member 10. The biasing force biasing toward the base 40 is smaller.

  Further, each of the two stopper protrusions 45a is positioned in a space 29 between the lower fixed side support part 21 and the lower movable side support part 22 of the lower leaf springs 20A and 20B. By positioning 45b between the two lower leaf springs 20A and 20B, the stopper protrusion can be arranged in a limited facing area between the support base 40 and the lower leaf springs 20A and 20B. It becomes easy to miniaturize the lens driving device 1.

  Contrary to the above-described embodiment, the stopper projections 45a and 45b are formed on the lower surface of the lens holding member 10, and the positions of the tip portions (lower surface) of the stopper projections 45a and 45b in the initial posture shown in FIG. However, the structure which corresponds to the height position along the Z direction of the lower surface of lower leaf | plate spring 20A, 20B may be sufficient. Further, the stopper protrusions 45 a and 45 b may be formed separately from the support base 40 or the lens holding member 10 and fixed to the support base 40 or the lens holding member 10. Further, when the stopper protrusion is provided on the support base 40 or the lens holding member 10, the tip of the stopper protrusion may not be located on the same plane as the upper surface or the lower surface of the lower leaf springs 20A and 20B. Absent.

Next, operations of the lens driving device 1 having the above structure and a camera module using the lens driving device 1 will be described.
As shown in FIG. 5, in the initial state in which no drive current is applied to the coil 60, the lower elastic arm portion 23 of the lower leaf springs 20A and 20B has almost zero deflection or slight deflection, The bending of the upper elastic arm portion 33 of the leaf spring 30 is increased. In addition, the spring constant of the lower elastic arm portion 23 is set smaller than the spring constant of the upper elastic arm portion 33. Therefore, the lower elastic arm portion 23 urges the lens holding member 10 toward the support base 40 rather than the urging force that the upper elastic arm portion 33 urges the lens holding member 10 toward the support base 40. The power is smaller. Since the lower plate springs 20 </ b> A and 20 </ b> B have a small urging force applied to the lens holding member 10, in the initial posture, the lower surface of the lens holding member 10 is mainly positioned at three locations on the support base 40 by the urging force of the upper plate spring 30. It will be pressed against the provided stopper protrusions 45a, 45b. Therefore, the lower surface of the lens holding member 10 comes into contact with the three stopper protrusions 45a and 45b, and the vertical posture of the lens holding member 10 is maintained with reference to the stopper protrusions 45a and 45b. Is possible.

  Further, the attachment portions 21a and 21b formed at both ends of the lower fixed side support portion 21 of the lower leaf springs 20A and 20B are fixed in contact with spring fixing surfaces 41A and 41B formed on the support base 40. . The support base 40 is injection-molded with a synthetic resin material, and the flatness of the four spring fixing surfaces 41A and 41B is maintained high. Since the lower fixed side support portion 21 is installed on the spring fixing surfaces 41A and 41B, the flatness of the lower leaf springs 20A and 20B can be maintained high, and the lens holding member 10 is held by the lower leaf springs 20A and 20B. The optical axis O coinciding with the central axis of the cylindrical portion 13 can be supported without tilting.

  When a drive current is applied to the connection terminals 27 and 27 protruding from the support base 40, the drive current flows through the pair of lower leaf springs 20A and 20B to the coil 60 between the winding start end 61a and the winding end 61b. The lens holding member 10 is driven in the optical axis direction (Z1 direction) by an electromagnetic force generated by a drive current flowing through the coil 60 and a magnetic field generated from the magnet M. By the operation of the lens holding member 10, the image formed on the imaging element is focused by the lens body held by the lens holding member 10.

  Since the spring constant of the lower elastic arm portion 23 is smaller than the spring constant of the upper elastic arm portion 33, in an initial state, the lower surface of the lens holding member 10 can be reliably returned to the posture where it hits the stopper protrusions 45a and 45b. Become.

  As shown in FIG. 5, the upper part of the lens holding member 10 enters the inside of the frame-shaped support member 50, and the upper surface of the lens holding member 10 is positioned above the lower surface of the support member 50. The drive device 1 can be thinned. Since there is a limit to reducing the vertical dimension h of the support member 50, as the thickness of the support member 50 is reduced, the size of the lens holding member 10 entering the inside of the frame shape of the support member 50 increases. Thus, in the upper leaf spring 30, the height distance H between the upper fixed side support portion 31 and the upper movable side support portion 32 is increased, and the amount of deflection of the upper elastic arm portion 33 is increased. Therefore, the biasing force by which the upper leaf spring 30 biases the lens holding member 10 toward the support base 40 is increased.

  However, in the lens driving device 1 of the embodiment, the spring constant of the lower elastic arm portion 23 of the lower leaf springs 20A and 20B is made smaller than the spring constant of the upper elastic arm portion 33, and in the initial state, the lower leaf spring 20A. , 20B is smaller than the urging force that urges the lens holding member 10 toward the support base 40 than the urging force that the upper leaf spring 30 urges the lens holding member 10 toward the support base 40. . Therefore, it is possible to suppress an increase in the urging force that is the sum of the urging forces of the upper leaf springs 30 and the urging forces of the lower leaf springs 20A and 20B, and even if the deflection of the upper elastic arm portion 33 is increased, The spring resistance when the lens holding member 10 is moved in the optical axis direction can be reduced. Therefore, the lens holding member 10 can be moved in the optical axis direction with power saving.

Next, a method for manufacturing the lens driving device 1 will be described.
First, a manufacturing process of a semi-finished product (called a case block) in which the support member 50, the upper leaf spring 30, and the magnet M are fixed inside the case 3 will be described. As shown in FIG. 8, the support raised portion 56 formed on the corner support portion 52 of the support member 50 is inserted between the corner facing portion 31 b of the upper leaf spring 30 and the upper elastic arm portion 33, The support member 50 and the upper leaf spring 30 are combined. The support member 50 and the upper leaf spring 30 are installed on the inner side (Z2 side) of the case 3 so that the case 3 is in a posture in which the ceiling 3a is directed downward under the action of gravity. However, in this installation step (arrangement step), the support member 50 may be installed in the case 3 first, and then the upper leaf spring 30 may be installed in the case 3. The upper leaf spring 30 installed in the case 3 is supported in a state where the side facing portion 31 a is in contact with a spring fixing surface 55 formed on the support member 50.

  At both ends of the side facing portion 31a of the upper leaf spring 30, a fluid thermosetting adhesive is applied to the surface facing the Z2 side (first application step). The applied adhesive enters the gap between the outer edge portion of the upper fixed side support portion 31 of the upper leaf spring 30 and the inner surface of the case 3 and flows down due to gravity, and the case contact portion 53 of the support member 50 and the ceiling portion. Go in between 3a. Further, the adhesive penetrates between the spring fixing surface 55 of the support member 50 and the side facing portion 31a of the upper leaf spring 30 by a capillary phenomenon. A part of the adhesive also remains in the gap between the outer edge of the upper leaf spring 30 and the inner surface of the case 3.

  Next, a fluid thermosetting adhesive is applied to the inner surface in the vicinity of the boundary between the side wall portion 3d and the corner wall portion 3e of the case 3 (second application step). Each of the four magnets M is installed on the four corner wall portions 3e by magnetically attracting the adhesion surface Mb to the inner surface of the side wall portion 3d. At this time, an adhesive is interposed between the adhesive surface Mb and the inner surface of the case 3. The four magnets M are positioned in the case 3 by bringing their upper surfaces Mc into contact with the magnet contact portions 57 formed on the corner support portions 52 of the support member 50.

  After the adhesive application step, the process proceeds to the heating step, and the bonding is located between the case 3 and the support member 50, and between the spring fixing surface 55 of the support member 50 and the side facing portion 31a of the upper leaf spring 30. The adhesive and the adhesive interposed between the magnet M and the inner surface of the case 3 are all thermally cured at the same time. Thereby, as shown in FIG. 6, the support member 50, the upper fixed side support portion 31 of the upper leaf spring 30, and the four magnets M are fixed inside the case 3.

  The case block manufacturing process is thus completed. In the present embodiment, the step of bonding and fixing the support member 50 and the upper fixed side support portion 31 of the upper leaf spring 30 to the inner side of the ceiling portion 3a of the case 3, and the inner surface of the case 3 and the magnet M are bonded and fixed. However, for example, a UV (ultraviolet) curable adhesive may be used as one of the adhesives, and the adhesive fixing process may be divided into two.

  Further, the first application step and the second application step are performed in the same adhesive application step (supply step), between the case 3 and the support member 50, between the spring fixing surface 55 of the support member 50 and the upper leaf spring 30. An adhesive may be supplied between the side facing portion 31 a and between the magnet M and the inner surface of the case 3. For example, after applying a large amount of adhesive on the inner surface of the case 3, the magnet M is magnetically attracted to the inner surface of the case 3, and the magnet M is slid toward the ceiling portion 3 a until it contacts the magnet contact portion 57. The moving force of the magnet M at this time allows the adhesive to flow between the case 3 and the support member 50 and between the spring fixing surface 55 and the side facing portion 31a of the upper leaf spring 30. And it transfers to a heating process (adhesion fixing process) after that. At least the installation step, the adhesive application step, and the heating step constitute a case block manufacturing step, and these steps are directed under the action of gravity on the ceiling portion 3a of the case 3. Try to do it in a posture.

Next, a manufacturing process of the assembly 70 will be described.
As shown in FIG. 10, the leaf spring blank 120 and the conductive plate blank 125 are used in the manufacturing process of the assembly 70. The leaf spring blank 120 is obtained by etching a metal plate having spring properties. However, the leaf spring blank 120 may be punched from a metal plate. The leaf spring blank 120 has outer shapes of a lower leaf spring 20A and a lower leaf spring 20B. The connecting branch portion 121b is continuous from the X1 side mounting portion 21b of the lower leaf spring 20A, and the connecting branch portion 121b is also continuous from the X1 side mounting portion 21b of the lower leaf spring 20B, and the two connecting branch portions 121b, The support plate portion 122b is continuous with 121b. Similarly, the connecting branch portion 121a is continuous from the X2 side mounting portion 21a of the lower leaf spring 20A, and the connecting branch portion 121a is also continuous from the X2 side mounting portion 21a of the lower leaf spring 20B. The support plate part 122a is continuous with 121a and 121a. Therefore, the lower leaf spring 20A and the lower leaf spring 20B are connected via the connecting branch portions 121a and 121b and the supporting plate portions 122a and 122b.

  The support plate portion 122a and the support plate portion 122b are band-shaped plate portions that are continuous in the Y1-Y2 direction. The support plate portion 122a and the support plate portion 122b extend long in the Y1-Y2 direction, and a plurality of lower leaf springs 20A and 20B are spaced apart in the Y1-Y2 direction from the common support plate portion 122a and the support plate portion 122b. Are connected. A feed hole 123a is formed in the support plate portion 122a, a feed hole 123b is formed in the support plate portion 122b, and the support plate portions 122a and 122b are sent in the Y direction using the feed holes 123a and 123b. Each lower leaf | plate spring 20A, 20B is sent in order according to a some assembly process.

  The conductive plate blank 125 is formed of a conductive metal plate, and the outer shapes of the two conductive plates 25A and 25B are punched out. A connecting branch 121 is continuous from the conductive plates 25 </ b> A and 25 </ b> B, and a support plate 122 is continuous with each connecting branch 121. The support plate portion 122 is a belt-like plate portion that extends continuously in the Y1-Y2 direction, and a plurality of conductive plates 25A and 25B are connected to the same support plate portion 122 at intervals in the Y1-Y2 direction. A feed hole 123 is formed in the support plate portion 122. In the conductive plate blank 125, the conductive plates 25A and 25B are formed with connection terminals 27 that are bent at the edge of the support plate portion 26 and project in the Z2 direction.

  As shown in FIG. 4, the mounting holes 22a formed on the X1 and X2 sides of the lower movable side support portion 22 of the lower leaf spring 20A are fitted into the protrusions 10c on the lower surface of the lens holding member 10, and the protrusions 10c are thereby fitted. Caulking with heat. At the same time, the mounting holes 22a formed on the X1 and X2 sides of the lower movable side support portion 22 of the lower leaf spring 20B on the Y2 side are fitted into the protrusions 10d on the lower surface of the lens holding member 10 to heat the protrusions 10d. To do. Accordingly, a lower movable side support portion fixing step of fixing the lower movable side support portion 22 of the lower leaf springs 20A and 20B to the spring fixing surface 10b of the lens holding member 10 is performed. This lower movable side support portion fixing step may be performed before the lower fixed side support portion and the conductive plate fixing step, which will be described later. In the present embodiment, the lower leaf springs 20A and 20B are replaced by the leaf spring blank 120. Performed in a supported state.

  As a step before or after the lower movable side support portion fixing step for fixing the lower movable side support portion 22 of the lower leaf springs 20A and 20B supported by the leaf spring blank 120 to the lens holding member 10, the lower plate A laminating process is performed in which the support plate portions 26 of the conductive plates 25A and 25B of the conductive plate blank 125 are stacked on the X2 side mounting portions 21a and 21a, which are the lower fixed side support portions 21 of the springs 20A and 20B. In this lamination step, the support plate portions 26 of the conductive plates 25A and 25B are overlapped on the Z1 side (upper surface side) of the attachment portion 21a of the lower leaf springs 20A and 20B. At this time, the support plate portion 26 and the attachment portion 21a are positioned with reference to the hole portion 28 formed in the support plate portion 26 and the attachment hole 24a formed in the attachment portion 21a. Subsequent to this laminating step, a welding step (joining step) is performed in which the overlapped attachment portion 21a and the support plate portion 26 of the conductive plates 25A and 25B are joined by welding. In this welding process, a laser spot is applied to the attachment portion 21a having a small thickness from the Z2 side in the Z1 direction, and the attachment portion 21a and the support plate portion 26 are welded.

  Since the plate thickness of the lower plate springs 20A and 20B is smaller than the plate thickness of the conductive plates 25A and 25B, the laser is irradiated from the lower plate springs 20A and 20B side to the overlapping portion of the mounting portion 21a and the support plate portion 26. Thus, the attachment portions 21a and 21a of the lower leaf springs 20A and 20B are melted, and the overlapping portions of the attachment portions 21a and 21a and the support plate portions 26 and 26 of the conductive plates 25A and 25B are reliably welded. it can.

  Following the welding process, a fixing process (fixing process of the lower fixed side support portion and the conductive plate) for fixing the leaf spring blank 120 and the conductive plate blank 125 to the support base 40 is performed. However, when the lower movable side support portion fixing step is not performed at the stage where the welding process is completed, the lower movable side support portion fixing step is performed before this fixing step. In this fixing step (lower fixing side support portion and conductive plate fixing step), the X2 side mounting portion 21a of the lower leaf springs 20A and 20B and the support plate portion of the conductive plates 25A and 25B which are overlapped and welded thereto. 26 is installed on the spring fixing surface 41A of the support base 40, the positioning projection 42a is inserted into the mounting hole 24a and the hole 28, and the mounting portion 21b on the X1 side of the lower leaf springs 20A and 20B is connected to the support base. It is installed on the spring fixing surface 41B of the base 40, and the positioning projection 42b is inserted through the mounting hole 24b. Then, an adhesive is applied to the positioning protrusions 42a and 42b, and the lower fixing side support portion 21 and the conductive plates 25A and 25B are fixed to the support base 40 with this adhesive. At this time, the attachment portion 21a of the lower fixed side support portion 21 is disposed between the upper surface (spring fixing surface 41A) of the support base 40 and the support plate portion 26 of the conductive plates 25A and 25B.

  Further, the connection terminals 27 of the conductive plates 25A and 25B are inserted into the through holes 43 formed in the support base 40, and the through holes 43 are filled with the adhesive from the Z1 side. If necessary, before applying the adhesive to the positioning projection 42a, a caulking deformation portion is formed at the tip of the positioning projection 42a to fix the mounting portion 21a and the support plate portion 26 to the support base 40. . Further, the positioning projection 42b and the attachment portion 21b are also fixed to the caulking deformation portion of the positioning projection 42b with an adhesive. By using a thermosetting adhesive as the adhesive filling the through holes 43 and the adhesive applied to the positioning protrusions 42a and 42b, these adhesives can be cured simultaneously by heating. As described above, the lower fixed side support portion 21 of the lower plate springs 20A and 20B and the support plate portion 26 of the conductive plates 25A and 25B are arranged and fixed on the spring fixing surfaces 41A and 41B of the support base 40. The fixing process ends.

  By completing this fixing step, the lens holding member 10 provided with the leaf spring blank 120, the conductive plate blank 125, and the coil 60 can be mounted on the support base 40. At this time, the lower surface of the lens holding member 10 is in contact with stopper protrusions 45 a and 45 b formed on the support base 40. Further, the lower movable side support portion 22 of the lower leaf springs 20A and 20B fixed to the lower portion of the lens holding member 10 and the lower fixed side support portion 21 supported by the support base 40 are located on the same plane in the Z direction. Therefore, the lower elastic arm portion 23 hardly bends.

  Next, the cutting process of a connection branch part is performed. In this cutting step, the overlapping portion of the connecting branch portion 121a of the leaf spring blank 120 extending to the X2 side and the connecting branch portion 121 of the conductive plate blank 125 is simultaneously cut, and the leaf spring blank extending to the X1 side. The 120 connecting branches 121b are cut. By completing the cutting process, the assembly manufacturing process is completed, and the assembly 70 shown in FIG. 2 is completed. The connecting branch portions 121a and 121b and the connecting branch portion 121 are cut using a mechanical cutting tool or cut using a laser cutter.

  As described above, the fabrication of the assembly 70 is completed, and after the case 3 (case block) in which the support member 50, the upper leaf spring 30, and the magnet M are fixed inside is fabricated, the assembly 70 is assembled. And the combination process of combining the case 3 is performed. It should be noted that either the semi-finished product (case block) manufacturing process in which the support member 50, the upper leaf spring 30, and the magnet M are fixed inside the case 3 or the manufacturing process of the assembly 70 may be performed first. It is preferable to perform both production steps in parallel.

  In the combination process, the support base 40, the lower leaf springs 20A and 20B, the conductive plates 25A and 25B, the lens holding member 10 and the coil 60 are combined in the assembly 70, and the support member 50 and the upper leaf spring 30 are combined. It is inserted from the lower side (Z2 side) into the case 3 to which the magnet M is fixed. Alternatively, the case 3 is put on the assembly 70 from above so that the assembly 70 is inserted into the case 3. Thereby, the upward spring fixing surface 10 a of the lens holding member 10 and the lower surface of the upper movable side support portion 32 of the upper leaf spring 30 come into contact with each other, and the upper elastic arm portion 33 of the upper leaf spring 30 is bent. In this state, the spring fixing surface 10a provided on the upper portion of the lens holding member 10 and the upper movable side support portion 32 are fixed with an adhesive. The support base 40 and the case 3 are also fixed to each other with an adhesive, and the lens driving device 1 is completed.

  Note that an adhesive such as thermosetting that fixes the spring fixing surface 10 a and the upper movable side support portion 32 is applied in advance to the spring fixing surface 10 a before combining the assembly 70 and the case 3, for example. However, after the assembly 70 and the case 3 are combined, an adhesive may be applied to the vicinity of the overlapping portion of the spring fixing surface 10a and the upper movable side support portion 32 through the opening 3b of the case 3. . Thus, when apply | coating an adhesive agent using the opening part 3b, after fixing the support base 40 and the case 3 with adhesives, such as thermosetting, the lens holding member 10, the upper leaf | plate spring 30, Fixing with an adhesive can be performed. These adhesives are cured by heating.

  When the assembly 70 and the case 3 are combined, the upper movable side support portion 32 of the upper leaf spring 30 is abutted against the upper portion of the lens holding member 10 and pushed up in the Z1 direction, as shown in FIG. The upper movable support 32 is positioned above the support base 40 by a distance H from the upper fixed support 31, and the upper elastic arm 33 is bent in the initial state. That is, by combining the assembly 70 and the case 3, a process of pushing up the upper movable side support portion 32 and causing the upper elastic arm portion 33 of the upper leaf spring 30 to bend is performed. Further, in a state where the assembly 70 and the case 3 are combined, the spring fixing surface 10a and the upper movable side support portion 32, and the support base 40 and the case 3 are fixed to each other with an adhesive, so that the upper elasticity It is possible to maintain a state in which the arm portion 33 is bent. In the combination process, the lower elastic arms 23 of the lower leaf springs 20A and 20B are not bent in the initial state.

  In addition, after the above-described lower movable side support portion fixing step, a conductive connection step of electrically connecting the lower movable side support portion 22 of the lower leaf springs 20A and 20B and the winding start end 61a and winding end 61b of the coil 60 with solder or the like, respectively. Is going. Since the configuration of the conductive connection has been described above with reference to FIG. 4, detailed description thereof is omitted here. This conductive connection step may be performed before the fixing step of the lower fixed side support portion and the conductive plate.

  In the embodiment, as shown in FIG. 4, the winding start end 61 a and winding end 61 b of the conductive wire constituting the coil 60 are wound around the protrusions 19 a and 19 b on the lower surface of the lens holding member 10. The portion and the lower leaf springs 20A and 20B are soldered to be conductive. However, the present invention has a structure in which the winding start end 61a and winding end 61b of the conductive wire extending from the coil 60 are directly connected to the lower leaf springs 20A and 20B by soldering or a conductive adhesive. Good.

DESCRIPTION OF SYMBOLS 1 Lens drive device 3 Case 3a Ceiling part 3b Opening part 3d Side wall part 3e Square wall part 10 Lens holding member 10a, 10b Spring fixed surface 20A, 20B Lower leaf | plate spring 21 Lower fixed side support part 22 Lower movable side support part 23 Lower part Elastic arm portions 25A, 25B Conductive plate 26 Support plate portion 27 Connection terminal 30 Upper leaf spring 31 Upper fixed side support portion 31a Side surface facing portion 31b Corner surface facing portion 32 Upper movable side support portion 33 Upper elastic arm portion 40 Support base 41A , 41B Spring fixing surface 42a, 42b Positioning projection 45a, 45b Stopper protrusion 50 Support member 51 Side support portion 52 Corner support portion 53 Case contact portion 55 Spring fixing surface 57 Magnet contact portion 60 Coil 70 Assembly M Magnet O Optical axis

Claims (15)

A support base; a case that covers the support base; a lens holding member that can be mounted at least partially inside the case and capable of mounting a lens body; and the lens holding member in an optical axis direction of the lens body. An upper leaf spring and a lower leaf spring that are movably supported; a coil mounted on the lens holding member; and a magnet that is provided inside the case and faces the coil.
The upper leaf spring is integrally formed with an upper fixed side support portion and an upper movable side support portion, and an upper elastic arm portion that connects the upper fixed side support portion and the upper movable side support portion. The leaf spring is integrally formed with a lower fixed side support portion and a lower movable side support portion, and a lower elastic arm portion connecting the lower fixed side support portion and the lower movable side support portion,
The upper fixed side support portion of the upper leaf spring is fixed to the case side, the upper movable side support portion is fixed to the upper portion of the lens holding member, and the lower fixed side support portion of the lower leaf spring is the support. It is fixed to the base side, the lower movable side support part is fixed to the lower part of the lens holding member,
In an initial state in which the coil is not energized, the lens holding member is in contact with the support base directly or via another member.
In the initial state, the lower elastic arm portion applies the lens holding member toward the support base rather than the urging force that the upper elastic arm portion urges the lens holding member toward the support base. A lens driving device characterized in that a biasing force to be biased is smaller.   The lens driving device according to claim 1, wherein a spring constant of the lower elastic arm portion is smaller than a spring constant of the upper elastic arm portion.   The lens driving device according to claim 2, wherein a cross-sectional area of the lower elastic arm portion is smaller than a cross-sectional area of the upper elastic arm portion.   The lens according to any one of claims 1 to 3, wherein in the initial state, the lower fixed side support portion and the lower movable side support portion of the lower leaf spring are located on the same plane perpendicular to the optical axis. Drive device.   Stopper protrusions are formed on either the lower part of the lens holding member and the support base to contact the lower part of the lens holding member and the support base in the initial state. The lens driving device according to claim 4, wherein a stopper protrusion is located between the lower fixed side support portion and the lower movable side support portion. Spring fixing surfaces are formed at a plurality of locations on the upper surface of the support base,
A pair of the lower leaf springs are provided, and the lower fixed side support portions of the lower leaf springs are supported on the spring fixing surfaces,
6. The lens driving device according to claim 1, wherein a conductive plate is overlapped on the lower fixed side support portion of each of the lower plate springs, and a connection terminal is formed on the conductive plate.   The lens driving device according to claim 6, wherein the lower fixed side support portion and the conductive plate are welded, and the lower fixed side support portion of the lower leaf spring is bonded to the support base.   A lens driving device according to any one of claims 1 to 7, a lens body held by the lens holding member of the lens driving device, and an imaging element facing the lens body. Camera module to do. A support base; a case that covers the support base; a lens holding member that can be mounted at least partially inside the case and capable of mounting a lens body; and the lens holding member in an optical axis direction of the lens body. An upper leaf spring and a lower leaf spring that are movably supported; a coil mounted on the lens holding member; and a magnet that is provided inside the case and faces the coil.
The upper leaf spring is integrally formed with an upper fixed side support portion and an upper movable side support portion, and an upper elastic arm portion that connects the upper fixed side support portion and the upper movable side support portion. The leaf spring is integrally formed with a lower fixed side support portion and a lower movable side support portion, and a lower elastic arm portion connecting the lower fixed side support portion and the lower movable side support portion,
The upper fixed side support portion of the upper leaf spring is fixed to the case side, the upper movable side support portion is fixed to the upper portion of the lens holding member, and the lower fixed side support portion of the lower leaf spring is the support. It is fixed to the base side, the lower movable side support part is fixed to the lower part of the lens holding member,
In the manufacturing method of the lens driving device in which the lens holding member is in contact with the support base directly or through another member in an initial state where the coil is not energized,
(A) using a pair of conductive plates having a connection terminal and a pair of lower leaf springs, and stacking the lower stationary side support portions of the lower leaf springs and the conductive plates;
(B) The lower fixed side stacked in the step (a) on the support base so that the lower fixed side support portion is disposed between the support base and the conductive plate. Arranging and fixing the support part and the conductive plate respectively;
Have
In the initial state, the lower elastic arm portion applies the lens holding member toward the support base rather than the urging force that the upper elastic arm portion urges the lens holding member toward the support base. A method of manufacturing a lens driving device, wherein the biasing force to be biased is set smaller.   The welding process of welding the said lower fixed side support part of the said lower leaf | plate spring and the said electrically conductive plate which were each piled up by the process of said (a), The said process of (b) is performed after that. The manufacturing method of the lens drive device of description. The plate thickness of the conductive plate is larger than the plate thickness of the lower leaf spring,
In the welding step, a laser is irradiated from the side of the lower fixed side support portion to the overlapping portion of the lower fixed side support portion and the conductive plate to weld the lower fixed side support portion and the conductive plate. The manufacturing method of the lens drive device of Claim 10.   The method for manufacturing a lens driving device according to claim 9, wherein a spring constant of the lower elastic arm portion is smaller than a spring constant of the upper elastic arm portion.   The method for manufacturing a lens driving device according to claim 12, wherein a cross-sectional area of the lower elastic arm portion is smaller than a cross-sectional area of the upper elastic arm portion.   14. The lens according to claim 9, wherein in the initial state, the lower fixed side support portion and the lower movable side support portion of the lower leaf spring are located on the same plane perpendicular to the optical axis. Manufacturing method of drive device.   A stopper protrusion for abutting the lower part of the lens holding member and the support base in the initial state is formed on either the lower part of the lens holding member and the support base, and at least a part of the stopper protrusion is formed. The method of manufacturing a lens driving device according to claim 14, wherein a portion is positioned between the lower fixed side support portion and the lower movable side support portion.

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