Optical element driving device and camera module

Abstract

To suppress the rotation of the lens body around the optical axis when moving the lens body along the optical axis. [Solution] In the lens driving device 101, the lens holding member 2 and the intermediate member 3 are rotatable relative to each other around the optical axis OA and can move together in the direction along the optical axis OA. The shape memory alloy wire SA includes a first wire SA1, one end of which is supported by the support member 8 and positioned higher than the other end of which is supported by the intermediate member 3, and a second wire SA2, one end of which is supported by the support member 8 and positioned lower than the other end of which is supported by the intermediate member 3. The rotation suppression member suppresses the rotation of the lens holding member 2 around the optical axis OA when a force acting on the intermediate member 3 causes the intermediate member 3 to rotate around the optical axis OA due to the contraction of the shape memory alloy wire SA.

Description

Technical Field

[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 Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the number of pixels of an imaging element increases (image quality improves), 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, in an optical element driving device configured to move an optical element along a predetermined axis while rotating a part of a movable side member including the optical element such as a lens body around the predetermined axis such as the optical axis, it is desirable to suppress the rotation of the optical element around the predetermined axis when moving the optical element along the predetermined 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 in 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; an intermediate member provided between the optical element holding member and the support member; and a rotation suppression member for suppressing the rotation of the optical element holding member around the predetermined axis relative to the support member, wherein the intermediate member is movable relative to the support member, the optical element holding member and the intermediate member are rotatable relative to the predetermined axis and move together in the direction along the predetermined axis. The shape memory alloy wire is movable and includes a first wire provided between the support member and the intermediate member, with one end supported by the support member positioned higher than the other end supported by the intermediate member, and a second wire provided between the support member and the intermediate member, with one end supported by the support member positioned lower than the other end supported by the intermediate member. The rotation suppression member is configured to suppress the rotation of the optical element holding member around the predetermined axis when a force acting on the intermediate member attempts to rotate the intermediate member around the predetermined axis due to the contraction of the shape memory alloy wire caused by energizing the shape memory alloy wire. [Effects of the Invention]

[0007] The optical element driving device described above can suppress the rotation of the optical element around the predetermined axis when moving the optical element along the 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 holder, leaf spring, magnet, and sphere. [Figure 4]This is a bottom view of the lens holder. [Figure 5] This is a perspective view of the intermediate member, the movable metal member, the leaf spring, and the sphere. [Figure 6] This is a top view of the intermediate member. [Figure 7] This is a perspective view of the support metal member, leaf spring, support member, and support embedded member. [Figure 8] This is a top view of the lens drive unit with the cover removed. [Figure 9] This figure shows an example of the configuration of metal components and shape memory alloy wires. [Figure 10] This is a perspective view of a metal component, a leaf spring, a support-side embedded component, and a shape memory alloy wire. [Figure 11] This is a perspective view of a metal component, a leaf spring, a support-side embedded component, and a shape memory alloy wire. [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. [Figure 14] These are top and front views of the lens holder, intermediate member, and support member. [Figure 15] This is a cross-sectional view of the lens drive device. [Modes for carrying out the invention]

[0009] Hereinafter, a lens drive device 101, which is an example of an optical element drive device according to the embodiment of this disclosure, will be described with reference to the drawings. Figure 1 is a perspective view of a camera module CM including a lens drive device 101 that drives a lens body LS, which is an example of an optical element OE. Figure 2 is an exploded perspective view of the lens drive device 101. Note that the optical element drive device may be a device that drives other optical elements OE other than the lens body LS, such as a prism, mirror, or polarizing element.

[0010] In FIGS. 1 and 2, X1 represents one direction of the X-axis that constitutes a three-dimensional orthogonal coordinate system, and X2 represents the other direction of the X-axis. Also, Y1 represents one direction of the Y-axis that constitutes a three-dimensional orthogonal coordinate system, and Y2 represents the other direction of the Y-axis. Similarly, Z1 represents one direction of the Z-axis that constitutes a 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 101 corresponds to the front side (front face side) of the lens driving device 101, and the X2 side of the lens driving device 101 corresponds to the rear side (back face side) of the lens driving device 101. Also, the Y1 side of the lens driving device 101 corresponds to the left side of the lens driving device 101, and the Y2 side of the lens driving device 101 corresponds to the right side of the lens driving device 101. Also, the Z1 side of the lens driving device 101 corresponds to the upper side (subject side) of the lens driving device 101, and the Z2 side of the lens driving device 101 corresponds to the lower side (image sensor side) of the lens driving device 101. The same applies to other figures.

[0011] As shown in FIG. 1, the camera module CM includes a substrate SU, a lens driving device 101 which is an example of an optical element driving device, a lens body LS which is an example of an optical element mounted on the lens driving device 101, and an image sensor IS mounted on the substrate SU so as to face the lens body LS. Also, the camera module CM is connected to a control device (not shown) composed of a microcomputer or the like including a CPU and a memory. In the illustrated example, the control device is disposed outside the camera module CM, but it may be disposed inside the camera module CM. The lens driving device 101 having a substantially rectangular parallelepiped outer shape is mounted on the substrate SU on which the image sensor IS is mounted, as shown in FIG. 1.

[0012] Specifically, as shown in FIGS. 1 and 2, the lens driving device 101 includes a cover member 1 and a support member 8 which are parts of a fixed-side member FB. The cover member 1 is configured to function as a part of the housing HS of the lens driving device 101. In the illustrated example, the cover member 1 is formed of a non-magnetic metal. However, the cover member 1 may be formed 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 circular 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. Further, 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. Then, 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 support-side embedded member 80, a magnet MG, a shape memory alloy wire SA, a sphere SB, 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] Furthermore, the lens holding member 2 is rotatable relative to the intermediate member 3 around the optical axis OA, and is movable in the Z-axis direction together with the intermediate member 3 relative to the fixed-side member FB (support member 8). In the illustrated example, the lens holding member 2 is formed by injection molding of a synthetic resin such as liquid crystal polymer (LCP). Specifically, the lens holding member 2 has a substantially circular outer shape in a plan view (top view) along the optical axis direction (Z-axis direction), and has a substantially circular opening 2K in the center. More specifically, the lens holding member 2 includes a substantially cylindrical tubular portion 2C formed to surround the opening 2K, and a base portion 2D formed to protrude from the tubular portion 2C radially outward from a circle centered on the optical axis OA. The base portion 2D includes the first base portion 2D1 to the fourth base portion 2D4. In the illustrated example, each of the first base portion 2D1 to the third base portion 2D3 is arranged at equal intervals (120-degree intervals) in the circumferential direction. Furthermore, the fourth base portion 2D4 is positioned between the first base portion 2D1 and the third base portion 2D3. Specifically, the first base portion 2D1, the fourth base portion 2D4, and the third base portion 2D3 are arranged at equal intervals (60-degree intervals) in the circumferential direction, and the second base portion 2D2 and the fourth base portion 2D4 are positioned facing each other in the radial direction with the optical axis OA in between. A part of the leaf spring 6 (movable portion 6I) is placed on the upper end surface of the second base portion 2D2 and the fourth base portion 2D4, respectively. In addition, each of the first to third base portions 2D1 to 2D3 has a housing recess 2U into which a magnet MG is fitted. Specifically, the first base portion 2D1 has a first housing recess 2U1 for housing the first magnet MG1, the second base portion 2D2 has a second housing recess 2U2 for housing the second magnet MG2, and the third base portion 2D3 has a third housing recess 2U3 for housing the third magnet MG3.

[0017] The sphere SB is a member positioned between the lens holding member 2 and the intermediate member 3 such that the lens holding member 2 and the intermediate member 3 can rotate relative to each other around the optical axis OA. In the illustrated example, the sphere SB is made of a magnetic material and includes a first sphere SB1, a second sphere SB2, and a third sphere SB3. Each of the first sphere SB1 to the third sphere SB3 is positioned at equal intervals (120-degree intervals) in the circumferential direction.

[0018] The magnet MG is a component that prevents the lens holding member 2 and the sphere SB from separating from each other in the Z-axis direction, and includes a first magnet MG1, a second magnet MG2, and a third magnet MG3. In the illustrated example, each of the first magnet MG1, the second magnet MG2, and the third magnet MG3 is a permanent magnet magnetized with two poles in the Z-axis direction. The first magnet MG1 magnetically attracts the first sphere SB1, thereby preventing the first sphere SB1 from separating from the lens holding member 2. The same applies to the second magnet MG2 and the third magnet MG3.

[0019] The drive unit DM is configured to move the movable side member MB relative 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 upward (towards Z1), and a second drive unit DM2 for moving the lens holding member 2 downward (towards Z2). More specifically, the shape memory alloy wire SA includes first wire SA1 to fourth wire SA4. The first drive unit DM1 includes the first wire SA1 and the third wire SA3, and the second drive unit DM2 includes the second wire SA2 and the fourth wire SA4.

[0020] The shape memory alloy wire SA is configured to contract as its temperature rises when an electric current flows through it. 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 movable side member MB (lens holding member 2 and intermediate member 3) to move relative to the support member 8. Each of the first wire SA1 to the fourth wire SA4 has one end fixed to the support side metal member 5F by crimping or welding, and the other end fixed to the movable side metal member 5M by crimping or welding. The support side metal member 5F is fixed to the support member 8, and the movable side metal member 5M is fixed to the intermediate member 3.

[0021] In the illustrated example, the first wire SA1 and the third wire SA3, and the second wire SA2 and the fourth wire SA4, 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 and the third wire SA3 are arranged to extend parallel to the Y axis in a plan view along the optical axis, and the second wire SA2 and the fourth wire SA4 are arranged to extend parallel to the X axis in a plan view along the optical axis.

[0022] The first drive unit DM1 can move the intermediate member 3 upward (towards Z1) along the optical axis direction (Z axis direction), which is parallel to the optical axis OA, by utilizing the contraction of the first wire SA1 and the third wire SA3, respectively. The second wire SA2 and the fourth wire SA4 are configured such that when the first wire SA1 and the third wire SA3 contract, the intermediate member 3 rotates around the optical axis OA and moves upward, and is stretched by this movement. Similarly, the second drive unit DM2 can move the lens holding member 2 downward (towards Z2) along the optical axis direction (Z axis direction) by utilizing the contraction of the second wire SA2 and the fourth wire SA4, respectively. The first wire SA1 and the third wire SA3 are configured such that when the second wire SA2 and the fourth wire SA4 contract, the intermediate member 3 rotates around the optical axis OA and moves downward, and is stretched by this movement.

[0023] 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 circular opening 3K in the center. More 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 fourth pedestal portion 3D4. The first pedestal portion 3D1 and the third pedestal portion 3D3 are arranged to face each other radially across the optical axis OA, and the second pedestal portion 3D2 and the fourth pedestal portion 3D4 are arranged to face each other radially across the optical axis OA. More specifically, the base 3B has a first base portion 3D1 at the right front corner, a second base portion 3D2 at the left front corner, a third base portion 3D3 at the left rear corner, and a fourth base portion 3D4 at the right rear corner. A part of the leaf spring 6 (terminal portion 6T) is placed on each of the first to fourth base portions 3D1 to 3D4.

[0024] 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 and a movable-side metal member 5M. Specifically, the support-side metal member 5F is configured to be fixed to the base portion 8D of the support member 8, and the movable-side metal member 5M is configured to be fixed to the base portion 3B of the intermediate member 3. The support-side metal member 5F may also be embedded in the base portion 8D of the support member 8, and the movable-side metal member 5M may be embedded in the base portion 3B of the intermediate member 3. More specifically, the support-side metal member 5F includes the first support-side metal member 5F1 to the fourth support-side metal member 5F4, and the movable-side metal member 5M includes the first movable-side metal member 5M1 to the fourth movable-side metal member 5M4.

[0025] 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 (Z-axis direction) 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). That is, the leaf spring 6 is formed to constitute a conductive path. Specifically, the leaf spring 6 connects the lens holding member 2, the intermediate member 3, and the support member 8 such that, in the neutral state of the lens driving device 101, the centers of the lens holding member 2, the intermediate member 3, and 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 base portion 2D of the lens holding member 2 (second base portion 2D2 and fourth base portion 2D4), the base portion 3D of the intermediate member 3 (first base portion 3D1 to fourth base portion 3D4), and the base portion 8D of the support member 8 (first base portion 8D1 to fourth base portion 8D4). 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 fourth wire SA4, and the movable side member MB (lens holding member 2 and intermediate member 3) is located in the middle of the movable range in the optical axis direction; in other words, the movable side member MB (lens holding member 2 and intermediate member 3) is 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 the movable range in the optical axis direction.

[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 a roughly circular opening 8K in the center. The support member 8 also has a rectangular annular base 8B formed to surround the opening 8K, and a pedestal portion 8D which is a portion that protrudes upward from the base 8B. The pedestal portion 8D includes the first pedestal portion 8D1 to the fourth pedestal portion 8D4. The first pedestal portion 8D1 and the third pedestal portion 8D3 are arranged to face each other in the radial direction (diagonal direction) with the optical axis OA in between, and the second pedestal portion 8D2 and the fourth pedestal portion 8D4 are arranged to face each other in the radial direction (another diagonal direction) with the optical axis OA in between. More specifically, the base 8B has a first base portion 8D1 at the left front corner, a second base portion 8D2 at the left rear corner, a third base portion 8D3 at the right rear corner, and a fourth base portion 3D4 at the right front corner. A part of the leaf spring 6 (support portion 6E) is placed on each of the first to fourth base portions 8D1 to 8D4.

[0027] 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 (the upper end surface of the base portion 8D) and used for joining with other metal members (the support portion 6E of the leaf spring 6). Specifically, as shown in Figure 2, the support-side embedded member 80 includes a first support-side embedded member 80A and a second support-side embedded member 80B.

[0028] 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 explained. Figure 3 is an overhead perspective view of the lens holding member 2, leaf spring 6, magnet MG, and sphere SB. Specifically, the upper part of Figure 3 (the figure above the block arrow) is an exploded perspective view, and the lower part of Figure 3 (the figure below the block arrow) is an assembled perspective view. Figure 4 is a bottom view of the lens holding member 2. Specifically, the upper part of Figure 4 is a bottom view of the lens holding member 2 without the sphere SB in place, and the lower part of Figure 4 is a bottom view of the lens holding member 2 with the sphere SB in place.

[0029] The leaf spring 6 includes a rear leaf spring 6B and a front leaf spring 6F. The leaf spring 6 also has a movable portion 6I fixed to the base portion 2D of the lens holding member 2, a terminal portion 6T fixed to the base portion 3D (see Figure 2) of the intermediate member 3, a support portion 6E fixed to the base portion 8D (see Figure 2) of the support member 8, an elastic portion 6G connecting the support portion 6E and the movable portion 6I, and a flexible portion 6H connecting the support portion 6E and the terminal portion 6T. The support portion 6E, the elastic portion 6G, and the movable portion 6I constitute a rotation suppression member RS ​​that prevents the lens holding member 2 from rotating around the optical axis OA relative to the support member 8, and also constitutes a support leaf spring SL that movably supports the lens holding member 2 relative to the support member 8 along the optical axis OA. In the illustrated example, the flexible portion 6H is configured to generate an elastic restoring force, similar to the elastic portion 6G, but it may also be configured to generate almost no elastic restoring force.

[0030] Specifically, the rear leaf spring 6B has a rear support portion 6EB (left rear support portion 6EBL and right rear support portion 6EBR), a rear elastic portion 6GB (left rear elastic portion 6GBL and right rear elastic portion 6GBR), a rear flexible portion 6HB (left rear flexible portion 6HBL and right rear flexible portion 6HBR), a rear movable portion 6IB, and a rear terminal portion 6TB (left rear terminal portion 6TBL and right rear terminal portion 6TBR). Similarly, the front leaf spring 6F has a front support portion 6EF (left front support portion 6EFL and right front support portion 6EFR), a front elastic portion 6GF (left front elastic portion 6GFL and right front elastic portion 6GFR), a front flexible portion 6HF (left front flexible portion 6HFL and right front flexible portion 6HFR), a front movable portion 6IF, and a front terminal portion 6TF (left front terminal portion 6TFL and right front terminal portion 6TFR).

[0031] Furthermore, the rear leaf spring 6B is positioned such that its rear movable portion 6IB is fixed to the upper surface of the second base portion 2D2, and the front leaf spring 6F is positioned such that its front movable portion 6IF is fixed to the upper surface of the fourth base portion 2D4.

[0032] Furthermore, the rear leaf spring 6B and the front leaf spring 6F are configured to be 2 rotationally symmetric with respect to the optical axis OA, as shown in Figure 3. 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 four shape memory alloy wires SA (first wire SA1 to fourth wire SA4).

[0033] The spherical body SB is positioned so that its upper part is housed in a recess 2R formed on the lower surface of the base portion 2D of the lens holding member 2. In the illustrated example, the recess 2R is a V-shaped groove extending radially in a circle centered on the optical axis OA, as shown in the upper part of Figure 4, and includes a first recess 2R1, a second recess 2R2, and a third recess 2R3. That is, the spherical body SB is positioned so as to contact the recess 2R at two points. In the upper part of Figure 4, the dashed line AL1 represents the extension of the bottom of the first recess 2R1, the dashed line AL2 represents the extension of the bottom of the second recess 2R2, and the dashed line AL3 represents the extension of the bottom of the third recess 2R3.

[0034] Furthermore, the extended length LG1 of the first recess 2R1 is approximately the same as the diameter of the first sphere SB1, as shown in the lower diagram of Figure 4. That is, the first sphere SB1 does not move in the circumferential direction within the first recess 2R1. The same applies to the second recess 2R2 and the third recess 2R3.

[0035] Specifically, a first recess 2R1 for receiving the first sphere SB1 is formed on the lower surface of the first base portion 2D1, a second recess 2R2 for receiving the second sphere SB2 is formed on the lower surface of the second base portion 2D2, and a third recess 2R3 for receiving the third sphere SB3 is formed on the lower surface of the third base portion 2D3. The first to third recesses 2R1 to 2R3 are formed at positions where the distance between each of the first to third recesses 2R1 to 2R3 and the optical axis OA is the same.

[0036] Next, with reference to Figures 5 and 6, 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 movable metal member 5M, the leaf spring 6, and the sphere SB. 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. Figure 6 is a top view of the intermediate member 3. Specifically, the upper part of Figure 6 is a top view of the intermediate member 3 without the sphere SB in place, and the lower part of Figure 6 is a top view of the intermediate member 3 with the sphere SB in place.

[0037] In the example shown in the upper part of Figure 5, the first movable metal member 5M1 is fixed to the right end of the front surface of the base 3B of the intermediate member 3, the second movable metal member 5M2 is fixed to the front end of the left side of the base 3B of the intermediate member 3, the third movable metal member 5M3 is fixed to the left end of the rear surface of the base 3B of the intermediate member 3, and the fourth movable metal member 5M4 is fixed to the rear end of the right end surface of the base 3B of the intermediate member 3.

[0038] The front leaf spring 6F is positioned such that the right front terminal portion 6TFR is fixed to the upper surface of the first base portion 3D1, and the left front terminal portion 6TFL is fixed to the upper surface of the second base portion 3D2. The rear leaf spring 6B is positioned such that the left rear terminal portion 6TBL is fixed to the upper surface of the third base portion 3D3, and the right rear terminal portion 6TBR is fixed to the upper surface of the fourth base portion 3D4. Furthermore, the first joint portion 5M1P of the first movable metal member 5M1 is joined to the upper surface of the right front terminal portion 6TFR fixed to the upper surface of the first base portion 3D1; the second joint portion 5M2P of the second movable metal member 5M2 is joined to the upper surface of the left front terminal portion 6TFL fixed to the upper surface of the second base portion 3D2; the third joint portion 5M3P of the third movable metal member 5M3 is joined to the upper surface of the left rear terminal portion 6TBL fixed to the upper surface of the third base portion 3D3; and the fourth joint portion 5M4P of the fourth movable metal member 5M4 is joined to the upper surface of the right rear terminal portion 6TBR fixed to the upper surface of the fourth base portion 3D4. The joining of the first joint portion 5M1P and the right front terminal portion 6TFR is achieved by welding, conductive adhesive, or solder. The same applies to the connection between the second joint 5M2P and the left front terminal portion 6TFL, the connection between the third joint 5M3P and the left rear terminal portion 6TBL, and the connection between the fourth joint 5M4P and the right rear terminal portion 6TBR.

[0039] The sphere SB is positioned so that its lower part is housed in a recess 3R formed on the upper surface of the base 3B of the intermediate member 3. In the illustrated example, the recess 3R is a V-shaped groove extending in the circumferential direction of a circle centered on the optical axis OA, as shown in the upper part of Figure 6, and includes a first recess 3R1, a second recess 3R2, and a third recess 3R3. That is, the sphere SB is positioned so as to contact the recess 3R at two points. In the upper part of Figure 6, the dashed circle CL1 represents a circle (line) that coincides with the outer edge of the recess 3R, the dashed circle CL2 represents a circle (line) that coincides with the bottom of the recess 3R, and the dashed circle CL3 represents a circle (line) that coincides with the inner edge of the recess 3R.

[0040] Furthermore, the extending length LG2 of the first recess 3R1 is greater than the diameter of the first sphere SB1, as shown in the lower diagram of Figure 6. That is, the first sphere SB1 is movable in the circumferential direction within the first recess 3R1. The same applies to the second recess 3R2 and the third recess 3R3.

[0041] Specifically, a first recess 3R1 for receiving the first sphere SB1 is formed on the upper surface of the left front corner of the base 3B, a second recess 3R2 for receiving the second sphere SB2 is formed on the upper surface of the rear central part of the base 3B, and a third recess 3R3 for receiving the third sphere SB3 is formed on the upper surface of the right front corner of the base 3B. The first to third recesses 3R1 to 3R3 are formed at positions where the distance between each of the first to third recesses 3R1 to 3R3 and the optical axis OA is the same.

[0042] Next, with reference to Figure 7, the positional relationship between the member attached to the support member 8 and the support member 8 will be explained. Figure 7 is an overhead perspective view of the support-side metal member 5F, leaf spring 6, support member 8, and support-side embedded member 80. Specifically, the upper part of Figure 7 (the figure above the block arrow) is an exploded perspective view, and the lower part of Figure 7 (the figure below the block arrow) is an assembled perspective view.

[0043] In the example shown in the upper part of Figure 7, the first support-side metal member 5F1 is fixed to the front surface of the first base portion 8D1 of the support member 8, the second support-side metal member 5F2 is fixed to the left side of the second base portion 8D2 of the support member 8, the third support-side metal member 5F3 is fixed to the rear surface of the third base portion 8D3 of the support member 8, and the fourth support-side metal member 5F4 is fixed to the right side of the fourth base portion 8D4 of the support member 8. In the illustrated example, the support-side metal members 5F are fixed to the base portion 8D of the support member 8 by adhesive.

[0044] Furthermore, as shown in Figure 7, the first support-side embedded member 80A has a first joint portion 80AP and a first terminal portion 80AT, and the second support-side embedded member 80B has a second joint portion 80BP and a second terminal portion 80BT. The first joint portion 80AP and the second joint portion 80BP are exposed on the upper surface of the base portion 8D of the support member 8, as shown in Figure 2.

[0045] Specifically, the first support-side embedded member 80A has a first joint portion 80AP exposed on the upper surface of the first base portion 8D1 and a first terminal portion 80AT exposed on the left side of the first base portion 8D1, and the second support-side embedded member 80B has a second joint portion 80BP exposed on the upper surface of the third base portion 8D3 and a second terminal portion 80BT exposed on the right side of the third base portion 8D3.

[0046] The first joint 80AP and the left front support portion 6EFL of the front leaf spring 6F are joined by welding. The joining of the first joint 80AP and the left front support portion 6EFL may also be achieved by conductive adhesive or solder. The same applies to the joining of the second joint 80BP and the right rear support portion 6EBR.

[0047] Next, the metal member 5 to which the shape memory alloy wire SA is attached will be described with reference to Figures 8 and 9. Figure 8 is a top view of the lens drive device 101 with the cover member 1 removed. Note that in Figure 8, for clarity, a cross pattern is applied to the lens holding member 2, a fine dot pattern to the intermediate member 3, and a coarse dot pattern to the support member 8. Figure 9 is a diagram showing an example of the configuration of the metal member 5 (support-side metal member 5F and movable-side metal member 5M) and the shape memory alloy wire SA. Specifically, the upper left of Figure 9 is a top view of the metal member 5 (support-side metal member 5F and movable-side metal member 5M) and the shape memory alloy wire SA, the lower left of Figure 9 is a front view of the metal member 5 (support-side metal member 5F and movable-side metal member 5M) and the shape memory alloy wire SA, and the right of Figure 9 is a right side view of the metal member 5 (support-side metal member 5F and movable-side metal member 5M) and the shape memory alloy wire SA. Note that the positional relationship of each component shown in Figure 9 corresponds to the positional relationship when the lens drive device 101 is in the neutral position.

[0048] Specifically, one end of the first wire SA1 is fixed to the first support-side metal member 5F1 at the first holding portion J1 of the first support-side metal member 5F1, and the other end of the first wire SA1 is fixed to the first movable-side metal member 5M1 at the second holding portion J2 of the first movable-side metal member 5M1. Also, one end of the second wire SA2 is fixed to the second support-side metal member 5F2 at the third holding portion J3 of the second support-side metal member 5F2, and the other end of the second wire SA2 is fixed to the second movable-side metal member 5M2 at the fourth holding portion J4 of the second movable-side metal member 5M2. Furthermore, one end of the third wire SA3 is fixed to the third support-side metal member 5F3 at the fifth holding portion J5 of the third support-side metal member 5F3, and the other end of the third wire SA3 is fixed to the third movable-side metal member 5M3 at the sixth holding portion J6 of the third movable-side metal member 5M3. Furthermore, one end of the fourth wire SA4 is fixed to the fourth support-side metal member 5F4 at the seventh holding portion J7 of the fourth support-side metal member 5F4, and the other end of the fourth wire SA4 is fixed to the fourth movable-side metal member 5M4 at the eighth holding portion J8 of the fourth movable-side metal member 5M4.

[0049] In the illustrated example, the first retaining portion J1 is formed by bending a part of the first support-side metal member 5F1. Specifically, the first retaining portion J1 is formed by bending a part of the first support-side metal member 5F1 while sandwiching one end of the first wire SA1. The one end of the first wire SA1 is then fixed to the first retaining portion J1 by welding. The same applies to the second retaining portions J2 to the eighth retaining portions J8.

[0050] Furthermore, as shown in the right diagram of Figure 9, the second wire SA2 is positioned so as to be angled downwards to the right when viewed from the right side, and the fourth wire SA4 is positioned so as to be angled upwards to the right when viewed from the right side. The second wire SA2 and the fourth wire SA4 are positioned to intersect when viewed from the right side. Similarly, as shown in the lower left diagram of Figure 9, the first wire SA1 is positioned so as to be angled downwards to the right when viewed from the front, and the third wire SA3 is positioned so as to be angled upwards to the right when viewed from the front. The first wire SA1 and the third wire SA3 are positioned to intersect when viewed from the front.

[0051] The support member 8 is configured to support one end of each of the first wires SA1 to the fourth wire SA4, and the intermediate member 3 is configured to support the other end of each of the first wires SA1 to the fourth wire SA4. With this configuration, the intermediate member 3 is connected to the support member 8 via the first wires SA1 to the fourth wire SA4 in a manner that allows it to move in the direction of the optical axis (Z-axis direction), which is parallel to the optical axis OA.

[0052] In the illustrated example, each of the support-side metal member 5F and the movable-side metal member 5M is made 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 movable-side metal member 5M1 has a base BPM1, the second movable-side metal member 5M2 has a base BPM2, the third movable-side metal member 5M3 has a base BPM3, and the fourth movable-side metal member 5M4 has a base BPM4.

[0053] As shown in the upper left of Figure 9, the eight metal members 5 (first support-side metal members 5F1 to the fourth support-side metal members 5F4, and first movable-side metal members 5M1 to the fourth movable-side metal members 5M4) are attached to the intermediate member 3 or support member 8 such that the plate surface of each base BP is perpendicular to the XY plane, that is, approximately parallel to the optical axis direction.

[0054] Furthermore, as shown in the upper left of Figure 9, with respect to the first wire SA1, the first retaining part J1 is positioned to the left of the second retaining part J2 by ​​a distance DS1 in the Y-axis direction; with respect to the second wire SA2, the third retaining part J3 is positioned to the rear of the fourth retaining part J4 by a distance DS2 in the X-axis direction; with respect to the third wire SA3, the fifth retaining part J5 is positioned to the right of the sixth retaining part J6 by a distance DS3 in the Y-axis direction; and with respect to the fourth wire SA4, the seventh retaining part J7 is positioned to the front of the eighth retaining part J8 by a distance DS4 in the X-axis direction. In the illustrated example, distances DS1 to DS4 are all the same size. Also, distances DS1 and DS3 are greater than the distance DS5 between the second retaining part J2 and the sixth retaining part J6 in the Y-axis direction (see the lower left of Figure 9), and distances DS2 and DS4 are greater than the distance DS6 between the fourth retaining part J4 and the eighth retaining part J8 in the X-axis direction (see the right of Figure 9). Furthermore, distances DS5 and DS6 are the same size.

[0055] Furthermore, as shown in the lower left and right figures of Figure 9, with respect to the first wire SA1, the first retaining part J1 is positioned at a height HT1 higher than the second retaining part J2 in the Z-axis direction; with respect to the second wire SA2, the third retaining part J3 is positioned at a height HT2 lower than the fourth retaining part J4 in the Z-axis direction; with respect to the third wire SA3, the fifth retaining part J5 is positioned at a height HT3 higher than the sixth retaining part J6 in the Z-axis direction; and with respect to the fourth wire SA4, the seventh retaining part J7 is positioned at a height HT4 lower than the eighth retaining part J8 in the Z-axis direction. In the illustrated example, heights HT1 to HT4 are all the same size.

[0056] Next, referring to Figures 10 and 11, the positional relationships of the members through which current flows—metal member 5 (support-side metal member 5F and movable-side metal member 5M), leaf spring 6, support-side embedded member 80, and shape memory alloy wire SA—will be explained. Figure 10 is a perspective view of the metal member 5 (support-side metal member 5F and movable-side metal member 5M), leaf spring 6, support-side embedded member 80, and shape memory alloy wire SA. Figure 11 is an excerpt of a part of Figure 10, where the lower left of Figure 11 shows the members related to the current-carrying path including the first wire SA1, the upper left of Figure 11 shows the members related to the current-carrying path including the second wire SA2, the upper right of Figure 11 shows the members related to the current-carrying path including the third wire SA3, and the lower right of Figure 11 shows the members related to the current-carrying path including the fourth wire SA4.

[0057] As shown in Figure 11, the first support-side metal member 5F1 to the fourth support-side metal member 5F4 each have a first terminal portion 5F1T to the fourth terminal portion 5F4T, and the first movable-side metal member 5M1 to the fourth movable-side metal member 5M4 each have a first joint portion 5M1P to the fourth joint portion 5M4P.

[0058] Then, as shown in the lower left of Figure 11, when the first terminal portion 5F1T of the first support-side metal member 5F1 is connected to a high potential and the first terminal portion 80AT of the first support-side embedded member 80A is connected to a low potential, current flows from the first terminal portion 5F1T of the first support-side metal member 5F1 through the first holding portion J1 of the first support-side metal member 5F1, the first wire SA1, the first movable-side metal member 5M1 (second holding portion J2 and first joint portion 5M1P), the front leaf spring 6F (right front terminal portion 6TFR, right front flexible portion 6HFR, right front support portion 6EFR, right front elastic portion 6GFR, front movable portion 6IF, left front elastic portion 6GFL, and left front support portion 6EFL), and the first joint portion 80AP of the first support-side embedded member 80A, to the first terminal portion 80AT of the first support-side embedded member 80A.

[0059] Furthermore, as shown in the upper left diagram of Figure 11, when the second terminal portion 5F2T of the second support-side metal member 5F2 is connected to a high potential and the first terminal portion 80AT of the first support-side embedded member 80A is connected to a low potential, current flows from the second terminal portion 5F2T of the second support-side metal member 5F2 through the third holding portion J3 of the second support-side metal member 5F2, the second wire SA2, the second movable-side metal member 5M2 (fourth holding portion J4 and second joint portion 5M2P), the front leaf spring 6F (left front terminal portion 6TFL, left front flexible portion 6HFL, and left front support portion 6EFL), and the first joint portion 80AP of the first support-side embedded member 80A, to the first terminal portion 80AT of the first support-side embedded member 80A.

[0060] Furthermore, as shown in the upper right diagram of Figure 11, when the third terminal portion 5F3T of the third support-side metal member 5F3 is connected to a high potential and the second terminal portion 80BT of the second support-side embedded member 80B is connected to a low potential, current flows from the third terminal portion 5F3T of the third support-side metal member 5F3 through the fifth holding portion J5 of the third support-side metal member 5F3, the third wire SA3, the third movable-side metal member 5M3 (sixth holding portion J6 and third joint portion 5M3P), the rear leaf spring 6B (left rear terminal portion 6TBL, left rear flexible portion 6HBL, left rear support portion 6EBL, left rear elastic portion 6GBL, rear movable portion 6IB, right rear elastic portion 6GBR, and right rear support portion 6EBR), and the second joint portion 80BP of the second support-side embedded member 80B, to the second terminal portion 80BT of the second support-side embedded member 80B.

[0061] Furthermore, as shown in the lower right diagram of Figure 11, when the fourth terminal portion 5F4T of the fourth support-side metal member 5F4 is connected to a high potential and the second terminal portion 80BT of the second support-side embedded member 80B is connected to a low potential, current flows from the fourth terminal portion 5F4T of the fourth support-side metal member 5F4 through the seventh holding portion J7, the fourth wire SA4, the fourth movable-side metal member 5M4 (eighth holding portion J8 and fourth joint portion 5M4P) of the fourth support-side metal member 5F4, the rear leaf spring 6B (right rear terminal portion 6TBR, right rear flexible portion 6HBR, and right rear support portion 6EBR), and the second joint portion 80BP of the second support-side embedded member 80B, to the second terminal portion 80BT of the second support-side embedded member 80B.

[0062] 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 fourth wire SA4) by controlling the voltage applied to the terminals (first terminal 5F1T to fourth terminal 5F4T, first terminal 80AT, and second terminal 80BT) of the first support side metal member 5F1 to fourth support side metal member 5F4, the first support side embedded member 80A, and the second support side embedded member 80B. 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.

[0063] 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.

[0064] Next, the movement of the movable member MB relative to the fixed member FB will be explained with reference to Figures 12 to 14. Figures 12 to 14 are schematic diagrams of the lens holding member 2, the intermediate member 3, and the support member 8. Specifically, the upper diagrams in Figures 12 to 14 are top views of the lens holding member 2, the intermediate member 3, and the support member 8, and the lower diagrams in Figures 12 to 14 are front views of the lens holding member 2, the intermediate member 3, and the support member 8. For clarity, in Figures 12 to 14, 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.

[0065] More specifically, Figure 12 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 13 shows the positional relationship of the lens holding member 2, intermediate member 3, and support member 8 when the intermediate member 3 is rotated around the optical axis OA by the first wire SA1 and the third wire SA3 and the intermediate member 3 (lens holding member 2) is moved toward the Z1 side relative to the support member 8; and Figure 14 shows the positional relationship of the lens holding member 2, intermediate member 3, and support member 8 when the intermediate member 3 is rotated around the optical axis OA by the second wire SA2 and the fourth wire SA4 and the intermediate member 3 (lens holding member 2) is moved toward the Z2 side relative to the support member 8.

[0066] As shown in Figure 12, in the neutral position, the lens holding member 2 and the intermediate member 3 are positioned such that a gap GP1 is formed between the fourth base portion 2D4 of the lens holding member 2 and the intermediate member 3 in the Y-axis direction, i.e., they are not in contact with each other. Furthermore, the intermediate member 3 and the support member 8 are positioned such that a gap GP2 is formed between the intermediate member 3 and the first base portion 8D1 of the support member 8 in the Y-axis direction, i.e., they are not in contact with each other. This is to allow the intermediate member 3 to rotate by a predetermined angle around the optical axis OA.

[0067] As shown in the upper part of Figure 13, when the first wire SA1 and the third wire SA3 contract by a predetermined amount, the intermediate member 3 rotates clockwise by an angle α in a top view around the optical axis OA, as indicated by arrow AR1, and moves a distance ST1 toward Z1 along the optical axis, as indicated by the Z-axis component of arrow AR1 in the lower part of Figure 13. Note that arrow AR1 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. Furthermore, the inclination of arrow AR1 with respect to the XY plane is approximately the same as the inclination of a virtual straight line passing through one end and the other end of the first wire SA1 and the third wire SA3 with respect to the XY plane.

[0068] Furthermore, in the upper and lower diagrams of Figure 13, a portion of the position (outer shape) of the lens holding member 2 and intermediate member 3 in the state shown in Figure 12 is represented by a dashed line, and in the upper diagram of Figure 13, the first wire SA1 and the third wire SA3 are represented by a thick dotted line.

[0069] At this time, the control device supplies a predetermined current not only to the first wire SA1 and the third wire SA3, but also to the second wire SA2 and the fourth wire SA4, so that the intermediate member 3 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, thereby causing the second wire SA2 and the fourth wire SA4 to contract.

[0070] Furthermore, when the intermediate member 3 rotates clockwise by an angle α around the optical axis OA in a top view, 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 the three spheres SB (first sphere SB1 to third sphere SB3), moves together with the intermediate member 3 by a distance ST2 toward the Z1 side along the optical axis, without rotating around the optical axis OA, as shown by the arrow AR2 in the lower diagram of Figure 13. Note that the magnitude of distance ST2 is the same as the magnitude of distance ST1.

[0071] Furthermore, as shown in the upper part of Figure 14, when the second wire SA2 and the fourth wire SA4 contract by a predetermined amount, the intermediate member 3 rotates clockwise by an angle β in a top view around the optical axis OA, as indicated by arrow AR3, and moves a distance ST3 toward the Z2 side along the optical axis, as indicated by the Z-axis component of arrow AR3 in the lower part of Figure 14. Note that arrow AR3 in the lower part of Figure 14 is shown decomposed into a Z-axis component and a circumferential component of a circle centered on the optical axis OA. Also, the inclination of arrow AR3 with respect to the XY plane is approximately the same as the inclination of a virtual straight line passing through one end and the other end of the second wire SA2 and the fourth wire SA4 with respect to the XY plane.

[0072] Furthermore, in the upper and lower diagrams of Figure 14, the positions (outer shapes) of the lens holding member 2 and intermediate member 3 in the state shown in Figure 12 are represented by dashed lines, and in the upper diagram of Figure 14, the second wire SA2 and the fourth wire SA4 are represented by thick dotted lines. Also, in the illustrated example, angle β has the same magnitude as angle α.

[0073] At this time, the control device supplies a predetermined current not only to the second wire SA2 and the fourth wire SA4, but also to the first wire SA1 and the third wire SA3, so that the intermediate member 3 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, thereby causing the first wire SA1 and the third wire SA3 to contract.

[0074] Furthermore, when the intermediate member 3 rotates clockwise by an angle β in a top view around the optical axis OA and moves a distance ST3 toward the Z2 side along the optical axis, the lens holding member 2, which is connected to the intermediate member 3 via the three spheres SB (first sphere SB1 to third sphere SB3), moves together with the intermediate member 3 by a distance ST4 toward the Z2 side along the optical axis without rotating around the optical axis OA, as shown by arrow AR4 in the lower diagram of Figure 14. Note that the magnitude of distance ST4 is the same as the magnitude of distance ST3.

[0075] Furthermore, in the examples shown in Figures 12 to 14, the control device is configured to translate the lens holding member 2 along the Z-axis direction without rotating it around the optical axis OA by mainly contracting two shape memory alloy wires SA (first wire SA1 and third wire SA3, or second wire SA2 and fourth wire SA4). However, the control device may be configured to translate the lens holding member 2 along the Z-axis direction without rotating it around the optical axis OA by mainly contracting one shape memory alloy wire SA (first wire SA1 or second wire SA2). In this case, the control device is configured to supply a predetermined current not only to the first wire SA1 or second wire SA2 but also to the other shape memory alloy wires SA, so that the intermediate member 3 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, thereby causing the other shape memory alloy wires SA to contract.

[0076] Next, with reference to Figure 15, the sphere SB that connects the lens holding member 2 and the intermediate member 3 so as to be rotatable relative to each other will be described. Figure 15 is a cross-sectional view of the lens driving device 101. Specifically, the upper part of Figure 15 is a view from the Y2 side of the cross-section of the lens driving device 101 in a virtual plane perpendicular to the XY plane containing the cutting line L1 shown in Figure 1. The lower part of Figure 15 is a view from the X1 side of the cross-section of the lens driving device 101 in a virtual plane perpendicular to the XY plane containing the cutting line L2 shown in Figure 1. The following explanation with reference to Figure 15 pertains to the second sphere SB2, but the same applies to the first sphere SB1 and the third sphere SB3.

[0077] Specifically, the second sphere SB2, which is one of the three spheres SB, has its upper part housed in a second recess 2R2 formed on the lower surface of the second base portion 2D2 of the lens holding member 2, and its lower part housed in a second recess 3R2 formed on the upper surface of the rear portion of the base 3B of the intermediate member 3.

[0078] As shown in the lower part of Figure 15, the second recess 2R2 is a V-shaped groove extending in the X-axis direction, and the second sphere SB2 is positioned to contact the second recess 2R2 at two points. Also, as shown in the upper part of Figure 15, the second recess 3R2 is a V-shaped groove extending in the circumferential direction of a circle centered on the optical axis OA in a top view along the optical axis, and the second sphere SB2 is positioned to contact the second recess 3R2 at two points.

[0079] The second magnet MG2, one of the three magnets MG, is housed in the second housing recess 2U2 formed on the upper surface of the second base portion 2D2 of the lens holding member 2, so as shown in the upper part of Figure 15, it is positioned above the second sphere SB2 in the Z-axis direction with a gap GP3 between them. In the illustrated example, the second magnet MG2 is fixed to the lens holding member 2 with adhesive.

[0080] Furthermore, in the illustrated example, as shown in the lower diagram of Figure 4, the extended length LG1 of the first recess 2R1 in the circumferential direction is approximately the same as the diameter of the first sphere SB1. Therefore, even when the intermediate member 3 rotates around the optical axis OA, the first sphere SB1 hardly moves in the circumferential direction within the first recess 2R1. That is, the relative positional relationship between the first sphere SB1 and the first magnet MG1 hardly changes. On the other hand, as shown in the lower diagram of Figure 6, the extended length LG2 of the first recess 3R1 in the circumferential direction is larger than the diameter of the first sphere SB1. Therefore, when the intermediate member 3 rotates around the optical axis OA, the first sphere SB1 moves relative to the first recess 3R1 in the circumferential direction. The same applies to the second recess 3R2 and the third recess 3R3. Also, in the illustrated example, the sphere SB is configured to roll between the recess 2R and the recess 3R. However, the sphere SB may be configured to slide relative to at least one of the recess 2R and the recess 3R.

[0081] In this configuration, as shown in Figure 13, when the intermediate member 3 rotates clockwise around the optical axis OA in a top view and translates upward along the optical axis OA, the sphere SB appears to move circumferentially counterclockwise around the optical axis OA within the recess 3R. This relative circumferential movement of the sphere SB cancels out the effect of the rotation of the intermediate member 3 around the optical axis OA on the lens holding member 2, and the lens holding member 2 moves upward by the same distance ST2 as the distance ST1 that the intermediate member 3 moved upward, without rotating around the optical axis OA. Similarly, as shown in Figure 14, when the intermediate member 3 rotates clockwise around the optical axis OA in a top view and translates downward along the optical axis OA, the sphere SB appears to move circumferentially counterclockwise around the optical axis OA within the recess 3R. Due to the relative movement of the sphere SB in the circumferential direction, the effect of the rotation of the intermediate member 3 around the optical axis OA on the lens holding member 2 is canceled out, and the lens holding member 2 moves downward by the same distance ST4 as the distance ST3 that the intermediate member 3 moved downward, without rotating around the optical axis OA.

[0082] Thus, the rotation of the lens holding member 2 around the optical axis OA is suppressed by the leaf spring 6 acting as a rotation suppression member RS. Furthermore, the sphere SB promotes the relative rotation of the intermediate member 3 with respect to the lens holding member 2, that is, reduces the frictional resistance between the lens holding member 2 and the intermediate member 3, thereby suppressing the rotation of the lens holding member 2 that would otherwise be induced by the rotation of the intermediate member 3 around the optical axis OA. Therefore, the lens driving device 101 can suppress the rotation of the lens body LS around the optical axis OA when moving the lens body LS along the optical axis OA.

[0083] As described above, the lens drive device 101, which is 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, a lens holding member 2 as an optical element holding member having an opening 2K on which a lens body LS, which is an example of an optical element OE, can be arranged, and which is movable in a predetermined direction (Z-axis direction) along a predetermined axis (optical axis OA) relative to the support member 8, a drive unit DM having a shape memory alloy wire SA for moving the lens holding member 2 in the Z-axis direction, an intermediate member 3 provided between the lens holding member 2 and the support member 8, and a rotation suppression member RS ​​that suppresses the rotation of the lens holding member 2 around the optical axis OA relative to the support member 8. The rotation suppression member RS ​​is, for example, a leaf spring, a gel-like member, a magnet, or a shaft. The intermediate member 3 is movable relative to the support member 8, and the lens holding member 2 and the intermediate member 3 are rotatable relative to each other around the optical axis OA and are movable together (integrally) in the direction along the optical axis OA. The shape memory alloy wire SA is provided between the support member 8 and the intermediate member 3, and includes a first wire SA1, as shown in Figure 10, in which one end supported by the support member 8 (first support-side metal member 5F1) is positioned higher than the other end supported by the intermediate member 3 (first movable-side metal member 5M1), and a second wire SA2, provided between the support member 8 and the intermediate member 3, in which one end supported by the support member 8 (second support-side metal member 5F2) is positioned lower than the other end supported by the intermediate member 3 (second movable-side metal member 5M2). The rotation suppression member RS ​​is configured to suppress the rotation of the lens holding member 2 around the optical axis OA when a force acting on the intermediate member 3 attempts to rotate the intermediate member 3 around the optical axis OA due to the contraction of the shape memory alloy wire SA caused by energizing the shape memory alloy wire SA, as the intermediate member 3 rotates.

[0084] This configuration provides an effect in an optical element driving device configured to move the optical element OE along a predetermined axis (optical axis OA) while rotating a part of the movable side member MB (intermediate member 3) that holds the optical element OE around a predetermined axis. This configuration suppresses the rotation of the optical element OE around the predetermined axis when moving the optical element OE along the predetermined axis. Therefore, in a lens driving device 101, which is an example of an optical element driving device, this configuration provides an effect that minimizes the impact on image quality even as the pixel count of the image sensor IS increases.

[0085] Furthermore, the rotation suppression member RS ​​is preferably composed of a leaf spring 6 having a support portion 6E fixed to the support member 8, a movable portion 6I fixed to the lens holding member 2, and an elastically deformable elastic portion 6G provided between the support portion 6E and the movable portion 6I, as shown in Figure 3.

[0086] This configuration offers the advantage of realizing a rotation suppression member RS ​​with a simple configuration, such as one that utilizes a leaf spring 6 formed from a metal plate.

[0087] Furthermore, preferably, as shown in Figure 2, at least three spheres SB are provided between the intermediate member 3 and the lens holding member 2, spaced apart from each other in the circumferential direction of a circle centered on the optical axis OA when viewed from above along the optical axis.

[0088] This configuration reduces frictional resistance between the lens holding member 2 and the intermediate member 3, and more specifically, reduces frictional resistance between each of the lens holding member 2 and the intermediate member 3 and the sphere SB, thereby facilitating the relative rotation between the lens holding member 2 and the intermediate member 3.

[0089] Furthermore, the shape memory alloy wire SA preferably includes, as shown in Figure 2, a third wire SA3 provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 (third support-side metal member 5F3) positioned higher than the other end supported by the intermediate member 3 (third movable-side metal member 5M3), and a fourth wire SA4 provided between the support member 8 and the intermediate member 3, with one end supported by the support member 8 (fourth support-side metal member 5F4) positioned lower than the other end supported by the intermediate member 3 (fourth movable-side metal member 5M4). The first wire SA1 and the third wire SA3 are provided at two opposing positions on either side of the aperture 2K in a first direction (X-axis direction) intersecting the optical axis OA, and the second wire SA2 and the fourth wire SA4 are provided at two opposing positions on either side of the aperture 2K in a second direction (Y-axis direction) that intersects the optical axis OA and is perpendicular to the first direction (X-axis direction). Furthermore, the rotation-restricting member RS ​​is positioned at two locations on either side of the opening 2K. In the illustrated example, the rotation-restricting member RS ​​is part of the leaf spring 6 and includes, as shown in Figure 3, a rear rotation-restricting member RSB (part of the rear leaf spring 6B) positioned on the X2 side (rear side) of the opening 2K, and a front rotation-restricting member RSF (part of the front leaf spring 6F) positioned on the X1 side (front side) of the opening 2K. In Figure 3, for the sake of clarity, the portion of the rear leaf spring 6B corresponding to the rear rotation-restricting member RSB and the portion of the front leaf spring 6F corresponding to the front rotation-restricting member RSF are enclosed by dashed lines. Specifically, the rear rotation suppression member RSB is composed of a rear support portion 6EB (left rear support portion 6EBL and right rear support portion 6EBR), a rear elastic portion 6GB (left rear elastic portion 6GBL and right rear elastic portion 6GBR), and a rear movable portion 6IB, while the front rotation suppression member RSF is composed of a front support portion 6EF (left front support portion 6EFL and right front support portion 6EFR), a front elastic portion 6GF (left front elastic portion 6GFL and right front elastic portion 6GFR), and a front movable portion 6IF. However, the rotation suppression member RS ​​may be a gel-like material, a magnet, or a shaft, or other component separate from the leaf spring 6.

[0090] In this configuration, the shape memory alloy wire SA and the rotation suppression member RS ​​are positioned in pairs across the optical axis OA. Compared to a configuration where the shape memory alloy wire SA and the rotation suppression member RS ​​are positioned not in pairs across the optical axis OA, this configuration provides the advantage of achieving stable operation of the movable side member MB.

[0091] Furthermore, the lens drive device 101 preferably includes a support leaf spring SL, provided between the support member 8 and the lens holding member 2, as shown in Figure 3, which movably supports the lens holding member 2 relative to the support member 8 along the optical axis OA. In the illustrated example, the support leaf spring SL is part of the leaf spring 6 and includes a rear support leaf spring SLB, which is part of the rear leaf spring 6B, and a front support leaf spring SLF, which is part of the front leaf spring 6F. In Figure 3, for the sake of clarity, the portion of the rear leaf spring 6B corresponding to the rear support leaf spring SLB and the portion of the front leaf spring 6F corresponding to the front support leaf spring SLF are enclosed by dashed lines. Specifically, the rear support leaf spring SLB consists of a rear support portion 6EB (left rear support portion 6EBL and right rear support portion 6EBR), a rear elastic portion 6GB (left rear elastic portion 6GBL and right rear elastic portion 6GBR), and a rear movable portion 6IB. The front support leaf spring SLF consists of a front support portion 6EF (left front support portion 6EFL and right front support portion 6EFR), a front elastic portion 6GF (left front elastic portion 6GFL and right front elastic portion 6GFR), and a front movable portion 6IF. However, the support leaf spring SL may be a separate and independent component from the leaf spring 6.

[0092] This configuration has the effect of suppressing the tilting of the lens holding member 2 relative to the optical axis OA, compared to a configuration without a supporting leaf spring SL. Furthermore, this configuration has the effect of suppressing changes in the position of the optical axis OA when viewed from above along the optical axis OA.

[0093] Furthermore, the rotation suppression member RS ​​is preferably composed of a support leaf spring SL, as shown in Figure 3. That is, the rotation suppression member RS ​​and the support leaf spring SL may be the same single component. In the illustrated example, both the rotation suppression member RS ​​and the support leaf spring SL are parts of the leaf spring 6 (the same single component). Specifically, the rear rotation suppression member RSB also functions as a rear support leaf spring SLB, and the front rotation suppression member RSF also functions as a front support leaf spring SLF. However, the rotation suppression member RS ​​and the support leaf spring SL may be separate and independent components.

[0094] This configuration allows the functions of both the rotation-suppressing member RS ​​and the supporting leaf spring SL to be realized by the same single component, resulting in a simpler configuration of the lens drive device 101 compared to a configuration where the rotation-suppressing member RS ​​and the supporting leaf spring SL are separate and independent components.

[0095] Furthermore, the sphere SB is preferably made of a magnetic material. A magnet MG corresponding to the sphere SB is attached to at least one of the lens holding member 2 and the intermediate member 3. In the illustrated example, the magnet MG corresponding to the sphere SB is attached to the lens holding member 2 as shown in Figure 3. The sphere SB may also be made of a magnet. In this case, the magnet MG may be replaced with a magnetic material other than a permanent magnet.

[0096] This configuration has the effect of preventing the spherical body SB from separating from the lens holding member 2 or the intermediate member 3, compared to a configuration in which the magnet MG is not attached.

[0097] 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.

[0098] For example, in the above embodiment, the metal member 5 is fixed to each member (the intermediate member 3 and the support member 8) by adhesive or the like, but it may also be embedded in each member, or a conductive pattern may be formed on the surface of each member. [Explanation of Symbols]

[0099] 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 2R...Recess 2R1...First recess 2R2...Second recess 2R3...Third recess 2U...Accommodation recess 2U1...First accommodation recess 2U2...Second accommodation recess 2U3...Third housing recess 3...Intermediate member 3B...Base 3D...Base section 3D1...First base section 3D2...Second base section 3D3...Third base section 3D4...Fourth base section 3K...Opening 3R...Recess 3R1...First recess 3R2...Second recess 3R3...Third recess 5...Metal member 5F...Support side metal member 5F1...First support side metal member 5F1T...First terminal section 5F2...Second support side metal member 5F2T...Second terminal section 5F3...Third support side metal member 5F3T...Third terminal section 5F4...Fourth support side metal member 5F4T...Fourth terminal section 5M...Movable metal member 5M1...First movable metal member 5M1P...First joint 5M2...Second movable metal member 5M2P...Second joint 5M3...Third movable metal member 5M3P...Third joint 5M4...Fourth movable metal member 5M4P...Fourth joint 6...Leaf spring 6B...Rear leaf spring 6E...Support part 6EBL...Left rear support part 6EBR...Right rear support part 6EFL...Left front support part 6EFR...Right front support part 6F...Front leaf spring 6G...Elastic part 6GBL...Left rear elastic part 6GBR...Right rear elastic part 6GFL...Left front elastic part 6GFR...Right front elastic part 6H...Flexible part 6HBL...Left rear flexible part 6HBR...Right rear flexible part 6HFL...Left front flexible part 6HFR...Right front flexible part 6I...Movable part 6IB...Rear movable part 6IF...Front movable part 6T...Terminal part 6TBL...Left rear terminal part 6TBR...Right rear terminal part 6TFL...Left front terminal part6TFR...Right front terminal section 8...Support member 8B...Base 8D...Pedestal section 8D1...First pedestal section 8D2...Second pedestal section 8D3...Third pedestal section 8D4...Fourth pedestal section 8K...Opening 80...Support side embedded member 80A...First support side embedded member 80AP...First joint section 80AT...First terminal section 80B...Second support side embedded member 80BP...Second joint section 80BT...Second terminal section 101...Lens drive device BP...Base CM...Camera module DM...Drive unit DM1...First drive unit DM2...Second drive unit FB...Fixed side member HS...Housing IS...Image sensor J1...First retaining part J2...Second retaining part J3...Third retaining part J4...Fourth retaining part J5...Fifth retaining part J6...Sixth retaining part J7...Seventh retaining part J8...Eighth retaining part LS...Lens body MB...Movable side member MG...Magnet MG1...First magnet MG2...Second magnet MG3...Third magnet OA...Optical axis OE...Optical element RS...Rotation suppression member RSB...Rear rotation suppression member RSF...Front rotation suppression member SA...Shape memory alloy wire SA1...First wire SA2...Second wire SA3...Third wire SA4...Fourth wire SB...Sphere SB1...First sphere SB2...Second sphere SB3...Third sphere SL... Support leaf spring SLB... Rear support leaf spring SLF... Front support leaf spring SU... 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 intermediate member provided between the optical element holding member and the support member, An optical element driving device comprising: a rotation suppression member that suppresses the rotation of the optical element holding member around a predetermined axis relative to the support member, The intermediate member is movable relative to the support member, The optical element holding member and the intermediate member are rotatable relative to each other around the predetermined axis and are movable together in the direction along the predetermined axis. The shape memory alloy wire includes a first wire provided between the support member and the intermediate member, with one end supported by the support member positioned higher than the other end supported by the intermediate member, and a second wire provided between the support member and the intermediate member, with one end supported by the support member positioned lower than the other end supported by the intermediate member. The rotation suppressing member is configured to suppress the rotation of the optical element holding member around the predetermined axis when a force acting on the intermediate member attempts to rotate the intermediate member around the predetermined axis due to the contraction of the shape memory alloy wire caused by energizing the shape memory alloy wire, thereby preventing the optical element holding member from rotating around the predetermined axis in conjunction with the rotation of the intermediate member. An optical element driving device characterized by the following:

2. The rotation suppressing member is composed of a leaf spring having a support portion fixed to the support member, a movable portion fixed to the optical element holding member, and an elastically deformable elastic portion provided between the support portion and the movable portion. The optical element driving device according to claim 1.

3. Between the intermediate member and the optical element holding member, at least three spheres are provided spaced apart from each other in the circumferential direction. The optical element driving device according to claim 1 or claim 2.

4. The shape memory alloy wire includes a third wire provided between the support member and the intermediate member, with one end supported by the support member positioned higher than the other end supported by the intermediate member, and a fourth wire provided between the support member and the intermediate member, with one end supported by the support member positioned lower than the other end supported by the intermediate member. The first wire and the third wire are provided at two opposing positions on either side of the opening in a first direction intersecting the predetermined axis. The second wire and the fourth wire are provided at two opposing positions across the opening in a second direction that intersects the predetermined axis and is perpendicular to the first direction. The rotation suppressing members are arranged at each of the two positions on either side of the opening. The optical element driving device according to claim 1 or claim 2.

5. A support leaf spring is provided between the support member and the optical element holding member, and supports the optical element holding member so that it can move relative to the support member along the predetermined axis. The optical element driving device according to claim 1.

6. The rotation suppression member is composed of the support leaf spring. The optical element driving device according to claim 5.

7. The aforementioned sphere is made of a magnetic material, A magnet corresponding to the sphere is attached to at least one of the optical element holding member and the intermediate member. The optical element driving device according to claim 3.

8. An optical element driving device according to any one of claims 1, 2, 5, or 6, 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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