Module drive device

Abstract

To provide a module drive device capable of more efficiently realizing heat radiation from an image pick-up device.SOLUTION: A module drive device MD comprises: a module holder 2 that can hold an optical module OM; a base member 18 that is provided in a manner of being unable to move relative to a heat dissipation member HR that dissipates heat generated by an image pick-up device IS; a drive unit DM that moves the module holder 2 relative to the base member 18 by using eight shape memory alloy wires SA disposed between the module holder 2 and the base member 18; and biasing means EG that biases the module holder 2 toward the side of the heat dissipation member HR which faces the lower surface of a board member SB. The biasing means EG biases the module holder 2 such that an inner portion SB2 of the board member SB and the heat dissipation member HR that are spaced apart from each other when the shape memory alloy wires SA are energized are brought closer to or into contact with each other when the shape memory alloy wires SA are not energized.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a module driving device.

Background Art

[0002] Conventionally, an imaging unit including a movable heat sink for discharging heat generated by an imaging device to the outside 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] The above-described imaging unit is configured to be able to thermally connect the movable heat sink and the imaging device by moving the movable heat sink as needed.

[0005] However, the above-described imaging unit is equipped with an electromagnetic drive mechanism for moving the movable heat sink. Therefore, when moving the movable heat sink, it is necessary to supply power to the electromagnetic drive mechanism, and there is a risk of consuming a large amount of power for the heat dissipation of the imaging device.

[0006] Therefore, it is desirable to provide a module driving device that can achieve more efficient heat dissipation of the imaging device.

Means for Solving the Problems

[0007] A module driving device according to an embodiment of the present disclosure includes a movable side member including a module holder capable of holding an optical module having a lens body, a substrate member, and an imaging element mounted on an upper surface of the substrate member so as to face the lens body in an optical axis direction, a fixed side member provided immovably relative to a heat radiating member that radiates heat generated by the imaging element, and a driving unit that moves the movable side member relative to the fixed side member by using a plurality of shape memory alloy wires provided between the fixed side member and the movable side member. The module driving device further includes biasing means for biasing the module holder toward a side of the heat radiating member facing a lower surface of the substrate member, and the biasing means biases the module holder such that the substrate member and the heat radiating member, which are separated from each other when the shape memory alloy wires are energized, approach or contact each other when the shape memory alloy wires are not energized.

Advantages of the Invention

[0008] The above-described module driving device can achieve more efficient heat dissipation of the imaging element.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an optical device OD including a module driving device MD according to an embodiment of the present disclosure will be described with reference to the drawings. The optical device OD is a device including a heat dissipation member HR, an optical module OM, and a module driving device MD, and is mounted on a portable device such as a smartphone, for example.

[0011] The module driving device MD is configured to be able to tilt the optical module OM. FIG. 1 is a perspective view of the heat dissipation member HR, the optical module OM, and the module driving device MD. Specifically, the upper view of FIG. 1 (the figure above the block arrow) is a perspective view of the module driving device MD in a state where the optical module OM is attached and disposed in the heat dissipation member HR, and the lower view of FIG. 1 (the figure below the block arrow) is a perspective view of the module driving device MD in a state where it is taken out from the heat dissipation member HR and the optical module OM is removed. FIG. 2 is an exploded perspective view of the optical module OM and the module driving device MD. FIG. 3 is a more detailed exploded perspective view of the module driving device MD.

[0012] In FIGS. 1, 2, and 3, 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, 2, and 3, the X1 side of the module driving device MD corresponds to the front side (front face side) of the module driving device MD, and the X2 side of the module driving device MD corresponds to the rear side (rear face side) of the module driving device MD. Also, the Y1 side of the module driving device MD corresponds to the left side of the module driving device MD, and the Y2 side of the module driving device MD corresponds to the right side of the module driving device MD. Also, the Z1 side of the module driving device MD corresponds to the upper side (subject side) of the module driving device MD, and the Z2 side of the module driving device MD corresponds to the lower side (imaging element side) of the module driving device MD. The same applies to other figures.

[0013] The optical module OM is a module including an optical element driving device for driving an optical element. In the illustrated example, the optical module OM includes a lens driving device LD which is an example of an optical element driving device for driving a lens body LS which is an example of an optical element. The lens body LS is, for example, a cylindrical lens barrel provided with at least one lens, and is configured such that its central axis line follows the optical axis OA.

[0014] Specifically, as shown in FIG. 2, the optical module OM includes a lens body LS, a lens driving device LD, an imaging element IS, an imaging element holder SH, and a substrate member SB.

[0015] The lens driving device LD is configured to be able to move the lens body LS at least along the optical axis direction (Z-axis direction) by using a voice coil motor composed of a coil and a magnet. That is, the lens driving device LD is configured to have an autofocus driving unit AD (see FIG. 11). Note that the optical axis direction includes the axial direction of the optical axis OA and a direction parallel to the axial direction of the optical axis OA. Also, in the illustrated example, the lens driving device LD is configured to move the lens body LS by using a voice coil motor, but it may be configured to move the lens body LS by using a member or mechanism other than the voice coil motor, such as a shape memory alloy wire or a piezoelectric element. Further, the autofocus driving unit AD may be omitted. In this case, the optical device OD functions as a fixed-focus camera with an anti-shake function.

[0016] The lens driving device LD includes a movable-side cover member 4 and a movable-side base member 28. The movable-side cover member 4 and the movable-side base member 28 function as a movable housing that covers each member constituting the lens driving device LD. In the illustrated example, the movable-side cover member 4 is formed of a non-magnetic metal such as austenitic stainless steel. However, the movable-side cover member 4 may be formed of a magnetic metal.

[0017] Specifically, as shown in FIG. 2, the movable-side cover member 4 has a bottomless box-shaped outer shape that defines a storage portion 4S. The movable-side cover member 4 also has a rectangular tubular side plate portion 4A and a rectangular annular and flat top plate portion 4B provided so as to be continuous with the upper end (the end on the Z1 side) of the side plate portion 4A. A substantially circular opening 4K is formed at the center of the top plate portion 4B. The side plate portion 4A includes a first side plate portion 4A1 to a fourth side plate portion 4A4. The first side plate portion 4A1 and the third side plate portion 4A3 face each other, and the second side plate portion 4A2 and the fourth side plate portion 4A4 face each other. The first side plate portion 4A1 and the third side plate portion 4A3 extend perpendicular to the second side plate portion 4A2 and the fourth side plate portion 4A4.

[0018] The movable-side base member 28 is a substantially rectangular frame-shaped member formed of synthetic resin, and is attached onto an image sensor holder SH mounted on a substrate member SB.

[0019] The image sensor holder SH is configured to accommodate and hold an image sensor IS. In the illustrated example, the image sensor holder SH is a substantially rectangular frame-shaped member formed of synthetic resin, and its upper surface is joined to the lower surface of the movable-side base member 28 by an adhesive. An opening SHK for exposing the image sensor IS is formed in the image sensor holder SH. A concave portion that is recessed upward with the lower side open is formed in the lower surface of the image sensor holder SH surrounding the opening SHK, and the image sensor IS is disposed within the concave portion (not shown).

[0020] The substrate member SB is a member for realizing an electrical connection between each of a module driving device MD and a lens driving device LD and a device outside the module driving device MD such as a control unit CTR. In the illustrated example, the control unit CTR is a microcomputer having a CPU, a volatile memory device, a non-volatile memory device, and the like. Further, the substrate member SB is a flexible printed circuit board, and has an outer portion SB1 fixed to the module driving device MD, an inner portion SB2 fixed to the image sensor holder SH, and a connecting portion SB3 connecting the outer portion SB1 and the inner portion SB2. And the connecting portion SB3 includes a left connecting portion SB3L and a right connecting portion SB3R.

[0021] The imaging element IS is mounted on the inner part SB2. Specifically, the imaging element IS is fixed to the inner part SB2 by a conductive adhesive or solder. Further, the imaging element holder SH houses the imaging element IS with the imaging surface of the imaging element IS exposed from the opening SHK, and is joined to the upper surface of the inner part SB2 by an adhesive. At least a part of the outer shape of the imaging element IS is held by the imaging element holder SH. That is, the imaging element holder SH functions as a spacer member disposed between the inner part SB2 and the lens driving device LD (movable-side base member 28). Also, a temperature sensor SR such as a thermistor for detecting the temperature of the imaging element IS is attached to the inner part SB2. The substrate member SB may be a combination of a rigid substrate on which the imaging element IS is mounted and a flexible printed circuit board connected to the rigid substrate.

[0022] The heat radiating member HR is a member that radiates the heat generated by the imaging element IS, and is formed of, for example, aluminum or a copper alloy. In the illustrated example, the heat radiating member HR is configured to be in contact with the substrate member SB and release the heat of the imaging element IS to the outside through the substrate member SB. In the illustrated example, the optical module OM attached to the module driving device MD is housed in the recess HC formed in the heat radiating member HR together with the module driving device MD as shown in the upper figure of FIG. 1. Then, the lower surface of the outer part SB1 of the substrate member SB is fixed to the bottom surface of the recess HC by an adhesive. Note that the heat radiating member HR may be a part of the housing of a mobile device such as a smartphone.

[0023] As shown in FIGS. 1 and 2, the module driving device MD includes a cover member 1 that is a part of a fixed-side member FB provided so as not to be relatively movable with respect to the heat radiating member HR. The cover member 1 is configured to function as a part of a housing HS that covers each member constituting the module driving device MD. In the illustrated example, the cover member 1 is formed of a non-magnetic metal such as austenitic stainless steel. However, the cover member 1 may be formed of a magnetic metal.

[0024] Specifically, as shown in FIG. 2, the cover member 1 has a bottomless box-shaped outer shape that defines the storage portion 1S. Further, the cover member 1 has a rectangular cylindrical side plate 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 side plate portion 1A. A substantially rectangular opening 1K is formed at the center of the top plate portion 1B. The side plate 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 perpendicularly to the second side plate portion 1A2 and the fourth side plate portion 1A4.

[0025] As shown in FIGS. 2 and 3, inside the cover member 1, a module holder 2, a metal member 5, a flexible metal member 6, an embedded metal member 7, a movable-side conductive member 8, a magnet 9, a fixed-side embedded member 10, a base member 18, a shape memory alloy wire SA, etc. are accommodated. The module holder 2 constitutes a movable-side member MB, and the base member 18 constitutes a fixed-side member FB. And the cover member 1 is joined to the base member 18 by an adhesive as shown in FIG. 1.

[0026] The module holder 2 is a rectangular frame-shaped member that holds the optical module OM, and is formed by injection molding a synthetic resin such as liquid crystal polymer (LCP). In the illustrated example, as shown in FIG. 3, the module holder 2 has a frame portion 2A and a pedestal portion 2D.

[0027] The frame portion 2A is constituted by four extending portions (a first extending portion 2A1 to a fourth extending portion 2A4) that surround a rectangular opening 2K. The pedestal portion 2D is a portion that protrudes radially outward from the frame portion 2A, and includes a first pedestal portion 2D1 disposed at the right rear corner portion of the frame portion 2A and a second pedestal portion 2D2 disposed at the left front corner portion of the frame portion 2A.

[0028] The embedded metal member 7 is a metal member partially exposed from the surface of the module holder 2 so as to be in contact with the optical module OM, and the remaining portion is embedded in the module holder 2. In the present embodiment, the embedded metal member 7 is a member formed of a metal such as stainless steel or copper, and is partially embedded in the frame portion 2A of the module holder 2 by insert molding.

[0029] In the illustrated example, the embedded metal member 7 has an exposed portion 7C exposed on the inner peripheral surface of the frame portion 2A of the module holder 2 (the inner peripheral surface of each of the first to fourth extending portions 2A1 to 2A4). As shown in FIG. 1, the outer peripheral surface of the side plate portion 4A of the movable side cover member 4 of the optical module OM is configured to be joined to the inner peripheral surface of the frame portion 2A of the module holder 2 with an adhesive. Specifically, the outer peripheral surface of the side plate portion 4A is configured to be joined to at least a part of the exposed portion 7C with an adhesive. Therefore, this configuration can increase the adhesive strength between the side plate portion 4A and the module holder 2 as compared with a configuration in which the embedded metal member 7 is not embedded in the module holder 2. This is because the adhesive strength between metals is higher than the adhesive strength between a metal and a synthetic resin material.

[0030] The movable side conductive member 8 is a member partially exposed from the module holder 2 so as to be in contact with the metal member 5 and the flexible metal member 6, and the remaining portion is embedded in the module holder 2. In the present embodiment, the movable side conductive member 8 is a member formed of a metal such as stainless steel or copper, and is partially embedded in the pedestal portion 2D of the module holder 2 by insert molding. In the illustrated example, the movable side conductive member 8 includes a first movable side conductive member 8A partially embedded in the first pedestal portion 2D1 and a second movable side conductive member 8B partially embedded in the second pedestal portion 2D2.

[0031] The magnet 9 is a member that constitutes a biasing means EG for biasing the module holder 2 along the optical axis direction. In the present embodiment, the magnet 9 is accommodated and fixed in a recess 2R (see FIG. 8) formed in a facing portion 2F (see FIG. 8) of the module holder 2 that faces the upper surface of the base member 18 in the optical axis direction. Note that the magnet that constitutes the biasing means EG may be a magnet that constitutes a voice coil motor in the lens driving device LD. In this case, the magnet 9 may be omitted.

[0032] The fixed-side embedded member 10 is a member embedded in the fixed-side member FB. In the present embodiment, the fixed-side embedded member 10 is a member formed of a magnetic metal such as ferritic stainless steel or iron, and is partially embedded in the base member 18 by insert molding.

[0033] As shown in FIG. 2, the module driving device MD has a driving portion DM that rotates (swings) the module holder 2 around each of the first axis AX1 and the second axis AX2. In the illustrated example, the first axis AX1 and the second axis AX2 are arranged so as to intersect the optical axis OA at the center point in the top view of the imaging element IS.

[0034] The driving portion DM is constituted by a shape memory alloy wire SA, which is an example of a shape memory actuator. In the illustrated example, the shape memory alloy wire SA includes first wires SA1 to eighth wires SA8 as shown in FIG. 3. When an electric current flows through the shape memory alloy wire SA, the temperature rises, and the wire contracts in response to the rise in temperature. The driving portion DM can swing the module holder 2 by utilizing the contraction of the shape memory alloy wire SA.

[0035] The base member 18 is formed by injection molding using a synthetic resin such as liquid crystal polymer (LCP). In the illustrated example, the base member 18 has a substantially rectangular outer shape in top view as shown in FIG. 3 and has an opening 18K at the center. Specifically, the base member 18 has a rectangular annular base portion 18B arranged so as to surround the substantially rectangular opening 18K. The base portion 18B includes a first base portion 18B1 to a fourth base portion 18B4.

[0036] On the upper surface, which is the subject side surface (Z1 side surface) of the base member 18, a pedestal portion 18D is formed. The pedestal portion 18D includes a first pedestal portion 18D1 that extends upward from the first base portion 18B1 and the second base portion 18B2 and is L-shaped in a top view, and a second pedestal portion 18D2 that extends upward from the third base portion 18B3 and the fourth base portion 18B4 and is L-shaped in a top view. The first pedestal portion 18D1 and the second pedestal portion 18D2 are arranged to face each other with the optical axis OA interposed therebetween.

[0037] The flexible metal member 6 is configured to be able to connect the fixed-side member FB (base member 18) and the movable-side member MB (module holder 2). In the present embodiment, the flexible metal member 6 is a conductive connecting member (leaf spring) that connects the module holder 2 and the base member 18, and is formed of a metal plate mainly made of, for example, a copper alloy, a titanium copper-based alloy (titanium copper), or a copper nickel alloy (nickel silver copper).

[0038] Specifically, the flexible metal member 6 has an inner portion 6N fixed to the module holder 2, an outer portion 6E fixed to the base member 18, and an elastic arm portion 6G that connects the inner portion 6N and the outer portion 6E. In the illustrated example, the flexible metal member 6 includes a first flexible metal member 6A and a second flexible metal member 6B as shown in FIG. 3. The first flexible metal member 6A has a first inner portion 6N1, a first outer portion 6E1, and a first elastic arm portion 6G1, and the second flexible metal member 6B has a second inner portion 6N2, a second outer portion 6E2, and a second elastic arm portion 6G2. Further, the inner portion 6N is joined to the upper end surface of the pedestal portion 2D of the module holder 2 by caulking, and the outer portion 6E is joined to the upper end surface of the pedestal portion 18D of the base member 18 by caulking. Note that the joining of the flexible metal member 6 to each of the module holder 2 and the base member 18 may be realized by an adhesive.

[0039] In this way, the flexible metal member 6 is configured to connect the upper surface of the pedestal portion 2D of the module holder 2 and the upper surface of the pedestal portion 18D of the base member 18. Specifically, the flexible metal member 6 is configured such that the first flexible metal member 6A connects the upper surfaces of the first pedestal portion 2D1 and the second pedestal portion 2D2 and the upper surface of the first pedestal portion 18D1, and the second flexible metal member 6B connects the upper surfaces of the first pedestal portion 2D1 and the second pedestal portion 2D2 and the upper surface of the second pedestal portion 18D2.

[0040] The metal member 5 is a member to which the end of the shape memory alloy wire SA is fixed. In this embodiment, the metal member 5 is a member formed of a non-magnetic metal such as phosphor bronze, and includes a fixed-side metal member 5F and a movable-side metal member 5M. The fixed-side metal member 5F is configured to be fixed to the base member 18, and the movable-side metal member 5M is configured to be fixed to the module holder 2.

[0041] More specifically, the fixed-side metal member 5F is also referred to as a fixed-side terminal plate and includes a first fixed-side metal member 5F1 to an eighth fixed-side metal member 5F8. The movable-side metal member 5M is also referred to as a movable-side terminal plate and includes a first movable-side metal member 5M1 to a fourth movable-side metal member 5M4.

[0042] Each of the first wire SA1 to the eighth wire SA8 has one end fixed to the fixed-side metal member 5F by crimping or welding, etc., and the other end fixed to the movable-side metal member 5M by crimping or welding, etc. And each of the first wire SA1 to the eighth wire SA8 is configured to be linear along the outer surface of the frame portion 2A of the module holder 2 when current flows, and to be able to swing the movable-side member MB (module holder 2) with respect to the fixed-side member FB (cover member 1 and base member 18).

[0043] Next, referring to FIG. 4, the positional relationship between the module holder 2 and each of the movable-side metal member 5M, the flexible metal member 6, the embedded metal member 7, and the movable-side conductive member 8 will be described. FIG. 4 is a perspective view of the module holder 2, the movable-side metal member 5M, the flexible metal member 6, the embedded metal member 7, the movable-side conductive member 8, and the magnet 9. Specifically, the upper view of FIG. 4 (the figure above the block arrow) is a perspective view of the separated module holder 2, movable-side metal member 5M, flexible metal member 6, embedded metal member 7, movable-side conductive member 8, and magnet 9, and the lower view of FIG. 4 (the figure below the block arrow) is a perspective view of the module holder 2 to which the movable-side metal member 5M, flexible metal member 6, and magnet 9 are attached and in which the embedded metal member 7 and the movable-side conductive member 8 are embedded.

[0044] In the illustrated example, the first movable-side metal member 5M1 is joined by welding to the front exposed portion 8B1 of the second movable-side conductive member 8B embedded in the second pedestal portion 2D2 of the module holder 2. The second movable-side metal member 5M2 is joined by welding to the right exposed portion 8A1 of the first movable-side conductive member 8A embedded in the first pedestal portion 2D1 of the module holder 2. The third movable-side metal member 5M3 is joined by welding to the rear exposed portion 8A2 of the first movable-side conductive member 8A embedded in the first pedestal portion 2D1 of the module holder 2. The fourth movable-side metal member 5M4 is joined by welding to the left exposed portion 8B2 of the second movable-side conductive member 8B embedded in the second pedestal portion 2D2 of the module holder 2. With this configuration, the adhesive for fixing the movable-side metal member 5M to the pedestal portion 2D may be omitted.

[0045] One of the two first inner portions 6N1 of the first flexible metal member 6A is joined by welding to the upper right exposed portion 8A3 of the first movable-side conductive member 8A embedded in the first pedestal portion 2D1 of the module holder 2, and the other of the two first inner portions 6N1 of the first flexible metal member 6A is joined by welding to the upper front exposed portion 8B3 of the second movable-side conductive member 8B embedded in the second pedestal portion 2D2 of the module holder 2. Similarly, one of the two second inner portions 6N2 of the second flexible metal member 6B is joined by welding to the upper rear exposed portion 8A4 of the first movable-side conductive member 8A embedded in the first pedestal portion 2D1 of the module holder 2, and the other of the two second inner portions 6N2 of the second flexible metal member 6B is joined by welding to the upper left exposed portion 8B4 of the second movable-side conductive member 8B embedded in the second pedestal portion 2D2 of the module holder 2.

[0046] The embedded metal member 7 has an embedded portion 7E embedded in the frame portion 2A of the module holder 2 and an exposed portion 7C exposed on the inner peripheral surface of the frame portion 2A of the module holder 2. The embedded metal member 7 is formed by punching and bending a single metal plate. In the illustrated example, the exposed portion 7C includes a first exposed portion 7C1 exposed on the inner peripheral surface of the first extending portion 2A1, a second exposed portion 7C2 exposed on the inner peripheral surface of the second extending portion 2A2, a third exposed portion 7C3 exposed on the inner peripheral surface of the third extending portion 2A3, and a fourth exposed portion 7C4 exposed on the inner peripheral surface of the fourth extending portion 2A4.

[0047] The magnet 9 includes a first magnet 9A and a second magnet 9B which are permanent magnets magnetized with two poles in a substantially cubic shape. The first magnet 9A is fitted into the first recess 2R1 formed on the lower surface of the first pedestal portion 2D1 which is a part of the opposing portion 2F (see FIG. 8) of the module holder 2 and fixed with an adhesive, and the second magnet 9B is fitted into the second recess 2R2 formed on the lower surface of the second pedestal portion 2D2 which is another part of the opposing portion 2F and fixed with an adhesive.

[0048] Next, referring to FIG. 5, the positional relationship between the base member 18 and each of the fixed-side metal member 5F, the flexible metal member 6, and the fixed-side embedded member 10 will be described. FIG. 5 is a perspective view of the fixed-side metal member 5F, the flexible metal member 6, the fixed-side embedded member 10, and the base member 18. Specifically, the upper diagram of FIG. 5 (the diagram above the block arrow) is a perspective view of the fixed-side metal member 5F, the flexible metal member 6, the fixed-side embedded member 10, and the base member 18 in a separated state, and the lower diagram of FIG. 5 (the diagram below the block arrow) is a perspective view of the base member 18 to which the fixed-side metal member 5F and the flexible metal member 6 are attached and in which the fixed-side embedded member 10 is embedded.

[0049] The fixed-side embedded member 10 is a member embedded in the fixed-side member FB. In the present embodiment, the fixed-side embedded member 10 is formed of a metal having magnetism such as iron and is embedded in the base member 18 so as to be partially exposed from the surface of the base member 18. In the illustrated example, the fixed-side embedded member 10 includes first fixed-side embedded members 10A to 10J that are members for electrically connecting the fixed-side metal member 5F and the flexible metal member 6 to the substrate member SB, respectively, and 11th fixed-side embedded member 10K and 12th fixed-side embedded member 10L that include a magnetic member MG constituting the biasing means EG.

[0050] Specifically, the first fixed-side embedded member 10A embedded in the first pedestal portion 18D1 has a first exposed portion 10AP exposed on the front surface of the first pedestal portion 18D1. The first fixed-side metal member 5F1 is joined to the first exposed portion 10AP by welding and is electrically connected to the substrate member SB via the first fixed-side embedded member 10A.

[0051] The second fixed-side embedded member 10B embedded in the first pedestal portion 18D1 has a second exposed portion 10BP exposed on the front surface of the first pedestal portion 18D1. The second fixed-side metal member 5F2 is joined to the second exposed portion 10BP by welding and is electrically connected to the substrate member SB via the second fixed-side embedded member 10B.

[0052] The third fixed-side embedded member 10C embedded in the first pedestal portion 18D1 has a third exposed portion 10CP that is exposed on the right side surface of the first pedestal portion 18D1. The third fixed-side metal member 5F3 is joined to the third exposed portion 10CP by welding and is electrically connected to the substrate member SB via the third fixed-side embedded member 10C.

[0053] The fourth fixed-side embedded member 10D embedded in the first pedestal portion 18D1 has a fourth exposed portion 10DP that is exposed on the right side surface of the first pedestal portion 18D1. The fourth fixed-side metal member 5F4 is joined to the fourth exposed portion 10DP by welding and is electrically connected to the substrate member SB via the fourth fixed-side embedded member 10D.

[0054] The fifth fixed-side embedded member 10E embedded in the second pedestal portion 18D2 has a fifth exposed portion 10EP that is exposed on the rear side surface of the second pedestal portion 18D2. The fifth fixed-side metal member 5F5 is joined to the fifth exposed portion 10EP by welding and is electrically connected to the substrate member SB via the fifth fixed-side embedded member 10E.

[0055] The sixth fixed-side embedded member 10F embedded in the second pedestal portion 18D2 has a sixth exposed portion 10FP that is exposed on the rear side surface of the second pedestal portion 18D2. The sixth fixed-side metal member 5F6 is joined to the sixth exposed portion 10FP by welding and is electrically connected to the substrate member SB via the sixth fixed-side embedded member 10F.

[0056] The seventh fixed-side embedded member 10G embedded in the second pedestal portion 18D2 has a seventh exposed portion 10GP that is exposed on the left side surface of the second pedestal portion 18D2. The seventh fixed-side metal member 5F7 is joined to the seventh exposed portion 10GP by welding and is electrically connected to the substrate member SB via the seventh fixed-side embedded member 10G.

[0057] The eighth fixed-side embedded member 10H embedded in the second pedestal portion 18D2 has an eighth exposed portion 10HP that is exposed on the left side surface of the second pedestal portion 18D2. The eighth fixed-side metal member 5F8 is joined to the eighth exposed portion 10HP by welding and is electrically connected to the substrate member SB via the eighth fixed-side embedded member 10H.

[0058] The ninth fixed-side embedded member 10I embedded in the first pedestal portion 18D1 has a ninth exposed portion 10IP exposed on the upper surface of the first pedestal portion 18D1. The first outer portion 6E1 of the first flexible metal member 6A is joined to the ninth exposed portion 10IP by welding and is electrically connected to the substrate member SB via the ninth fixed-side embedded member 10I.

[0059] The tenth fixed-side embedded member 10J embedded in the second pedestal portion 18D2 has a tenth exposed portion 10JP exposed on the upper surface of the second pedestal portion 18D2. The second outer portion 6E2 of the second flexible metal member 6B is joined to the tenth exposed portion 10JP by welding and is electrically connected to the substrate member SB via the tenth fixed-side embedded member 10J.

[0060] The eleventh fixed-side embedded member 10K has an eleventh exposed portion 10KP exposed on the upper surface of the base member 18 so as to face the first magnet 9A with a space therebetween. The eleventh exposed portion 10KP functions as the first metal plate MG1 which is one of the magnetic members MG constituting the biasing means EG. Similarly, the twelfth fixed-side embedded member 10L has a twelfth exposed portion 10LP exposed on the upper surface of the base member 18 so as to face the second magnet 9B with a space therebetween. The twelfth exposed portion 10LP functions as the second metal plate MG2 which is another one of the magnetic members MG constituting the biasing means EG.

[0061] The base member 18 is configured to function as a wire support member that supports one end of each of the first wire SA1 to the eighth wire SA8. With this configuration, the movable-side member MB is supported in a swingable state about each of the first axis AX1 and the second axis AX2 by the first wire SA1 to the eighth wire SA8. Note that the axial direction of the first axis AX1 and the axial direction of the second axis AX2 are perpendicular to each other.

[0062] Next, referring to FIG. 6, the metal member 5 to which the shape memory alloy wire SA is attached will be described. FIG. 6 is a front view of the first fixed-side metal member 5F1, the second fixed-side metal member 5F2, the first movable-side metal member 5M1, the first wire SA1, and the second wire SA2. Specifically, the positional relationship of each member shown in the upper diagram of FIG. 6 corresponds to the positional relationship when the module driving device MD is assembled and current is supplied to each of the first wire SA1 and the second wire SA2, and each of the first wire SA1 and the second wire SA2 is in a straight line state. Further, the positional relationship of each member shown in the lower diagram of FIG. 6 corresponds to the positional relationship when the module driving device MD is assembled and no current is supplied to each of the first wire SA1 and the second wire SA2, and each of the first wire SA1 and the second wire SA2 is in a slack state. And in FIG. 6, for clarity, the illustration of other members is omitted. Also, the following description with reference to FIG. 6 relates to the combination of the first wire SA1 and the second wire SA2, but the same can be similarly applied to the combination of the third wire SA3 and the fourth wire SA4, the combination of the fifth wire SA5 and the sixth wire SA6, and the combination of the seventh wire SA7 and the eighth wire SA8.

[0063] Specifically, one end of the first wire SA1 is fixed to the first fixed-side metal member 5F1 at the holding portion J1 of the first fixed-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 holding portion J2 on the lower side (Z2 side) of the first movable-side metal member 5M1. Similarly, one end of the second wire SA2 is fixed to the second fixed-side metal member 5F2 at the holding portion J3 of the second fixed-side metal member 5F2, and the other end of the second wire SA2 is fixed to the first movable-side metal member 5M1 at the holding portion J4 on the upper side (Z1 side) of the first movable-side metal member 5M1.

[0064] The holding part J1 is formed by bending a part of the first fixed-side metal member 5F1. Specifically, a part of the first fixed-side metal member 5F1 is caulked in a state of sandwiching the end (one end) of the first wire SA1 to form the holding part J1. Note that the coating of the end (one end) of the first wire SA1 has been peeled off before being sandwiched by the holding part J1. And the end (one end) of the first wire SA1 is fixed to the holding part J1 by welding. Thereafter, the end (one end) of the first wire SA1 may be protected by a protective resin. The same applies to the holding parts J2 to J4.

[0065] Also, the first wire SA1 and the second wire SA2 are arranged so as to be in a twisted position with respect to each other when current is supplied. That is, the first wire SA1 and the second wire SA2 are arranged so as not to contact each other (to be non-contact) when current is supplied. Specifically, as shown in the upper figure of FIG. 6, when viewed from the X1 side (the direction perpendicular to the plate surface of the first fixed-side metal member 5F1), the first wire SA1 and the second wire SA2 are arranged so as to intersect.

[0066] Next, referring to FIG. 7, the path of the current flowing through the shape memory alloy wire SA will be described. FIG. 7 is a perspective view of the metal member 5, the flexible metal member 6, the movable-side conductive member 8, the fixed-side embedded member 10, and the shape memory alloy wire SA.

[0067] When the first terminal part 10AT of the first fixed-side embedded member 10A is connected to a high potential and the ninth terminal part 10IT of the ninth fixed-side embedded member 10I is connected to a low potential, the current flows through the first terminal part 10AT to the first fixed-side metal member 5F1. Thereafter, the current passes through the first wire SA1 and further through the first movable-side metal member 5M1. Thereafter, the current passes through the front exposed part 8B1 and the upper front exposed part 8B3 of the second movable-side conductive member 8B, through the first inner part 6N1 on the left front side, the first elastic arm part 6G1 on the front side, and the first outer part 6E1 of the first flexible metal member 6A, and then through the ninth exposed part 10IP of the ninth fixed-side embedded member 10I to flow to the ninth terminal part 10IT.

[0068] When the second terminal portion 10BT of the second fixed-side embedded member 10B is connected to a high potential and the ninth terminal portion 10IT of the ninth fixed-side embedded member 10I is connected to a low potential, current flows through the second terminal portion 10BT to the second fixed-side metal member 5F2. Thereafter, the current passes through the second wire SA2 and further through the first movable-side metal member 5M1. Thereafter, the current passes through the front exposed portion 8B1 and the upper front exposed portion 8B3 of the second movable-side conductive member 8B, through the first inner portion 6N1 on the left front side, the first elastic arm portion 6G1 on the front side, and the first outer portion 6E1 of the first flexible metal member 6A, and then through the ninth exposed portion 10IP of the ninth fixed-side embedded member 10I to the ninth terminal portion 10IT.

[0069] When the third terminal portion 10CT of the third fixed-side embedded member 10C is connected to a high potential and the ninth terminal portion 10IT of the ninth fixed-side embedded member 10I is connected to a low potential, current flows through the third terminal portion 10CT to the third fixed-side metal member 5F3. Thereafter, the current passes through the third wire SA3 and further through the second movable-side metal member 5M2. Thereafter, the current passes through the right exposed portion 8A1 and the upper right exposed portion 8A3 of the first movable-side conductive member 8A, through the first inner portion 6N1 on the right rear side, the first elastic arm portion 6G1 on the right side, and the first outer portion 6E1 of the first flexible metal member 6A, and then through the ninth exposed portion 10IP of the ninth fixed-side embedded member 10I to the ninth terminal portion 10IT.

[0070] When the fourth terminal portion 10DT of the fourth fixed-side embedded member 10D is connected to a high potential and the ninth terminal portion 10IT of the ninth fixed-side embedded member 10I is connected to a low potential, current flows through the fourth terminal portion 10DT to the fourth fixed-side metal member 5F4. Thereafter, the current passes through the fourth wire SA4 and further through the second movable-side metal member 5M2. Thereafter, the current passes through the right exposed portion 8A1 and the upper right exposed portion 8A3 of the first movable-side conductive member 8A, through the first inner portion 6N1 on the right rear side, the first elastic arm portion 6G1 on the right side, and the first outer portion 6E1 of the first flexible metal member 6A, and then through the ninth exposed portion 10IP of the ninth fixed-side embedded member 10I to the ninth terminal portion 10IT.

[0071] Even when either the first terminal portion 10AT or the second terminal portion 10BT is connected to a high potential, the current path from the first movable-side metal member 5M1 to the ninth terminal portion 10IT of the ninth fixed-side embedded member 10I is the same. Also, even when either the third terminal portion 10CT or the fourth terminal portion 10DT is connected to a high potential, the current path from the second movable-side metal member 5M2 to the ninth terminal portion 10IT of the ninth fixed-side embedded member 10I is the same.

[0072] Similarly, when the fifth terminal portion 10ET, the sixth terminal portion 10FT, the seventh terminal portion 10GT, and the eighth terminal portion 10HT are connected to a high potential while the tenth terminal portion 10JT of the tenth fixed-side embedded member 10J is connected to a low potential, the current flows through the fifth wire SA5, the sixth wire SA6, the seventh wire SA7, and the eighth wire SA8, respectively.

[0073] The control unit CTR (see FIG. 1) outside the module driving device MD as described above can individually control the contraction of each of the first wire SA1 to the eighth wire SA8 by controlling the voltage applied to each of the first terminal portion 10AT to the tenth terminal portion 10JT. Each of the first terminal portion 10AT to the tenth terminal portion 10JT is electrically connected to a conductor pattern on the outer portion SB1 of the substrate member SB by jet solder or the like. Further, the control unit CTR may be configured to detect the resistance value of each of the first wire SA1 to the eighth wire SA8 and perform feedback control on the contraction amount of each of the first wire SA1 to the eighth wire SA8. In this case, the control unit CTR can derive the position and orientation of the module holder 2 based on the resistance value of each of the first wire SA1 to the eighth wire SA8. Also, the control unit CTR may be arranged inside the module driving device MD. Further, the control unit CTR may be a component of the module driving device MD.

[0074] With such a configuration, the control unit CTR can utilize the driving force generated by the contraction of the shape memory alloy wire SA as the driving unit DM to swing the module holder 2 around each of the first axis AX1 and the second axis AX2.

[0075] Next, referring to FIG. 7, the swinging of the module holder 2 (not shown in FIG. 7) by the drive unit DM (shape memory alloy wire SA) will be described. The swinging of the movable-side metal member 5M attached to the module holder 2 in the following description corresponds to the swinging of the module holder 2.

[0076] The control unit CTR typically supplies current to each of eight shape memory alloy wires SA (first wire SA1 to eighth wire SA8) having the same effective length to realize the neutral state of the module drive device MD. The neutral state of the module drive device MD is, for example, a state in which the module holder 2 is positioned in the middle of the movable range in each of three mutually orthogonal axial directions (X-axis direction, Y-axis direction, and Z-axis direction). Typically, in the neutral state of the module drive device MD, the module holder 2 is positioned at the center of the movable range in each of the three axial directions.

[0077] Thereafter, the control unit CTR swings the module holder 2 (movable-side metal member 5M) by supplying a current larger than the current supplied to the remaining shape memory alloy wires SA to a part of the eight shape memory alloy wires SA (first wire SA1 to eighth wire SA8) by, for example, the method disclosed in International Publication No. 2022 / 219984. At this time, typically, a part of the eight shape memory alloy wires SA contracts and the remaining shape memory alloy wires SA expand.

[0078] Specifically, the control unit CTR can swing the movable-side metal member 5M in the direction indicated by the arrow AR1 around the first axis AX1 by contracting each of the second wire SA2, the third wire SA3, the fourth wire SA4, and the fifth wire SA5.

[0079] Further, the control unit CTR can swing the movable-side metal member 5M in the direction indicated by the arrow AR2 around the first axis AX1 by contracting each of the first wire SA1, the sixth wire SA6, the seventh wire SA7, and the eighth wire SA8.

[0080] Further, the control unit CTR can swing the movable-side metal member 5M in the direction indicated by the arrow AR3 around the second axis AX2 by contracting each of the first wire SA1, the second wire SA2, the fourth wire SA4, and the seventh wire SA7.

[0081] Further, the control unit CTR can swing the movable-side metal member 5M in the direction indicated by the arrow AR4 around the second axis AX2 by contracting each of the third wire SA3, the fifth wire SA5, the sixth wire SA6, and the eighth wire SA8.

[0082] Next, referring to FIG. 8, the positional relationship between the magnet 9 and the magnetic member MG that constitute the biasing means EG will be described. The magnet 9 includes a first magnet 9A fitted into a first recess 2R1 formed in the lower surface of the module holder 2 and a second magnet 9B fitted into a second recess 2R2 formed in the lower surface of the module holder 2. The magnetic member MG includes a first metal plate MG1 as a first exposed portion 10KP of an eleventh fixed-side embedded member 10K, which is one of the fixed-side embedded members 10, and a second metal plate MG2 as a twelfth exposed portion 10LP of a twelfth fixed-side embedded member 10L, which is another one of the fixed-side embedded members 10. FIG. 8 shows the positional relationship between the magnet 9 (the first magnet 9A and the second magnet 9B) attached to the module holder 2 and the fixed-side embedded members 10 (the eleventh fixed-side embedded member 10K and the twelfth fixed-side embedded member 10L) embedded in the base member 18 in the neutral state of the module driving device MD. Specifically, the upper diagram of FIG. 8 is a bottom perspective view of the module holder 2 and the magnet 9, the central diagram of FIG. 8 is an upper perspective view of the magnet 9 and the fixed-side embedded member 10, and the lower diagram of FIG. 8 is an upper perspective view of the magnet 9, the fixed-side embedded member 10, and the base member 18.

[0083] The magnetic member MG is a member for generating a magnetic attractive force with the magnet 9 attached to the module holder 2. In the example shown in FIG. 8, the magnetic member MG includes a first metal plate MG1 and a second metal plate MG2. Both the first metal plate MG1 and the second metal plate MG2 are formed of magnetic metal. Specifically, the first metal plate MG1 is formed as a part of the first fixed-side embedded member 10K, and the second metal plate MG2 is formed as a part of the second fixed-side embedded member 10L. However, the magnetic member MG does not have to be a magnetic metal as long as it can generate a magnetic attractive force with the magnet 9. In this case, the magnetic member MG may be a magnet. Also, the magnetic member MG may be configured as a member independent of the fixed-side embedded member 10. In this case, the fixed-side embedded member 10 may be formed of a non-magnetic material such as non-magnetic metal. Further, the magnetic member MG does not have to be embedded in the base member 18 and may be attached to the base member 18.

[0084] In the neutral state of the module driving device MD, as shown in the central view of FIG. 8 and the lower view of FIG. 8, the magnet 9 is disposed in the recess 2R formed in the lower surface of the module holder 2 so as to be located directly above the magnetic member MG at a predetermined distance from the magnetic member MG.

[0085] And, as shown in the lower view of FIG. 8, the biasing means EG (magnet 9 and magnetic member MG) is configured such that the area of the lower surface of the magnet 9 facing the magnetic member MG is substantially equal to the area of the upper surface of the magnetic member MG facing the magnet 9. This is because when the area of the lower surface of the magnet 9 and the area of the upper surface of the magnetic member MG are significantly different, the positional relationship between the magnet 9 and the magnetic member MG when the magnet 9 is attracted by the magnetic attractive force generated between the magnet 9 and the magnetic member MG and comes to rest will vary.

[0086] Specifically, as shown in the lower diagram of FIG. 8, the first magnet 9A and the first metal plate MG1 are configured such that the area of the lower surface of the first magnet 9A facing the first metal plate MG1 is substantially equal to the area of the upper surface of the first metal plate MG1 facing the first magnet 9A. Also, the second magnet 9B and the second metal plate MG2 are configured such that the area of the lower surface of the second magnet 9B facing the second metal plate MG2 is substantially equal to the area of the upper surface of the second metal plate MG2 facing the second magnet 9B.

[0087] Also, in the example shown in FIG. 8, the magnet 9 has a substantially cubic outer shape, but may have other outer shapes such as a cylinder or a hexagonal prism. That is, in the example shown in FIG. 8, the lower surface of the magnet 9 has a rectangular outer shape, but may have other outer shapes such as a circular or hexagonal shape. In this case, the upper surface of the magnetic member MG is preferably configured to have the same outer shape as the lower surface of the magnet 9.

[0088] Next, referring to FIGS. 9 and 10, the operation of the biasing means EG will be described. FIG. 9 is a top view of the optical device OD. Specifically, the upper diagram of FIG. 9 is a top view of the optical device OD in a state where the lens driving device LD is attached to the module driving device MD, and the lower diagram of FIG. 9 is a top view of the optical device OD in a state where the lens driving device LD is removed from the module driving device MD. FIG. 10 is a cross-sectional view of the optical device OD, showing a cross-section of the optical device OD in a virtual plane perpendicular to the XY plane including the dashed line L1 in the lower diagram of FIG. 9. Specifically, the left diagram of FIG. 10 shows the state when no current is supplied to the shape memory alloy wire SA, and the right diagram of FIG. 10 shows the state when current is supplied to the shape memory alloy wire SA and the module driving device MD is in a neutral state.

[0089] In the neutral state of the module driving device MD, as shown in the right diagram of FIG. 10, the center point CP of the inner portion SB2 of the substrate member SB on which the imaging element IS is mounted is located at a position separated from the heat radiating member HR by a distance GP1 in the optical axis direction (Z-axis direction). That is, the inner portion SB2 is not in contact with the heat radiating member HR and is in a floating state. In the illustrated example, the center point CP of the inner portion SB2 is the intersection of the lower surface of the inner portion SB2 and the optical axis OA. At this time, the magnet 9 fitted in the recess 2R of the module holder 2 is located at a position separated from the magnetic member MG by a distance DS1 in the optical axis direction (Z-axis direction).

[0090] When the supply of current to the shape memory alloy wire SA is stopped, the biasing means EG biases the module holder 2 downward so that the inner portion SB2 of the substrate member SB and the heat radiating member HR approach or come into contact with each other. The fact that the inner portion SB2 and the heat radiating member HR approach each other means, for example, that the distance between the center point CP of the inner portion SB2 and the heat radiating member HR becomes smaller than the distance between the center point CP of the inner portion SB2 and the heat radiating member HR when the module driving device MD is in the neutral state. Specifically, the magnet 9 and the magnetic member MG constituting the biasing means EG approach each other by attracting each other by magnetic force. This is because the shape memory alloy wire SA, which had contracted and become linear by the supply of current, becomes slack as shown in the lower diagram of FIG. 6 when the supply of current is stopped, and the force that lifts the module holder 2 disappears. In other words, the shape memory alloy wire SA constituting the drive unit DM lifts the module holder 2 against the magnetic force (attractive force) acting between the magnet 9 and the magnetic member MG constituting the biasing means EG when current is supplied.

[0091] In the illustrated example, when the supply of current to the shape memory alloy wire SA is stopped, as shown in the left diagram of Fig. 10, the lower surface of the inner portion SB2 and the upper surface of the heat radiating member HR are in contact with each other. That is, the distance between the center point CP of the inner portion SB2 and the heat radiating member HR becomes zero. At this time, the magnet 9 fitted in the recess 2R of the module holder 2 approaches the magnetic member MG to a position separated from the magnetic member MG by a distance DS2 in the optical axis direction (Z-axis direction). That is, in the illustrated example, even when the supply of current to the shape memory alloy wire SA is stopped, the magnet 9 and the magnetic member MG do not come into contact with each other. This is to prevent the upward movement of the module holder 2 when the supply of current to the shape memory alloy wire SA is resumed from being excessively hindered by the magnetic force (adsorption force). Note that the distance DS2 is a value obtained by subtracting the distance GP1 from the distance DS1. Also, the module holder 2 and the base member 18 do not come into contact with each other. This is to prevent the generation of abrasion powder due to the contact between the module holder 2 and the base member 18.

[0092] Specifically, as shown in the left diagram of Fig. 10, the entire lower surface of the inner portion SB2 is in contact with the upper surface of the heat radiating member HR. As a result, the heat generated by the imaging device IS mounted on the upper surface of the inner portion SB2 is transmitted to the heat radiating member HR through the entire lower surface of the inner portion SB2 and is released to the outside through the heat radiating member HR. Note that if the heat radiation of the imaging device IS can be efficiently realized, the optical device OD may be configured such that when the supply of current to the shape memory alloy wire SA is stopped, the lower surface of the inner portion SB2 and the upper surface of the heat radiating member HR face each other with a slight gap therebetween. That is, the inner portion SB2 and the heat radiating member HR do not necessarily need to be in contact with each other.

[0093] As described above, the biasing means EG composed of the magnet 9 and the magnetic member MG can move the movable member MB (module holder 2) downward so that the lower surface of the inner portion SB2 and the upper surface of the heat radiating member HR approach or contact each other when the supply of current to the shape memory alloy wire SA is stopped. Therefore, when the supply of current to the shape memory alloy wire SA is stopped, the biasing means EG can release the heat generated by the imaging element IS to the outside through the substrate member SB and the heat radiating member HR.

[0094] Next, with reference to FIGS. 11 and 12, a process in which the control unit CTR switches the operation mode of the module driving device MD (hereinafter referred to as "operation mode switching process") will be described. FIG. 11 is a functional block diagram of the optical device OD. FIG. 12 is a flowchart showing an example of the flow of the operation mode switching process. The control unit CTR repeatedly executes this operation mode switching process at a predetermined control cycle when power is supplied to the imaging element IS.

[0095] As shown in FIG. 11, the control unit CTR is electrically connected to the driving unit DM of the module driving device MD, the temperature sensor SR mounted near the imaging element IS on the upper surface of the inner portion SB2 of the substrate member SB constituting the optical module OM, and the autofocus driving unit AD of the lens driving device LD constituting the optical module OM, respectively.

[0096] First, the control unit CTR determines whether or not the temperature of the imaging element IS has exceeded a predetermined upper limit temperature (step ST1). In the illustrated example, the control unit CTR measures the temperature of the imaging element IS based on the output of the temperature sensor SR mounted near the imaging element IS on the upper surface of the inner portion SB2 of the substrate member SB. Then, the control unit CTR compares the measured temperature of the imaging element IS with the first threshold temperature stored in the non-volatile storage device of the control unit CTR, and if the measured temperature of the imaging element IS exceeds the first threshold temperature, it is determined that the temperature of the imaging element IS has exceeded the predetermined upper limit temperature.

[0097] When it is determined that the temperature of the imaging device IS does not exceed a predetermined upper limit temperature (NO in step ST1), the control unit CTR continues to measure the temperature of the imaging device IS. On the other hand, when it is determined that the temperature of the imaging device IS exceeds the predetermined upper limit temperature (YES in step ST1), the control unit CTR switches the operation mode of the module driving device MD to the high-temperature mode (step ST2). In the illustrated example, the control unit CTR stops supplying current to the shape memory alloy wire SA that constitutes the driving unit DM of the module driving device MD while allowing the supply of current to the coil that constitutes the autofocus driving unit AD of the lens driving device LD. That is, the control unit CTR can stop the shake correction function while making the autofocus function available.

[0098] When the supply of current to the shape memory alloy wire SA is stopped, the biasing means EG biases the module holder 2 downward so that the inner portion SB2 of the substrate member SB and the heat radiating member HR come into contact with each other as shown in the left diagram of FIG. 10. That is, the magnet 9 fitted in the recess 2R of the module holder 2 is attracted to the magnetic member MG, and the inner portion SB2 of the substrate member SB that constitutes the optical module OM held by the module holder 2 comes into contact with the heat radiating member HR. Therefore, the control unit CTR can start radiating heat of the imaging device IS through the substrate member SB and the heat radiating member HR. When the heat radiation of the imaging device IS is started, the temperature of the imaging device IS decreases.

[0099] Thereafter, the control unit CTR determines whether the temperature of the imaging device IS has fallen below a predetermined lower limit temperature (step ST3). In the illustrated example, the control unit CTR measures the temperature of the imaging device IS based on the output of the temperature sensor SR. Then, the control unit CTR compares the measured temperature of the imaging device IS with the second threshold temperature stored in the non-volatile memory device of the control unit CTR, and determines that the temperature of the imaging device IS has fallen below the predetermined lower limit temperature when the measured temperature of the imaging device IS is lower than the second threshold temperature. Note that the second threshold temperature is lower than the first threshold temperature.

[0100] When it is determined that the temperature of the imaging device IS is not lower than a predetermined lower limit temperature (NO in step ST3), the control unit CTR continues to measure the temperature of the imaging device IS. On the other hand, when it is determined that the temperature of the imaging device IS is lower than the predetermined lower limit temperature (YES in step ST3), the control unit CTR switches the operation mode of the module driving device MD to the normal mode (step ST4). In the illustrated example, the control unit CTR allows the supply of current to the shape memory alloy wire SA that constitutes the driving unit DM of the module driving device MD while allowing the supply of current to the coil that constitutes the autofocus driving unit AD of the lens driving device LD. That is, the control unit CTR can make the shake correction function available while making the autofocus function available.

[0101] When the supply of current to the shape memory alloy wire SA is resumed, the shape memory alloy wire SA moves (lifts) the module holder 2 upward so that the inner portion SB2 of the substrate member SB and the heat radiating member HR move away from each other as shown in the right diagram of FIG. 10. Therefore, the control unit CTR can swing the optical module OM held by the module holder 2 around each of the first axis AX1 and the second axis AX2.

[0102] In this way, the control unit CTR can switch the operation mode of the module driving device MD between the normal mode and the high temperature mode according to the temperature of the imaging device IS. Therefore, when the temperature of the imaging device IS exceeds a predetermined upper limit temperature, the control unit CTR can continue the autofocus function while stopping the shake correction function. Further, after the control unit CTR stops the shake correction function, when the temperature of the imaging device IS is lower than a predetermined lower limit temperature, the control unit CTR can resume the shake correction function.

[0103] As described above, as shown in FIGS. 1 and 2, the module driving device MD according to the embodiment of the present disclosure includes a movable-side member MB including a module holder 2 capable of holding an optical module OM having a lens body LS, a substrate member SB, and an imaging element IS mounted on the upper surface (the surface on the Z1 side) of the substrate member SB so as to face the lens body LS in the optical axis direction, a heat radiating member HR that radiates heat generated by the imaging element IS, a fixed-side member FB provided immovably relative to the heat radiating member HR, and a driving unit DM that moves the movable-side member MB relative to the fixed-side member FB using a plurality of shape memory alloy wires SA provided between the fixed-side member FB and the movable-side member MB. Further, as shown in FIG. 3, the module driving device MD further includes a biasing means EG that biases the module holder 2 on the side (the Z2 side, the lower side) of the heat radiating member HR facing the lower surface (the surface on the Z2 side) of the substrate member SB. The biasing means EG is configured to bias the module holder 2 such that the substrate member SB (the inner portion SB2) and the heat radiating member HR, which are separated from each other when the shape memory alloy wire SA is energized, approach or contact each other when the shape memory alloy wire SA is not energized.

[0104] With this configuration, when the temperature of the imaging element IS rises, by stopping the energization of the shape memory alloy wire SA, the substrate member SB (the inner portion SB2) and the heat radiating member HR can be brought closer or into contact with each other. Therefore, with this configuration, the heat generated by the imaging element IS mounted on the substrate member SB can be radiated to the outside through the substrate member SB (the inner portion SB2) and the heat radiating member HR. Therefore, this configuration does not require a separate driving mechanism for moving the heat radiating member HR. Further, since this configuration does not move the heat radiating member HR, it has the effect that it is easier to increase the size of the heat radiating member HR (it is easier to enhance the heat radiation effect) compared to a configuration including a driving mechanism for moving the heat radiating member HR.

[0105] Further, the biasing means EG may include a magnet 9 provided on one of the movable-side member MB or the optical module OM and the fixed-side member FB, and a magnetic member MG provided on the other of the movable-side member MB or the optical module OM and the fixed-side member FB. In the illustrated example, the biasing means EG includes a magnet 9 provided on the movable-side member MB (module holder 2) and a magnetic member MG (first metal plate MG1 (first exposed portion 10KP of the first fixed-side embedded member 10K) and second metal plate MG2 (second exposed portion 10LP of the twelfth fixed-side embedded member 10L)) provided on the fixed-side member FB (base member 18). However, the biasing means EG may include a magnet provided on the optical module OM, such as the magnet of the voice coil motor constituting the autofocus driving unit AD.

[0106] This configuration brings about the effect that a biasing means EG with a simple structure can be realized.

[0107] Further, the fixed-side member FB may include the base member 18. In this case, the module holder 2 may have a facing portion 2F facing the upper surface of the base member 18 in the optical axis direction. And in a plan view (top view) along the optical axis direction, the plurality of magnets 9 may be provided at different positions in the facing portion 2F. And a plurality of magnetic members MG may be provided to face the plurality of magnets 9 and may be embedded in the base member 18. In the illustrated example, as shown in the upper figure of FIG. 8, the magnet 9 includes a first magnet 9A fitted into a first recess 2R1 formed on the lower surface of a first pedestal portion 2D1 which is a part of the facing portion 2F and fixed with an adhesive, and a second magnet 9B fitted into a second recess 2R2 formed on the lower surface of a second pedestal portion 2D2 which is another part of the facing portion 2F and fixed with an adhesive. And the magnetic member MG includes a first metal plate MG1 which is a part of the eleventh fixed-side embedded member 10K embedded in the base member 18 and exposed from the upper surface of the base member 18 so as to face the first magnet 9A, and a second metal plate MG2 which is a part of the twelfth fixed-side embedded member 10L embedded in the base member 18 and exposed from the upper surface of the base member 18 so as to face the second magnet 9B.

[0108] This configuration brings about the effect that the biasing of the module holder 2 by the biasing means EG can be made more reliable.

[0109] Also, the drive unit DM may be configured to swing the module holder 2 around two axes intersecting the optical axis OA. Note that these two axes are not physical rotation axes. In the illustrated example, as shown in FIG. 2, the drive unit DM is configured to be able to swing the module holder 2 around each of the first axis AX1 and the second axis AX2, which are virtual lines.

[0110] This configuration brings about the effect that it can cope with larger camera shakes compared to the camera shake correction function realized by translating the module holder 2 in each of the X-axis direction and the Y-axis direction.

[0111] Also, as shown in FIG. 7, the drive unit DM may be constituted by eight shape memory alloy wires SA (first wire SA1 to eighth wire SA8).

[0112] This configuration brings about the effect that the response speed of the camera shake correction function can be increased compared to the case where the drive unit is constituted by a smaller number of shape memory alloy wires SA.

[0113] Also, as shown in the right figure of FIG. 10, the biasing means EG may be configured to bias the module holder 2 such that the substrate member SB (inner portion SB2) and the heat radiating member HR, which are separated from each other when the temperature of the imaging element IS is below a predetermined temperature, come close to or contact each other when the temperature of the imaging element IS exceeds the predetermined temperature. In the example shown in the left figure of FIG. 10, the biasing means EG biases the module holder 2 downward so that the inner portion SB2 of the substrate member SB and the heat radiating member HR contact each other when the temperature of the imaging element IS exceeds the predetermined temperature.

[0114] This configuration brings about the effect that it can suppress the continuous high temperature state of the imaging element IS.

[0115] Further, the temperature of the imaging device IS may be detected by a temperature sensor SR (see FIG. 2) provided on the substrate member SB.

[0116] This configuration brings about the effect that the temperature sensor SR can be installed near the imaging device IS. Further, this configuration brings about the effect that the temperature of the imaging device IS can be easily measured.

[0117] Also, the energization of the shape memory alloy wire SA may be stopped when the temperature of the imaging device IS exceeds a predetermined temperature.

[0118] This configuration brings about the effect that when the temperature of the imaging device IS exceeds a predetermined temperature, the substrate member SB (inner portion SB2) on which the imaging device IS is mounted can be more reliably brought close to or into contact with the heat dissipation member HR. Therefore, this configuration brings about the effect that further heat generation of the imaging device IS can be suppressed.

[0119] Further, the optical module OM may include a lens holder LH (see FIG. 2) that holds the lens body LS, and an autofocus drive unit AD (see FIG. 11) that moves the lens holder LH in the optical axis direction with respect to the imaging device IS. And the biasing means EG may be configured to bias the module holder 2 so that the substrate member SB and the heat dissipation member HR are close to or in contact with each other when the shape memory alloy wire SA is not energized, regardless of whether the autofocus drive unit AD is operable.

[0120] This configuration brings about the effect that long-time shooting becomes possible in order to continuously utilize the autofocus function even when the shake correction function is temporarily unavailable.

[0121] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments. Various modifications, substitutions, etc. can be applied without departing from the scope of the present invention. Also, each of the features described with reference to the above embodiments may be appropriately combined as long as there is no technical contradiction.

[0122] For example, in the above-described embodiment, the biasing means EG is composed of the magnet 9 and the magnetic member MG, but it may be composed of a spring. That is, in the above-described embodiment, the biasing means EG is configured to utilize magnetic force, but it may be configured to utilize the restoring force of a spring.

Explanation of Reference Numerals

[0123] 1... Cover member 1A... Side plate part 1A1... First side plate part 1A2... Second side plate part 1A3... Third side plate part 1A4... Fourth side plate part 1B... Top plate part 1K... Opening 1S... Storage part 2... Module holder 2A... Frame part 2A1... First extending part 2A2... Second extending part 2A3... Third extending part 2A4... Fourth extending part 2D... Base part 2D1... First base part 2D2... Second base part 2F... Opposing part 2K... Opening 2R... Recess 2R1... First recess 2R2... Second recess 4... Movable side cover member 4A... Side plate part 4A1... First side plate part 4A2... Second side plate part 4A3... Third side plate part 4A4... Fourth side plate part 4B... Top plate part 4K... Opening 4S... Storage part 5... Metal member 5F... Fixed side metal member 5F1... First fixed side metal member 5F2... Second fixed side metal member 5F3... Third fixed side metal member 5F4... Fourth fixed side metal member 5F5... Fifth fixed side metal member 5F6... Sixth fixed side metal member 5F7... Seventh fixed side metal member 5F8... Eighth fixed side metal member 5M... Movable side metal member 5M1... First movable side metal member 5M2... Second movable side metal member 5M3... Third movable side metal member 5M4... Fourth movable side metal member 6... Flexible metal member 6A... First flexible metal member 6B... Second flexible metal member 6E... Outer part 6E1... First outer part 6E2... Second outer part 6G... Elastic arm part 6G1... First elastic arm part 6G2... Second elastic arm part 6N... Inner part 6N1... First inner part 6N2... Second inner part 7... Embedded metal member 7C... Exposed part 7C1... First exposed part 7C2... Second exposed part 7C3... Third exposed part 7C4... Fourth exposed part 7E... Embedded part 8... Movable side conductive member 8A... First movable side conductive member 8A1... Right side exposed part 8A2... Rear side exposed part 8A3... Upper right side exposed part 8A4... Upper rear side exposed part 8B... Second movable side conductive member 8B1... Front side exposed part 8B2... Left side exposed part 8B3... Upper front side exposed part 8B4... Upper left side exposed part 9... Magnet 9A... First magnet 9B... Second magnet 10... Fixed side embedded member 10A... First fixed side embedded member10AP ··· First exposed portion 10AT ··· First terminal portion 10B ··· Second fixed-side embedded member 10BP ··· Second exposed portion 10BT ··· Second terminal portion 10C ··· Third fixed-side embedded member 10CP ··· Third exposed portion 10CT ··· Third terminal portion 10D ··· Fourth fixed-side embedded member 10DP ··· Fourth exposed portion 10DT ··· Fourth terminal portion 10E ··· Fifth fixed-side embedded member 10EP ··· Fifth exposed portion 10ET ··· Fifth terminal portion 10F ··· Sixth fixed-side embedded member 10FP ··· Sixth exposed portion 10FT ··· Sixth terminal portion 10G ··· Seventh fixed-side embedded member 10GP ··· Seventh exposed portion 10GT ··· Seventh terminal portion 10H ··· Eighth fixed-side embedded member 10HP ··· Eighth exposed portion 10HT ··· Eighth terminal portion 10I ··· Ninth fixed-side embedded member 10IP ··· Ninth exposed portion 10IT ··· Ninth terminal portion 10J ··· Tenth fixed-side embedded member 10JP ··· Tenth exposed portion 10JT ··· Tenth terminal portion 10K ··· Eleventh fixed-side embedded member 10KP ··· Eleventh exposed portion 10L ··· Twelfth fixed-side embedded member 10LP ··· Twelfth exposed portion 18 ··· Base member 18B ··· Base 18B1 ··· First base 18B2 ··· Second base 18B3 ··· Third base 18B4 ··· Fourth base 18D ··· Pedestal portion 18D1 ··· First pedestal portion 18D2 ··· Second pedestal portion 18K ··· Opening AX1 ··· First axis AX2 ··· Second axis CTR ··· Control unit DM ··· Driving unit EG ··· Biasing means FB ··· Fixed-side member HC ··· Recess HS ··· Housing HR ··· Heat radiating member IS ··· Imaging element J1~J4 ··· Holding portion LD ··· Lens driving device LH ··· Lens holder LS ··· Lens body MB ··· Movable-side member MD ··· Module driving device MG ··· Magnetic member MG1 ··· First metal plate MG2 ··· Second metal plate OA ··· Optical axis OD ··· Optical device OM ··· Optical module 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 wire SB ··· Substrate member SB1 ··· Outer portion SB2 ··· Inner portion SB3 ··· Connecting portion SB3L ··· Left connecting portion SB3R ··· Right connecting portionSH... imaging element holder, SHK... aperture, SR... temperature sensor

Claims

1. a movable member including a module holder capable of holding an optical module having a lens body, a substrate member, and an image pickup element mounted on an upper surface of the substrate member so as to face the lens body in the optical axis direction; a heat dissipation member that dissipates heat generated by the imaging element and a fixed member that is provided so as not to move relative to the heat dissipation member; a drive unit that moves the movable member relative to the fixed member by utilizing a plurality of shape memory alloy wires provided between the fixed member and the movable member, a biasing means for biasing the module holder toward the heat dissipation member facing the lower surface of the substrate member, the biasing means biases the module holder so that the substrate member and the heat dissipation member, which are spaced apart when the shape memory alloy wire is energized, approach or come into contact with each other when the shape memory alloy wire is not energized. A module drive device comprising:

2. the biasing means is configured to include a magnet provided on one of the movable-side member or the optical module and the fixed-side member, and a magnetic member provided on the other of the movable-side member or the optical module and the fixed-side member.

2. The module drive device according to claim 1.

3. The fixed member includes a base member, the module holder has a facing portion facing an upper surface of the base member in an optical axis direction, In a plan view along the optical axis direction, the magnets are provided at different positions in the opposing portion, The magnetic members are provided in a plurality of positions facing the plurality of magnets and are embedded in the base member.

3. The module drive device according to claim 2.

4. The drive unit swings the module holder about two axes intersecting an optical axis.

3. The module drive device according to claim 2.

5. The driving unit is composed of eight of the shape memory alloy wires.

5. The module drive device according to claim 4.

6. the biasing means biases the module holder so that the board member and the heat dissipation member, which are spaced apart when the temperature of the imaging element is equal to or lower than a predetermined temperature, approach or come into contact with each other when the temperature of the imaging element exceeds the predetermined temperature.

6. A module driving device according to claim 1.

7. The temperature of the imaging element is detected by a temperature sensor provided on the substrate member.

7. The module drive device according to claim 6.

8. The current supply to the shape memory alloy wire is stopped when the temperature of the imaging element exceeds a predetermined temperature.

6. A module driving device according to claim 1.

9. the optical module includes a lens holder that holds the lens body, and an autofocus drive unit that moves the lens holder in an optical axis direction relative to the image sensor, the biasing means biases the module holder so that the substrate member and the heat dissipation member approach or contact each other when the shape memory alloy wire is not energized, regardless of whether the autofocus driving unit is operable or not.

2. The module drive device according to claim 1.

Images