Lens drive device and camera module

Abstract

To provide a lens drive device with which it is possible to generate a sufficient drive force (thrust), even when a cover member is formed from non-magnetic material.SOLUTION: A lens drive device 100 comprises a housing HS that includes a base member 18 and a cover member 4 which is formed from a non-magnetic material, a lens holding member 2 that is disposed within the housing HS, a coil 3 that is fixed to the lens holding member 2, a magnet 5 that faces the coil 3 and is fixed to the inner surface of the cover member 4, and an upper leaf spring 16 and a lower leaf spring 26 that support the lens holding member 2 so as to be movable in the optical axis direction. The magnet 5 is fixed to the inner surface of the cover member 4 so that its top face is located upward of the upper leaf spring 16 and its underside is located downward of the lower leaf spring 26.SELECTED DRAWING: Figure 2

Description

Technical Field

[0006] , ,

[0001] The present disclosure relates to a lens driving device mounted on, for example, a portable device with a camera, and a camera module including the lens driving device.

Background Art

[0002] Conventionally, a lens driving device including a cover member formed of a non-magnetic material, a lens holding member disposed within the cover member and capable of holding a lens body, a coil fixed to the lens holding member, a magnet facing the coil and fixed to the inner surface of the cover member, and a leaf spring that supports the lens holding member so as to be movable in the optical axis direction has been known (see Patent Document 1). In this device, a driving force (thrust force) for moving the lens holding member along the optical axis direction is electromagnetically generated by a driving unit constituted by a magnet and a coil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in this device, since the cover member is formed of a non-magnetic material, there is a risk that the driving force (thrust force) may be insufficient depending on the weight of the lens body.

[0005] Therefore, it is desired to provide a lens driving device that can generate a sufficient driving force (thrust force) even when the cover member is formed of a non-magnetic material.

Means for Solving the Problems

[0006] A lens driving device according to an embodiment of the present invention comprises a housing including a base member and a cover member made of a non-magnetic material; a lens holding member disposed within the housing and capable of holding a lens body; a coil fixed to the lens holding member; a magnet facing the coil and fixed to the inner surface of the cover member; and an upper leaf spring and a lower leaf spring that support the lens holding member so as to be movable in the optical axis direction, wherein the upper leaf spring has an upper movable support portion fixed to the upper part of the lens holding member, an upper fixed support portion fixed to a stepped portion provided on the cover member, and an elastic arm portion provided between the upper movable support portion and the upper fixed support portion; and the lower leaf spring has a lower movable support portion fixed to the lower part of the lens holding member, a lower fixed support portion fixed to the base member, and an elastic arm portion provided between the lower movable support portion and the lower fixed support portion. The ceiling surface of the stepped portion of the cover member to which the upper surface of the upper fixed support portion of the upper leaf spring is fixed is located below the ceiling surface of the ceiling portion of the cover member to which the upper surface of the magnet is in contact. The magnet's upper surface is located above the upper leaf spring, and its lower surface is located below the lower leaf spring. [Effects of the Invention]

[0007] The lens driving device described above can generate sufficient driving force (thrust) even when the cover member is made of a non-magnetic material. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the lens drive mechanism. [Figure 2] This is a disassembled perspective view of the lens drive mechanism. [Figure 3A] This is a perspective view of the lens holder. [Figure 3B] This is a perspective view of a lens holder member to which a coil and an upper leaf spring are attached. [Figure 3C] This is a perspective view of the bottom surface of the lens holder member to which the coil and lower leaf spring are attached. [Figure 4A] This is a bottom view of the lens holder with the coil attached. [Figure 4B]This is a bottom view of a portion of the lens holder member to which the coil is attached. [Figure 5A] This is a top view of the upper leaf spring. [Figure 5B] This is a top view of the lower leaf spring. [Figure 6] This is a perspective view of a component that forms part of the fixed-side member. [Figure 7] This is a diagram illustrating the assembly procedure for the upper assembly. [Figure 8] This is a diagram illustrating the assembly procedure for the lens drive device. [Figure 9A] This is a perspective view of the lens drive unit with the cover removed. [Figure 9B] This is a front view of the lens drive mechanism. [Figure 9C] This is a left side view of the lens drive mechanism. [Figure 10] This is a cross-sectional view of the cover member, magnet, and base member. [Modes for carrying out the invention]

[0009] Hereinafter, a lens drive device 100, which is an example of an embodiment of the present invention, will be described with reference to the drawings. Figure 1 is a perspective view of the lens drive device 100. Figure 2 is an exploded perspective view of the lens drive device 100.

[0010] In FIGS. 1 and 2, X1 represents one direction of the X-axis constituting the three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X-axis. Also, Y1 represents one direction of the Y-axis constituting the three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y-axis. Similarly, Z1 represents one direction of the Z-axis constituting the three-dimensional orthogonal coordinate system, and Z2 represents the other direction of the Z-axis. In FIGS. 1 and 2, the X1 side of the lens driving device 100 corresponds to the front side (front face side) of the lens driving device 100, and the X2 side of the lens driving device 100 corresponds to the rear side (rear face side) of the lens driving device 100. Also, the Y1 side of the lens driving device 100 corresponds to the left side of the lens driving device 100, and the Y2 side of the lens driving device 100 corresponds to the right side of the lens driving device 100. Also, the Z1 side of the lens driving device 100 corresponds to the upper side (subject side) of the lens driving device 100, and the Z2 side of the lens driving device 100 corresponds to the lower side (imaging element side) of the lens driving device 100. The same applies to other figures.

[0011] As shown in FIG. 2, the lens driving device 100 includes a lens holding member 2 capable of holding a lens body (not shown), a driving unit DM that generates a driving force (thrust) for moving the lens holding member 2 along the optical axis direction (Z-axis direction), a leaf spring 6 that supports the lens holding member 2 so as to be movable in the optical axis direction, a fixed-side member FB to which the leaf spring 6 is fixed, and a metal member 7 that provides an electrical connection between an external power source and the lens driving device 100. The lens body is, for example, a cylindrical lens barrel provided with at least one lens, and is configured such that its central axis line extends along the optical axis direction. The "optical axis direction" includes the direction of the optical axis OA with respect to the lens body and directions parallel to the optical axis OA.

[0012] As shown in FIG. 2, the driving unit DM includes a coil 3 having two oval-shaped winding portions 13 (first winding portion 13A and second winding portion 13B) held on two opposing side portions of the lens holding member 2 having a substantially rectangular parallelepiped outer shape, and a magnet 5 disposed to face the coil 3 in the radial direction (direction perpendicular to the optical axis OA). In FIG. 2, for clarity, the detailed winding state of the conductive wire material whose surface is covered with an insulating member is not shown for the winding portion 13. The same applies to other figures showing the winding portion 13.

[0013] The cover member 4 is a cylindrical outer case made of a non-magnetic material and constitutes a part of the fixed-side member FB. In the illustrated example, the cover member 4 is manufactured by performing punching, drawing, and other processes on a plate material made of austenitic stainless steel.

[0014] Specifically, as shown in FIG. 1, the cover member 4 has a rectangular cylindrical outer peripheral wall portion 4A and a rectangular annular top plate portion 4B provided so as to be continuous with the upper end (the end on the Z1 side) of the outer peripheral wall portion 4A, and forms a storage portion 4S. A circular opening is formed in the center of the top plate portion 4B. Further, the top plate portion 4B has four stepped portions 4C formed at each of the four corner portions. The four stepped portions 4C are formed so as to be recessed downward (in the Z2 direction) and include a first stepped portion 4C1 to a fourth stepped portion 4C4.

[0015] The outer peripheral wall portion 4A includes a first side plate portion 4A1 to a fourth side plate portion 4A4. The first side plate portion 4A1 and the third side plate portion 4A3 face each other and constitute a pair of side plate portions. Similarly, the second side plate portion 4A2 and the fourth side plate portion 4A4 face each other and constitute another pair of side plate portions. And each of the first side plate portion 4A1 and the third side plate portion 4A3 is perpendicular to each of the second side plate portion 4A2 and the fourth side plate portion 4A4.

[0016] Further, as shown in FIG. 2, a plurality of cutout portions CU are formed in the lower part of the outer peripheral wall portion 4A. Specifically, four first cutout portions CU1 are formed in the lower part of the first side plate portion 4A1, four second cutout portions CU2 are formed in the lower part of the second side plate portion 4A2, four third cutout portions CU3 are formed in the lower part of the third side plate portion 4A3, and four fourth cutout portions CU4 are formed in the lower part of the fourth side plate portion 4A4.

[0017] The cover member 4 configured as described above houses the lens holding member 2, the coil 3, the magnet 5, and the leaf spring 6 in the storage portion 4S, and is coupled to the base member 18 as shown in FIG. 1 to constitute the housing HS together with the base member 18.

[0018] The magnet 5 constitutes part of the drive unit DM. In the illustrated example, the magnet 5 includes a first magnet 5A positioned opposite the second side plate portion 4A2 and a second magnet 5B positioned opposite the fourth side plate portion 4A4.

[0019] The first magnet 5A is composed of a combination of two radially polarized permanent magnets (dipole magnets). In Figure 2, the north pole is represented by cross-hatching and the south pole by diagonal hatching. The combination of two dipole magnets has the advantage of more reliably suppressing magnetic field leakage to the outside of the cover member 4 compared to a single dipole magnet or a single quadruple magnet polarized in the optical axis direction. However, the first magnet 5A may be composed of a single dipole magnet or a single quadruple magnet. The same applies to the second magnet 5B.

[0020] Specifically, the first magnet 5A includes a first upper magnet 5AU and a first lower magnet 5AL, as shown in Figure 2. The second magnet 5B includes a second upper magnet 5BU and a second lower magnet 5BL. The first upper magnet 5AU, the first lower magnet 5AL, the second upper magnet 5BU, and the second lower magnet 5BL all have a roughly rectangular parallelepiped shape.

[0021] Furthermore, the magnet 5 is located on the outside of the coil 3 (winding portion 13) and is positioned along two surfaces of the outer peripheral wall portion 4A of the cover member 4. The magnet 5 is also fixed to the inner surface of the outer peripheral wall portion 4A by adhesive AD2 (see Figure 7). Specifically, the first upper magnet 5AU and the first lower magnet 5AL are located on the outside of the first winding portion 13A and are fixed to the inner surface of the second side plate portion 4A2. The second upper magnet 5BU and the second lower magnet 5BL are located on the outside of the second winding portion 13B and are fixed to the inner surface of the fourth side plate portion 4A4.

[0022] The leaf spring 6 includes an upper leaf spring 16 positioned between the lens holding member 2 and the cover member 4, and a lower leaf spring 26 positioned between the lens holding member 2 and the base member 18. The lower leaf spring 26 includes a first lower leaf spring 26A and a second lower leaf spring 26B.

[0023] The fixed-side member FB includes a cover member 4 and a base member 18 into which a metal member 7 is embedded.

[0024] The lens drive unit 100 has a roughly rectangular parallelepiped shape and is mounted on a substrate (not shown) on which an image sensor (not shown) is mounted. The substrate, the lens drive unit 100, the lens body attached to the lens holding member 2, and the image sensor mounted on the substrate facing the lens body constitute a camera module. The coil 3 is connected to an external power source via the lower leaf spring 26, the metal member 7, and the substrate. When current flows through the coil 3, the drive unit DM electromagnetically generates a driving force (thrust) along the optical axis.

[0025] The lens drive device 100 utilizes this driving force to move the lens holding member 2 along the optical axis on the Z1 side (subject side) of the image sensor, thereby realizing an automatic focus adjustment function. Specifically, the lens drive device 100 enables macro photography by moving the lens holding member 2 away from the image sensor, and enables infinity focus photography by moving the lens holding member 2 closer to the image sensor.

[0026] Next, the lens holding member 2 will be described with reference to Figures 3A to 3C, Figure 4A, and Figure 4B. Figure 3A is a perspective view of the lens holding member 2. Figure 3B shows the lens holding member 2 in Figure 3A with the coil 3 and upper leaf spring 16 attached. Figure 3C is a perspective view of the bottom of the lens holding member 2, showing the coil 3 and lower leaf spring 26 attached to the lens holding member 2. Figure 4A is a bottom view of the lens holding member 2, and Figure 4B is an enlarged view of the portion R1 enclosed by the dashed line in Figure 4A. Note that in Figures 3B and 3C, a dot pattern has been added to the coil 3 and leaf spring 6 for clarity. Also, in Figure 4B, a dot pattern has been added to the coil 3 for clarity.

[0027] In the illustrated example, the lens holding member 2 is manufactured by injection molding of a synthetic resin such as liquid crystal polymer (LCP). Specifically, as shown in Figure 3A, the lens holding member 2 includes a cylindrical portion 12 in which a through hole 2K extending along the optical axis is formed.

[0028] The cylindrical inner surface of the cylindrical portion 12 is provided with a helical groove to allow adhesive to spread between the inner surface and the lens body. The cylindrical portion 12 is also provided with an annular base portion 12D having four recesses 12H on the end face facing the subject. As shown in Figure 3B, the annular inner portion 16i that constitutes the upper leaf spring 16 is placed on the base portion 12D.

[0029] As shown in Figure 3A, projections 12P for holding the coil 3 are provided on the outer circumferential surface of the cylindrical portion 12. In the illustrated example, the projections 12P protrude radially outward from the outer circumferential surface of the cylindrical portion 12 and have a substantially rectangular parallelepiped shape, so that a conductive wire is wound around the coil axis CX perpendicular to the optical axis. Specifically, the projections 12P are arranged on two opposing outer surfaces of the lens holding member 2. In the illustrated example, the projections 12P include a first projection 12PA located on the outer surface on the Y1 side and a second projection 12PB located on the outer surface on the Y2 side.

[0030] As shown in Figure 3B, the winding portion 13 of the coil 3 is formed by winding a conductive wire around a projection 12P. Specifically, the winding portion 13 includes a first winding portion 13A (see Figure 3B) positioned opposite the second side plate portion 4A2, and a second winding portion 13B (see Figure 3C) positioned opposite the fourth side plate portion 4A4. The first winding portion 13A and the second winding portion 13B are connected by a connecting portion 3C. The first winding portion 13A is wound around the first projection 12PA (see Figure 3B), and the second winding portion 13B is wound around the second projection 12PB (see Figure 3C). In the illustrated example, the winding portion 13 is fixed to the projection 12P without using adhesive, but it may be fixed to the projection 12P using adhesive. The winding direction of the winding portion 13 is arbitrary and is determined, for example, according to the arrangement (magnetization direction) of the magnet 5. Alternatively, the winding portion 13 may be attached to the projection 12P while it is wound.

[0031] As shown in Figure 3C, the lens holding member 2 includes two rectangular convex protrusions 72 and four round convex protrusions 2T that project downward (in the Z2 direction) from the end face on the image sensor side (Z2 side).

[0032] As shown in Figure 4A, the holding portion 72 includes a first holding portion 72A around which one end of the wire constituting the coil 3 is wound, and a second holding portion 72B around which the other end of the wire constituting the coil 3 is wound. In this way, both ends of the wire constituting the coil 3 are wound around and held by the holding portion 72.

[0033] As shown in Figure 3C, the protruding portion 2T includes two protruding portions 2T corresponding to the first lower leaf spring 26A and two protruding portions 2T corresponding to the second lower leaf spring 26B. The inner portions 26i of the first lower leaf spring 26A and the second lower leaf spring 26B, respectively, are attached to and fixed to the protruding portion 2T as lower movable support portions. The fixing of the inner portions 26i of the first lower leaf spring 26A and the second lower leaf spring 26B is achieved by heat-crimping the protruding portion 2T, which is inserted through holes formed in the inner portions 26i. In Figure 3C, the protruding portion 2T is shown in a deformed state at the tip after heat-crimping. The same applies to the other figures.

[0034] Next, the drive unit DM of the lens drive device 100 will be described. As shown in Figure 2, the drive unit DM includes a coil 3 and a magnet 5. Specifically, the coil 3 includes a first winding portion 13A arranged to face the second side plate portion 4A2 and a second winding portion 13B arranged to face the fourth side plate portion 4A4. The magnet 5 includes a first magnet 5A bonded and fixed to the inner surface of the second side plate portion 4A2 and a second magnet 5B bonded and fixed to the inner surface of the fourth side plate portion 4A4. The drive unit DM generates a driving force (thrust) using the current flowing through the coil 3 and the magnetic field generated by the magnet 5, causing the lens holding member 2 to move up and down along the optical axis.

[0035] As shown in Figure 4A, the extended portion 33 of the coil 3 includes a first extended portion 33A connected to the first winding portion 13A at one end of the wire constituting the coil 3, and a second extended portion 33B connected to the second winding portion 13B at the other end of the wire constituting the coil 3.

[0036] Specifically, as shown in Figure 4B, the first extending portion 33A includes a winding portion 33m that is wrapped around the first holding portion 72A and a facing portion 33c that extends opposite to the bottom surface (Z2 side surface) of the lens holding member 2. The same applies to the second extending portion 33B.

[0037] In the illustrated example, the first extension portion 33A is wound around the first holding portion 72A of the lens holding member 2 before the wire of the coil 3 is wound around the outer circumference of the first projection 12PA. In the example shown in Figure 4B, a portion of the wire of the coil 3 is wound around the first holding portion 72A three times. As a result, a wound portion 33m is formed on the first holding portion 72A, and a portion of the first extension portion 33A is held by the first holding portion 72A.

[0038] Next, a wire is wrapped around the outer circumference of the first projection 12PA. At this time, as shown in Figure 4B, the wire extending from the wrapping portion 33m toward the first projection 12PA extends so as to face the bottom surface of the lens holding member 2. The portion facing the bottom surface of the lens holding member 2 constitutes the opposing portion 33c of the first extending portion 33A.

[0039] After the first winding portion 13A is formed at the first projection 12PA, the wire drawn out from the first winding portion 13A is wound around the outer circumference of the second projection 12PB. Once the winding of the wire around the outer circumference of the first projection 12PA and the winding of the wire around the outer circumference of the second projection 12PB is completed, the second extending portion 33B, which is connected to the other end of the wire constituting the coil 3, is drawn out from the right side (Y2 surface) of the lens holding member 2 to the bottom surface (Z2 surface), as shown in Figure 4A. Specifically, the opposing portion 33c extends opposite the bottom surface of the lens holding member 2, and the winding portion 33m is wound around the second holding portion 72B of the lens holding member 2. In the example shown in Figure 4A, the second extending portion 33B is wound around the second holding portion 72B three times.

[0040] Next, the details of the leaf spring 6 will be described with reference to Figures 5A and 5B. Figure 5A is a top view of the upper leaf spring 16, and Figure 5B is a top view of the lower leaf spring 26.

[0041] In the illustrated example, the leaf spring 6 is made from a metal plate primarily composed of a copper alloy. Specifically, the leaf spring 6 includes an upper leaf spring 16 positioned between the lens holding member 2 and the cover member 4, and a lower leaf spring 26 positioned between the lens holding member 2 and the base member 18. Each of the leaf springs 6 (upper leaf spring 16, first lower leaf spring 26A, and second lower leaf spring 26B) connects the lens holding member 2 to the fixed-side member FB, supporting the lens holding member 2 in the air so that it can move in the optical axis direction relative to the fixed-side member FB. The first lower leaf spring 26A and the second lower leaf spring 26B also function as power supply members for supplying current to the coil 3. Therefore, the first lower leaf spring 26A is electrically connected to one end of the wire constituting the coil 3, and the second lower leaf spring 26B is electrically connected to the other end of the wire constituting the coil 3.

[0042] Specifically, as shown in Figure 5A, the upper leaf spring 16 has a substantially rectangular outer shape when viewed from above and includes an annular inner portion 16i as an upper movable support portion fixed to the lens holding member 2, two outer portions 16e as upper fixed support portions fixed to the cover member 4 as a fixed member FB, and four elastic arm portions 16g located between the inner portion 16i and each of the two outer portions 16e. Specifically, the inner portion 16i is provided so as to face the base portion 12D (see Figure 3A) of the lens holding member 2. Each of the two outer portions 16e has two corner portions 16b and a crossbar portion 16r connecting the two corner portions 16b. The crossbar portion 16r includes a first crossbar portion 16r1 extending along the first side plate portion 4A1 and a second crossbar portion 16r2 extending along the third side plate portion 4A3. The corner portion 16b is fixed to the stepped portion 4C formed at the corner of the cover member 4 (top plate portion 4B) with adhesive AD1 (see Figure 7).

[0043] More specifically, when the upper leaf spring 16 is incorporated into the lens drive device 100, as shown in Figure 3B, the inner portion 16i is placed on the base portion 12D (see Figure 3A) of the lens holding member 2. The inner portion 16i is then fixed to the lens holding member 2 by adhesive AD3 (see Figure 8) applied to each of the four recesses 12H formed in the base portion 12D. The outer portion 16e is fixed to the top surface of the cover member 4 (top plate portion 4B) by adhesive AD1 (see Figure 7) applied to the top surface of the stepped portion 4C formed at the corner of the cover member 4.

[0044] As shown in Figure 5A, the upper leaf spring 16 has a shape that is substantially rotationally symmetrical twice with respect to the optical axis OA. The upper leaf spring 16 is fixed to the lens holding member 2 at its inner portion 16i and to the cover member 4 at its outer portion 16e. Therefore, the upper leaf spring 16 can support the lens holding member 2 in a balanced manner in the air.

[0045] As shown in Figure 5B, the first lower leaf spring 26A and the second lower leaf spring 26B are configured such that their inner shapes are approximately semicircular. Each of the first lower leaf spring 26A and the second lower leaf spring 26B includes an inner portion 26i as a lower movable support portion fixed to the lens holding member 2, two outer portions 26e as lower fixed support portions fixed to the base member 18 as a fixed member FB, and an elastic arm portion 26g located between the inner portion 26i and the outer portion 26e.

[0046] As shown in Figure 5B, the inner portions 26i of the first lower leaf spring 26A and the second lower leaf spring 26B each include two inner joining portions 26c fixed to the lens holding member 2, a connecting portion 26p connecting the two inner joining portions 26c, and a connecting plate portion 26h facing the extended portion 33 of the coil 3 in the optical axis direction (Z axis direction).

[0047] When the first lower leaf spring 26A and the second lower leaf spring 26B are incorporated into the lens drive device 100, each of the four protruding portions 2T of the lens holding member 2 shown in Figure 3C is inserted into and fitted into the circular through holes provided in the inner joining portions 26c of the first lower leaf spring 26A and the second lower leaf spring 26B shown in Figure 5B. As a result, the inner portions 26i of the first lower leaf spring 26A and the second lower leaf spring 26B are positioned and fixed to the lens holding member 2. The first lower leaf spring 26A and the second lower leaf spring 26B are fixed to the lens holding member 2, for example, by applying heat crimping or cold crimping to the protruding portions 2T of the lens holding member 2.

[0048] The following explanation, referring to Figure 4B, mainly concerns the relationship between the first lower leaf spring 26A, the lens holding member 2, and the coil 3. However, the explanation regarding the first lower leaf spring 26A also applies to the second lower leaf spring 26B.

[0049] As shown in Figures 3C and 4B, the connecting plate portion 26h (see Figure 5B) of the inner portion 26i of the first lower leaf spring 26A faces the protruding portion 82 of the lens holding member 2 when the lens driving device 100 is assembled. That is, the subject-side (Z1 side) surface of the connecting plate portion 26h faces the housing portion 82s formed by the protruding portion 82. The opposing portion 33c of the first extending portion 33A of the coil 3 extends through the space between the subject-side surface of the inner portion 26i (connecting plate portion 26h) of the first lower leaf spring 26A and the image sensor-side (Z2 side) surface of the lens holding member 2.

[0050] As shown in Figure 4B, the pier portion 82 includes an inner wall portion 82u located on the central side of the lens holding member 2, an outer wall portion 82v located on the outside opposite to the inner wall portion 82u, and a side wall portion 82w located between the inner wall portion 82u and the outer wall portion 82v on the side closer to the first holding portion 72A. On the tip side of the pier portion 82 furthest from the first holding portion 72A, an open portion 82z is formed by cutting out a wall portion, as shown in Figure 4B. The opposing portion 33c of the first extension portion 33A extends outward through the open portion 82z. The space enclosed by the three wall portions (inner wall portion 82u, outer wall portion 82v, and side wall portion 82w) forms the housing portion 82s. The housing portion 82s is configured to accommodate the conductive adhesive that connects the first extension portion 33A of the coil 3 and the first lower leaf spring 26A.

[0051] When the first lower leaf spring 26A is assembled to the lens holding member 2, as shown in Figure 3C, the first holding portion 72A protrudes downward (in the Z2 direction) from the inner portion 26i of the first lower leaf spring 26A, so that its tip is located on the image sensor side (Z2 side) of the inner portion 26i. In addition, a part of the winding portion 33m is also wound around the first holding portion 72A so that it is located on the image sensor side (Z2 side) of the inner portion 26i.

[0052] The first lower leaf spring 26A and the first extended portion 33A of the coil 3 are electrically and physically connected by a conductive adhesive in which conductive fillers such as silver particles are dispersed in a synthetic resin. Specifically, before attaching the first lower leaf spring 26A to the lens holding member 2, the conductive adhesive is applied to the housing portion 82s surrounded by the protruding portion 82 of the lens holding member 2, and then the first lower leaf spring 26A is attached to the lens holding member 2. Then, the protruding portion 2T of the lens holding member 2 is heat-crimped, and the conductive adhesive is heat-cured. From the application of the conductive adhesive to the housing portion 82s to the heat curing of the conductive adhesive, the lens holding member 2 is placed upside down so that the first holding portion 72A protrudes vertically upward. Therefore, even if the conductive adhesive is fluid, it remains appropriately in the desired position (position within the housing portion 82s). Furthermore, a part of the opposing portion 33c is located within the housing portion 82s and is therefore embedded in the conductive adhesive. Furthermore, the conductive adhesive is not limited to a thermosetting type; it may also be an ultraviolet-curing type or a moisture-curing type, etc.

[0053] The outer portion 26e of the first lower leaf spring 26A includes two outer connecting portions 26d that are fixed to the base member 18, as shown in Figure 5B. The through holes provided in the outer connecting portions 26d of the first lower leaf spring 26A fit with the protruding portion 18T (see Figure 6) provided on the upper surface of the base member 18. As a result, the outer portion 26e of the first lower leaf spring 26A is positioned and fixed to the base member 18.

[0054] As shown in Figure 5B, the first lower leaf spring 26A and the second lower leaf spring 26B have a shape that is approximately two rotationally symmetric with respect to the optical axis OA. The first lower leaf spring 26A is connected to the lens holding member 2 by two inner connecting portions 26c and to the base member 18 by two outer connecting portions 26d. The same applies to the second lower leaf spring 26B. With this configuration, the first lower leaf spring 26A and the second lower leaf spring 26B can support the lens holding member 2 in the air in a balanced manner while allowing it to move in the direction of the optical axis.

[0055] Next, the details of the base member 18 will be described with reference to Figure 6. Figure 6 is a perspective view of a component that constitutes part of the fixed-side member FB. Specifically, the top image in Figure 6 is a perspective view of the base member 18 without the metal member 7 embedded, the middle image in Figure 6 is a perspective view of the metal member 7 embedded in the base member 18, and the bottom image in Figure 6 is a perspective view of the base member 18 with the metal member 7 embedded. In the illustrated example, the fixed-side member FB includes the cover member 4, the magnet 5, the metal member 7, and the base member 18. Also, in Figure 6, a dot pattern is applied to the metal member 7 for clarity.

[0056] The base member 18 is manufactured by injection molding using a synthetic resin such as a liquid crystal polymer. In the illustrated example, as shown in Figure 6, the base member 18 has a roughly rectangular shape when viewed from above and has a circular opening 18K in the center.

[0057] Furthermore, the surface (upper surface) of the base member 18 facing the subject (Z1 side) is provided with six projections 18T that protrude upward. The projections 18T are inserted into and fitted into through holes provided in the outer joint portions 26d of the first lower leaf spring 26A and the second lower leaf spring 26B, respectively. At this time, the projections 18T are heat-crimped to fix them to the outer joint portions 26d. In Figure 6, the projections 18T are shown in a state where the tips have been deformed after heat crimping. Alternatively, the projections 18T may be cold-crimped to fix them to the outer joint portions 26d.

[0058] Furthermore, the upper surface of the base member 18 is provided with two recesses 18G that are recessed downwards. In the illustrated example, the recesses 18G include a left recess 18GL that is positioned opposite the lower surface of the first magnet 5A (first lower magnet 5AL), and a right recess 18GR that is positioned opposite the lower surface of the second magnet 5B (second lower magnet 5BL).

[0059] Furthermore, the upper surface of the base member 18 is provided with four wall portions 18W that protrude upward. In the illustrated example, the wall portions 18W are configured to prevent the adhesive AD4 (see Figure 8) used to bond and fix the cover member 4 and the base member 18 from entering the opening 18K through the upper surface of the base member 18. Specifically, the wall portions 18W include a rear wall portion 18WB, a front wall portion 18WF, a left wall portion 18WL, and a right wall portion 18WR. The front wall portion 18WF is configured to face the inner surface of the first side plate portion 4A1 and extend along the Y-axis direction. The rear wall portion 18WB is configured to face the inner surface of the third side plate portion 4A3 and extend along the Y-axis direction. The left wall portion 18WL is configured to face the inner surface of the second side plate portion 4A2 and extend along the inner bottom surface of the left recess 18GL in the X-axis direction. The right side wall portion 18WR is configured to face the inner surface of the fourth side plate portion 4A4 and to extend in the X-axis direction along the inner bottom surface of the right side recess 18GR.

[0060] Furthermore, four protrusions 18S projecting upward are provided at the corners of the base member 18. In the illustrated example, the four protrusions 18S are configured such that their upper surfaces lie on the same plane. The outer joining portion 26d of the lower leaf spring 26 is placed on and fixed to the upper surface of each of the four protrusions 18S. The projection portion 18T is configured to project upward from the upper surface of the protrusion 18S.

[0061] Furthermore, as shown in Figure 6, a metal member 7, formed from a metal plate containing copper, iron, or an alloy mainly composed of these materials, is insert-molded and embedded in the base member 18.

[0062] The metal member 7 includes the first metal member 7A to the sixth metal member 7F. The first metal member 7A has a connecting portion 7AC that is exposed on the upper surface (Z1 side surface) of a protrusion 18S formed on the base member 18, and the second metal member 7B has a connecting portion 7BC that is exposed on the upper surface (Z1 side surface) of another protrusion 18S formed on the base member 18. The surfaces of the connecting portions 7AC and 7BC are located on the same plane as the upper surfaces of the four protrusions 18S.

[0063] The connecting portion 7AC is joined to the outer joint portion 26d of the first lower leaf spring 26A via a conductive bonding material, while in contact with the portion of the outer joint portion 26d of the first lower leaf spring 26A that includes the through hole 26dt (see Figure 5B). The conductive bonding material is, for example, solder or a conductive adhesive. In the illustrated example, the conductive bonding material is a conductive adhesive.

[0064] Similarly, the connecting portion 7BC is joined to the outer joining portion 26d of the second lower leaf spring 26B via a conductive joining material, while in contact with the portion of the outer joining portion 26d of the second lower leaf spring 26B that includes the through hole 26dt (see Figure 5B).

[0065] The first metal member 7A has a terminal portion 7AT that protrudes downward from the bottom surface (Z2 side surface) of the base member 18, and the second metal member 7B has a terminal portion 7BT that protrudes downward from the bottom surface (Z2 side surface) of the base member 18.

[0066] The third metal member 7C has a terminal portion 7CT that protrudes downward from the bottom surface (Z2 side surface) of the base member 18, and an end portion 7CP that protrudes outward from the corner of the base member 18 in a direction perpendicular to the optical axis direction. The fourth metal member 7D has an end portion 7DP that protrudes outward from the corner of the base member 18 in a direction perpendicular to the optical axis direction. The fifth metal member 7E has an end portion 7EP that protrudes outward from the corner of the base member 18 in a direction perpendicular to the optical axis direction. The sixth metal member 7F has an end portion 7FP that protrudes outward from the corner of the base member 18 in a direction perpendicular to the optical axis direction.

[0067] The base member 18 is positioned by combining the inner surface of the outer peripheral wall portion 4A of the cover member 4 with the outer peripheral side portion 18E of the base member 18. Then, the ends 7CP to 7FP are welded to the lower ends of the four corners of the cover member 4 to fix it to the cover member 4. The cover member 4 and the base member 18 are also fixed together with adhesive AD4 (see Figure 8). The cover member 4 is connected to the ground via the terminal portion 7CT of the third metal member 7C.

[0068] Next, with reference to Figure 7, the upper assembly UA of the lens drive device 100 will be described. The upper assembly UA mainly consists of a cover member 4, an upper leaf spring 16, and a magnet 5. Figure 7 is a diagram illustrating the assembly procedure of the upper assembly UA. Specifically, the topmost figure in Figure 7 shows a perspective view of the cover member 4 in an upside-down position, and the second figure from the top of Figure 7 shows a perspective view of the cover member 4 with the upper leaf spring 16 fitted inside. The third figure from the top of Figure 7 shows a perspective view of the cover member 4 with the first upper magnet 5AU (not visible in Figure 7) and the second upper magnet 5BU fitted inside, and the bottommost figure in Figure 7 shows a perspective view of the cover member 4 with the first lower magnet 5AL and the second lower magnet 5BL fitted inside. In other words, the bottommost figure in Figure 7 shows the completed state of the upper assembly UA. In Figure 7, for clarity, a dot pattern is applied to the component immediately after it is fitted into the cover component 4.

[0069] The assembly of the upper assembly UA of the lens drive unit 100 is typically performed with the cover member 4 placed upside down, as shown in Figure 7, that is, with the inner (Z2 side) surface (ceiling surface) of the top plate portion 4B facing upwards. In this state, adhesive AD1 is applied to the ceiling surface (Z2 side surface) of the stepped portion 4C formed at each of the four corners of the cover member 4 (top plate portion 4B). The stepped portion 4C is configured to come into contact with the corner portion 16b of the outer portion 16e, which is the upper fixed support portion of the upper leaf spring 16.

[0070] Subsequently, the upper leaf spring 16 is fitted into the cover member 4 in an inverted state, as shown in the second diagram from the top in Figure 7. Specifically, the upper leaf spring 16 is positioned inside the cover member 4 such that the upper surface (Z1 side) of the corner portion 16b is in contact with the ceiling surface (Z2 side) of the stepped portion 4C of the cover member 4, and the upper surface (Z1 side) of the crossbar portion 16r is not in contact with the ceiling surface (Z2 side) of the top plate portion 4B of the cover member 4. In the illustrated example, the outer portion 16e (corner portion 16b) of the upper leaf spring 16 is bonded and fixed to the ceiling surface of the stepped portion 4C of the cover member 4 with adhesive AD1.

[0071] Subsequently, adhesive AD2 is applied to the inner surfaces of the second side plate portion 4A2 and the fourth side plate portion 4A4 of the cover member 4. Specifically, adhesive AD2 is applied to the inner surface of the fourth side plate portion 4A4, as shown in the second figure from the top of Figure 7, to bond and fix the outer surface of the second magnet 5B to the inner surface of the fourth side plate portion 4A4. Although not visible in Figure 7, adhesive AD2 is also applied to the inner surface of the second side plate portion 4A2 to bond and fix the outer surface of the first magnet 5A to the inner surface of the second side plate portion 4A2.

[0072] In the illustrated example, adhesives AD1 and AD2 are applied at different times, but they may be applied simultaneously. Adhesives AD1 and AD2 are hybrid adhesives that cure by both ultraviolet light and heat. Curing by ultraviolet light is effective for rapid bonding (temporary fixing), while curing by heat is effective for achieving higher adhesive strength than curing by ultraviolet light. However, adhesives AD1 and AD2 may be other adhesives such as moisture-curing adhesives, ultraviolet-curing adhesives, or thermosetting adhesives.

[0073] Subsequently, the second upper magnet 5BU of the second magnet 5B is fitted into the cover member 4, as shown in the third figure from the top in Figure 7. Specifically, the second upper magnet 5BU is fitted into the cover member 4 such that its outer surface is in contact with the inner surface of the fourth side plate portion 4A4. In the illustrated example, the second upper magnet 5BU is fitted into the cover member 4 so as not to come into contact with the corner portion 16b of the upper leaf spring 16. The same applies to the first upper magnet 5AU, which is not visible in Figure 7. In the illustrated example, the crossbar portion 16r of the upper leaf spring 16 is formed to follow the first side plate portion 4A1 and the third side plate portion 4A3, respectively, but not to follow the second side plate portion 4A2 and the fourth side plate portion 4A4, respectively. This is to avoid interference with the magnet 5 fitted into the cover member 4.

[0074] Subsequently, the second lower magnet 5BL of the second magnet 5B is fitted into the cover member 4, similar to the second upper magnet 5BU, as shown in the bottommost diagram of Figure 7. Specifically, the second lower magnet 5BL is fitted into the cover member 4 so that its outer surface is in contact with the inner surface of the fourth side plate portion 4A4 on the lower side (Z2 side) of the second upper magnet 5BU. The same applies to the first lower magnet 5AL.

[0075] Next, with reference to Figure 8, the lower assembly LA of the lens drive device 100 will be described. The lower assembly LA mainly consists of a lens holding member 2, a coil 3, a metal member 7, a lower leaf spring 26, and a base member 18.

[0076] The upper assembly UA is assembled to the lower assembly LA as shown in Figure 8. Figure 8 is a diagram illustrating the assembly procedure of the lens drive device 100. Specifically, the topmost figure in Figure 8 shows a perspective view of the lower assembly LA. The second figure from the top in Figure 8 shows a perspective view of the lower assembly LA with adhesive AD3 applied to the four recesses 12H formed in the base portion 12D of the cylindrical portion 12 of the lens holding member 2, and vibration damping member VC attached between the lens holding member 2 and the base member 18. The third figure from the top in Figure 8 shows a perspective view of the lower assembly LA with the upper assembly UA attached, and the bottommost figure in Figure 8 shows a perspective view of the lens drive device 100 with the lower ends of the four corners of the cover member 4 welded to the metal member 7 by welding metal WM, and adhesive AD4 applied between the cover member 4 and the base member 18. In Figure 8, for clarity, cross patterns are applied to adhesives AD3 and AD4, vibration damping member VC, and weld metal WM.

[0077] The joining of the upper assembly UA and the lower assembly LA is typically performed with the upper surface of the lower assembly LA facing upwards, as shown in Figure 8, that is, with the upper surface of the base portion 12D of the cylindrical portion 12 of the lens holding member 2 facing upwards. In this state, as shown in the second figure from the top in Figure 8, adhesive AD3 is applied to the four recesses 12H formed in the base portion 12D, and vibration damping members VC are attached between the front surface of the lens holding member 2 and the front wall portion 18WF of the base member 18, and between the rear surface of the lens holding member 2 and the rear wall portion 18WB of the base member 18. The vibration damping member VC is a member that suppresses vibration of the lens holding member 2. In the illustrated example, the vibration damping member VC is a gel-like member formed by curing the adhesive.

[0078] Subsequently, the lower assembly LA is fitted into the upper assembly UA, as shown in the third figure from the top in Figure 8. Specifically, the lower assembly LA is fitted into the upper assembly UA such that the inner portion 16i of the upper leaf spring 16 is in contact with the base portion 12D of the lens holding member 2, and the lower ends of the four corners of the cover member 4 are in contact with the third metal member 7C to the sixth metal member 7F, respectively.

[0079] In this state, the front wall portion 18WF of the base member 18 is configured so that its outer surface is exposed from each of the four first notches CU1 formed at the lower part of the first side plate portion 4A1. The same applies to the rear wall portion 18WB of the base member 18, although it is not visible in Figure 8. In this state, the first lower magnet 5AL is configured so that its outer surface is exposed from each of the four second notches CU2 formed at the lower part of the second side plate portion 4A2. The same applies to the second lower magnet 5BL, although it is not visible in Figure 8.

[0080] Subsequently, as shown in the bottom diagram of Figure 8, the lower end of the cover member 4 is welded to the third metal member 7C to the sixth metal member 7F, respectively, with welding metal WM. In addition, the cover member 4, the magnet 5, and the base member 18 are bonded and fixed together with adhesive AD4.

[0081] Specifically, the first side plate portion 4A1 of the cover member 4 and the front side wall portion 18WF of the base member 18 are bonded and fixed together by adhesive AD4 applied to the first notch portion CU1, as shown in the bottommost diagram of Figure 8. In addition, the second side plate portion 4A2 of the cover member 4, the first lower magnet 5AL, and the left side recess portion 18GL of the base member 18 are bonded and fixed together by adhesive AD4 applied to the second notch portion CU2, as shown in the bottommost diagram of Figure 8.

[0082] In the illustrated example, adhesives AD3 and AD4 are thermosetting adhesives, and are different from adhesives AD1 and AD2, which are hybrids of UV-curing adhesives and thermosetting adhesives. This is because thermosetting adhesives can achieve higher adhesive strength than hybrid adhesives. However, adhesives AD3 and AD4 may be other adhesives such as moisture-curing adhesives, UV-curing adhesives, or hybrid adhesives.

[0083] Next, with reference to Figures 9A to 9C, the positional relationship between the coil 3, magnet 5, and leaf spring 6 housed within the housing HS will be explained. Figure 9A is a perspective view of the lens drive device 100 with the cover member 4 removed, Figure 9B is a front view of the lens drive device 100, and Figure 9C is a left side view of the lens drive device 100. Figures 9A to 9C also show the lens drive device 100 in its initial state. The initial state of the lens drive device 100 refers to the state of the lens drive device 100 when no current is flowing through the coil 3. In Figures 9B and 9C, the cover member 4 is shown in cross-section to illustrate the inside of the housing HS. In Figure 9C, the first winding portion 13A of the coil 3, which is hidden behind the first magnet 5A, is shown by a dashed line.

[0084] As shown in Figures 9A to 9C, the magnet 5 is adhesively fixed to the inner surface of the outer peripheral wall portion 4A such that its upper end protrudes above the upper leaf spring 16 and its lower end protrudes below the lower leaf spring 26. Also, as shown in Figure 9B, the magnet 5 is adhesively fixed to the inner surface of the outer peripheral wall portion 4A such that its upper surface is in contact with the ceiling surface of the top plate portion 4B of the cover member 4. Furthermore, as shown in Figure 9C, the corner portion 16b of the upper leaf spring 16 is adhesively fixed to the ceiling surface of the stepped portion 4C of the cover member 4.

[0085] Specifically, as shown in Figures 9B and 9C, the width H1, which is the distance between the upper and lower ends of the magnet 5 in the Z-axis direction, is greater than the width H2, which is the distance between the upper leaf spring 16 and the lower leaf spring 26 in the Z-axis direction. Also, the width H2 is greater than the width H3, which is the distance between the upper and lower ends of the winding portion 13 of the coil 3 in the Z-axis direction.

[0086] The dimensions of widths H1, H2, and H3 are set so that even when the lens holding member 2 is moved upward along the optical axis OA by the drive unit DM, the upper end of the coil 3 (winding portion 13) is positioned below the upper end of the magnet 5. Furthermore, the dimensions of widths H1, H2, and H3 are set so that even when the lens holding member 2 is moved downward along the optical axis OA by the drive unit DM, the lower end of the coil 3 (winding portion 13) is positioned above the lower end of the magnet 5. In other words, the dimensions of widths H1, H2, and H3 are set so that the coil 3 (winding portion 13) moves up and down within width H1, i.e., the coil 3 (winding portion 13) does not move up and down beyond the range of width H1. In other words, the maximum value of the current flowing through the coil 3 is limited so that the coil 3 (winding portion 13) does not move up and down beyond the range of width H1.

[0087] Furthermore, as shown in Figure 9C, the width W1, which is the distance between one end and the other end of the first magnet 5A in the X-axis direction, is approximately the same as the width W2, which is the distance between one end and the other end of the first winding portion 13A of the coil 3 in the X-axis direction. However, width W1 may be greater than width W2.

[0088] Thus, the sizes of widths W1 and W2 are set so that the magnetic field generated by the magnet 5 can perpendicularly cross the entire length of the straight section (the part extending in a straight line along the X-axis) of the coil 3 (winding section 13).

[0089] Furthermore, as shown in Figure 9C, the width W1 is smaller than the width W3, which is the distance between one end and the other end of the recess 18G of the base member 18 in the X-axis direction. The sizes of widths W1 and W3 are set so that the lower end of the magnet 5 can fit into the recess 18G without the magnet 5 coming into contact with the base member 18. In other words, the sizes of widths W1 and W3 are set so that interference between the magnet 5 and the base member 18 is avoided when the upper assembly UA is assembled to the lower assembly LA.

[0090] Next, referring to Figure 10, the adhesive fixing of the cover member 4, the magnet 5, and the base member 18 will be explained. Figure 10 is a cross-sectional view of the cover member 4, the magnet 5, and the base member 18, showing the cross-section at the cut surface CS shown in Figure 8.

[0091] As shown in Figure 10, a gap GP is formed between the lower surface LF of the magnet 5 (first lower magnet 5AL) and the inner bottom surface BF of the recess 18G in the base member 18. This is because the magnet 5 is fixed to the inner surface of the second side plate portion 4A2 of the cover member 4 by adhesive AD2, with its upper surface in contact with the ceiling surface of the top plate portion 4B of the cover member 4. Therefore, the adhesive AD4 applied to the second notch portion CU2 penetrates into the gap GP and hardens while adhering to the magnet 5, the cover member 4, and the base member 18.

[0092] This configuration allows for increased adhesive strength of the magnet 5 to the fixed-side member FB compared to the case where the magnet 5 is adhesively fixed only to the cover member 4. Therefore, this configuration has the effect of more reliably preventing the magnet 5 from detaching from the cover member 4 when a strong force such as an impact is applied to the lens drive device 100.

[0093] As described above, the lens drive device 100, which is an example of this embodiment, includes, as shown in Figure 2, a housing HS including a base member 18 and a cover member 4 made of a non-magnetic material, a lens holding member 2 disposed inside the housing HS and capable of holding a lens body, a coil 3 fixed to the lens holding member 2, a magnet 5 facing the coil 3 and fixed to the inner surface of the cover member 4, and an upper leaf spring 16 and a lower leaf spring 26 that support the lens holding member 2 so as to be movable in the optical axis direction. The upper leaf spring 16, as shown in Figure 5A, has an inner portion 16i as an upper movable support portion fixed to the upper part of the lens holding member 2, an outer portion 16e as an upper fixed support portion fixed to the cover member 4, and an elastic arm portion 16g provided between the inner portion 16i and the outer portion 16e. As shown in Figure 5B, the lower leaf spring 26 has an inner portion 26i as a lower movable support portion fixed to the lower part of the lens holding member 2, an outer portion 26e as a lower fixed support portion fixed to the base member 18, and an elastic arm portion 26g provided between the inner portion 26i and the outer portion 26e. As shown in Figure 9B, the magnet 5 is attached to the cover member 4 such that its upper surface is located above the upper leaf spring 16 and its lower surface is located below the lower leaf spring 26.

[0094] In this configuration, the magnet 5 is sized to face the entire side surface of the coil 3 (winding portion 13) fixed to the lens holding member 2, even when the lens holding member 2 moves up and down in the optical axis direction, and is attached to the cover member 4. Therefore, this configuration allows the drive unit DM to generate sufficient driving force (thrust) even when the cover member 4 is made of a non-magnetic material.

[0095] In other words, in this configuration, the magnet 5 is formed to have a greater length (height) in the optical axis direction compared to the magnet in a configuration that includes a cover member made of a magnetic material. Therefore, this configuration can suppress the decrease in driving force (thrust) when the cover member made of a magnetic material is replaced with a cover member 4 made of a non-magnetic material by increasing the length (height) of the magnet 5.

[0096] Furthermore, in the lens drive device 100, the base member 18 may have a recess 18G formed below the upper surface of the convex portion 18S, which serves as a fixing portion, as shown in the upper diagram of Figure 6. The lower end of the magnet 5 may be placed in the recess 18G. The convex portion 18S is configured to support the outer portion 26e of the lower leaf spring 26, which serves as the lower fixing support portion.

[0097] In this configuration, the recess 18G can accommodate the lower end of the magnet 5. Therefore, this configuration has the effect of avoiding the increase in the length (height) of the lens drive device 100 in the optical axis direction, which would occur if the length (height) of the magnet 5 in the optical axis direction were increased, in a configuration where the magnet 5 is placed on the base member 18. Alternatively, this configuration has the effect of reducing the height of the lens drive device 100.

[0098] Furthermore, in the lens drive device 100, there is a gap GP between the lower surface LF of the magnet 5 and the inner bottom surface BF of the recess 18G, as shown in Figure 10, and some of the adhesive AD4 adhering to the magnet 5, the cover member 4, and the base member 18 may be contained within the gap GP.

[0099] This configuration has the effect of increasing the adhesive strength between the magnet 5 and the fixed-side member FB compared to a configuration where the adhesive AD4 adheres to the cover member 4 and the base member 18 but not to the magnet 5.

[0100] In the lens drive device 100, the cover member 4 may also include an outer peripheral wall portion 4A and a top plate portion 4B. In this case, the lower part of the outer peripheral wall portion 4A is placed over the outer peripheral side portion 18E of the base member 18. The magnet 5 is fixed to the inner surface of the outer peripheral wall portion 4A such that the lower part of the magnet 5 is exposed through a notch portion CU formed in the lower part of the outer peripheral wall portion 4A. The adhesive AD4, which is provided to cover the notch portion CU that is open at the bottom, adheres to the magnet 5, the cover member 4, and the base member 18. In the example shown in Figure 8, the first lower magnet 5AL is fixed to the inner surface of the second side plate portion 4A2 such that the lower part is exposed through a second notch portion CU2 formed in the lower part of the second side plate portion 4A2 of the outer peripheral wall portion 4A. The adhesive AD4, which is provided to cover the second notch portion CU2, adheres to the first lower magnet 5AL, the cover member 4 (second side plate portion 4A2), and the base member 18.

[0101] Furthermore, in the lens drive device 100, the outer peripheral wall portion 4A may include a first side plate portion 4A1, a second side plate portion 4A2, a third side plate portion 4A3, and a fourth side plate portion 4A4, as shown in Figure 2, and the first side plate portion 4A1 and the third side plate portion 4A3 may face each other, and the second side plate portion 4A2 and the fourth side plate portion 4A4 may face each other. In this case, the magnet 5 may include a first magnet 5A fixed to the inner surface of the second side plate portion 4A2 and a second magnet 5B fixed to the inner surface of the fourth side plate portion 4A4. The upper leaf spring 16 or the lower leaf spring 26 may include a crossbar that extends along the first side plate portion 4A1 and the third side plate portion 4A3, respectively. In the example shown in Figure 2, the upper leaf spring 16 includes a crossbar 16r that extends along the first side plate portion 4A1 and the third side plate portion 4A3, respectively.

[0102] Furthermore, in the lens drive device 100, the top plate portion 4B may have four stepped portions 4C formed at each of its four corners, as shown in Figure 1. In this case, the upper surface of the magnet 5 is in contact with the ceiling surface of the top plate portion 4B between two stepped portions 4C. In the illustrated example, the upper surface of the first upper magnet 5AU is in contact with the ceiling surface of the top plate portion 4B between the second stepped portion 4C2 and the third stepped portion 4C3. Also, the upper surface of the second upper magnet 5BU is in contact with the ceiling surface of the top plate portion 4B between the first stepped portion 4C1 and the fourth stepped portion 4C4.

[0103] In this configuration, the upper leaf spring 16 can bring its upper surface into contact with the ceiling surface of the stepped portion 4C, which is located below the upper surface of the magnet 5. Therefore, this configuration ensures that the upper end of the lens holding member 2 can enter a space between the upper leaf spring 16 and the top plate portion 4B of the cover member 4, eliminating the need for other members such as spacers to secure such a space. Consequently, this configuration has the effect of reducing the number of parts compared to a configuration that includes spacers.

[0104] Furthermore, in the lens driving device 100, the coil 3 may have a coil axis CX perpendicular to the vertical direction (optical axis direction), as shown in Figures 3B and 3C. The magnet 5 may include an upper magnet and a lower magnet stacked in the vertical direction (optical axis direction). The coil 3 may be fixed to the lens holding member 2 so as to move up and down within the width between the upper end of the upper magnet and the lower end of the lower magnet.

[0105] In the illustrated example, the magnet 5 includes a first magnet 5A and a second magnet 5B. The first magnet 5A includes a first upper magnet 5AU and a first lower magnet 5AL, and the second magnet 5B includes a second upper magnet 5BU and a second lower magnet 5BL. The coil 3 also includes a first winding section 13A and a second winding section 13B. The first winding section 13A is fixed to the first projection 12PA of the lens holding member 2 so as to move up and down within a width H1 between the upper end of the first upper magnet 5AU and the lower end of the first lower magnet 5AL, as shown in Figure 9B. The second winding section 13B is fixed to the second projection 12PB of the lens holding member 2 so as to move up and down within a width H1 between the upper end of the second upper magnet 5BU and the lower end of the second lower magnet 5BL, as shown in Figure 9B.

[0106] In this configuration, the size of the first magnet 5A is determined so that it can face the entire side surface of the first winding portion 13A fixed to the lens holding member 2, even when the lens holding member 2 moves up and down in the optical axis direction. Similarly, the size of the second magnet 5B is determined so that it can face the entire side surface of the second winding portion 13B fixed to the lens holding member 2, even when the lens holding member 2 moves up and down in the optical axis direction. Therefore, this configuration allows the drive unit DM to generate sufficient driving force (thrust) even when the cover member 4 is made of a non-magnetic material.

[0107] Furthermore, in the lens drive device 100, an adhesive AD2 (see Figure 7), separate from the adhesive AD4 (see Figure 8) that adheres to the lower part of the magnet 5, the cover member 4, and the base member 18, may be applied between the outer surface of the magnet 5 and the inner surface of the cover member 4. For example, adhesive AD2 may be a hybrid adhesive that is both UV-curable and thermosetting, and adhesive AD4 may be a thermosetting adhesive. In this case, when assembling the upper assembly UA, the magnet 5 is temporarily fixed to the cover member 4 by adhesive AD2, which is cured by UV light, and then, after the upper assembly UA is assembled to the lower assembly LA, it is completely fixed to the cover member 4 by adhesives AD2 and AD4, which are cured by heat. Also, the curing of adhesive AD4 by heat may occur simultaneously with the curing of adhesive AD2 by heat.

[0108] In this configuration, the magnet 5 is temporarily fixed to the cover member 4 with adhesive AD2, which hardens with ultraviolet light, and then permanently fixed to the cover member 4 with the same adhesive AD2 and adhesive AD4, which also harden with heat. Therefore, this configuration improves the ease of assembling the magnet 5 to the cover member 4, while simultaneously increasing the adhesive strength between the cover member 4 and the magnet 5.

[0109] Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications and substitutions can be applied to the embodiments described above without departing from the scope of the present invention. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict the technical invention.

[0110] For example, in the above embodiment, the first magnet 5A is composed of a combination of a first upper magnet 5AU and a first lower magnet 5AL, which are magnetized in a direction perpendicular to the optical axis OA. However, it may also be composed of a single dipole magnet magnetized along the optical axis. In this case, the magnetic poles of the upper part of this dipole magnet correspond to the magnetic poles of the inner part of the first upper magnet 5AU, and the magnetic poles of the lower part correspond to the magnetic poles of the inner part of the first lower magnet 5AL. The same applies to the second magnet 5B.

[0111] Furthermore, in the above embodiment, the coil 3 has a coil axis CX perpendicular to the optical axis direction, but it may also be a coil whose coil axis is aligned with the optical axis OA and wound around the outer circumference of the lens holding member 2.

[0112] Furthermore, in the above embodiment, the outer portion 16e of the upper leaf spring 16 is fixed in contact with the top plate portion 4B of the cover member 4. However, a spacer may be provided between the top plate portion 4B and the outer portion 16e. In this case, the outer portion 16e may be fixed to the cover member 4 via this spacer. [Explanation of symbols]

[0113] 2···Lens Holding Material 2K···Through Hole 2T···Protruding Part 3···Coil 3C···Connecting Part 4···Cover Material 4A···Outer Peripheral Wall Part 4A1···First Side Plate Part 4A2···Second Side Plate Part 4A3···Third Side Plate Part 4A4···Fourth Side Plate Part 4B···Top Plate Part 4C···Step Difference Part 4C1···First Step Difference Part 4C2···Second Step Difference Part 4C3···Third Step Difference Part 4C4···Fourth Step Difference Part 4S···Storage Part 5···Magnet 5A···First Magnet 5AL···First Lower Magnet 5AU···First Upper Magnet 5B···Second Magnet 5BL··· 2nd lower magnet 5BU···2nd upper magnet 6···plate 7···metal component 7A···1st metal component 7AC···connection 7AT···terminal 7B···2nd metal component 7BC···connection 7BT···terminal 7C···3rd metal component 7CP···end 7CT···terminal 7D···4th metal component 7DP···end 7E···5th metal component 7EP···end 7F···6th metal component 7FP···end 12···cylindrical part 12D···base part 12H···recess 12P···protrusion 12PA···1st protrusion 12PB·· 2nd protrusion 13...Curled section 13A...1st curled section 13B...2nd curled section 16...Upper side plate 16b...Corner part 16e...Outer side part 16g...Elastic wrist part 16i...Inner side part 16r...Support part 18...Bass part 18E...Outer peripheral side part 18G...Concave part 18GL...Left concave part 18GR...Right concave part 18K...Opening 18S...Protrusion 18T...Protruding part 18W...Wall part 18WB...Rear side wall part 18WF...Front side wall part 18WL...Left side wall part 18WR...Right side wall part 26...Lower side plate 26A···First lower side plate 26B···Second lower side plate 26c···Inner joint portion 26d···Outer joint portion 26dt···Through hole 26e···Outer portion 26g···Elastic wrist portion 26h···Connecting plate portion 26i···Inner portion 26p···Connecting portion 33···Extension portion 33A···First extension portion 33B···Second extension portion 33c···Opposite portion 33m···Rolling part 72···Retaining part 72A···First retaining part 72B···Second retaining part 82···Protrusion portion 82s···Reception portion 82u···Inner wall portion 82v···Outer wall portion82w...Side wall section 82z...Open section 100...Lens drive unit AD1~AD4...Adhesive CU...Notch section CU1...First notch section CU2...Second notch section CU3...Third notch section CU4...Fourth notch section DM...Drive unit FB...Fixed side member HS...Housing LA...Lower assembly OA...Optical axis UA...Upper assembly VC...Vibration damping member WM...Weld metal

Claims

1. A housing including a base member and a cover member made of a non-magnetic material, A lens holding member disposed within the housing and capable of holding the lens body, A coil fixed to the lens holding member, A magnet is fixed to the inner surface of the cover member, facing the coil, A lens driving device comprising an upper leaf spring and a lower leaf spring that support the lens holding member so as to be movable in the optical axis direction, The upper leaf spring has an upper movable support portion fixed to the upper part of the lens holding member, an upper fixed support portion fixed to a stepped portion provided on the cover member, and an elastic arm portion provided between the upper movable support portion and the upper fixed support portion. The lower leaf spring has a lower movable support portion fixed to the lower part of the lens holding member, a lower fixed support portion fixed to the base member, and an elastic arm portion provided between the lower movable support portion and the lower fixed support portion. The ceiling surface of the stepped portion of the cover member to which the upper surface of the upper fixed support portion of the upper leaf spring is fixed is located below the ceiling surface of the ceiling portion of the cover member to which the upper surface of the magnet is in contact. The lens driving device is characterized in that the magnet's upper surface is located above the upper leaf spring and its lower surface is located below the lower leaf spring.

2. The base member has a recess formed therein that is recessed below the upper surface of the fixing part that supports the lower fixed side support part of the lower leaf spring, The lower end of the magnet is positioned in the recess. The lens driving device according to claim 1.

3. There is a gap between the lower surface of the magnet and the inner bottom surface of the recess, and some of the adhesive adhering to the magnet, the cover member, and the base member has entered this gap. The lens driving device according to claim 2.

4. A housing including a base member and a cover member made of a non-magnetic material, A lens holding member disposed within the housing and capable of holding the lens body, A coil fixed to the lens holding member, A magnet is fixed to the inner surface of the cover member, facing the coil, A lens driving device comprising an upper leaf spring and a lower leaf spring that support the lens holding member so as to be movable in the optical axis direction, The upper leaf spring has an upper movable support portion fixed to the upper part of the lens holding member, an upper fixed support portion fixed to the cover member, and an elastic arm portion provided between the upper movable support portion and the upper fixed support portion. The lower leaf spring has a lower movable support portion fixed to the lower part of the lens holding member, a lower fixed support portion fixed to the base member, and an elastic arm portion provided between the lower movable support portion and the lower fixed support portion. The magnet has its upper surface positioned above the upper leaf spring and its lower surface positioned below the lower leaf spring. The cover member comprises an outer peripheral wall portion and a top plate portion. The lower part of the outer peripheral wall is placed over the outer peripheral side of the base member. The magnet is fixed to the inner surface of the outer peripheral wall such that the lower part of the magnet is exposed through a notch formed in the lower part of the outer peripheral wall. The adhesive provided to cover the open cutout portion is attached to the magnet, the cover member, and the base member. A lens drive device characterized by the following features.

5. The outer peripheral wall portion includes a first side plate portion, a second side plate portion, a third side plate portion, and a fourth side plate portion, and is configured such that the first side plate portion and the third side plate portion face each other, and the second side plate portion and the fourth side plate portion face each other. The magnet includes a first magnet fixed to the inner surface of the second side plate and a second magnet fixed to the inner surface of the fourth side plate. The upper leaf spring or the lower leaf spring includes a crossbar extending along the first side plate portion and the third side plate portion, respectively. The lens driving device according to claim 4.

6. The aforementioned top plate has four stepped sections formed at each of its four corners, The upper surface of the magnet is in contact with the ceiling surface of the top plate between the two stepped portions. The lens driving device according to claim 4 or claim 5.

7. The coil has a coil axis that is vertical in the vertical direction, The aforementioned magnet includes an upper magnet and a lower magnet stacked vertically, The coil is fixed to the lens holding member so as to move up and down within the width between the upper end of the upper magnet and the lower end of the lower magnet. A lens driving device according to any one of claims 1 to 6.

8. A different adhesive from the one used to adhere to the lower part of the magnet, the cover member, and the base member is applied between the outer surface of the magnet and the inner surface of the cover member. A lens driving device according to any one of claims 1 to 7.

9. A lens drive device according to any one of claims 1 to 8, The aforementioned lens body, The lens body has an image sensor facing it, Camera module.

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