Optical element driving device and camera module

Abstract

To suppress the rotation of the lens around the optical axis when moving the lens along the optical axis. [Solution] The lens driving device 101 includes a drive unit DM which has a shape memory alloy wire SA that moves the lens holding member 2 in the direction of the optical axis. The shape memory alloy wire SA includes a first wire SA1 provided between a support member 8 and an intermediate member 3, and a second wire SA2 provided between the intermediate member 3 and the lens holding member 2. The front end of the first wire SA1 is positioned higher than the rear end, and the front end of the second wire SA2 is positioned higher than the rear end. When current is passed through the first wire SA1 and the second wire SA2, the contraction of the first wire SA1 and the contraction of the second wire SA2 suppresses rotation around the optical axis OA, causing the lens holding member 2 to move in the direction of the optical axis.

Description

Technical Field

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[0001] The present disclosure relates to an optical element driving device and a camera module.

Background Art

[0002] Conventionally, a lens driving device configured to move a lens holding member along an optical axis while rotating it around the optical axis with respect to a support structure by a shape memory alloy wire is known (see Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the number of pixels (image quality improvement) of the imaging element increases, this lens driving device may cause an adverse effect on the image quality due to the rotation of the lens body around the optical axis.

[0005] Therefore, it is desirable to provide an optical element driving device that can suppress the rotation of an optical element such as a lens body around a predetermined axis such as an optical axis.

Means for Solving the Problems

[0006] An optical element driving device according to one embodiment of the present disclosure comprises a support member, an optical element holding member having an opening into which an optical element can be placed and movable in a predetermined direction along a predetermined axis relative to the support member, a drive unit comprising a shape memory alloy wire for moving the optical element holding member in the predetermined direction, and an intermediate member provided between the optical element holding member and the support member, wherein the intermediate member is movable relative to the support member and also movable relative to the optical element holding member, and the shape memory alloy wire is provided between the support member and the intermediate member The device includes a first wire and a second wire provided between the intermediate member and the optical element holding member, wherein one end of the first wire supported by the support member is positioned higher than the other end supported by the intermediate member, and one end of the second wire supported by the intermediate member is positioned higher than the other end supported by the optical element holding member, and when current flows through the first and second wires, the contraction of the first wire and the contraction of the second wire suppress rotation around the predetermined axis, causing the optical element holding member to move in the predetermined direction. [Effects of the Invention]

[0007] The optical element driving device described above can suppress the rotation of the optical element around a predetermined axis when moving the optical element along that predetermined axis. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of a camera module including a lens drive device according to an embodiment of the present disclosure. [Figure 2] This is a disassembled perspective view of the lens drive mechanism. [Figure 3] This is a perspective view of the lens holding member, lens-side metal member, leaf spring, flexible metal member, and lens-side embedded member. [Figure 4] This is a perspective view of the lens holding member and the flexible metal member. [Figure 5] This is a perspective view of the intermediate member, the intermediate metal member, and the intermediate embedded member. [Figure 6] This is a perspective view of the support-side metal member, leaf spring, flexible metal member, support member, and support-side embedded member. [Figure 7] This is a perspective view of the lens drive unit with the cover removed. [Figure 8] This figure shows an example of the configuration of metal components and shape memory alloy wires. [Figure 9] This is a perspective view of the metal component, flexible metal component, lens-side embedded component, intermediate-side embedded component, support-side embedded component, and shape memory alloy wire. [Figure 10] This is a perspective view of the metal component, flexible metal component, lens-side embedded component, intermediate-side embedded component, support-side embedded component, and shape memory alloy wire. [Figure 11] These are top and front views of the lens holder, intermediate member, and support member. [Figure 12] These are top and front views of the lens holder, intermediate member, and support member. [Figure 13] These are top and front views of the lens holder, intermediate member, and support member. [Modes for carrying out the invention]

[0009] Hereinafter, a lens drive device 101 according to an embodiment of this disclosure will be described with reference to the drawings. Figure 1 is a perspective view of a camera module CM including the lens drive device 101. Figure 2 is an exploded perspective view of the lens drive device 101.

[0010] In Figures 1 and 2, X1 represents one direction of the X-axis in the three-dimensional Cartesian coordinate system, and X2 represents the other direction of the X-axis. Similarly, Y1 represents one direction of the Y-axis in the three-dimensional Cartesian coordinate system, and Y2 represents the other direction of the Y-axis. Likewise, Z1 represents one direction of the Z-axis in the three-dimensional Cartesian coordinate system, and Z2 represents the other direction of the Z-axis. In Figures 1 and 2, the X1 side of the lens drive unit 101 corresponds to the front side of the lens drive unit 101, and the X2 side of the lens drive unit 101 corresponds to the rear side of the lens drive unit 101. Furthermore, the Y1 side of the lens drive unit 101 corresponds to the left side of the lens drive unit 101, and the Y2 side of the lens drive unit 101 corresponds to the right side of the lens drive unit 101. Furthermore, the Z1 side of the lens drive unit 101 corresponds to the upper side (subject side) of the lens drive unit 101, and the Z2 side of the lens drive unit 101 corresponds to the lower side (image sensor side) of the lens drive unit 101. The same applies to the other figures.

[0011] As shown in Figure 1, the camera module CM comprises a substrate SU, a lens drive device 101, a lens body LS mounted on the lens drive device 101, and an image sensor IS mounted on the substrate SU facing the lens body LS. The camera module CM is also connected to a control device (not shown) which consists of a microcomputer including a CPU and memory. In the illustrated example, the control device is located outside the camera module CM, but it may be located inside the camera module CM. The lens drive device 101, which has a roughly rectangular shape, is mounted on the substrate SU on which the image sensor IS is mounted, as shown in Figure 1.

[0012] Specifically, as shown in Figures 1 and 2, the lens drive unit 101 includes a cover member 1 and a support member 8, which are part of the fixed-side member FB. The cover member 1 is configured to function as part of the housing HS of the lens drive unit 101. In the illustrated example, the cover member 1 is made of a non-magnetic metal. However, the cover member 1 may be made of a magnetic metal.

[0013] Specifically, as shown in FIG. 2, the cover member 1 has a bottomless box-shaped outer shape that defines the storage portion 1S. That is, the cover member 1 has a rectangular cylindrical outer peripheral wall portion 1A and a rectangular annular and flat top plate portion 1B provided so as to be continuous with the upper end (the end on the Z1 side) of the outer peripheral wall portion 1A. A substantially rounded rectangular opening 1K is formed at the center of the top plate portion 1B. The outer peripheral wall portion 1A includes a first side plate portion 1A1 to a fourth side plate portion 1A4. The first side plate portion 1A1 and the third side plate portion 1A3 face each other, and the second side plate portion 1A2 and the fourth side plate portion 1A4 face each other. And the first side plate portion 1A1 and the third side plate portion 1A3 extend perpendicular to the second side plate portion 1A2 and the fourth side plate portion 1A4. And as shown in FIG. 1, the cover member 1 and the support member 8 are joined by an adhesive to form the housing HS.

[0014] As shown in FIG. 2, between the cover member 1 and the support member 8, a lens holding member 2, an intermediate member 3, a metal member 5, a leaf spring 6, a flexible metal member 7, a lens-side embedded member 20, an intermediate-side embedded member 30, a support-side embedded member 80, a shape memory alloy wire SA, etc. are accommodated.

[0015] The lens holding member 2 is a member capable of holding the lens body LS (see FIG. 1) and constitutes the movable-side member MB. The lens body LS is, for example, a lens barrel provided with at least one lens, and is configured such that its central axis is along the optical axis OA.

[0016] Further, the lens holding member 2 is a member that can move in the Z-axis direction with respect to the intermediate member 3 while rotating around the optical axis OA, and constitutes the movable side member MB. In the illustrated example, the lens holding member 2 is formed by injection molding a synthetic resin such as liquid crystal polymer (LCP). Specifically, the lens holding member 2 has a substantially rectangular outer shape in a plan view (top view) along the optical axis direction, and has a substantially rounded rectangular opening 2K at the center. Specifically, the lens holding member 2 includes a rectangular annular cylindrical portion 2C formed so as to surround the opening 2K, and a pedestal portion 2D formed so as to protrude from the cylindrical portion 2C to the outside in the radial direction of a circle centered on the optical axis OA. The pedestal portion 2D includes a first pedestal portion 2D1 to a fourth pedestal portion 2D4. The first pedestal portion 2D1 and the third pedestal portion 2D3 are arranged so as to extend in opposite directions in the radial direction (X-axis direction) with the optical axis OA interposed therebetween, and the second pedestal portion 2D2 and the fourth pedestal portion 2D4 are arranged so as to extend in opposite directions in the radial direction (Y-axis direction) with the optical axis OA interposed therebetween. And a part of the leaf spring 6 is placed on the upper end surface of the cylindrical portion 2C. Further, a lens-side metal member 5L is placed on each of the first pedestal portion 2D1 to the fourth pedestal portion 2D4.

[0017] The drive unit DM is configured to be able to move the movable side member MB with respect to the fixed side member FB. In the illustrated example, the drive unit DM includes a shape memory alloy wire SA which is an example of a shape memory actuator. Specifically, the drive unit DM includes a first drive unit DM1 for moving the lens holding member 2 downward (Z2 side), and a second drive unit DM2 for moving the lens holding member 2 upward (Z1 side). The shape memory alloy wire SA includes a first wire SA1 to an eighth wire SA8. And the first drive unit DM1 includes the third wire SA3, the fourth wire SA4, the seventh wire SA7, and the eighth wire SA8, and the second drive unit DM2 includes the first wire SA1, the second wire SA2, the fifth wire SA5, and the sixth wire SA6.

[0018] The shape memory alloy wire SA is configured to increase in temperature when an electric current flows through it and to contract in accordance with this temperature increase. Specifically, as shown in Figure 2, the shape memory alloy wire SA is stretched in a straight line along the inner surface of the outer peripheral wall portion 1A of the cover member 1 when an electric current is supplied, and is configured to allow the lens holding member 2 to move relative to the support member 8. The first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7 are each fixed at one end to the support-side metal member 5F by crimping or welding, and at the other end to the intermediate-side metal member 5M by crimping or welding. The second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8 are each fixed at one end to the intermediate-side metal member 5M by crimping or welding, and at the other end to the lens-side metal member 5L by crimping or welding.

[0019] In the illustrated example, the first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6, and the third wire SA3, fourth wire SA4, seventh wire SA7, and eighth wire SA8, are arranged to intersect (approximately orthogonal to) each other when viewed along the optical axis (Z axis). The intersection of two shape memory alloy wires means that a straight line passing through one end and the other end of one shape memory alloy wire intersects a straight line passing through one end and the other end of the other shape memory alloy wire. In other words, the first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6 are arranged to extend parallel to the X axis, and the third wire SA3, fourth wire SA4, seventh wire SA7, and eighth wire SA8 are arranged to extend parallel to the Y axis.

[0020] The first drive unit DM1 can move the lens holding member 2 downward (towards Z2) along the optical axis direction (Z axis direction), which is parallel to the optical axis OA, by utilizing the contraction of the third wire SA3, fourth wire SA4, seventh wire SA7, and eighth wire SA8. The third wire SA3, fourth wire SA4, seventh wire SA7, and eighth wire SA8 are configured such that when one or more of them contract, the lens holding member 2 moves, and this movement stretches one or more of the other wires. Similarly, the second drive unit DM2 can move the lens holding member 2 upward (towards Z1) along the optical axis direction (Z axis direction) by utilizing the contraction of the first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6. The first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6 are configured such that when one or more of them contract, the lens holding member 2 moves, and this movement stretches one or more of the other wires.

[0021] The intermediate member 3 is a member that can move in the Z-axis direction relative to the fixed-side member FB (support member 8) while rotating around the optical axis OA, and constitutes the movable-side member MB. In the illustrated example, the intermediate member 3 is formed by injection molding using a synthetic resin such as liquid crystal polymer (LCP). Specifically, the intermediate member 3 has a roughly rectangular outer shape in plan view (top view) and a roughly rounded rectangular opening 3K in the center. Specifically, the intermediate member 3 has a rectangular annular base 3B formed to surround the opening 3K, and a pedestal portion 3D which is a portion that protrudes upward from the base 3B. The pedestal portion 3D includes the first pedestal portion 3D1 to the eighth pedestal portion 3D8. The first pedestal portion 3D1 to the fourth pedestal portion 3D4 and the fifth pedestal portion 3D5 to the eighth pedestal portion 3D8 are arranged to face each other radially across the optical axis OA. More specifically, the base 3B has the first to fourth base sections 3D1 to 3D4 at the right front corner, and the fifth to eighth base sections 3D5 to 3D8 at the left rear corner. An intermediate metal member 5M is placed on each of the first to eighth base sections 3D1 to 3D8.

[0022] The metal member 5 is configured to hold a portion of the shape memory alloy wire SA. In the illustrated example, the metal member 5 is made of a non-magnetic metal and includes a support-side metal member 5F, a lens-side metal member 5L, and an intermediate-side metal member 5M. The support-side metal member 5F is configured to be fixed to the base portion 8D of the support member 8. The lens-side metal member 5L is configured to be fixed to the base portion 2D of the lens-holding member 2. The intermediate-side metal member 5M is configured to be fixed to the base portion 3D of the intermediate member 3. Note that the support-side metal member 5F may be embedded in the base portion 8D of the support member 8, the lens-side metal member 5L may be embedded in the base portion 2D of the lens-holding member 2, and the intermediate-side metal member 5M may be embedded in the base portion 3D of the intermediate member 3.

[0023] More specifically, the support-side metal member 5F includes the first support-side metal member 5F1 to the fourth support-side metal member 5F4, the lens-side metal member 5L includes the first lens-side metal member 5L1 to the fourth lens-side metal member 5L4, and the intermediate-side metal member 5M includes the first intermediate-side metal member 5M1 to the eighth intermediate-side metal member 5M8.

[0024] The leaf spring 6 is configured to support the lens holding member 2 so that it can move in a direction parallel to the optical axis OA relative to the support member 8. In the illustrated example, the leaf spring 6 is made from a metal plate mainly composed of, for example, a copper alloy, a titanium-copper alloy (titanium copper), or a copper-nickel alloy (nickel-tin copper). In the illustrated example, the leaf spring 6 connects the lens holding member 2 and the support member 8 so that, in the neutral state of the lens driving device 101, the center of the lens holding member 2, the center of the intermediate member 3, and the center of the support member 8 coincide. That is, the leaf spring 6 is configured to center the lens holding member 2 in the XY plane relative to the intermediate member 3 and the support member 8, respectively. Specifically, the leaf spring 6 is configured to connect the cylindrical portion 2C of the lens holding member 2 and the base portion 8D (first base portion 8D1 and fourth base portion 8D4) of the support member 8. The neutral state of the lens drive device 101 is, for example, a state in which current is supplied to each of the first wires SA1 to the eighth wire SA8, and the movable side members MB (lens holding member 2 and intermediate member 3) are located in the middle of their movable range in the optical axis direction, that is, a state in which the movable side members MB (lens holding member 2 and intermediate member 3) are in the neutral position. Typically, in the neutral state of the lens drive device 101, each of the lens holding member 2 and intermediate member 3 is located in the center of their movable range in the optical axis direction.

[0025] The flexible metal member 7 is a component for supplying current to each of the shape memory alloy wires SA. Specifically, the flexible metal member 7 has a fixed joint fixed to the support member 8, a movable joint fixed to the lens holding member 2, and an elastically deformable elastic arm connecting the fixed joint and the movable joint. In the illustrated example, the flexible metal member 7 includes the first flexible metal member 7A to the fourth flexible metal member 7D.

[0026] The support member 8 is a member for supporting the movable side member MB. In the illustrated example, the support member 8 is formed by injection molding using a synthetic resin such as liquid crystal polymer (LCP) and constitutes the fixed side member FB. Specifically, the support member 8 has a roughly rectangular outer shape in plan view (top view) and has a roughly rounded rectangular opening 8K in the center. The support member 8 also has a rectangular annular base 8B formed to surround the opening 8K.

[0027] The lens-side embedded member 20 is a metal member embedded in the lens-holding member 2. In the illustrated example, the lens-side embedded member 20 is a member embedded in the lens-holding member 2 by insert molding, and has an upper joint portion and a lower joint portion that are exposed on the surface of the lens-holding member 2 and used for joining with other metal members. Specifically, as shown in Figure 3, the lens-side embedded member 20 includes the first lens-side embedded member 20A to the fourth lens-side embedded member 20D.

[0028] The intermediate embedded member 30 is a metal member embedded in the intermediate member 3. In the illustrated example, the intermediate embedded member 30 is a member embedded in the intermediate member 3 by insert molding and has a front joint portion and a rear joint portion that are exposed on the surface of the intermediate member 3 and used for joining with other metal members. Specifically, as shown in Figure 5, the intermediate embedded member 30 includes the first intermediate embedded member 30A to the fourth intermediate embedded member 30D.

[0029] The support-side embedded member 80 is a metal member embedded in the support member 8. In the illustrated example, the support-side embedded member 80 is a member embedded in the support member 8 by insert molding, and has a terminal portion used for electrical connection with the outside and a joint portion exposed on the surface of the support member 8 and used for joining with other metal members. Specifically, as shown in Figure 6, the support-side embedded member 80 includes the first support-side embedded member 80A to the eighth support-side embedded member 80H.

[0030] Next, with reference to Figures 3 and 4, the positional relationship between the member attached to the lens holding member 2 and the lens holding member 2 will be described. Figure 3 is an upper perspective view of the lens holding member 2, the lens-side metal member 5L, the leaf spring 6, the flexible metal member 7, and the lens-side embedded member 20. Specifically, the upper part of Figure 3 (the part above the block arrow) is an exploded perspective view, and the lower part of Figure 3 (the part below the block arrow) is an assembled perspective view. Figure 4 is a lower perspective view of the lens holding member 2 and the flexible metal member 7.

[0031] In the example shown in the upper part of Figure 3, the first lens-side metal member 5L1 is fixed to the upper surface of the first base portion 2D1. Specifically, the first lens-side metal member 5L1 is fixed to the first base portion 2D1 by adhesive while in contact with the first upper joint portion 20AP of the first lens-side embedded member 20A which is exposed on the upper surface of the first base portion 2D1. The adhesive is, for example, a light-curing adhesive. A light-curing adhesive is, for example, an ultraviolet-curing adhesive or a visible-light-curing adhesive. Similarly, the second lens-side metal member 5L2 is fixed to the second base portion 2D2 by adhesive in contact with the second upper joint portion 20BP of the second lens-side embedded member 20B which is exposed on the upper surface of the second base portion 2D2; the third lens-side metal member 5L3 is fixed to the third base portion 2D3 by adhesive in contact with the third upper joint portion 20CP of the third lens-side embedded member 20C which is exposed on the upper surface of the third base portion 2D3; and the fourth lens-side metal member 5L4 is fixed to the fourth base portion 2D4 by adhesive in contact with the fourth upper joint portion 20DP of the fourth lens-side embedded member 20D which is exposed on the upper surface of the fourth base portion 2D4. In the illustrated example, the lens-side metal member 5L is welded to the lens-side embedded member 20.

[0032] The leaf spring 6 has an outer portion 6E fixed to the base portion 8D (see Figure 2) of the support member 8, an inner portion 6I fixed to the cylindrical portion 2C of the lens holding member 2, and an elastic portion 6G connecting the outer portion 6E and the inner portion 6I. Specifically, the outer portion 6E includes a first outer portion 6E1 and a second outer portion 6E2, and the elastic portion 6G includes a first elastic portion 6G1 and a second elastic portion 6G2. The first elastic portion 6G1 connects the inner portion 6I and the first outer portion 6E1, and the second elastic portion 6G2 connects the inner portion 6I and the second outer portion 6E2.

[0033] Furthermore, as shown in Figure 3, the leaf spring 6 is configured to be 2 rotationally symmetric with respect to the optical axis OA. Therefore, the leaf spring 6 can support the lens holding member 2 in a balanced manner in the air. In addition, the leaf spring 6 does not adversely affect the weight balance of the movable side member MB (lens holding member 2 and intermediate member 3) which is supported by eight shape memory alloy wires SA (first wire SA1 to eighth wire SA8).

[0034] The first lens-side embedded member 20A has a first upper joint portion 20AP exposed on the upper surface of the first base portion 2D1 and a first lower joint portion 20AQ exposed on the lower surface of the second base portion 2D2, and the second lens-side embedded member 20B has a second upper joint portion 20BP exposed on the upper surface of the second base portion 2D2 and a second lower joint portion 20BQ exposed on the lower surface of the second base portion 2D2. The first upper joint portion 20AP and the first lens-side metal member 5L1 are joined by welding, the second upper joint portion 20BP and the second lens-side metal member 5L2 are joined by welding, the first lower joint portion 20AQ and the first movable joint portion 7AP of the first flexible metal member 7A are joined by welding, and the second lower joint portion 20BQ and the second movable joint portion 7BP of the second flexible metal member 7B are joined by welding. Similarly, the third lens-side embedded member 20C has a third upper joint 20CP exposed on the upper surface of the third base portion 2D3 and a third lower joint 20CQ exposed on the lower surface of the fourth base portion 2D4, and the fourth lens-side embedded member 20D has a fourth upper joint 20DP exposed on the upper surface of the fourth base portion 2D4 and a fourth lower joint 20DQ exposed on the lower surface of the fourth base portion 2D4. The third upper joint 20CP and the third lens-side metal member 5L3 are joined by welding, the fourth upper joint 20DP and the fourth lens-side metal member 5L4 are joined by welding, the third lower joint 20CQ and the third movable joint 7CP of the third flexible metal member 7C are joined by welding, and the fourth lower joint 20DQ and the fourth movable joint 7DP of the fourth flexible metal member 7D are joined by welding. Furthermore, welding may be replaced with joining using conductive adhesive or solder.

[0035] Next, referring to Figure 5, the positional relationship between the member in contact with the intermediate member 3 and the intermediate member 3 will be explained. Figure 5 is an overhead perspective view of the intermediate member 3, the intermediate metal member 5M, and the intermediate embedded member 30. Specifically, the upper part of Figure 5 (the figure above the block arrow) is an exploded perspective view, and the lower part of Figure 5 (the figure below the block arrow) is an assembled perspective view.

[0036] In the example shown in the upper part of Figure 5, the first intermediate metal member 5M1 is fixed to the upper surface of the first base portion 3D1 of the intermediate member 3, the second intermediate metal member 5M2 is fixed to the upper surface of the second base portion 3D2 of the intermediate member 3, the third intermediate metal member 5M3 is fixed to the upper surface of the third base portion 3D3 of the intermediate member 3, and the fourth intermediate metal member 5M4 is fixed to the upper surface of the fourth base portion 3D4 of the intermediate member 3. Similarly, the fifth intermediate metal member 5M5 is fixed to the upper surface of the fifth base portion 3D5 of the intermediate member 3, the sixth intermediate metal member 5M6 is fixed to the upper surface of the sixth base portion 3D6 of the intermediate member 3, the seventh intermediate metal member 5M7 is fixed to the upper surface of the seventh base portion 3D7 of the intermediate member 3, and the eighth intermediate metal member 5M8 is fixed to the upper surface of the eighth base portion 3D8 of the intermediate member 3. In the illustrated example, the top surface of each of the eight base sections 3D is perpendicular to the optical axis OA. Furthermore, the top surfaces of the first base section 3D1, the second base section 3D2, the fifth base section 3D5, and the sixth base section 3D6 are at the same height, the top surfaces of the third base section 3D3 and the seventh base section 3D7 are at the same height, and the top surfaces of the fourth base section 3D4 and the eighth base section 3D8 are at the same height.

[0037] The first intermediate buried member 30A has a first front joint 30AP exposed on the upper surface of the first base portion 3D1 of the intermediate member 3, and a first rear joint 30AQ exposed on the upper surface of the seventh base portion 3D7 of the intermediate member 3. The second intermediate buried member 30B has a second front joint 30BP exposed on the upper surface of the second base portion 3D2 of the intermediate member 3, and a second rear joint 30BQ exposed on the upper surface of the eighth base portion 3D8 of the intermediate member 3. The third intermediate buried member 30C has a third front joint 30CP exposed on the upper surface of the third base portion 3D3 of the intermediate member 3, and a third rear joint 30CQ exposed on the upper surface of the fifth base portion 3D5 of the intermediate member 3. The fourth intermediate embedded member 30D has a fourth front joint portion 30DP exposed on the upper surface of the fourth base portion 3D4 of the intermediate member 3, and a fourth rear joint portion 30DQ exposed on the upper surface of the sixth base portion 3D6 of the intermediate member 3.

[0038] The first front joint 30AP and the first intermediate metal member 5M1 are joined by welding. The joining of the first front joint 30AP and the first intermediate metal member 5M1 may be achieved by conductive adhesive or solder. The same applies to the joining of the second front joint 30BP and the second intermediate metal member 5M2, the joining of the third front joint 30CP and the third intermediate metal member 5M3, the joining of the fourth front joint 30DP and the fourth intermediate metal member 5M4, the joining of the third rear joint 30CQ and the fifth intermediate metal member 5M5, the joining of the fourth rear joint 30DQ and the sixth intermediate metal member 5M6, the joining of the first rear joint 30AQ and the seventh intermediate metal member 5M7, and the joining of the second rear joint 30BQ and the eighth intermediate metal member 5M8.

[0039] Next, with reference to Figure 6, the positional relationship between the member attached to the support member 8 and the support member 8 will be explained. Figure 6 is an overhead perspective view of the support-side metal member 5F, leaf spring 6, flexible metal member 7, support member 8, and support-side embedded member 80. Specifically, the upper part of Figure 6 (the figure above the block arrow) is an exploded perspective view, and the lower part of Figure 6 (the figure below the block arrow) is an assembled perspective view.

[0040] In the example shown in the upper part of Figure 6, the first support metal member 5F1 is fixed to the upper surface of the third base portion 8D3 of the support member 8, the second support metal member 5F2 is fixed to the upper surface of the second base portion 8D2 of the support member 8, the third support metal member 5F3 is fixed to the upper surface of the sixth base portion 8D6 (see Figure 7) of the support member 8, and the fourth support metal member 5F4 is fixed to the upper surface of the fifth base portion 8D5 of the support member 8. In the illustrated example, the upper surface of each of the six base portions 8D is a plane perpendicular to the optical axis OA. Also, the upper surfaces of the first base portion 8D1 and the fourth base portion 8D4 are at the same height, the upper surfaces of the second base portion 8D2 and the fifth base portion 8D5 are at the same height, and the upper surfaces of the third base portion 8D3 and the sixth base portion 8D6 are at the same height.

[0041] Furthermore, as shown in Figure 6, the first flexible metal members 7A to the fourth flexible metal members 7D each have a first fixed joint portion 7AQ to the fourth fixed joint portion 7DQ. In addition, the first support-side embedded members 80A to the eighth support-side embedded members 80H each have a first terminal portion 80AT to the eighth terminal portion 80HT, and also have a first joint portion 80AP to the eighth joint portion 80HP. The first joint portion 80AP to the eighth joint portion 80HP are exposed on the upper surface of the support member 8.

[0042] Specifically, the first support-side embedded member 80A has a first joint portion 80AP exposed on the upper surface of the third base portion 8D3 of the support member 8 and a first terminal portion 80AT exposed on the front side surface of the support member 8. The second support-side embedded member 80B has a second joint portion 80BP exposed on the upper surface of the second base portion 8D2 of the support member 8 and a second terminal portion 80BT exposed on the front side surface of the support member 8. The third support-side embedded member 80C has a third joint portion 80CP exposed on the upper surface of the sixth base portion 8D6 of the support member 8 and a third terminal portion 80CT exposed on the rear side surface of the support member 8. The fourth support-side embedded member 80D has a fourth joint portion 80DP exposed on the upper surface of the fifth base portion 8D5 of the support member 8 and a fourth terminal portion 80DT exposed on the rear side surface of the support member 8. The fifth support-side embedded member 80E has a fifth joint portion 80EP exposed on the upper surface of the left side of the base portion 8B of the support member 8, and a fifth terminal portion 80ET exposed on the rear side of the support member 8. The sixth support-side embedded member 80F has a sixth joint portion 80FP exposed on the upper surface of the left side of the base portion 8B of the support member 8, and a sixth terminal portion 80FT exposed on the rear side of the support member 8. The seventh support-side embedded member 80G has a seventh joint portion 80GP exposed on the upper surface of the right side of the base portion 8B of the support member 8, and a seventh terminal portion 80GT exposed on the front side of the support member 8. The eighth support-side embedded member 80H has an eighth joint portion 80HP exposed on the upper surface of the right side of the base portion 8B of the support member 8, and an eighth terminal portion 80HT exposed on the front side of the support member 8.

[0043] The first joint 80AP and the first support-side metal member 5F1 are joined by welding. The joining of the first joint 80AP and the first support-side metal member 5F1 may be achieved by conductive adhesive or solder. The same applies to the joining of the second joint 80BP and the second support-side metal member 5F2, the joining of the third joint 80CP and the third support-side metal member 5F3, the joining of the fourth joint 80DP and the fourth support-side metal member 5F4, the joining of the fifth joint 80EP and the first fixed joint 7AQ, the joining of the sixth joint 80FP and the second fixed joint 7BQ, the joining of the seventh joint 80GP and the third fixed joint 7CQ, and the joining of the eighth joint 80HP and the fourth fixed joint 7DQ.

[0044] Next, the metal member 5 to which the shape memory alloy wire SA is attached will be described with reference to Figures 7 and 8. Figure 7 is a perspective view of the lens drive device 101 with the cover member 1 removed. Note that in Figure 7, a dot pattern is added to the intermediate member 3 for clarity. Figure 8 is a diagram showing an example of the configuration of the metal member 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M) and the shape memory alloy wire SA. Specifically, the upper left of Figure 8 is a top view of the metal member 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M) and the shape memory alloy wire SA. The lower left of Figure 8 is a front view of the metal member 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M) and the shape memory alloy wire SA. The right-hand diagram in Figure 8 shows the right side view of the metal members 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M) and the shape memory alloy wire SA. The positional relationship of each member shown in Figure 8 corresponds to the positional relationship when the lens drive device 101 is in the neutral position.

[0045] Specifically, one end of the first wire SA1 is fixed to the second support metal member 5F2 at the holding portion J1 of the second support metal member 5F2, and the other end of the first wire SA1 is fixed to the eighth intermediate metal member 5M8 at the holding portion J2 of the eighth intermediate metal member 5M8. Also, one end of the second wire SA2 is fixed to the second intermediate metal member 5M2 at the holding portion J3 of the second intermediate metal member 5M2, and the other end of the second wire SA2 is fixed to the fourth lens-side metal member 5L4 at the holding portion J4 of the fourth lens-side metal member 5L4. Furthermore, one end of the third wire SA3 is fixed to the first support metal member 5F1 at the holding portion J5 of the first support metal member 5F1, and the other end of the third wire SA3 is fixed to the first intermediate metal member 5M1 at the holding portion J6 of the first intermediate metal member 5M1. Furthermore, one end of the fourth wire SA4 is fixed to the seventh intermediate metal member 5M7 at the holding portion J7 of the seventh intermediate metal member 5M7, and the other end of the fourth wire SA4 is fixed to the third lens-side metal member 5L3 at the holding portion J8 of the third lens-side metal member 5L3.

[0046] Similarly, one end of the fifth wire SA5 is fixed to the fourth support-side metal member 5F4 at the holding portion J9 of the fourth support-side metal member 5F4, and the other end of the fifth wire SA5 is fixed to the fourth intermediate-side metal member 5M4 at the holding portion J10 of the fourth intermediate-side metal member 5M4. Also, one end of the sixth wire SA6 is fixed to the sixth intermediate-side metal member 5M6 at the holding portion J11 of the sixth intermediate-side metal member 5M6, and the other end of the sixth wire SA6 is fixed to the second lens-side metal member 5L2 at the holding portion J12 of the second lens-side metal member 5L2. Furthermore, one end of the seventh wire SA7 is fixed to the third support-side metal member 5F3 at the holding portion J13 of the third support-side metal member 5F3, and the other end of the seventh wire SA7 is fixed to the fifth intermediate-side metal member 5M5 at the holding portion J14 of the fifth intermediate-side metal member 5M5. Furthermore, one end of the eighth wire SA8 is fixed to the third intermediate metal member 5M3 at the holding portion J15 of the third intermediate metal member 5M3, and the other end of the eighth wire SA8 is fixed to the first lens-side metal member 5L1 at the holding portion J16 of the first lens-side metal member 5L1.

[0047] The retaining portion J1 is formed by bending a part of the second support-side metal member 5F2. Specifically, the retaining portion J1 is formed by bending a part of the second support-side metal member 5F2 while sandwiching one end of the first wire SA1. The one end of the first wire SA1 is then fixed to the retaining portion J1 by welding. The same applies to the retaining portions J2 to J16.

[0048] Furthermore, as shown in the right-hand diagram of Figure 8, the first wire SA1 and the second wire SA2 are positioned so as to be angled downwards to the right when viewed from the right side, and the fifth wire SA5 and the sixth wire SA6 are positioned so as to be angled upwards to the right when viewed from the right side. The first wire SA1 and the second wire SA2 are positioned to intersect with the fifth wire SA5 and the sixth wire SA6 when viewed from the right side. Similarly, as shown in the lower-left diagram of Figure 8, the third wire SA3 and the fourth wire SA4 are positioned so as to be angled upwards to the right when viewed from the front, and the seventh wire SA7 and the eighth wire SA8 are positioned so as to be angled downwards to the right when viewed from the front. The third wire SA3 and the fourth wire SA4 are positioned to intersect with the seventh wire SA7 and the eighth wire SA8 when viewed from the front.

[0049] The support member 8 is configured to support one end of each of the first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7, while the intermediate member 3 is configured to support the other end of each of the first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7. With this configuration, the intermediate member 3 is connected to the support member 8 via the first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7 in a manner that allows it to move in the optical axis direction (Z axis direction), which is parallel to the optical axis OA.

[0050] Furthermore, the intermediate member 3 is configured to support one end of each of the second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8, and the lens holding member 2 is configured to support the other ends of each of the second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8. With this configuration, the lens holding member 2 is connected to the intermediate member 3 via the second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8 in a manner that allows it to move in the optical axis direction (Z axis direction), which is parallel to the optical axis OA.

[0051] In the illustrated example, the support-side metal member 5F, the lens-side metal member 5L, and the intermediate-side metal member 5M are each composed of a metal plate having a plate-shaped base BP. Specifically, the first support-side metal member 5F1 has a base BPF1, the second support-side metal member 5F2 has a base BPF2, the third support-side metal member 5F3 has a base BPF3, the fourth support-side metal member 5F4 has a base BPF4, the first lens-side metal member 5L1 has a base BPL1, the second lens-side metal member 5L2 has a base BPL2, the third lens-side metal member 5L3 has a base BPL3, and the fourth lens-side metal member 5L4 has a base BPL The first intermediate metal member 5M1 has a base BPM1, the second intermediate metal member 5M2 has a base BPM2, the third intermediate metal member 5M3 has a base BPM3, the fourth intermediate metal member 5M4 has a base BPM4, the fifth intermediate metal member 5M5 has a base BPM5, the sixth intermediate metal member 5M6 has a base BPM6, the seventh intermediate metal member 5M7 has a base BPM7, and the eighth intermediate metal member 5M8 has a base BPM8.

[0052] As shown in the right-hand diagram of Figure 8, the 16 metal members 5 (first support-side metal members 5F1 to fourth support-side metal members 5F4, first lens-side metal members 5L1 to fourth lens-side metal members 5L4, and first intermediate-side metal members 5M1 to eighth intermediate-side metal members 5M8) are attached to the lens holding member 2, intermediate member 3, or support member 8 such that the plate surfaces of their respective bases BP are parallel to the XY plane, that is, they are substantially parallel to each other.

[0053] Furthermore, as shown in Figure 7, with respect to the first wire SA1, the second support-side metal member 5F2 is positioned higher than the eighth intermediate-side metal member 5M8 in the Z-axis direction; with respect to the second wire SA2, the second intermediate-side metal member 5M2 is positioned higher than the fourth lens-side metal member 5L4 in the Z-axis direction; with respect to the third wire SA3, the first intermediate-side metal member 5M1 is positioned higher than the first support-side metal member 5F1 in the Z-axis direction; and with respect to the fourth wire SA4, the third lens-side metal member 5L3 is positioned higher than the seventh intermediate-side metal member 5M7 in the Z-axis direction. Similarly, with respect to the fifth wire SA5, the fourth support-side metal member 5F4 is positioned higher than the fourth intermediate-side metal member 5M4 in the Z-axis direction; with respect to the sixth wire SA6, the sixth intermediate-side metal member 5M6 is positioned higher than the second lens-side metal member 5L2 in the Z-axis direction; with respect to the seventh wire SA7, the fifth intermediate-side metal member 5M5 is positioned higher than the third support-side metal member 5F3 in the Z-axis direction; and with respect to the eighth wire SA8, the first lens-side metal member 5L1 is positioned higher than the third intermediate-side metal member 5M3 in the Z-axis direction.

[0054] Next, referring to Figures 9 and 10, the positional relationships of the current-carrying components—metal member 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M), flexible metal member 7, lens-side embedded member 20, intermediate-side embedded member 30, support-side embedded member 80, and shape memory alloy wire SA—will be explained. Figure 9 is a perspective view of the metal member 5 (support-side metal member 5F, lens-side metal member 5L, and intermediate-side metal member 5M), flexible metal member 7, lens-side embedded member 20, intermediate-side embedded member 30, support-side embedded member 80, and shape memory alloy wire SA. Figure 10 is an excerpt from Figure 9. The upper left of Figure 10 shows components related to the current-carrying circuit, including the first wire SA1 and the second wire SA2. The lower left of Figure 10 shows components related to the current-carrying circuit, including the third wire SA3 and the fourth wire SA4. The upper right of Figure 10 shows components related to the current-carrying circuit, including the fifth wire SA5 and the sixth wire SA6. The lower right of Figure 10 shows components related to the current-carrying circuit, including the seventh wire SA7 and the eighth wire SA8.

[0055] As shown in the upper left diagram of Figure 10, when the second terminal portion 80BT of the second support-side buried member 80B is connected to a high potential and the eighth terminal portion 80HT of the eighth support-side buried member 80H is connected to a low potential, the current flows from the second terminal portion 80BT of the second support-side buried member 80B to the second joint portion 80BP of the second support-side buried member 80B, the second support-side metal member 5F2, the first wire SA1, the eighth intermediate-side metal member 5M8, and the second intermediate-side buried member 30B (second rear joint portion). The wire flows through 30BQ and the second front joint 30BP), the second intermediate metal member 5M2, the second wire SA2, the fourth lens-side metal member 5L4, the fourth lens-side embedded member 20D (the fourth upper joint 20DP and the fourth lower joint 20DQ), the fourth flexible metal member 7D (the fourth movable joint 7DP and the fourth fixed joint 7DQ), and the eighth joint 80HP of the eighth support-side embedded member 80H, and then to the eighth terminal portion 80HT of the eighth support-side embedded member 80H.

[0056] Furthermore, as shown in the lower left diagram of Figure 10, when the first terminal portion 80AT of the first support-side buried member 80A is connected to a high potential and the seventh terminal portion 80GT of the seventh support-side buried member 80G is connected to a low potential, the current flows from the first terminal portion 80AT of the first support-side buried member 80A to the first joint portion 80AP of the first support-side buried member 80A, the first support-side metal member 5F1, the third wire SA3, the first intermediate-side metal member 5M1, and the first intermediate-side buried member 30A (first front joint). The current flows through the 30AP and 1st rear joint 30AQ, the 7th intermediate metal member 5M7, the 4th wire SA4, the 3rd lens-side metal member 5L3, the 3rd lens-side embedded member 20C (3rd upper joint 20CP and 3rd lower joint 20CQ), the 3rd flexible metal member 7C (3rd movable joint 7CP and 3rd fixed joint 7CQ), and the 7th joint 80GP of the 7th support-side embedded member 80G, and then to the 7th terminal portion 80GT of the 7th support-side embedded member 80G.

[0057] Furthermore, as shown in the upper right diagram of Figure 10, when the fourth terminal portion 80DT of the fourth support-side buried member 80D is connected to a high potential and the sixth terminal portion 80FT of the sixth support-side buried member 80F is connected to a low potential, the current flows from the fourth terminal portion 80DT of the fourth support-side buried member 80D to the fourth joint portion 80DP of the fourth support-side buried member 80D, the fourth support-side metal member 5F4, the fifth wire SA5, the fourth intermediate-side metal member 5M4, and the fourth intermediate-side buried member 30D (fourth front joint). The current flows through the 30DP and 4th rear joint 30DQ, the 6th intermediate metal member 5M6, the 6th wire SA6, the 2nd lens-side metal member 5L2, the 2nd lens-side embedded member 20B (2nd upper joint 20BP and 2nd lower joint 20BQ), the 2nd flexible metal member 7B (2nd movable joint 7BP and 2nd fixed joint 7BQ), and the 6th joint 80FP of the 6th support-side embedded member 80F, and into the 6th terminal portion 80FT of the 6th support-side embedded member 80F.

[0058] Furthermore, as shown in the lower right diagram of Figure 10, when the third terminal portion 80CT of the third support-side buried member 80C is connected to a high potential and the fifth terminal portion 80ET of the fifth support-side buried member 80E is connected to a low potential, the current flows from the third terminal portion 80CT of the third support-side buried member 80C to the third joint portion 80CP of the third support-side buried member 80C, the third support-side metal member 5F3, the seventh wire SA7, the fifth intermediate-side metal member 5M5, and the third intermediate-side buried member 30C (third rear joint). The wire flows through the section 30CQ and the third front joint 30CP, the third intermediate metal member 5M3, the eighth wire SA8, the first lens-side metal member 5L1, the first lens-side embedded member 20A (first upper joint 20AP and first lower joint 20AQ), the first flexible metal member 7A (first movable joint 7AP and first fixed joint 7AQ), and the fifth joint 80EP of the fifth support-side embedded member 80E, and then to the fifth terminal portion 80ET of the fifth support-side embedded member 80E.

[0059] The control device located outside the lens drive device 101, as described above, can control the length of each shape memory alloy wire SA (first wire SA1 to eighth wire SA8) by controlling the voltage applied to each terminal portion (first terminal portion 80AT to eighth terminal portion 80HT) of the first support-side embedded member 80A to eighth support-side embedded member 80H. For example, the control device may detect the electrical resistance value of each shape memory alloy wire SA and control the length of each shape memory alloy wire SA according to the detection result. The control device may be located inside the lens drive device 101. Alternatively, the control device may be a component of the lens drive device 101.

[0060] The control device may, for example, utilize the driving force produced by the contraction of a shape memory alloy wire SA acting as a drive unit DM, along a direction parallel to the optical axis OA, to move the lens holding member 2 along a direction parallel to the optical axis OA (Z-axis direction) on the Z1 side (subject side) of the image sensor IS. By moving the lens holding member 2 in this way, the control device may realize an autofocus adjustment function, which is one of the lens adjustment functions. Specifically, the control device may enable macro photography by moving the lens holding member 2 away from the image sensor, and enable infinity focus photography by moving the lens holding member 2 closer to the image sensor.

[0061] Next, the movement of the movable member MB relative to the fixed member FB will be explained with reference to Figures 11 to 13. Figures 11 to 13 are schematic diagrams of the lens holding member 2, the intermediate member 3, and the support member 8. Specifically, the upper diagrams in Figures 11 to 13 are top views of the lens holding member 2, the intermediate member 3, and the support member 8, and the lower diagrams in Figures 11 to 13 are front views of the lens holding member 2, the intermediate member 3, and the support member 8. For clarity, in Figures 11 to 13, the lens holding member 2 is marked with a cross pattern, the intermediate member 3 with a fine dot pattern, and the support member 8 with a coarse dot pattern.

[0062] More specifically, Figure 11 shows the positional relationship of the lens holding member 2, intermediate member 3, and support member 8 when the lens driving device 101 is in a neutral state; Figure 12 shows the positional relationship of the lens holding member 2, intermediate member 3, and support member 8 when the intermediate member 3 (lens holding member 2) is moved toward the Z1 side relative to the support member 8 by the first wire SA1 and fifth wire SA5; and Figure 13 shows the positional relationship of the lens holding member 2, intermediate member 3, and support member 8 when the lens holding member 2 is further moved toward the Z1 side relative to the intermediate member 3 by the second wire SA2 and sixth wire SA6. In the following explanation referring to Figures 11 to 13, for the sake of clarity, the movements by the first wire SA1 and fifth wire SA5 and the movements by the second wire SA2 and sixth wire SA6 are shown separately, but in reality, the movements by the first wire SA1 and fifth wire SA5 and the movements by the second wire SA2 and sixth wire SA6 occur simultaneously. Therefore, the lens holding member 2 does not rotate substantially around the optical axis OA.

[0063] When the first wire SA1 and the fifth wire SA5 contract by a predetermined amount, the intermediate member 3 rotates counterclockwise by an angle α in a top view around the optical axis OA, as shown by arrow AR1 in the upper part of Figure 12, and moves a distance ST1 toward Z1 along the optical axis, as shown by the Z-axis component of arrow AR1 in the lower part of Figure 12. Note that arrow AR1 in the lower part of Figure 12 is shown decomposed into a Z-axis component and a circumferential component of a circle centered on the optical axis OA.

[0064] In addition, in the upper and lower diagrams of Figure 12, the positions (outer shapes) of the lens holding member 2 and the intermediate member 3 in the state shown in Figure 11 are represented by dashed lines, and in the upper diagram of Figure 12, the first wire SA1 and the fifth wire SA5 are represented by thick dotted lines.

[0065] At this time, the control device ensures that the intermediate member 3 does not tilt with respect to the optical axis OA, and that the position of the optical axis OA in the XY plane does not shift. In this manner, a predetermined current is supplied not only to the first wire SA1 and the fifth wire SA5, but also to the third wire SA3 and the seventh wire SA7, one end of which is fixed to the support member 8.

[0066] Furthermore, when the intermediate member 3 rotates counterclockwise by an angle α when viewed from above around the optical axis OA, and moves a distance ST1 toward the Z1 side along the optical axis, the lens holding member 2, which is connected to the intermediate member 3 via four shape memory alloy wires SA (second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8), rotates counterclockwise by an angle α when viewed from above around the optical axis OA, as shown by arrow AR2 in the upper part of Figure 12, and moves a distance ST1 toward the Z1 side along the optical axis, as shown by the Z-axis component of arrow AR2 in the lower part of Figure 12. Note that arrow AR2 in the lower part of Figure 12 is shown decomposed into a Z-axis component and a circumferential component of a circle centered on the optical axis OA.

[0067] Furthermore, when the second wire SA2 and the sixth wire SA6 contract by a predetermined amount, the lens holding member 2 rotates clockwise by an angle β in a top view around the optical axis OA, as shown by arrow AR3 in the upper part of Figure 13, and moves by a distance ST2 toward Z1 along the optical axis, as shown by the Z-axis component of arrow AR3 in the lower part of Figure 13. Note that arrow AR3 in the lower part of Figure 13 is shown decomposed into a Z-axis component and a circumferential component of a circle centered on the optical axis OA.

[0068] Furthermore, in the upper and lower diagrams of Figure 13, the position (outer shape) of the lens holding member 2 in the state shown in Figure 12 is represented by a dashed line, and in the upper diagram of Figure 13, the second wire SA2 and the sixth wire SA6 are represented by thick dotted lines. Also, in the illustrated example, angle β has approximately the same magnitude as angle α.

[0069] At this time, the control device ensures that the lens holding member 2 does not tilt with respect to the optical axis OA, and that the position of the optical axis OA in the XY plane does not shift. In this manner, a predetermined current is supplied not only to the second wire SA2 and the sixth wire SA6, but also to the fourth wire SA4 and the eighth wire SA8, one end of which is fixed to the lens holding member 2.

[0070] Therefore, when the first wire SA1, the second wire SA2, the fifth wire SA5, and the sixth wire SA6 contract by a predetermined amount, the lens holding member 2 moves toward Z1 along the optical axis direction by the sum of distances ST1 and ST2 without tilting with respect to the optical axis OA. On the other hand, the counterclockwise rotation of the lens holding member 2 by angle α around the optical axis OA and the clockwise rotation of the lens holding member 2 by angle β around the optical axis OA cancel each other out, and if angles α and β are of the same magnitude, the lens holding member 2 does not rotate around the optical axis OA.

[0071] Furthermore, in the examples shown in Figures 11 to 13, the control device is configured to translate the lens holding member 2 toward Z1 without rotating it around the optical axis OA by contracting four shape memory alloy wires SA (first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6). However, the control device may also be configured to translate the lens holding member 2 toward Z1 without rotating it around the optical axis OA by contracting two shape memory alloy wires SA (first wire SA1 and second wire SA2). In this case, the control device ensures that a predetermined current is supplied not only to the first wire SA1 and second wire SA2, but also to the other shape memory alloy wires SA (third wire SA3 to eighth wire SA8) so that the lens holding member 2 does not tilt with respect to the optical axis OA and the position of the optical axis OA in the XY plane does not shift.

[0072] Furthermore, the above explanation with reference to Figures 11 to 13 mainly concerns the case where the lens holding member 2 and intermediate member 3 are moved upward (towards Z1) by contracting the first wire SA1, second wire SA2, fifth wire SA5, and sixth wire SA6. However, it also applies similarly to the case where the lens holding member 2 and intermediate member 3 are moved downward (towards Z2) by contracting the third wire SA3, fourth wire SA4, seventh wire SA7, and eighth wire SA8.

[0073] As described above, the lens drive device 101, an example of an optical element drive device according to the embodiment of this disclosure, as shown in Figure 2, comprises a support member 8, an optical element holding member (lens holding member 2) having an opening 2K in which an optical element (lens body LS) can be placed and movable in a predetermined direction (optical axis direction) along a predetermined axis (optical axis OA) relative to the support member 8, a drive unit DM comprising a shape memory alloy wire SA for moving the lens holding member 2 in the optical axis direction, and an intermediate member 3 provided between the lens holding member 2 and the support member 8. The intermediate member 3 is movable relative to the support member 8 and also movable relative to the lens holding member 2. The shape memory alloy wire SA includes a first wire SA1 provided between the support member 8 and the intermediate member 3, and a second wire SA2 provided between the intermediate member 3 and the lens holding member 2. The first wire SA1 has one end supported by the support member 8 positioned higher than the other end supported by the intermediate member 3. The second wire SA2 has one end supported by the intermediate member 3 positioned higher than the other end supported by the lens holding member 2. When current is passed through the first wire SA1 and the second wire SA2, the contraction of the first wire SA1 and the contraction of the second wire SA2 suppress the rotation of the lens holding member 2 around the optical axis OA, thereby causing the lens holding member 2 to move in the optical axis direction.

[0074] This configuration suppresses the rotation of the lens holding member 2 around the optical axis OA when moving the lens holding member 2 along the optical axis OA. Therefore, this configuration has the effect of being less affected to image quality even as the pixel count of the image sensor IS increases. Furthermore, this configuration allows the intermediate member 3 to be moved along one side of the optical axis relative to the support member 8, and the lens holding member 2 to be moved along one side of the optical axis relative to the intermediate member 3. Therefore, this configuration has the effect of increasing the amount of movement of the lens holding member 2 in the optical axis direction compared to a configuration in which only the lens holding member 2 or the intermediate member 3 is moved relative to the support member 8.

[0075] Furthermore, the first wire SA1 and the second wire SA2 are preferably positioned opposite each other in a first direction (Y-axis direction) that intersects the optical axis direction (Z-axis direction), with the opening 2K of the lens holding member 2 in between, as shown in Figure 7.

[0076] This configuration improves the weight balance of the lens drive device 101 compared to a configuration in which the first wire SA1 and the second wire SA2 are positioned so as not to face each other across the opening 2K of the lens holding member 2. This has the effect of appropriately suppressing the rotation of the lens holding member 2 around the optical axis OA.

[0077] Furthermore, the shape memory alloy wire SA preferably includes, as shown in Figure 7, a first wire SA1 and a second wire SA2, respectively, positioned opposite each other across the opening 2K of the lens holding member 2 in a first direction (Y-axis direction); a third wire SA3 and a fourth wire SA4, respectively, positioned opposite each other across the opening 2K of the lens holding member 2 in a second direction (X-axis direction) that intersects with the optical axis direction and is perpendicular to the first direction (Y-axis direction); a fifth wire SA5 and a sixth wire SA6, respectively, positioned opposite each other across the opening 2K of the lens holding member 2 in a first direction (Y-axis direction); and a seventh wire SA7 and an eighth wire SA8, respectively, positioned opposite each other across the opening 2K of the lens holding member 2 in a second direction (X-axis direction). The first wire SA1 is provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 positioned higher than the other end supported by the intermediate member 3; the second wire SA2 is provided between the intermediate member 3 and the lens holding member 2, with one end supported by the intermediate member 3 positioned higher than the other end supported by the lens holding member 2; the third wire SA3 is provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 positioned lower than the other end supported by the intermediate member 3; and the fourth wire SA4 is provided between the intermediate member 3 and the lens holding member 2, with one end supported by the intermediate member 3 positioned lower than the other end supported by the lens holding member 2. The fifth wire SA5 is provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 positioned higher than the other end supported by the intermediate member 3. The sixth wire SA6 is provided between the intermediate member 3 and the lens holding member 2, with one end supported by the intermediate member 3 positioned higher than the other end supported by the lens holding member 2. The seventh wire SA7 is provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 positioned lower than the other end supported by the intermediate member 3. The eighth wire SA8 is provided between the intermediate member 3 and the lens holding member 2, with one end supported by the intermediate member 3 positioned lower than the other end supported by the lens holding member 2.As shown in the right side view of Figure 8, when viewed along the first direction (Y-axis direction), the first wire SA1 and the fifth wire SA5 are arranged to intersect each other, and the second wire SA2 and the sixth wire SA6 are arranged to intersect each other. As shown in the front view of Figure 8, when viewed along the second direction (X-axis direction), the third wire SA3 and the seventh wire SA7 are arranged to intersect each other, and the fourth wire SA4 and the eighth wire SA8 are arranged to intersect each other.

[0078] This configuration has the effect of suppressing the rotation of the lens holding member 2 around the optical axis OA, regardless of whether the lens holding member 2 is moved in the direction of the optical axis, that is, whether it is moved upward or downward.

[0079] Preferably, as shown in Figure 7, one end of each of the first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7 is fixed to separate metal members 5 (support-side metal members 5F (second support-side metal member 5F2, first support-side metal member 5F1, fourth support-side metal member 5F4, and third support-side metal member 5F3)) which are fixed to the support member 8, and the other end of each of the first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7 is fixed to separate metal members 5 (intermediate-side metal members 5M (eighth intermediate-side metal member 5M8, first intermediate-side metal member 5M1, fourth intermediate-side metal member 5M4, and fifth intermediate-side metal member 5M5)) which are fixed to the intermediate member 3. The second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8 are each fixed to separate metal members 5 (intermediate side metal member 5M (second intermediate side metal member 5M2, seventh intermediate side metal member 5M7, sixth intermediate side metal member 5M6, and third intermediate side metal member 5M3)) which are fixed to the intermediate member 3, and the other ends of the second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8 are each fixed to separate metal members 5 (lens side metal member 5L (fourth lens side metal member 5L4, third lens side metal member 5L3, second lens side metal member 5L2, and first lens side metal member 5L1)) which are fixed to the lens holding member 2. Each of the metal members 5 is formed from a metal plate having a plate-shaped base BP, and the plate surface of the base BP is fixed to the corresponding member in a state where it is substantially perpendicular to the optical axis OA.

[0080] This configuration allows all (16) metal members 5 to be attached to the corresponding components from a single side (Z1 side, upper side), which has the effect of increasing the productivity (manufacturability) of the lens drive device 101 compared to a configuration that requires attachment from at least two sides.

[0081] Furthermore, each of the metal members 5 is preferably positioned so as not to overlap with each other in a top view along the optical axis, as shown in the top view of Figure 8.

[0082] This configuration allows all (16) metal members 5 to be attached in any order from one side (Z1 side, upper side), thus increasing the productivity (manufacturability) of the lens drive device 101 compared to a configuration where at least some of the members are placed in overlapping positions, i.e., a configuration where the attachment order is limited.

[0083] Furthermore, the lens drive device 101 preferably includes a leaf spring 6 connecting the lens holding member 2 and the support member 8, as shown in Figure 7.

[0084] This configuration has the effect of allowing the lens holding member 2 to be centered in the XY plane relative to both the intermediate member 3 and the support member 8.

[0085] Furthermore, preferably, as shown in the top view of Figure 8, in a top view along the optical axis, the distance DS1 between one end and the other end of the first wire SA1 is greater than the distance DS2 between one end and the other end of the second wire SA2. In other words, in a top view along the optical axis, the shape memory alloy wires SA (first wire SA1, third wire SA3, fifth wire SA5, and seventh wire SA7) that are positioned farther from the optical axis OA are longer than the shape memory alloy wires SA (second wire SA2, fourth wire SA4, sixth wire SA6, and eighth wire SA8) that are positioned closer to the optical axis OA.

[0086] This configuration has the effect of improving space efficiency within the housing HS compared to a configuration in which the shape memory alloy wire SA positioned farther from the optical axis OA in a top view along the optical axis is shorter than the shape memory alloy wire SA positioned closer to the optical axis OA.

[0087] Furthermore, preferably, as shown in the right side view of Figure 8, the distance HT1 in the optical axis direction between one end and the other end of the first wire SA1 is greater than the distance HT2 in the optical axis direction between one end and the other end of the second wire SA2. In other words, in a side view along the X-axis or Y-axis direction, each of the multiple shape memory alloy wires SA is arranged to be inclined by approximately the same angle (angle of inclination) with respect to the XY plane.

[0088] This configuration allows for more stable movement of the movable member MB compared to the case where the inclination angles of the multiple shape memory alloy wires SA differ significantly from each other. Furthermore, this configuration allows for a larger amount of movement along the optical axis compared to the case where the inclination angles of the multiple shape memory alloy wires SA are smaller.

[0089] 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 and those described later without departing from the scope of the present invention. Each of the features described with reference to the embodiments described above and those described later may be combined as appropriate, as long as they do not conflict technically.

[0090] For example, in the above embodiment, the metal member 5 is fixed to each member (lens holding member 2, intermediate member 3, and support member 8) by adhesive or the like, but it may also be embedded in each member, or it may be a conductive pattern formed on the surface of each member. [Explanation of Symbols]

[0091] 1. Cover member 1A. Outer wall section 1A1. First side plate section 1A2. Second side plate section 1A3. Third side plate section 1A4. Fourth side plate section 1B. Top plate section 1K. Opening 1S. Storage section 2. Lens holding member 2C. Cylindrical section 2D. Base section 2D1. First base section 2D2. Second base section 2D3. Third base section 2D4. Fourth base section 2K. Opening 3. Intermediate member 3B. Base section 3D. Base section 3D1. First base section 3D2. Second base section 3D3. Third base section 3D4. Fourth base section 3D5...5th base section 3D6...6th base section 3D7...7th base section 3D8...8th base section 3K...Opening 5...Metal component 5F...Support side metal component 5F1...1st support side metal component 5F2...2nd support side metal component 5F3...3rd support side metal component 5F4...4th support side metal component 5L...Lens side metal component 5L1...1st lens side metal component 5L2...2nd lens side metal component 5L3...3rd lens side metal component 5L4...4th lens side metal component 5M...Intermediate side metal component 5M1...1st intermediate side metal component 5M2...2nd intermediate side metal component 5M3...3rd intermediate side metal component 5M4... Fourth intermediate metal member 5M5... Fifth intermediate metal member 5M6... Sixth intermediate metal member 5M7... Seventh intermediate metal member 5M8... Eighth intermediate metal member 6... Leaf spring 6E... Outer part 6E1... First outer part 6E2... Second outer part 6G... Elastic part 6G1...First elastic part 6G2...Second elastic part 6I...Inner part 7...Flexible metal member 7A...First flexible metal member 7AP...First movable joint part 7AQ...First fixed joint part 7B...Second flexible metal member 7BP...Second movable joint part 7BQ...Second fixed joint part 7C...Third flexible metal member 7CP...Third movable joint 7CQ...Third fixed joint 7D...Fourth flexible metal member 7DP...Fourth movable joint 7DQ...Fourth fixed joint 8...Support member 8B...Base 8D...Pedestal 8D1...First pedestal 8D2...Second pedestal 8D3...Third pedestal 8D4...Fourth pedestal 8D5...Fifth pedestal 8D6...Sixth pedestal 8K...Opening20...Lens-side embedded member 20A...First lens-side embedded member 20AP...First upper joint 20AQ...First lower joint 20B...Second lens-side embedded member 20BP...Second upper joint 20BQ...Second lower joint 20C...Third lens-side embedded member 20CP...Third upper joint 20CQ...Third lower joint 20D...Fourth lens-side embedded member 20DP...Fourth upper joint 20DQ...Fourth lower joint 30...Intermediate-side embedded member 30A...First intermediate-side embedded member 30AP...First front joint 30AQ...First rear joint 30B...Second intermediate-side embedded member 30BP...Second front joint 30BQ...Second rear joint 30C...Third intermediate buried member 30CP...Third front joint 30CQ...Third rear joint 30D...Fourth intermediate buried member 30DP...Fourth front joint 30DQ...Fourth rear joint 80...Support side buried member 80A...1st support side buried member 80AP...1st joint 80AT...1st terminal part 80B...2nd support side buried member 80BP...2nd joint 80BT...2nd terminal part 80C...3rd support side buried member 80CP...3rd joint 80CT...Third terminal part 80D...Fourth support side buried member 80DP...4th joint 80DT...4th terminal 80E...5th support-side embedded member 80EP...5th joint 80ET...5th terminal 80F...6th support-side embedded member 80FP...6th joint 80FT...6th terminal 80G...7th support-side embedded member 80GP...7th joint 80GT...7th terminal 80H...8th support-side embedded member 80HP...8th joint 80HT...8th terminal 101...Lens drive unit BP...Base CM...Camera module DM...Drive unit DM1...1st drive unit DM2...2nd drive unit FB...Fixed-side member HS...Housing IS...Image sensor J1-J16...Holding part LS...Lens body MB...Movable side member OA...Optical axis SA...Shape memory alloy wire SA1...First wire SA2...Second wire SA3...Third wire SA4...Fourth wire SA5...Fifth wire SA6...Sixth wire SA7...Seventh wire SA8...Eighth wireSU... circuit board

Claims

1. Support member and An optical element holding member having an opening into which an optical element can be placed, and which is movable in a predetermined direction along a predetermined axis relative to the support member, A drive unit comprising a shape memory alloy wire for moving the optical element holding member in the predetermined direction, An optical element driving device comprising an intermediate member provided between the optical element holding member and the support member, The intermediate member is movable relative to the support member and also movable relative to the optical element holding member. The shape memory alloy wire includes a first wire provided between the support member and the intermediate member, and a second wire provided between the intermediate member and the optical element holding member. The first wire is positioned such that one end, supported by the support member, is higher than the other end, supported by the intermediate member. The second wire is positioned such that one end, supported by the intermediate member, is higher than the other end, supported by the optical element holding member. When current is passed through the first wire and the second wire, the contraction of the first wire and the contraction of the second wire suppress rotation around the predetermined axis, thereby causing the optical element holding member to move in the predetermined direction. An optical element driving device characterized by the following:

2. The first wire and the second wire are respectively provided at positions facing each other across the opening of the optical element holding member in a first direction intersecting the predetermined direction. The optical element driving device according to claim 1.

3. The shape memory alloy wire includes a third wire and a fourth wire, respectively, positioned opposite each other across the opening of the optical element holding member in a second direction that intersects the predetermined direction and is perpendicular to the first direction; a fifth wire and a sixth wire, respectively, positioned opposite each other across the opening of the optical element holding member in the first direction; and a seventh wire and an eighth wire, respectively, positioned opposite each other across the opening of the optical element holding member in the second direction. The third wire is provided between the support member and the intermediate member, and one end supported by the support member is positioned lower than the other end supported by the intermediate member. The fourth wire is provided between the intermediate member and the optical element holding member, and one end supported by the intermediate member is positioned lower than the other end supported by the optical element holding member. The fifth wire is provided between the support member and the intermediate member, and one end supported by the support member is positioned higher than the other end supported by the intermediate member. The sixth wire is provided between the intermediate member and the optical element holding member, and one end supported by the intermediate member is positioned higher than the other end supported by the optical element holding member. The seventh wire is provided between the support member and the intermediate member, and one end supported by the support member is positioned lower than the other end supported by the intermediate member. The eighth wire is provided between the intermediate member and the optical element holding member, and one end supported by the intermediate member is positioned lower than the other end supported by the optical element holding member. When viewed along the first direction, the first wire and the fifth wire are arranged to intersect each other, and the second wire and the sixth wire are arranged to intersect each other. When viewed along the second direction, the third wire and the seventh wire are arranged to intersect each other, and the fourth wire and the eighth wire are arranged to intersect each other. The optical element driving device according to claim 2.

4. Each of the first wire, the third wire, the fifth wire, and the seventh wire has one end fixed to a separate metal member which is fixed to the support member. The other ends of the first wire, the third wire, the fifth wire, and the seventh wire are fixed to separate metal members which are fixed to the intermediate member. The first end of each of the second wire, the fourth wire, the sixth wire, and the eighth wire is fixed to a separate metal member which is fixed to the intermediate member. The other ends of the second wire, the fourth wire, the sixth wire, and the eighth wire are fixed to separate metal members that are fixed to the optical element holding member. Each of the aforementioned metal members is formed from a metal plate having a plate-shaped base, and the plate surface of the base is fixed to the corresponding member in a state where it is substantially perpendicular to the predetermined axis. The optical element driving device according to claim 3.

5. Each of the aforementioned metal members is positioned so as not to overlap with each other when viewed from above along the predetermined direction. The optical element driving device according to claim 4.

6. The optical element holding member and the support member are connected by a leaf spring. The optical element driving device according to claim 1.

7. In a top view along the predetermined direction, the distance between one end and the other end of the first wire is greater than the distance between one end and the other end of the second wire. The optical element driving device according to claim 1.

8. The distance in the predetermined direction between one end and the other end of the first wire is greater than the distance in the predetermined direction between one end and the other end of the second wire. The optical element driving device according to claim 1 or claim 7.

9. An optical element driving device according to any one of claims 1 to 7, A lens body fixed to the optical element holding member, The lens body has an image sensor facing it, Camera module.

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