Imaging device and camera module

Abstract

To reduce the magnitude of a magnetic field that is formed around a conductive path for supplying current to a shape memory alloy wire.SOLUTION: An imaging apparatus 101 comprises a driving device 10 that can drive a first wire SA1 and a second wire SA2. The driving device 10 executes, in combination, a first mode for causing current to flow from a first point PT1 to a second point PT2 of a first conductive path CD1 and causing current to flow from a second point PT12 to a first point PT11 of a second conductive path CD2, and at least one of a second mode for causing current to flow only in the first conductive path CD1 and a third mode for causing current to flow only in the second conductive path CD2. A portion connecting the first point PT1 and the second point PT2, and a portion connecting the first point PT11 and the second point PT12, are installed in parallel to each other. The first point PT1 is provided in parallel to the first point PT11, and the second point PT2 is provided in parallel to the second point PT12.SELECTED DRAWING: Figure 12A

Description

[Technical Field]

[0001] The present disclosure relates to an imaging device, a camera module, and a method for controlling an imaging device. [Background technology]

[0002] Conventionally, an imaging device using eight shape memory alloy wires is known (see Patent Document 1). In this imaging device, a control circuit uses a PWM signal to individually supply current to each of the eight shape memory alloy wires, causing them to heat and shrink, and moving a lens holder connected to the eight shape memory alloy wires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2013-546023 Summary of the Invention [Problem to be solved by the invention]

[0004] In the imaging device described above, the control circuit controls the drive circuit so that a conductive path for passing a predetermined current through one of the eight shape memory alloy wires that is to be heated, and parallel-connected conductive paths for passing the predetermined current in seven divided portions through the remaining seven of the eight shape memory alloy wires that are not to be heated, are simultaneously formed. With this configuration, the control circuit can appropriately heat and shrink the specific one shape memory alloy wire.

[0005] However, in the above-mentioned imaging device, a relatively large magnetic field (induced magnetic field) may be generated around the conductive path for passing a current through one of the heating targets, and this relatively large magnetic field may become a noise source for the imaging element, adversely affecting the image quality of the imaging element.

[0006] Therefore, it is desirable to provide an imaging device that can reduce the magnitude of the magnetic field formed around the conductive path for supplying current to the shape memory alloy wire. [Means for solving the problem]

[0007] An imaging device according to one embodiment of the present invention includes a fixed-side member including a fixed base, a movable-side member including a lens holder capable of holding a lens body so as to face an imaging element and movable relative to the fixed-side member, a first shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member, a second shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member, a first conductive path provided on the fixed base and electrically connected to one end of the first shape memory alloy wire, and a second conductive path provided on the fixed base and electrically connected to one end of the second shape memory alloy wire. a second conductive path electrically connected to one end of the memory alloy wire; a common conductive path electrically connected to the other end of each of the first shape memory alloy wire and the second shape memory alloy wire; and a drive device configured to be electrically connected to each of the first conductive path, the second conductive path, and the common conductive path, and capable of supplying current to each of the first shape memory alloy wire and the second shape memory alloy wire to drive each of the first shape memory alloy wire and the second shape memory alloy wire, wherein a portion connecting a first point and a second point on the first conductive path and a portion connecting the second point and the second shape memory alloy wire are electrically connected to each of the first conductive path, the second conductive path, and the common conductive path. The portions connecting the first point and the second point on the conductive path are installed parallel to each other on the fixed base, the first point on the first conductive path is juxtaposed to the first point on the second conductive path, and the second point on the first conductive path is juxtaposed to the second point on the second conductive path, and the driving device electrically connects the first conductive path, the first shape memory alloy wire, the common conductive path, the second shape memory alloy wire, and the second conductive path in series to supply current to the first shape memory alloy wire and the second shape memory alloy wire, so that current flows from the first point to the second point on the first conductive path. a second mode in which the first conductive path, the first shape memory alloy wire, and the common conductive path are electrically connected in series to supply a current to the first shape memory alloy wire, causing a current to flow in the first conductive path; and a third mode in which the second conductive path, the second shape memory alloy wire, and the common conductive path are electrically connected in series to supply a current to the second shape memory alloy wire, causing a current to flow in the second conductive path, and the first mode andThe second mode and / or the third mode are configured to be executed in combination. [Effects of the Invention]

[0008] The imaging device described above can reduce the magnitude of the magnetic field formed around the conductive path for supplying current to the shape memory alloy wire. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an imaging device. [Figure 2] FIG. 2 is an exploded perspective view of the imaging device. [Figure 3A] FIG. 10 is a perspective view of a lens holder to which a movable metal member and a leaf spring are attached. [Figure 3B] FIG. 2 is a perspective view of a base member to which a fixed metal member is attached. [Figure 4A] FIG. 2 is a side view of a metal member having a shape memory alloy wire attached thereto. [Figure 4B] FIG. 2 is a top view of a metal member having a shape memory alloy wire attached thereto. [Figure 5] FIG. [Figure 6A] 10 is a diagram showing the positional relationship between a leaf spring, a shape memory alloy wire, a metal member, and a conductive member. FIG. [Figure 6B] 10A and 10B are diagrams illustrating the positional relationship between a leaf spring and a metal member. [Figure 7A] FIG. 1 is a diagram showing an example of a path of a current flowing through a shape memory alloy wire. [Figure 7B] FIG. 10 is a diagram showing another example of a path of a current flowing through a shape memory alloy wire. [Figure 7C] FIG. 10 is a diagram showing yet another example of a path of a current flowing through a shape memory alloy wire. [Figure 7D] FIG. 10 is a diagram showing yet another example of a path of a current flowing through a shape memory alloy wire. [Figure 7E] FIG. 10 is a diagram showing yet another example of a path of a current flowing through a shape memory alloy wire. [Figure 7F]FIG. 10 is a diagram showing yet another example of a path of a current flowing through a shape memory alloy wire. [Figure 8A] 10A and 10B are diagrams illustrating an example of a connection structure that connects a fixed metal member and a conductive member. [Figure 8B] 10A and 10B are diagrams illustrating an example of a connection structure that connects a fixed metal member and a conductive member. [Figure 9] FIG. 2 is a diagram illustrating an example of the configuration of a drive device and a control device. [Figure 10A] FIG. 2 is a diagram illustrating an example of a current path in a driving device. [Figure 10B] FIG. 10 is a diagram illustrating another example of a current path in the drive device. [Figure 10C] FIG. 10 is a diagram showing yet another example of a current path in the drive device. [Figure 10D] FIG. 10 is a diagram showing yet another example of a current path in the drive device. [Figure 11] 10 is an example of a timing chart of a driving current and a measuring current flowing through a shape memory alloy wire. [Figure 12A] FIG. 2 is a perspective view of a first conductive member and a second conductive member. [Figure 12B] 10 is another example of a timing chart of a driving current and a measuring current flowing through a shape memory alloy wire. [Figure 13] FIG. 10 is a diagram illustrating another example of the configuration of the drive device. DETAILED DESCRIPTION OF THE INVENTION

[0010] An imaging device 101 (lens actuator) according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a perspective view of the imaging device 101. Fig. 2 is an exploded perspective view of the imaging device 101.

[0011] 1 and 2, X1 represents one direction of the X axis constituting the three-dimensional Cartesian coordinate system, and X2 represents the other direction of the X axis. Furthermore, Y1 represents one direction of the Y axis constituting the three-dimensional Cartesian coordinate system, and Y2 represents the other direction of the Y axis. Similarly, Z1 represents one direction of the Z axis constituting the three-dimensional Cartesian coordinate system, and Z2 represents the other direction of the Z axis. In FIGS. 1 and 2, the X1 side of the imaging device 101 corresponds to the front side (front face side) of the imaging device 101, and the X2 side of the imaging device 101 corresponds to the rear side (rear face side) of the imaging device 101. Furthermore, the Y1 side of the imaging device 101 corresponds to the left side of the imaging device 101, and the Y2 side of the imaging device 101 corresponds to the right side of the imaging device 101. Moreover, the Z1 side of the imaging device 101 corresponds to the upper side (subject side) of the imaging device 101, and the Z2 side of the imaging device 101 corresponds to the lower side (image sensor side) of the imaging device 101. This is the same in the other figures.

[0012] As shown in FIGS. 1 and 2, the imaging device 101 includes a cover member 4 that is a part of the fixed-side member FB.

[0013] The cover member 4 is configured to function as a housing that covers other members. In this embodiment, the cover member 4 is made of a non-magnetic metal. However, the cover member 4 may also be made of a magnetic metal. Furthermore, the cover member 4 defines a storage section 4S, as shown in FIG. 1.

[0014] The cover member 4 has a rectangular cylindrical outer wall portion 4A and a rectangular, annular, flat top plate portion 4B that is continuous with the upper end (the end on the Z1 side) of the outer wall portion 4A. A circular opening 4K is formed in the center of the top plate portion 4B. The outer wall portion 4A includes a first side plate portion 4A1 to a fourth side plate portion 4A4. The first side plate portion 4A1 and the third side plate portion 4A3 face each other, and 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.

[0015] As shown in FIG. 2, the cover member 4 accommodates the lens holder 2, the metal member 5, the leaf spring 6, the base member 18, the shape memory alloy wire SA, and the like.

[0016] The movable member MB includes a lens holder 2 capable of holding a lens body (not shown), and a leaf spring 6 that supports the lens holder 2 movably along the optical axis OA. The lens body is, for example, a cylindrical lens barrel equipped with at least one lens, and is configured so that its central axis is aligned with the optical axis OA.

[0017] The lens holder 2 is formed by injection molding a synthetic resin such as liquid crystal polymer (LCP). Specifically, as shown in Fig. 2, the lens holder 2 includes a cylindrical portion 2P formed to extend along the optical axis OA, and a movable-side base portion 2D and a protruding portion 2S formed to protrude radially outward from the cylindrical portion 2P. In this embodiment, the lens body is configured to be fixed to the inner circumferential surface of the cylindrical portion 2P with an adhesive.

[0018] The movable-side pedestal portion 2D includes a first movable-side pedestal portion 2D1 and a second movable-side pedestal portion 2D2. The first movable-side pedestal portion 2D1 and the second movable-side pedestal portion 2D2 are arranged to protrude in opposite directions relative to each other across the optical axis OA. Similarly, the protruding portion 2S includes a first protruding portion 2S1 and a second protruding portion 2S2. The first protruding portion 2S1 and the second protruding portion 2S2 are arranged to protrude in opposite directions relative to each other across the optical axis OA. Specifically, the movable-side pedestal portion 2D and the protruding portions 2S are arranged to correspond to the four corners of the lens holder 2, which has a substantially rectangular outer shape in a top view, and are arranged alternately. A portion of the leaf spring 6 is placed on each of the two movable-side pedestals 2D.

[0019] The shape memory alloy wire SA is an example of a shape memory actuator. In this embodiment, the shape memory alloy wire SA includes a first wire SA1 to an eighth wire SA8. When a current flows through the shape memory alloy wire SA, the temperature rises and the wire contracts in response to the temperature rise. The imaging device 101 can move the lens holder 2 up and down along the optical axis OA by utilizing the contraction of the shape memory alloy wire SA. In this embodiment, the shape memory alloy wire SA is configured such that when one or more of the first wire SA1 to the eighth wire SA8 contract, the lens holder 2 moves, and the movement causes one or more of the other wires to stretch.

[0020] The leaf springs 6 are configured to be electrically connected to the shape memory alloy wire SA through the metal member 5. In this embodiment, the leaf springs 6 are made from metal plates whose main material is, for example, a copper alloy, a titanium-copper alloy (titanium-copper), or a copper-nickel alloy (nickel-tin-copper). Specifically, the leaf springs 6 include a first leaf spring 6A and a second leaf spring 6B.

[0021] The base member 18 (fixed base) is formed by injection molding using a synthetic resin such as liquid crystal polymer (LCP). In this embodiment, the base member 18 has a generally rectangular outline in top view, and has an opening 18K in the center. Specifically, the base member 18 has four sides 18E (first side 18E1 to fourth side 18E4) that are arranged to surround the opening 18K.

[0022] The leaf spring 6 is configured to connect a movable-side pedestal portion 2D formed on the lens holder 2 and a fixed-side pedestal portion 18D formed on the base member 18. The fixed-side pedestal portion 18D includes a first fixed-side pedestal portion 18D1 and a second fixed-side pedestal portion 18D2.

[0023] More specifically, the first plate spring 6A is configured to connect the first movable-side pedestal portion 2D1 formed on the lens holder 2 to each of the first fixed-side pedestal portion 18D1 and the second fixed-side pedestal portion 18D2 formed on the base member 18. Similarly, the second plate spring 6B is configured to connect the second movable-side pedestal portion 2D2 formed on the lens holder 2 to each of the first fixed-side pedestal portion 18D1 and the second fixed-side pedestal portion 18D2 formed on the base member 18.

[0024] The metal member 5 is configured so that an end of the shape memory alloy wire SA is fixed. In this embodiment, the metal member 5 includes a fixed-side metal member 5F and a movable-side metal member 5M. The fixed-side metal member 5F constitutes a part of the fixed-side member FB, and is configured so as to be fixed to the fixed-side pedestal portion 18D of the base member 18. The movable-side metal member 5M constitutes a part of the movable-side member MB, and is configured so as to be fixed to the movable-side pedestal portion 2D of the lens holder 2.

[0025] More specifically, the fixed metal member 5F is also referred to as a fixed terminal plate and includes a first fixed terminal plate 5F1 to an eighth fixed terminal plate 5F8, and the movable metal member 5M is also referred to as a movable terminal plate and includes a first movable terminal plate 5M1 to a fourth movable terminal plate 5M4.

[0026] Next, the positional relationship between the lens holder 2 and the base member 18 and the metal member 5 will be described with reference to Figures 3A and 3B. Figure 3A is a perspective view of the lens holder 2 to which a movable-side metal member 5M (movable-side terminal plate) and a leaf spring 6 are attached. Figure 3B is a perspective view of the base member 18 to which a fixed-side metal member 5F (fixed-side terminal plate) is attached. For clarity, dot patterns are applied to the movable-side metal member 5M and the leaf spring 6 in Figure 3A, and a dot pattern is applied to the fixed-side metal member 5F in Figure 3B.

[0027] In the example shown in Fig. 3A, the first movable-side terminal plate 5M1 is fixed to the Y2-side side wall (right-side mounting surface) of the first movable-side pedestal portion 2D1. Specifically, the first movable-side terminal plate 5M1 is fixed to the first movable-side pedestal portion 2D1 by an adhesive in a state in which a square-shaped protrusion 2V formed on the first movable-side pedestal portion 2D1 and protruding outward (toward the Y2 side) is engaged with a rectangular hole AH (see Fig. 4A) formed in the first movable-side terminal plate 5M1. The adhesive is, for example, a light-curing adhesive. The light-curing adhesive is, for example, an ultraviolet-curing adhesive or a visible-light-curing adhesive. Similarly, the second movable side terminal plate 5M2 is fixed to the X2 side wall (rear mounting surface) of the first movable side base portion 2D1, the third movable side terminal plate 5M3 is fixed to the X1 side wall (front mounting surface) of the second movable side base portion 2D2, and the fourth movable side terminal plate 5M4 is fixed to the Y1 side wall (left mounting surface) of the second movable side base portion 2D2.

[0028] In the example shown in FIG. 3B, the first fixed-side terminal plate 5F1 and the second fixed-side terminal plate 5F2 are fixed to the Y2-side side wall (right-side mounting surface) of the first fixed-side pedestal 18D1, which is disposed along the second side 18E2 of the base member 18. Specifically, the first fixed-side terminal plate 5F1 and the second fixed-side terminal plate 5F2 are fixed to the first fixed-side pedestal 18D1 with an adhesive. More specifically, the second fixed-side terminal plate 5F2 is fixed to the first fixed-side pedestal 18D1 with an adhesive in a state in which a rectangular protrusion 18V formed on the first fixed-side pedestal 18D1 and protruding outward (toward the Y2 side) is engaged with a through-hole RH (see FIG. 4A) formed in the second fixed-side terminal plate 5F2. The adhesive is, for example, a photocurable adhesive. The photocurable adhesive is, for example, an ultraviolet-curable adhesive or a visible-light-curable adhesive. Similarly, the third fixed-side terminal plate 5F3 and the fourth fixed-side terminal plate 5F4 (not visible in FIG. 3B) are fixed to the X2-side side wall (rear-side mounting surface) of the second fixed-side pedestal portion 18D2 arranged along the third side 18E3 of the base member 18. The fifth fixed-side terminal plate 5F5 and the sixth fixed-side terminal plate 5F6 are fixed to the X1-side side wall (front-side mounting surface) of the first fixed-side pedestal portion 18D1 arranged along the first side 18E1 of the base member 18. The seventh fixed-side terminal plate 5F7 and the eighth fixed-side terminal plate 5F8 (not visible in FIG. 3B) are fixed to the Y1-side side wall (left-side mounting surface) of the second fixed-side pedestal portion 18D2 arranged along the fourth side 18E4 of the base member 18.

[0029] The shape memory alloy wires SA extend along the inner surface of the outer peripheral wall portion 4A of the cover member 4, and are configured to movably support the movable-side member MB relative to the fixed-side member FB. In this embodiment, the shape memory alloy wires SA include a first wire SA1 to an eighth wire SA8, and are configured to movably support the lens holder 2 as the movable-side member MB relative to a base member 18 as the fixed-side member FB. As shown in FIG. 2, each of the first wire SA1 to the eighth wire SA8 has one end fixed to the fixed-side metal member 5F by crimping, welding, or the like, and the other end fixed to the movable-side metal member 5M by crimping, welding, or the like.

[0030] Next, the metal member 5 to which the shape memory alloy wire SA is attached will be described with reference to FIGS. 4A and 4B. FIG. 4A is a view of the first wire SA1 attached to the first movable terminal plate 5M1 and the first fixed terminal plate 5F1, respectively, and the second wire SA2 attached to the first movable terminal plate 5M1 and the second fixed terminal plate 5F2, respectively, as viewed from the Y2 side. FIG. 4B is a view of the first wire SA1 attached to the first movable terminal plate 5M1 and the first fixed terminal plate 5F1, respectively, and the second wire SA2 attached to the first movable terminal plate 5M1 and the second fixed terminal plate 5F2, respectively, as viewed from the Z1 side. Note that the positional relationship of each component shown in FIGS. 4A and 4B corresponds to the positional relationship when the imaging device 101 is assembled. For clarity, other components are omitted from FIGS. 4A and 4B. Furthermore, the following description with reference to Figures 4A and 4B relates to the combination of the first wire SA1 and the second wire SA2, but also applies similarly 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.

[0031] Specifically, one end of the first wire SA1 is fixed to the first movable terminal plate 5M1 at the lower retaining portion J3 of the first movable terminal plate 5M1, and the other end of the first wire SA1 is fixed to the first fixed terminal plate 5F1 at the retaining portion J2 of the first fixed terminal plate 5F1. Similarly, one end of the second wire SA2 is fixed to the first movable terminal plate 5M1 at the upper retaining portion J1 of the first movable terminal plate 5M1, and the other end of the second wire SA2 is fixed to the second fixed terminal plate 5F2 at the retaining portion J4 of the second fixed terminal plate 5F2.

[0032] The holding portion J1 is formed by bending a portion of the first movable terminal plate 5M1. Specifically, the holding portion J1 is formed by bending a portion of the first movable terminal plate 5M1 while sandwiching one end of the second wire SA2. The one end of the second wire SA2 is fixed to the holding portion J1 by welding. The same applies to the holding portions J2 to J4.

[0033] 4A and 4B, the first wire SA1 and the second wire SA2 are arranged so as to be twisted relative to each other. That is, the first wire SA1 and the second wire SA2 are arranged so as not to contact each other (are non-contacting).

[0034] Next, the base member 18, which is a part of the fixed-side member FB, will be described in detail with reference to Fig. 5. Fig. 5 is a perspective view of the base member 18. Specifically, the upper view of Fig. 5 is a perspective view of the base member 18 with the conductive member CM removed, the center view of Fig. 5 is a perspective view of the conductive member CM embedded in the base member 18, and the bottom view of Fig. 5 is a perspective view of the base member 18 with the conductive member CM embedded. Note that in the center and bottom views of Fig. 5, a dot pattern is added to the conductive member CM for clarity.

[0035] The base member 18 is configured to function as a wire supporting member that supports one end of each of the first wire SA1 to eighth wire SA8. With this configuration, the movable-side member MB is supported by the first wire SA1 to eighth wire SA8 in a state where it can move in the Z-axis direction, which is a direction parallel to the optical axis OA.

[0036] A fixed-side pedestal portion 18D is formed on the upper surface, which is the surface on the subject side (the surface on the Z1 side) of the base member 18. The fixed-side pedestal portion 18D includes a first fixed-side pedestal portion 18D1 and a second fixed-side pedestal portion 18D2. The first fixed-side pedestal portion 18D1 and the second fixed-side pedestal portion 18D2 are arranged to face each other with the optical axis OA in between.

[0037] 5, a conductive member CM formed from a metal plate containing a material such as copper, iron, or an alloy containing these as a main component is embedded in the base member 18 by insert molding. In this embodiment, the conductive member CM is configured to have first to sixth terminal portions TM1 to TM6 exposed from the front surface (X1 side surface) and rear surface (X2 side surface) of the base member 18 and extending downward (in the Z2 direction), and a fifth bonding surface portion CP5 and a sixth bonding surface portion CP6 exposed on the top surface (Z1 side surface) of the base member 18.

[0038] Specifically, the conductive member CM includes a first conductive member CM1 to a sixth conductive member CM6. The first conductive member CM1 includes a first terminal portion TM1 and a first connection portion ED1. The second conductive member CM2 includes a second terminal portion TM2 and a second connection portion ED2. The third conductive member CM3 includes a third terminal portion TM3 and a third connection portion ED3. The fourth conductive member CM4 includes a fourth terminal portion TM4 and a fourth connection portion ED4. The fifth conductive member CM5 includes a fifth terminal portion TM5 and a fifth bonding surface portion CP5. The sixth conductive member CM6 includes a sixth terminal portion TM6 and a sixth bonding surface portion CP6.

[0039] The first terminal TM1, the second terminal TM2, and the sixth terminal TM6 are arranged along a third side 18E3 of the base member 18. The third terminal TM3 to the fifth terminal TM5 are arranged along a first side 18E1 of the base member 18.

[0040] The first connection portion ED1 of the first conductive member CM1 is arranged along the second side 18E2 of the base member 18, and the first terminal portion TM1 of the first conductive member CM1 is arranged along the third side 18E3, not the second side 18E2, of the base member 18. Similarly, the second connection portion ED2 of the second conductive member CM2 is arranged along the second side 18E2 of the base member 18, and the second terminal portion TM2 of the second conductive member CM2 is arranged along the third side 18E3, not the second side 18E2, of the base member 18.

[0041] Furthermore, the third connection portion ED3 of the third conductive member CM3 is arranged along the fourth side 18E4 of the base member 18, and the third terminal portion TM3 of the third conductive member CM3 is arranged along the first side 18E1, not the fourth side 18E4, of the base member 18. Similarly, the fourth connection portion ED4 of the fourth conductive member CM4 is arranged along the fourth side 18E4 of the base member 18, and the fourth terminal portion TM4 of the fourth conductive member CM4 is arranged along the first side 18E1, not the fourth side 18E4, of the base member 18.

[0042] In this way, the first terminal portion TM1 to the sixth terminal portion TM6 are arranged along the first side portion 18E1 or the third side portion 18E3 of the base member 18, but are not arranged along the second side portion 18E2 or the fourth side portion 18E4 of the base member 18. This is to facilitate the mounting of the imaging element. Specifically, this is to ensure that a flexible printed circuit board or the like connected to the imaging element passes under at least one of the second side portion 18E2 and the fourth side portion 18E4 of the base member 18.

[0043] Next, the positional relationship between the leaf spring 6, the shape memory alloy wire SA, the metal member 5, and the conductive member CM will be described with reference to Figures 6A and 6B. Figure 6 is a diagram showing the positional relationship between the leaf spring 6, the shape memory alloy wire SA, the metal member 5, and the conductive member CM. Specifically, Figure 6A is a perspective view of the metal member 5, the leaf spring 6, the shape memory alloy wire SA, and the conductive member CM, and Figure 6B is a top view of the metal member 5 and the leaf spring 6. Note that, for clarity, the shape memory alloy wire SA and the conductive member CM are omitted from Figure 6B. Also, for clarity, a dot pattern is added to the leaf spring 6 in Figures 6A and 6B.

[0044] 6B, the leaf spring 6 includes a first leaf spring 6A and a second leaf spring 6B. The first leaf spring 6A has a first portion 6A1 fixed to a first fixed-side pedestal portion 18D1 (see FIG. 2) of the base member 18, a second portion 6A2 fixed to a second fixed-side pedestal portion 18D2 (see FIG. 2) of the base member 18, a third portion 6A3 fixed to a first movable-side pedestal portion 2D1 (see FIG. 2) of the lens holder 2, a fourth portion 6A4 connecting the first portion 6A1 and the third portion 6A3, and a fifth portion 6A5 connecting the second portion 6A2 and the third portion 6A3.

[0045] The first portion 6A1 is formed with a first through hole 6AH1 and a second through hole 6AH2, through which a round protrusion 18T (see FIG. 3B) formed on the first fixed-side pedestal portion 18D1 protruding upward is inserted. In this embodiment, the leaf spring 6 and the protrusion 18T are fixed to each other by hot crimping or cold crimping the protrusion 18T. However, the leaf spring 6 and the protrusion 18T may also be fixed to each other by an adhesive.

[0046] The second portion 6A2 is formed with a third through-hole 6AH3 through which a round protrusion 18T (see FIG. 3B) formed on the second fixed-side pedestal portion 18D2 protruding upward is inserted, and a fourth through-hole 6AH4 used for joining the sixth bonding surface portion CP6 (see the lower diagram in FIG. 5) of the sixth conductive member CM6. In this embodiment, the leaf spring 6 and the conductive member CM are joined by welding such as laser welding. However, the leaf spring 6 and the conductive member CM may also be joined by soldering, a conductive adhesive, or the like.

[0047] The third portion 6A3 is formed with a fifth through hole 6AH5 and a sixth through hole 6AH6, through which a round protruding portion 2T (see FIG. 3A) formed on the first movable-side pedestal portion 2D1 and protruding upward is inserted. In this embodiment, the leaf spring 6 and the protruding portion 2T are fixed by hot crimping or cold crimping the protruding portion 2T. However, the leaf spring 6 and the protruding portion 2T may also be fixed with an adhesive.

[0048] Similarly, the second leaf spring 6B has a first portion 6B1 fixed to the first fixed side base portion 18D1 (see Figure 2) of the base member 18, a second portion 6B2 fixed to the second fixed side base portion 18D2 (see Figure 2) of the base member 18, a third portion 6B3 fixed to the second movable side base portion 2D2 (see Figure 2) of the lens holder 2, a fourth portion 6B4 connecting the first portion 6B1 and the third portion 6B3, and a fifth portion 6B5 connecting the second portion 6B2 and the third portion 6B3.

[0049] The first portion 6B1 is formed with a first through hole 6BH1 through which a round protrusion 18T (see Figure 3B) protruding upward formed on the first fixed side base portion 18D1 is inserted, and a second through hole 6BH2 used for joining to the fifth joining surface portion CP5 (see the lower diagram in Figure 5) of the fifth conductive member CM5.

[0050] The second portion 6B2 is formed with a third through-hole 6BH3 and a fourth through-hole 6BH4, through which a round protrusion 18T (see FIG. 3B) formed on the second fixed-side pedestal portion 18D2 and protruding upward is inserted.

[0051] The third portion 6B3 is formed with a fifth through-hole 6BH5 and a sixth through-hole 6BH6, through which a round protrusion 2T (see FIG. 3A) formed on the second movable-side pedestal portion 2D2 and protruding upward is inserted.

[0052] The fourth portion 6A4 and the fifth portion 6A5 of the first leaf spring 6A and the fourth portion 6B4 and the fifth portion 6B5 of the second leaf spring 6B are elastically deformable arms having multiple bends, so that the lens holder 2 can move relative to the base member 18 (fixed member FB) not only in a direction parallel to the optical axis OA but also in a direction intersecting the optical axis OA.

[0053] As shown in Fig. 6B, the first leaf spring 6A and the second leaf spring 6B have substantially the same shape. Specifically, the first leaf spring 6A and the second leaf spring 6B are configured to have two-fold rotational symmetry about the optical axis OA. Therefore, this configuration can reduce the number of parts in the imaging device 101. Furthermore, the first leaf spring 6A and the second leaf spring 6B can support the lens holder 2 in a well-balanced manner in the air. Furthermore, the leaf spring 6 does not adversely affect the weight balance of the movable member MB supported by eight shape memory alloy wires SA (first wire SA1 to eighth wire SA8).

[0054] As shown in FIG. 6A , the first connection portion ED1 of the first conductive member CM1 is joined to the first contact portion CT1 of the adjacent first fixed-side terminal plate 5F1 with a bonding material SD. The bonding material SD is, for example, solder or a conductive adhesive. Specifically, the first connection portion ED1 and the first contact portion CT1 are joined adjacently with their surfaces substantially parallel to each other. Similarly, the second connection portion ED2 of the second conductive member CM2 is joined to the second contact portion CT2 of the adjacent second fixed-side terminal plate 5F2 with the bonding material SD, the third connection portion ED3 of the third conductive member CM3 is joined to the seventh contact portion CT7 of the adjacent seventh fixed-side terminal plate 5F7 with the bonding material SD, and the fourth connection portion ED4 of the fourth conductive member CM4 is joined to the eighth contact portion CT8 of the adjacent eighth fixed-side terminal plate 5F8 with the bonding material SD. Note that in FIGS. 6A and 6B , the bonding material SD is represented by a dashed circle for clarity.

[0055] As shown in Figures 6A and 6B, the ninth contact portion CT9 of the first movable terminal plate 5M1 is joined perpendicularly to the third portion 6A3 of the first leaf spring 6A by the bonding material SD. That is, the ninth contact portion CT9 and the third portion 6A3 are joined with their surfaces substantially perpendicular to each other. Similarly, the tenth contact portion CT10 of the second movable terminal plate 5M2 is joined perpendicularly to the third portion 6A3 of the first leaf spring 6A by the bonding material SD, the eleventh contact portion CT11 of the third movable terminal plate 5M3 is joined perpendicularly to the third portion 6B3 of the second leaf spring 6B by the bonding material SD, and the twelfth contact portion CT12 of the fourth movable terminal plate 5M4 is joined perpendicularly to the third portion 6B3 of the second leaf spring 6B by the bonding material SD.

[0056] 6B, the first fixed-side terminal plate 5F1 is spaced apart from the first portion 6A1 of the first leaf spring 6A and is not in contact with the first portion 6A1 of the first leaf spring 6A. Similarly, the third fixed-side terminal plate 5F3 is not in contact with the second portion 6A2 of the first leaf spring 6A, the fifth fixed-side terminal plate 5F5 is not in contact with the first portion 6B1 of the second leaf spring 6B, and the seventh fixed-side terminal plate 5F7 is not in contact with the second portion 6B2 of the second leaf spring 6B.

[0057] The fifth bonding surface CP5 (see the center diagram in FIG. 5 ) of the fifth conductive member CM5 is joined in parallel to the first portion 6B1 of the second leaf spring 6B by welding such as laser welding at the location of the second through hole 6BH2 formed in the first portion 6B1 of the second leaf spring 6B. That is, the fifth bonding surface CP5 and the first portion 6B1 are joined with their surfaces substantially parallel to each other. Similarly, the sixth bonding surface CP6 (see the center diagram in FIG. 5 ) of the sixth conductive member CM6 is joined in parallel to the second portion 6A2 of the first leaf spring 6A by welding such as laser welding at the location of the fourth through hole 6AH4 formed in the second portion 6A2 of the first leaf spring 6A.

[0058] Next, the path of current flowing through the shape memory alloy wire SA will be described with reference to FIGS. 7A to 7F. FIGS. 7A to 7F are diagrams of a portion of the configuration shown in FIG. 6A. For clarity, in FIGS. 7A to 7F, dot patterns are applied to components through which current flows. Specifically, in FIG. 7A, a coarse dot pattern is applied to the first conductive member CM1 and the second conductive member CM2, and a fine dot pattern is applied to the first movable terminal plate 5M1, the first fixed terminal plate 5F1, and the second fixed terminal plate 5F2. In FIG. 7B, a coarse dot pattern is applied to the first conductive member CM1 and the sixth conductive member CM6, a fine dot pattern is applied to the first leaf spring 6A, and an even finer dot pattern is applied to the first movable terminal plate 5M1 and the first fixed terminal plate 5F1. In Fig. 7C, the second conductive member CM2 and the sixth conductive member CM6 are marked with a coarse dot pattern, the first leaf spring 6A is marked with a fine dot pattern, and the first movable terminal plate 5M1 and the second fixed terminal plate 5F2 are marked with an even finer dot pattern. In Fig. 7D, the second movable terminal plate 5M2, the third fixed terminal plate 5F3, and the fourth fixed terminal plate 5F4 are marked with a fine dot pattern. In Fig. 7E, the sixth conductive member CM6 is marked with a coarse dot pattern, the first leaf spring 6A is marked with a fine dot pattern, and the second movable terminal plate 5M2 and the third fixed terminal plate 5F3 are marked with even finer dot patterns. In Fig. 7F, the sixth conductive member CM6 is marked with a coarse dot pattern, the first leaf spring 6A is marked with a fine dot pattern, and the second movable terminal plate 5M2 and the fourth fixed terminal plate 5F4 are marked with even finer dot patterns.

[0059] Specifically, Fig. 7A shows the current path when the first terminal TM1 of the first conductive member CM1 is connected to a high potential and the second terminal TM2 of the second conductive member CM2 is connected to a low potential. Fig. 7B shows the current path when the first terminal TM1 of the first conductive member CM1 is connected to a high potential and the sixth terminal TM6 of the sixth conductive member CM6 is connected to a low potential. Fig. 7C shows the current path when the second terminal TM2 of the second conductive member CM2 is connected to a high potential and the sixth terminal TM6 of the sixth conductive member CM6 is connected to a low potential. The following description with reference to Figs. 7A to 7C relates to the current path flowing through the first wire SA1 or the second wire SA2, but similarly applies to the current path flowing through the seventh wire SA7 or the eighth wire SA8.

[0060] When the first terminal TM1 of the first conductive member CM1 is connected to a high potential and the second terminal TM2 of the second conductive member CM2 is connected to a low potential, current flows from the first terminal TM1 through the first conductive member CM1 to the first fixed terminal plate 5F1 as shown by arrow AR1 in FIG. 7A. The current then flows through the first fixed terminal plate 5F1 as shown by arrow AR2, the first wire SA1 as shown by arrow AR3, and the first movable terminal plate 5M1 as shown by arrow AR4. The current then flows through the second wire SA2 as shown by arrow AR5, the second fixed terminal plate 5F2 as shown by arrow AR6, and the second conductive member CM2 to the second terminal TM2 as shown by arrow AR7.

[0061] When the first terminal TM1 of the first conductive member CM1 is connected to a high potential and the sixth terminal TM6 of the sixth conductive member CM6 is connected to a low potential, current flows from the first terminal TM1 through the first conductive member CM1 to the first fixed terminal plate 5F1 as shown by arrow AR11 in FIG. 7B. The current then flows through the first fixed terminal plate 5F1 as shown by arrow AR12, the first wire SA1 as shown by arrow AR13, and the first movable terminal plate 5M1 as shown by arrow AR14. The current then flows through the third portion 6A3, the fifth portion 6A5, and the second portion 6A2 of the first leaf spring 6A as shown by arrow AR15, and then through the sixth conductive member CM6 to the sixth terminal TM6 as shown by arrows AR16 and AR17.

[0062] When the second terminal TM2 of the second conductive member CM2 is connected to a high potential and the sixth terminal TM6 of the sixth conductive member CM6 is connected to a low potential, current flows from the second terminal TM2 through the second conductive member CM2 to the second fixed terminal plate 5F2 as shown by arrow AR21 in FIG. 7C. The current then flows through the second fixed terminal plate 5F2 as shown by arrow AR22, the second wire SA2 as shown by arrow AR23, and the first movable terminal plate 5M1 as shown by arrow AR24. The current then flows through the third portion 6A3, the fifth portion 6A5, and the second portion 6A2 of the first leaf spring 6A as shown by arrow AR25, and then through the sixth conductive member CM6 to the sixth terminal TM6 as shown by arrows AR26 and AR27.

[0063] 7D shows the current path when the third contact portion CT3 of the third fixed-side terminal plate 5F3 is connected to a high potential and the fourth contact portion CT4 of the fourth fixed-side terminal plate 5F4 is connected to a low potential. FIG. 7E shows the current path when the third contact portion CT3 of the third fixed-side terminal plate 5F3 is connected to a high potential and the sixth terminal portion TM6 of the sixth conductive member CM6 is connected to a low potential. FIG. 7F shows the current path when the fourth contact portion CT4 of the fourth fixed-side terminal plate 5F4 is connected to a high potential and the sixth terminal portion TM6 of the sixth conductive member CM6 is connected to a low potential. The following description with reference to FIGS. 7D to 7F relates to the current path flowing through the third wire SA3 or the fourth wire SA4, but also applies similarly to the current path flowing through the fifth wire SA5 or the sixth wire SA6.

[0064] When the third contact portion CT3 of the third fixed terminal plate 5F3 is connected to a high potential and the fourth contact portion CT4 of the fourth fixed terminal plate 5F4 is connected to a low potential, current flows from the third contact portion CT3 through the third fixed terminal plate 5F3 to the third wire SA3 as shown by arrow AR31 in FIG. 7D. The current then flows through the third wire SA3 as shown by arrow AR32, through the second movable terminal plate 5M2 as shown by arrow AR33, and through the fourth wire SA4 as shown by arrow AR34. The current then flows through the fourth fixed terminal plate 5F4 to the fourth contact portion CT4 as shown by arrow AR35.

[0065] When the third contact portion CT3 of the third fixed terminal plate 5F3 is connected to a high potential and the sixth terminal portion TM6 of the sixth conductive member CM6 is connected to a low potential, current flows from the third contact portion CT3 through the third fixed terminal plate 5F3 to the third wire SA3 as shown by arrow AR41 in FIG. 7E. The current then flows through the third wire SA3 as shown by arrow AR42, through the second movable terminal plate 5M2 as shown by arrow AR43, and through the third portion 6A3, fifth portion 6A5, and second portion 6A2 of the first leaf spring 6A as shown by arrow AR44. The current then flows through the sixth conductive member CM6 from the sixth joint surface portion CP6 to the sixth terminal portion TM6 as shown by arrow AR45.

[0066] When the fourth contact portion CT4 of the fourth fixed terminal plate 5F4 is connected to a high potential and the sixth terminal portion TM6 of the sixth conductive member CM6 is connected to a low potential, current flows from the fourth contact portion CT4 through the fourth fixed terminal plate 5F4 to the fourth wire SA4 as shown by arrow AR51 in FIG. 7F. The current then flows through the fourth wire SA4 as shown by arrow AR52, the second movable terminal plate 5M2 as shown by arrow AR53, and the third portion 6A3, the fifth portion 6A5, and the second portion 6A2 of the first leaf spring 6A as shown by arrow AR54. The current then flows through the sixth conductive member CM6 from the sixth joint surface portion CP6 to the sixth terminal portion TM6 as shown by arrow AR55.

[0067] Next, an example of a connection structure for connecting the fixed-side metal member 5F and the conductive member CM will be described with reference to Figs. 8A and 8B. Figs. 8A and 8B are diagrams showing an example of a connection structure for connecting the fixed-side metal member 5F and the conductive member CM. Specifically, Fig. 8A is an enlarged view (perspective view) of the area R1 surrounded by the dashed line shown in Fig. 3B. Fig. 8B is a right side view of the area R1 surrounded by the dashed line shown in Fig. 3B. Note that in Figs. 8A and 8B, a fine dot pattern is applied to the base member 18 for clarity.

[0068] 8A and 8B, the first fixed-side terminal plate 5F1 is attached to the Y2-side side wall (right-side mounting surface) of the first fixed-side pedestal portion 18D1 of the base member 18 with a photocurable adhesive. The first contact portion CT1 of the first fixed-side terminal plate 5F1 is joined to the first connection portion ED1 of the first conductive member CM1 via a bonding material SD. Note that in FIGS. 8A and 8B, a cross pattern is applied to the bonding material SD for clarity.

[0069] Similarly, the second fixed-side terminal plate 5F2 is attached with a light-curing adhesive to the Y2-side side wall (right-side mounting surface) of the first fixed-side pedestal portion 18D1 of the base member 18. The second contact portion CT2 of the second fixed-side terminal plate 5F2 is joined to the second connection portion ED2 of the second conductive member CM2 via the bonding material SD.

[0070] 8B, the first connection portion ED1 is disposed so that its end face on the X1 side (front side) faces the end face on the X2 side (rear side) of the first contact portion CT1 in the X-axis direction. Similarly, the second connection portion ED2 is disposed so that its end face on the X1 side (front side) faces the end face on the X2 side (rear side) of the second contact portion CT2 in the X-axis direction.

[0071] This arrangement allows the bonding material SD to adhere to at least the front surface (X1 side surface) of the first connection portion ED1 and the rear surface (X2 side surface) and top surface (Z1 side surface) of the first contact portion CT1, thereby increasing the connection strength between the first contact portion CT1 and the first connection portion ED1 by the bonding material SD. The same applies to the connection strength between the second contact portion CT2 and the second connection portion ED2 by the bonding material SD.

[0072] This arrangement also prevents the first contact portion CT1 from being joined with the joining material SD only to the right end surface (the surface on the Y2 side) of the first connection portion ED1, which is not plated. The same applies to the joint between the second connection portion ED2 and the second contact portion CT2. Note that the right end surface (the surface on the Y2 side) of the first connection portion ED1 is not plated because it is a cut surface formed when a truncated connecting portion (not shown) is cut off. The truncated connecting portion is a portion for connecting multiple conductive members, and is used when multiple conductive members are embedded in the base member 18 by insert molding, but is ultimately truncated.

[0073] Next, the driving device 10 and the control device 20, which are components of the imaging device 101 described above, will be described with reference to Fig. 9. Fig. 9 is a diagram showing an example of the configuration of the driving device 10 and the control device 20. In Fig. 9, for clarity, the parts that make up the driving device 10 are represented by solid lines, and the parts that make up the control device 20 are represented by dashed lines.

[0074] The driving device 10 is configured to supply a driving current to each of the plurality of shape memory alloy wires SA to drive each of the plurality of shape memory alloy wires SA. The driving current is a current for driving (heating and shrinking) the shape memory alloy wires SA, and is, for example, a pulse current. In this embodiment, the driving device 10 is an electronic circuit configured with active elements AE such as switching elements, operational amplifiers, or ICs, and is configured to operate in response to a control signal from the control device 20.

[0075] In the illustrated example, the driving device 10 includes a first driving device 10A configured to be able to drive each of the first wire SA1 to fourth wire SA4, and a second driving device 10B (details not shown) configured to be able to drive each of the fifth wire SA5 to eighth wire SA8. The second driving device 10B has a similar configuration to the first driving device 10A.

[0076] The control device 20 is configured to be able to control the drive device 10. In this embodiment, the control device 20 is a microcomputer including a CPU, a volatile storage device, a nonvolatile storage device, and the like.

[0077] In the illustrated example, the control device 20 can control the driving device 10 to move the lens holder 2 in a direction parallel to the optical axis OA on the Z1 side (subject side) of the imaging element by utilizing the driving force along the direction parallel to the optical axis OA due to the contraction of the shape memory alloy wire SA. By moving the lens holder 2 in this manner, the control device 20 can realize an autofocus adjustment function, which is one of the lens adjustment functions. Specifically, the control device 20 can realize macro photography by moving the lens holder 2 in a direction away from the imaging element, and can realize infinity photography by moving the lens holder 2 in a direction toward the imaging element.

[0078] Furthermore, the control device 20 can control the driving device 10 to move the lens holder 2 in a direction intersecting with the optical axis OA by controlling the current flowing through the plurality of shape memory alloy wires SA, thereby enabling the control device 20 to realize an image stabilization function.

[0079] In the illustrated example, the imaging device 101, which has a substantially rectangular parallelepiped shape, is mounted on an external board (not shown) on which an imaging element (not shown) is mounted. The camera module is composed of, for example, the external board, the imaging device 101, a lens body attached to the lens holder 2, and an imaging element disposed opposite the lens body. The driving unit 10 and the control unit 20 are mounted on the external board. However, at least one of the driving unit 10 and the control unit 20 may be disposed inside the imaging device 101. The imaging element may be mounted on the imaging device 101.

[0080] In the illustrated example, the control device 20 can control the driving device 10 so that the measurement current is supplied to each of the eight shape memory alloy wires SA at a timing different from the timing at which the driving current is supplied.

[0081] The measurement current is a current for measuring the resistance between both ends of the shape memory alloy wire SA. The measurement current is preferably a weak current that does not affect the length of the shape memory alloy wire SA, for example, a pulse current. In the illustrated example, the control device 20 can derive the magnitude of the resistance between both ends of the shape memory alloy wire SA (measured resistance value) by measuring the voltage between both ends of the shape memory alloy wire SA when a measurement current of a known magnitude is passed through the shape memory alloy wire SA. The measured resistance values of each of the eight shape memory alloy wires SA are then used to achieve a desired posture of the lens holder 2 (lens body). For example, the control device 20 can set target lengths for each of the eight shape memory alloy wires SA corresponding to the desired posture of the lens holder 2 (lens body), and can further set target resistance values for each of the eight shape memory alloy wires SA corresponding to each of the eight target lengths. Then, the control device 20 can achieve a desired posture of the lens holder 2 (lens body) by controlling the drive device 10 so that the difference between the measured resistance value and the target resistance value of each of the eight shape memory alloy wires SA approaches zero. The measurement current is a weak current that does not affect the length of the shape memory alloy wire SA, and therefore its magnitude is significantly smaller than that of the driving current.

[0082] In the illustrated example, the control device 20 sets a target resistance value for each of the eight shape memory alloy wires SA to achieve a desired posture of the lens holder 2 (lens body). Then, the control device 20 controls the driving device 10 so that the measured resistance value of each of the eight shape memory alloy wires SA becomes the same as the target resistance value. In other words, the control device 20 executes feedback control of the resistance value of each of the eight shape memory alloy wires SA.

[0083] Specifically, the control device 20 controls the drive device 10 so that the difference between the target resistance value and the measured resistance value approaches zero for each of the eight shape memory alloy wires SA, and adjusts at least one of the magnitude and supply time (duration) of the driving current supplied to each of the eight shape memory alloy wires SA. In the illustrated example, when the target resistance value of a specific shape memory alloy wire SA is smaller than the measured resistance value, the control device 20 increases the amount of power supplied to the specific shape memory alloy wire SA to contract the specific shape memory alloy wire SA. For example, the control device 20 lengthens the supply time of the driving current, i.e., the time during which a predetermined voltage is applied between both ends of the specific shape memory alloy wire SA. Conversely, when the target resistance value of the specific shape memory alloy wire SA is larger than the measured resistance value, the control device 20 reduces the amount of power supplied to the specific shape memory alloy wire SA and increases the amount of power supplied to other shape memory alloy wires SA other than the specific shape memory alloy wire SA to elongate the specific shape memory alloy wire SA. For example, the control device 20 increases the time for which a predetermined voltage is applied between both ends of another shape memory alloy wire SA other than the particular shape memory alloy wire SA.

[0084] Specifically, the first driving device 10A includes a high potential source 11, a low potential source 12, a constant current source 13, and an active element AE, as shown in Fig. 9. The following description with reference to Fig. 9 relates to the first driving device 10A, but also applies to the second driving device 10B.

[0085] The high potential source 11 is a potential source configured to have a potential higher than the potentials of the ground (GND) and the low potential source 12 .

[0086] The low potential source 12 is a potential source configured to have a potential higher than the potential of the ground (GND) and lower than the high potential source 11 .

[0087] Although the high potential source 11 and the low potential source 12 both have fixed potentials, at least one of the high potential source 11 and the low potential source 12 may be configured so that the potential changes dynamically in response to a control signal from the control device 20.

[0088] The constant current source 13 is an electric circuit that can supply a current having a constant magnitude even when the resistance value of the load changes. In the illustrated example, the constant current source 13 is configured to supply a measurement current having a constant magnitude to each of the first wire SA1 to the fourth wire SA4. The magnitude of the measurement current is set, for example, by the control device 20. In this case, the magnitude of the measurement current may be stored in a non-volatile storage device in the control device 20. For example, the magnitude of the measurement current may be set based on the results of a factory inspection performed before shipping the product (imaging device 101) so as to be compatible with each of the first wire SA1 to the fourth wire SA4. In this case, variation in characteristics due to individual differences in shape memory alloy wires is suppressed.

[0089] The active elements AE are elements that perform active operations such as amplification or rectification using supplied power. In the illustrated example, the active elements AE include a first active element AE1 to a sixth active element AE6.

[0090] The first active element AE1 is a multiplexer that combines three inputs into one output. In the illustrated example, the three inputs of the first active element AE1 are connected to a high potential source 11, a low potential source 12, and a constant current source 13, and one output of the first active element AE1 is connected to a second active element AE2.

[0091] The second active element AE2 is a demultiplexer that distributes one input to four outputs. In the illustrated example, one input of the second active element AE2 is connected to the first active element AE1, and four outputs of the second active element AE2 are connected to the first wire SA1, the third wire SA3, the third active element AE3, and the fourth active element AE4.

[0092] The third active element AE3 is a multiplexer that combines two inputs into one output. In the illustrated example, the two inputs of the third active element AE3 are connected to the second active element AE2 and ground (GND), and one output of the third active element AE3 is connected to the second wire SA2.

[0093] The fourth active element AE4 is a multiplexer that combines two inputs into one output. In the illustrated example, the two inputs of the fourth active element AE4 are connected to the second active element AE2 and ground (GND), and one output of the fourth active element AE4 is connected to the fourth wire SA4.

[0094] The fifth active element AE5 is a switching element that controls the connection between the input and the output. In the illustrated example, the input of the fifth active element AE5 is connected to a common conductive path CD0, which is a conductive path that is connected to each of the first wire SA1, the second wire SA2, the third wire SA3, and the fourth wire SA4, and one output of the fifth active element AE5 is connected to ground (GND).

[0095] The sixth active element AE6 is an operational amplifier (op-amp) having two inputs and one output. In the illustrated example, one input of the sixth active element AE6 is connected to a first measurement point MP1 on the conductive path between the first active element AE1 and the second active element AE2, the other input of the sixth active element AE6 is connected to a second measurement point MP2 on the common conductive path CD0, and one output of the sixth active element AE6 is connected to the control device 20.

[0096] In the illustrated example, one end of the first wire SA1 is connected to the second active element AE2 through the first conductive path CD1, and the other end is connected to the common conductive path CD0. Furthermore, one end of the second wire SA2 is connected to the third active element AE3 through the second conductive path CD2, and the other end is connected to the common conductive path CD0. Furthermore, one end of the third wire SA3 is connected to the second active element AE2 through the third conductive path CD3, and the other end is connected to the common conductive path CD0. Furthermore, one end of the fourth wire SA4 is connected to the fourth active element AE4 through the fourth conductive path CD4, and the other end is connected to the common conductive path CD0.

[0097] Specifically, as shown in Fig. 7A, the first conductive path CD1 includes the first fixed-side terminal plate 5F1, and the second conductive path CD2 includes the second fixed-side terminal plate 5F2. Also, as shown in Fig. 7D, the third conductive path CD3 includes the third fixed-side terminal plate 5F3, and the fourth conductive path CD4 includes the fourth fixed-side terminal plate 5F4. Also, as shown in Figs. 7B, 7C, 7E, and 7F, the common conductive path CD0 includes the first movable-side terminal plate 5M1, the second movable-side terminal plate 5M2, the first leaf spring 6A (the third portion 6A3, the fifth portion 6A5, and the second portion 6A2), and the sixth conductive member CM6.

[0098] 7A to 7F, the first driving device 10A can control the contraction of each of the first wire SA1 to fourth wire SA4 by controlling the voltages applied to the first terminal TM1, the second terminal TM2, the sixth terminal TM6, the third contact portion CT3, and the fourth contact portion CT4, respectively. The same applies to the second driving device 10B.

[0099] Furthermore, in the illustrated example, when current is passed through each of the third wire SA3 and the fourth wire SA4, the first driving device 10A does not use a long conductive path (first conductive member CM1 and second conductive member CM2 extending along the opening 18K of the base member 18) that is used when current is passed through each of the first wire SA1 and the second wire SA2. Therefore, this configuration has the advantage of being able to reduce a magnetic field (induced magnetic field) formed around the conductive path, which can adversely affect the image quality of the imaging element, when current is passed through each of the third wire SA3 and the fourth wire SA4. In other words, this configuration has the advantage of being able to relax the restrictions on the magnitude of the current flowing through each of the third wire SA3 and the fourth wire SA4 compared to the restrictions on the magnitude of the current flowing through each of the first wire SA1 and the second wire SA2.

[0100] In the illustrated example, the first driver 10A and the second driver 10B are configured to share the high potential source 11, the low potential source 12, and the constant current source 13, respectively, but they may be configured to have at least one of the high potential source 11, the low potential source 12, and the constant current source 13 individually. For example, the constant current source 13 may include a first constant current source connected to the first active element AE1 of the first driver 10A and a second constant current source connected to the first active element (not shown) of the second driver 10B.

[0101] In the illustrated example, the driving device 10 is configured to be connected to both the high potential source 11 and the low potential source 12, but may be configured to be connected to either the high potential source 11 or the low potential source 12. In this case, the other of the high potential source 11 and the low potential source 12 may be omitted.

[0102] In the illustrated example, the driving device 10 has a constant current source 13 and is configured to electrically connect the constant current source 13 to the shape memory alloy wire SA when a measurement current is passed through the shape memory alloy wire SA. However, the constant current source 13 may be omitted. In this case, the driving device 10 may be provided with an AD converter for detecting the magnitude of the measurement current flowing through the shape memory alloy wire SA as a voltage value. Alternatively, the driving device 10 may be provided with a shunt resistor for measuring the magnitude of the measurement current flowing through the shape memory alloy wire SA.

[0103] In the illustrated example, the common conductive path CD0 is configured to be connected to ground (GND) via the fifth active element AE5, but may be configured to be connected to one of the high potential source 11 and the low potential source 12 via an active element. In this case, each of the first wire SA1 to the fourth wire SA4 may be configured so that one end is connected to ground (GND) via an active element such as an N-channel transistor, and the other end is connected to the common conductive path CD0.

[0104] Next, examples of paths of current flowing through the shape memory alloy wire SA will be described with reference to Figures 10A to 10D. Figures 10A to 10D are diagrams showing examples of paths of current in the driving device 10, and correspond to Figure 9. In Figures 10A to 10D, for clarity, conductive paths through which current flows are represented by thick solid lines, and conductive paths through which no current flows are represented by dashed lines.

[0105] 10A shows an example of a path of a driving current flowing through two shape memory alloy wires SA (a first wire SA1 and a second wire SA2) electrically connected in series. The path of the driving current shown in FIG. 7A is one specific example of the path of the driving current shown in FIG. 10A. Specifically, FIG. 10A shows the path of a driving current flowing from the high potential source 11 to the ground (GND) when the high potential source 11, the first conductive path CD1, the first wire SA1, the common conductive path CD0, the second wire SA2, the second conductive path CD2, and the ground (GND) are electrically connected in series. In this case, the first conductive path CD1 is realized by the first conductive member CM1 and the first fixed-side terminal plate 5F1 in FIG. 7A, the second conductive path CD2 is realized by the second fixed-side terminal plate 5F2 and the second conductive member CM2 in FIG. 7A, and the common conductive path CD0 is realized by the first movable-side terminal plate 5M1.

[0106] 10B shows an example of a path of a driving current flowing through a single shape memory alloy wire SA (first wire SA1). The path of the driving current shown in FIG. 7B is one specific example of the path of the driving current shown in FIG. 10B. Specifically, FIG. 10B shows the path of the driving current flowing from the low potential source 12 to the ground (GND) when the low potential source 12, the first conductive path CD1, the first wire SA1, the common conductive path CD0, and the ground (GND) are electrically connected in series. In this case, the first conductive path CD1 is realized by the first conductive member CM1 and the first fixed side terminal plate 5F1 in FIG. 7B, and the common conductive path CD0 is realized by the first movable side terminal plate 5M1, the first leaf spring 6A (the third portion 6A3, the fifth portion 6A5, and the second portion 6A2), and the sixth conductive member CM6 in FIG. 7B.

[0107] 10C shows another example of the path of the driving current flowing through a single shape memory alloy wire SA (second wire SA2). The path of the driving current shown in FIG. 7C is one specific example of the path of the driving current shown in FIG. 10C. Specifically, FIG. 10C shows the path of the driving current flowing from the low potential source 12 to the ground (GND) when the low potential source 12, the second conductive path CD2, the second wire SA2, the common conductive path CD0, and the ground (GND) are electrically connected in series. In this case, the second conductive path CD2 is realized by the second conductive member CM2 and the second fixed side terminal plate 5F2 in FIG. 7C, and the common conductive path CD0 is realized by the first movable side terminal plate 5M1, the first leaf spring 6A (the third portion 6A3, the fifth portion 6A5, and the second portion 6A2), and the sixth conductive member CM6 in FIG. 7C.

[0108] 10D shows an example of a path of a measurement current flowing through a single shape memory alloy wire SA (first wire SA1). The current path shown in FIG. 7B is one specific example of the current path shown in FIG. 10D. Specifically, FIG. 10D shows the path of a measurement current flowing from the constant current source 13 to ground (GND) when the constant current source 13, the first conductive path CD1, the first wire SA1, the common conductive path CD0, and ground (GND) are electrically connected in series. In this case, the first conductive path CD1 is realized by the first conductive member CM1 and the first fixed-side terminal plate 5F1 in FIG. 7B, and the common conductive path CD0 is realized by the first movable-side terminal plate 5M1, the first leaf spring 6A (the third portion 6A3, the fifth portion 6A5, and the second portion 6A2), and the sixth conductive member CM6 in FIG. 7B.

[0109] In this state, one input of the sixth active element AE6 is connected to a first measurement point MP1 on the conduction path between the first active element AE1 and the second active element AE2, and the other input of the sixth active element AE6 is connected to a second measurement point MP2 on the common conduction path CD0. Therefore, the sixth active element AE6, which functions as an operational amplifier, outputs the potential difference (voltage) between the potential at the first measurement point MP1 and the potential at the second measurement point MP2 to the control device 20. The control device 20 can calculate the resistance of the first wire SA1 based on the magnitude of the voltage and the magnitude of the current output by the constant current source 13. The control device 20 can similarly calculate the resistance of each of the second wire SA2 to the fourth wire SA4.

[0110] Next, an example of the timing relationship between the driving current and the measurement current flowing through the shape memory alloy wire SA will be described with reference to Fig. 11. Fig. 11 is an example of a timing chart of the driving current and the measurement current flowing through each of the first wire SA1 to the fourth wire SA4. Specifically, Fig. 11 shows the timing relationship between the driving current and the measurement current flowing through each of the first wire SA1 to the fourth wire SA4 by showing the transition over time of the voltage applied to each of the first wire SA1 to the fourth wire SA4. Note that the following description with reference to Fig. 11 relates to the timing relationship between the driving current and the measurement current flowing through each of the first wire SA1 to the fourth wire SA4, but it also applies to the timing relationship between the driving current and the measurement current flowing through each of the fifth wire SA5 to the eighth wire SA8.

[0111] 11, the control of the drive device 10 by the control device 20 is realized by a pulse width modulation method. Note that the control of the drive device 10 by the control device 20 may be realized by another method such as a pulse amplitude modulation method.

[0112] Specifically, the control device 20 controls the drive device 10 so that a drive current flows through the first wire SA1 during the first drive time slot D1, a drive current flows through the second wire SA2 during the second drive time slot D2, a drive current flows through the third wire SA3 during the third drive time slot D3, and a drive current flows through the fourth wire SA4 during the fourth drive time slot D4.

[0113] The first drive time slot D1 is a time slot that is preset as a period during which a drive current can be passed through the first wire SA1. The same applies to the second drive time slot D2 to the fourth drive time slot D4. In the illustrated example, the drive device 10 is configured so that the first drive time slot D1 to the fourth drive time slot D4 have the same length (duration). However, the drive device 10 may also be configured so that the first drive time slot D1 to the fourth drive time slot D4 have different lengths (durations).

[0114] In addition, the control device 20 controls the driving device 10 so that a measurement current flows through the first wire SA1 during the first measurement time slot M1, a measurement current flows through the second wire SA2 during the second measurement time slot M2, a measurement current flows through the third wire SA3 during the third measurement time slot M3, and a measurement current flows through the fourth wire SA4 during the fourth measurement time slot M4.

[0115] The first measurement time slot M1 is a time slot preset as a period during which a measurement current can be passed through the first wire SA1. During the first measurement time slot M1, no drive current is supplied to the first wire SA1 to the fourth wire SA4. Therefore, if pulse width modulation is employed, the period of the first measurement time slot M1 is also referred to as a "PWM OFF period." The same applies to the second measurement time slot M2 to the fourth measurement time slot M4. In the illustrated example, the drive unit 10 is configured so that the first measurement time slot M1 to the fourth measurement time slot M4 have the same magnitude (duration). However, the drive unit 10 may be configured so that the first measurement time slot M1 to the fourth measurement time slot M4 have different magnitudes (durations). In the illustrated example, the duration of the measurement current is the same as the duration of the measurement time slot, but it may be shorter or longer than the duration of the measurement time slot.

[0116] In addition, in the illustrated example, the control device 20 controls the drive device 10 so that the combination of the first drive time slot D1 to the fourth drive time slot D4 and the first measurement time slot M1 constitutes the first drive cycle, the combination of the first drive time slot D1 to the fourth drive time slot D4 and the second measurement time slot M2 constitutes the second drive cycle, the combination of the first drive time slot D1 to the fourth drive time slot D4 and the third measurement time slot M3 constitutes the third drive cycle, and the combination of the first drive time slot D1 to the fourth drive time slot D4 and the fourth measurement time slot M4 constitutes the fourth drive cycle.

[0117] In the illustrated example, the control device 20 controls the drive device 10 so that the first measurement time slot M1 is set after the first drive time slot D1 to the fourth drive time slot D4 in the first drive cycle, but the control device 20 may also control the drive device 10 so that the first measurement time slot is set between two drive time slots. For example, the control device 20 may control the drive device 10 so that the first measurement time slot M1 is set between the first drive time slot D1 and the second drive time slot D2. The same applies to the second drive cycle to the fourth drive cycle.

[0118] In the illustrated example, the control device 20 controls the drive device 10 so that a combination of the first drive cycle, the second drive cycle, the third drive cycle, and the fourth drive cycle constitutes one measurement cycle. That is, the control device 20 controls the drive device 10 so that the magnitude of the resistance of each of the four shape memory alloy wires SA (the first wire SA1 to the fourth wire SA4) can be obtained by executing one measurement cycle.

[0119] In the illustrated example, the control device 20 controls the drive device 10 so that four drive cycles are executed in the order of the first drive cycle, the second drive cycle, the third drive cycle, and the fourth drive cycle, but the control device 20 may also control the drive device 10 so that the four drive cycles are executed in another order.

[0120] In the illustrated example, the control device 20 controls the drive device 10 so that the magnitude of resistance of one shape memory alloy wire SA can be obtained when one drive cycle is executed, but the control device 20 may also control the drive device 10 so that the magnitude of resistance of two or more shape memory alloy wires SA can be obtained when one drive cycle is executed. For example, the first drive cycle may be composed of a combination of the first drive time slot D1 to the fourth drive time slot D4, the first measurement time slot M1, and the second measurement time slot M2. In this case, the second measurement time slot M2 in the second drive cycle may be omitted.

[0121] In the example shown in Figure 11, the first drive time slot D1 of the first drive cycle begins at time t1, the first drive time slot D1 ends and the second drive time slot D2 begins at time t2, the second drive time slot D2 ends and the third drive time slot D3 begins at time t3, the third drive time slot D3 ends and the fourth drive time slot D4 begins at time t4, the fourth drive time slot D4 ends and the first measurement time slot M1 begins at time t5, and the first measurement time slot M1 ends and the first drive time slot D1 of the second drive cycle begins at time t6.

[0122] During the first drive time slot D1 of the first drive cycle, the control device 20 controls the drive device 10 so that a drive current flows through the first wire SA1 for a duration E1 that is the same as the duration of the first drive time slot D1. During the second drive time slot D2 of the first drive cycle, the control device 20 controls the drive device 10 so that a drive current flows through the second wire SA2 for a duration E2 that is shorter than the duration of the second drive time slot D2. During the third drive time slot D3 of the first drive cycle, the control device 20 controls the drive device 10 so that a drive current flows through the third wire SA3 for a duration E3 that is shorter than the duration of the third drive time slot D3. During the fourth drive time slot D4 of the first drive cycle, the control device 20 controls the drive device 10 so that a drive current flows through the fourth wire SA4 for a duration E4 that is shorter than the duration of the fourth drive time slot D4. Furthermore, in the first measurement time slot M1 of the first driving cycle, the control device 20 controls the driving device 10 so that a measurement current flows through the first wire SA1 for a duration E5 that is the same as the duration of the first measurement time slot M1.

[0123] The duration E5 during which the measurement current flows through the first wire SA1 is set, for example, according to the conversion speed of an AD converter that converts the analog signal output by the sixth active element AE6 serving as an operational amplifier into a digital signal. The faster the conversion speed of the AD converter, the shorter the duration E5 can be set. In other words, if the control device 20 sets the duration E5 longer, that is, if it sets the measurement time longer, it can accurately obtain the resistance of the four shape memory alloy wires SA even if an AD converter with a slow conversion speed is used.

[0124] Furthermore, in a configuration in which the resistance of the first wire SA1 is measured while a driving current is flowing through the first wire SA1, the duration E1 during which the driving current flows through the first wire SA1 must be set to be longer than the minimum duration determined by the conversion speed of the AD converter. However, in the configuration according to this embodiment, the first driving time slot D1 and the first measurement time slot M1 are set separately, so the duration E1 does not necessarily have to be longer than the duration E5. In other words, the control device 20 can adopt a duration E1 that is shorter than the duration E5 during which the measurement current flows through the first wire SA1. The same applies to the second wire SA2 to the fourth wire SA4.

[0125] In the illustrated example, the driving device 10 includes a first driving device 10A configured to drive each of the first wire SA1 to the fourth wire SA4, and a second driving device 10B configured to drive each of the fifth wire SA5 to the eighth wire SA8. That is, the imaging device 101 is configured to have two driving devices capable of driving four shape memory alloy wires SA. This configuration increases the number of driving time slots that can be assigned to each shape memory alloy wire SA compared to a configuration having only one driving device capable of driving eight shape memory alloy wires SA, thereby reducing the magnitude of the current when supplying a desired amount of power to one shape memory alloy wire SA and ultimately reducing the magnetic field formed around the conductive path. However, the imaging device 101 may also be configured to have only one driving device capable of driving eight shape memory alloy wires SA. In this case, the control device 20 may control the one driving device so that, for example, one measurement cycle is composed of eight driving cycles, and one driving cycle is composed of a combination of eight driving time slots and one measurement time slot. Alternatively, the imaging device 101 may be configured to have four driving devices capable of driving two shape memory alloy wires SA, or may be configured to have eight driving devices capable of driving one shape memory alloy wire SA.

[0126] In the illustrated example, the control device 20 controls the drive device 10 so that a drive current is supplied to one shape memory alloy wire SA in one drive time slot, but the drive device 10 may also be controlled so that a drive current is supplied simultaneously to multiple shape memory alloy wires SA in one drive time slot. This is because, even if a drive current is supplied simultaneously to multiple shape memory alloy wires SA in one drive time slot, the drive time slot and the measurement time slot are separated, so the control device 20 can accurately measure the resistance values of each of the multiple shape memory alloy wires SA. Specifically, in a configuration in which the resistance value of a shape memory alloy wire is measured while a drive current is being supplied to the shape memory alloy wire, if a drive current (measurement current) is supplied to multiple shape memory alloy wires simultaneously, it becomes impossible to accurately measure the resistance values of each of the multiple shape memory alloy wires. This is because the magnitudes of the drive currents (measurement currents) flowing through each of the multiple shape memory alloy wires affect each other, resulting in instability. On the other hand, in a configuration in which the driving time slot and the measurement time slot are separated, such a problem does not occur.

[0127] Next, with reference to FIGS. 12A and 12B, another example of the timing relationship between the driving current and the measurement current flowing through the shape memory alloy wire SA will be described. FIG. 12A is a perspective view of a first conductive member CM1 constituting a part of the first conductive path CD1 (see FIG. 9) and a second conductive member CM2 constituting a part of the second conductive path CD2 (see FIG. 9). FIG. 12B is another example of a timing chart of the driving current and the measurement current flowing through each of the first wire SA1 to the fourth wire SA4, and corresponds to FIG. 11. Specifically, FIG. 12B illustrates the timing relationship between the driving current and the measurement current flowing through each of the first wire SA1 to the fourth wire SA4 by showing the temporal transition of the voltage applied to each of the first wire SA1 to the fourth wire SA4. Note that the following description with reference to FIG. 12A relates to the current flowing through each of the first conductive member CM1 and the second conductive member CM2, but similarly applies to the current flowing through each of the third conductive member CM3 and the fourth conductive member CM4. Furthermore, the following explanation with reference to Figures 12A and 12B relates to the timing relationship between the driving current and measurement current flowing through each of the first wire SA1 to fourth wire SA4, but it also applies to the timing relationship between the driving current and measurement current flowing through each of the fifth wire SA5 to eighth wire SA8.

[0128] In the example shown in Figure 12B, the control device 20 controls the drive device 10 so that a drive current flows through each of the first wire SA1 and the second wire SA2 during the period when the first drive time slot D1 and the second drive time slot D2 are combined, and a drive current flows through each of the third wire SA3 and the fourth wire SA4 during the period when the third drive time slot D3 and the fourth drive time slot D4 are combined.

[0129] Specifically, the control device 20 controls the drive device 10 so that drive current flows simultaneously through each of the first wire SA1 and the second wire SA2 for the period from time t1 to time td, i.e., for a duration E11 that is shorter than the duration of the first drive time slot D1.

[0130] More specifically, as shown in Fig. 10A, the control device 20 controls the drive device 10 so that the high potential source 11, the first conductive path CD1, the first wire SA1, the common conductive path CD0, the second wire SA2, the second conductive path CD2, and ground (GND) are electrically connected in series and a relatively large current is simultaneously supplied to the first wire SA1 and the second wire SA2. That is, the control device 20 controls the drive device 10 so that a current flows from a first point PT1 to a second point PT2 on the first conductive path CD1 (first conductive member CM1) as indicated by an arrow AR61 in Fig. 12A, and simultaneously a current flows from a second point PT12 to a first point PT11 on the second conductive path CD2 (second conductive member CM2) as indicated by an arrow AR62 in Fig. 12A. Hereinafter, the operating mode of the drive device 10 at this time is referred to as the "first mode," and the state of the imaging device 101 at this time is referred to as the "strong drive state." This state is also called a "common drive state" because the first wire SA1 and the second wire SA2 are driven simultaneously.

[0131] In this "strong drive state," the direction of current flowing through the first conductive path CD1 (first conductive member CM1) (the direction indicated by arrow AR61) and the direction of current flowing through the second conductive path CD2 (second conductive member CM2) (the direction indicated by arrow AR62) are opposite to each other. Therefore, the magnetic fields formed around the first conductive path CD1 (first conductive member CM1) and the magnetic fields formed around the second conductive path CD2 (second conductive member CM2) cancel each other out. As a result, the net magnetic field (induced magnetic field) that may adversely affect the image quality of the imaging element is reduced or eliminated.

[0132] Furthermore, by causing the drive device 10 to execute the "first mode" that realizes the "common drive state," the control device 20 has the effect of lengthening the "PWM OFF period" when the pulse width modulation method is employed, compared to when the "first mode" is not executed.

[0133] Thereafter, the control device 20 controls the drive device 10 so that a drive current flows through only one of the first wire SA1 or the second wire SA2 during the remaining period of the combination of the first drive time slot D1 and the second drive time slot D2, and so that a drive current flows through only one of the third wire SA3 or the fourth wire SA4 during the remaining period of the combination of the third drive time slot D3 and the fourth drive time slot D4.

[0134] In the example shown in Figure 12B, the control device 20 controls the drive device 10 so that a drive current flows only through the first wire SA1 for the period from time td to time te, i.e., for a duration E12 that is shorter than the duration of the first drive time slot D1.

[0135] More specifically, as shown in Fig. 10B, the control device 20 controls the drive device 10 so that the low potential source 12, the first conductive path CD1, the first wire SA1, the common conductive path CD0, and ground (GND) are electrically connected in series and a relatively small current is supplied to the first wire SA1. That is, as shown by arrow AR61 in Fig. 12A, the control device 20 controls the drive device 10 so that a current flows from a first point PT1 to a second point PT2 of the first conductive path CD1 (first conductive member CM1) and no current flows in the second conductive path CD2 (second conductive member CM2). Hereinafter, the operating mode of the drive device 10 at this time is referred to as the "second mode," and the state of the imaging device 101 at this time is referred to as the "weak drive state" or the "first weak drive state."

[0136] 12B, the sum of the amount of power supplied to the first wire SA1 in the "strong drive state" of the first drive cycle and the amount of power supplied to the first wire SA1 in the "first weak drive state" of the first drive cycle corresponds to the amount of power that would be supplied to the first wire SA1 if the high potential source 11 and the first wire SA1 were connected for the duration of the first drive time slot D1. Note that in FIG. 12B, the dotted line shows the voltage waveform if the high potential source 11 and the first wire SA1 were connected for the duration of the first drive time slot D1.

[0137] Furthermore, in the "first weak drive state," the magnitude of the current flowing through the first conductive path CD1 (first conductive member CM1) is smaller than in the "strong drive state," and the magnitude of the magnetic field formed around the first conductive path CD1 (first conductive member CM1) is also reduced. As a result, even when no current is supplied to the second conductive path CD2 (second conductive member CM2) and no magnetic field is formed that offsets the magnetic field formed around the first conductive path CD1 (first conductive member CM1), the magnetic field (induced magnetic field) that may adversely affect the image quality of the image sensor is reduced by the amount of the reduced magnitude of the current flowing through the first conductive path CD1 (first conductive member CM1).

[0138] In addition, the control device 20 may control the drive device 10 so that a drive current flows only through the second wire SA2 after causing the drive device 10 to execute the "first mode" during the remaining period of the combination of the first drive time slot D1 and the second drive time slot D2, i.e., during the combination of the first drive time slot D1 and the second drive time slot D2.

[0139] 10C , the control device 20 may control the driving device 10 so that the low potential source 12, the second conductive path CD2, the second wire SA2, the common conductive path CD0, and ground (GND) are electrically connected in series and a relatively small current is supplied to the second wire SA2. That is, the control device 20 may control the driving device 10 so that a current flows from the first point PT11 to the second point PT12 of the second conductive path CD2 (second conductive member CM2) and no current flows in the first conductive path CD1 (first conductive member CM1). Hereinafter, the operating mode of the driving device 10 at this time is referred to as a "third mode," and the state of the imaging device 101 at this time is referred to as a "weak drive state" or a "second weak drive state."

[0140] Alternatively, the control device 20 may control the drive device 10 to execute the "first mode" and the "second mode" during a period that combines the first drive time slot D1 and the second drive time slot D2, and then to execute the "third mode." For example, the control device 20 may control the drive device 10 so that a drive current flows only through the second wire SA2 during the period from time tf to time tg, i.e., a duration E13 that is shorter than the duration of the second drive time slot D2. This is, for example, to fine-tune the amount of power supplied to the second wire SA2. Note that FIG. 12B shows, with a dotted line, a voltage waveform that would occur if the low-potential source 12 and the second wire SA2 were connected during the period from time tf to time tg. In this manner, the drive device 10 may be configured to execute a combination of the "first mode," the "second mode," and the "third mode."

[0141] In addition, the state of the imaging device 101 when the driving device 10 is caused to execute the "second mode" or the "third mode" is also referred to as the "individual driving state" because the first wire SA1 or the second wire SA2 is driven individually.

[0142] The control device 20 can supply a desired amount of power to each of the four shape memory alloy wires SA (first wire SA1 to fourth wire SA4) by causing the drive device 10 to execute a combined mode that combines the "first mode" with the "second mode" or the "third mode." The "first mode" for the first wire SA1 and the second wire SA2 can be more effective the greater the amount of power to be supplied to the first wire SA1 and the second wire SA2 and the smaller the difference between them. This is because a large amount of power can be supplied to each of the first wire SA1 and the second wire SA2 in a short period of time while minimizing adverse effects on the image quality of the imaging element. Furthermore, the greater the difference between the amount of power to be supplied to the first wire SA1 and the amount of power to be supplied to the second wire SA2, the more dominant the "second mode" or the "third mode" becomes on the time axis. However, the control device 20 can reduce adverse effects on the image quality of the imaging element by extending the duration of the "second mode" or the "third mode" as much as possible. This is because the current flowing through the first conductive path CD1 (first conductive member CM1) or the second conductive path CD2 (second conductive member CM2) can be reduced, and the magnetic field formed around the first conductive path CD1 (first conductive member CM1) or the second conductive path CD2 (second conductive member CM2) can be reduced.

[0143] In the illustrated example, when the control device 20 causes the drive device 10 to execute the "second mode," it controls the drive device 10 so that the low potential source 12 having a fixed potential is connected to the first wire SA1, as shown in FIG. 10B . However, the control device 20 may be configured to connect a variable potential source having an adjustable potential to the first wire SA1 when the drive device 10 executes the "second mode." In this case, the control device 20 may control the drive device 10 so that an amount of power equal to the amount of power supplied to the first wire SA1 when the low potential source 12 and the first wire SA1 are connected is supplied to the first wire SA1 by lengthening the duration E12 to E12a while making the potential of the variable potential source lower than the potential of the low potential source 12. In other words, the control device 20 may lengthen the duration E12a as much as possible to lower the potential of the variable potential source as much as possible. 12B shows, with a dotted line, a voltage waveform in the case where the variable potential source and the first wire SA1 are connected for a duration E12a. The state of the imaging device 101 at this time is called the "variable weak drive state." In this "variable weak drive state," the magnitude of the current flowing through the first conductive path CD1 (first conductive member CM1) is smaller than in the "first weak drive state," and therefore the magnitude of the magnetic field formed around the first conductive path CD1 (first conductive member CM1) is further reduced. The same applies when the driving device 10 is caused to execute the "third mode."

[0144] The magnitude of the potential of the variable potential source is preferably changed at a change period that is sufficiently long relative to the period of the measurement cycle. In the example shown in Fig. 12B, the change is made in synchronization with the measurement cycle. For example, the change may be made each time one measurement cycle consisting of the first drive cycle, the second drive cycle, the third drive cycle, and the fourth drive cycle is executed and the resistance values of the four shape memory alloy wires SA (the first wire SA1 to the fourth wire SA4) are obtained. In this case, the change may be made during the period of the fourth measurement time slot M4.

[0145] Next, another configuration example of the drive device 10 will be described with reference to FIG. 13. FIG. 13 is a diagram showing another configuration example of the drive device 10. Note that the following description with reference to FIG. 13 relates to a first drive device 10A configured to be able to drive each of the first wire SA1 to the fourth wire SA4, but it also applies similarly to a second drive device 10B configured to be able to drive each of the fifth wire SA5 to the eighth wire SA8. Also, for clarity, FIG. 13 omits the illustration of active elements and other components for estimating the resistance values of each of the first wire SA1 to the fourth wire SA4, but in reality, such components are connected.

[0146] The first driving device 10A shown in FIG. 13 differs from the first driving device 10A shown in FIG. 9 in that it includes five active elements AE (tenth active element AE10 to fourteenth active element AE14).

[0147] The tenth active element AE10 is a switching element that controls the connection between the common conductive path CD0 connected to the other ends of the first wire SA1 to the fourth wire SA4 and either the low potential source (LOW) or the ground (GND).

[0148] The eleventh active element AE11 is a switching element that controls the connection between the first conductive path CD1 connected to one end of the first wire SA1 and either the high potential source (HIGH) or the low potential source (LOW).

[0149] The twelfth active element AE12 is a switching element that controls the connection between the second conductive path CD2 connected to one end of the second wire SA2 and the ground (GND).

[0150] The thirteenth active element AE13 is a switching element that controls the connection between the third conductive path CD3 connected to one end of the third wire SA3 and either the high potential source (HIGH) or the low potential source (LOW).

[0151] The fourteenth active element AE14 is a switching element that controls the connection between the fourth conductive path CD4 connected to one end of the fourth wire SA4 and the ground (GND).

[0152] The control device 20 can supply a relatively large current to the first wire SA1 and the second wire SA2 simultaneously by controlling the eleventh active element AE11 and the twelfth active element AE12 so that the high potential source (HIGH), the first conductive path CD1, the first wire SA1, the common conductive path CD0, the second wire SA2, and the ground (GND) are electrically connected in series. Also, the control device 20 can supply a relatively small current only to the first wire SA1 by controlling the tenth active element AE10 and the eleventh active element AE11 so that the low potential source (LOW), the first conductive path CD1, the first wire SA1, the common conductive path CD0, and the ground (GND) are electrically connected in series. In addition, the control device 20 can supply a relatively small current only to the second wire SA2 by controlling the tenth active element AE10 and the twelfth active element AE12 so that the low potential source (LOW), the common conductive path CD0, the second wire SA2, the second conductive path CD2, and the ground (GND) are electrically connected in series.

[0153] Similarly, the control device 20 can supply a relatively large current to the third wire SA3 and the fourth wire SA4 simultaneously by controlling the thirteenth active element AE13 and the fourteenth active element AE14 so that the high potential source (HIGH), the third conductive path CD3, the third wire SA3, the common conductive path CD0, the fourth wire SA4, and the ground (GND) are electrically connected in series. Also, the control device 20 can supply a relatively small current only to the third wire SA3 by controlling the tenth active element AE10 and the thirteenth active element AE13 so that the low potential source (LOW), the third conductive path CD3, the third wire SA3, the common conductive path CD0, and the ground (GND) are electrically connected in series. In addition, the control device 20 can supply a relatively small current only to the fourth wire SA4 by controlling the tenth active element AE10 and the fourteenth active element AE14 so that the low potential source (LOW), the common conductive path CD0, the fourth wire SA4, the fourth conductive path CD4, and the ground (GND) are electrically connected in series.

[0154] 13, the high potential source (HIGH) has a fixed potential, but may be configured so that the potential changes dynamically in response to a control signal from the control device 20. Conversely, the low potential source (LOW) has a fixed potential, but may be configured so that the potential changes dynamically in response to a control signal from the control device 20.

[0155] Alternatively, the driving device 10 shown in FIG. 13 may be configured so that one end of each of the first wire SA1 to the fourth wire SA4 can be selectively connected to ground (GND) via an active element such as an N-channel transistor while the common conductive path CD0 to which the other ends of each of the first wire SA1 to the fourth wire SA4 are connected is connected to a potential source having a potential of 3 V or the like.

[0156] Even with these configurations, the driving device 10 can execute a combined mode that combines the "first mode" with the "second mode" or the "third mode." The driving device 10 can also execute a combined mode that combines the "first mode," the "second mode," and the "third mode." The driving device 10 can also supply a measurement current to each of the eight shape memory alloy wires SA at a timing different from the timing at which the driving current is supplied.

[0157] As described above, the imaging device 101 according to the embodiment of the present invention includes, as shown in Fig. 2, a fixed member FB including a base member 18 as a fixed base, a movable member MB including a lens holder 2 capable of holding a lens body and movably provided relative to the fixed member FB, a plurality of shape memory alloy wires SA each having one end fixed to the fixed member FB and the other end fixed to the movable member MB so as to be able to move the movable member MB, a driving device 10 (see Fig. 9) capable of supplying a driving current to each of the plurality of shape memory alloy wires SA to drive each of the plurality of shape memory alloy wires SA, and a control device 20 (see Fig. 9) capable of acquiring the resistance values of each of the plurality of shape memory alloy wires SA and controlling the driving device 10. The control device 20 is configured to control the driving device 10 so that a measurement current is supplied to each of the plurality of shape memory alloy wires SA at a timing different from the timing at which the driving current is supplied, thereby acquiring the resistance values (measured resistance values) of the plurality of shape memory alloy wires SA.

[0158] The control device 20 is configured to be able to set target lengths (target resistance values) of the eight shape memory alloy wires SA corresponding to the desired posture of the lens holder 2 (lens body). The control device 20 is configured to be able to realize the desired posture of the lens holder 2 (lens body) by controlling the drive device 10 so that the difference between the measured resistance value and the target resistance value of each of the eight shape memory alloy wires SA approaches zero. The control device 20 can also increase the amount of power supplied to a specific shape memory alloy wire SA, thereby contracting the specific shape memory alloy wire SA and reducing its measured resistance value.

[0159] This configuration has the effect of enabling more accurate estimation of the length of the shape memory alloy wire SA. This is because, in this configuration, the time period for which the measurement current is continuously supplied is set independently of the time period for which the driving current is continuously supplied. In other words, in this configuration, the time period for which the measurement current is continuously supplied is set to a necessary and sufficient length.

[0160] In addition, when an AD converter is provided to detect the voltage across both ends of the shape memory alloy wire SA in order to derive the resistance value of the shape memory alloy wire SA, this configuration has the effect of allowing the operating speed of the AD converter to be set low, that is, allowing a relatively inexpensive AD converter to be used. In this configuration, the measurement current is supplied to the shape memory alloy wire SA at a timing different from the timing at which the drive current is supplied, that is, the time for which the measurement current is supplied can be set relatively freely.

[0161] Furthermore, the control device 20 may control the driving device 10 so as to supply driving currents to the plurality of shape memory alloy wires SA at different timings.

[0162] This configuration has the effect of enabling more accurate control of the expansion and contraction of each of the multiple shape memory alloy wires SA, because it is possible to prevent a portion of the driving current that should be supplied to a specific shape memory alloy wire SA from being supplied to another shape memory alloy wire SA.

[0163] Furthermore, the control device 20 may control the driving device 10 so as to supply measurement currents to the plurality of shape memory alloy wires SA at different timings.

[0164] This configuration has the effect of enabling the resistance value of each of the plurality of shape memory alloy wires SA to be obtained more accurately, because this configuration can prevent a part of the measurement current that should be supplied to a specific shape memory alloy wire SA from being supplied to another shape memory alloy wire SA.

[0165] In addition, the control device 20 may control the driving device 10 so that the minimum time for which a driving current is continuously supplied to each of the multiple shape memory alloy wires SA is shorter than the time for which a measurement current is continuously supplied to each of the multiple shape memory alloy wires SA.

[0166] This configuration has the effect of enabling more flexible adjustment of the time period during which the supply of the driving current is continued. This configuration is because the time period during which the supply of the driving current is continued can be made shorter than the time period during which the supply of the measurement current is continued. Note that being able to shorten the time period during which the supply of the driving current is continued means that the amount of power supplied to a specific shape memory alloy wire SA in one driving cycle (driving time slot) can be reduced, that is, the shape memory alloy wire SA can be slightly heated and slightly contracted.

[0167] Furthermore, the control device 20 may control the driving device 10 so that the magnitude of the measurement current is smaller than the magnitude of the driving current.

[0168] This configuration brings about the effect of reducing the influence of the measurement current on the driving of the shape memory alloy wire SA.

[0169] Furthermore, the control device 20 may control the driving device 10 to supply a driving current to each of the plurality of shape memory alloy wires SA once in one driving cycle, and to supply a measurement current to any one of the plurality of shape memory alloy wires SA. The control device 20 may also control the driving device 10 to supply a measurement current to each of the plurality of shape memory alloy wires SA by repeating the driving cycle multiple times.

[0170] This configuration has the effect of enabling smoother driving of the lens holder 2 (lens body), because it is possible to supply a driving current to each of the multiple shape memory alloy wires SA at relatively short intervals, and it is also possible to prevent an excessively long period during which a driving current cannot be supplied to one of the multiple shape memory alloy wires SA.

[0171] The control device 20 may also control the driving device 10 to supply a measurement current to each of the plurality of shape memory alloy wires SA by repeating the driving cycle the same number of times as the number of the plurality of shape memory alloy wires SA.

[0172] This configuration has the effect of suppressing a decrease in control response speed and enabling smoother driving of the lens holder 2 (lens body). This is because a measurement current can be supplied to each of the multiple shape memory alloy wires SA at relatively short intervals. Also, this configuration can suppress an excessively long period during which a measurement current cannot be supplied to one of the multiple shape memory alloy wires SA.

[0173] The driving device 10 may also include a first driving device 10A that can supply a driving current to each of the four shape memory alloy wires (first wire SA1 to fourth wire SA4) to drive each of the four shape memory alloy wires (first wire SA1 to fourth wire SA4), and a second driving device 10B that can supply a driving current to each of the other four shape memory alloy wires (fifth wire SA5 to eighth wire SA8) to drive each of the other four shape memory alloy wires (fifth wire SA5 to eighth wire SA8).

[0174] This configuration has the effect of shortening the time required for one drive cycle. In other words, this configuration has the effect of suppressing a decrease in control response speed. Furthermore, this configuration has the effect of lengthening the duration of the measurement time slot without increasing the time required for one drive cycle, compared to a case where one drive device is provided that supplies a drive current to each of the eight shape memory alloy wires (the first wire SA1 to the eighth wire SA8) to drive each of the eight shape memory alloy wires (the first wire SA1 to the eighth wire SA8). Therefore, this configuration does not require increasing the applied voltage when supplying a drive current to the shape memory alloy wire SA in order to lengthen the duration of the measurement time slot. As a result, this configuration can suppress the influence of noise on the image caused by increasing the applied voltage.

[0175] As shown in FIG. 2, the imaging device 101 according to the embodiment of the present invention comprises a fixed-side member FB including a base member 18 as a fixed base, a movable-side member MB including a lens holder 2 capable of holding a lens body so as to face the imaging element and movable relative to the fixed-side member FB, a first wire SA1 as a first shape memory alloy wire having one end fixed to the fixed-side member FB and the other end fixed to the movable-side member MB, a second wire SA2 as a second shape memory alloy wire having one end fixed to the fixed-side member FB and the other end fixed to the movable-side member MB, and a second wire SA2 provided on the base member 18 and fixed to the first wire SA1. 12A, the driving device 10 includes a first conductive path CD1 (see FIG. 9) electrically connected to one end of the second wire SA2, a second conductive path CD2 (see FIG. 9) provided on the base member 18 and electrically connected to one end of the second wire SA2, a common conductive path CD0 (see FIG. 9) electrically connected to the other end of each of the first wire SA1 and the second wire SA2, and a driving device 10 (see FIG. 9) configured to be electrically connectable to each of the first conductive path CD1, the second conductive path CD2, and the common conductive path CD0 and capable of supplying current to each of the first wire SA1 and the second wire SA2 to drive each of the first wire SA1 and the second wire SA2. As shown in FIG. 12A, a portion connecting the first point PT1 and the second point PT2 on the first conductive path CD1 (first conductive member CM1) and a portion connecting the first point PT11 and the second point PT12 on the second conductive path CD2 (second conductive member CM2) are arranged parallel to each other on the base member 18. In addition, a first point PT1 on the first conductive path CD1 (first conductive member CM1) is juxtaposed to a first point PT11 on the second conductive path CD2 (second conductive member CM2), and a second point PT2 on the first conductive path CD1 (first conductive member CM1) is juxtaposed to a second point PT12 on the second conductive path CD2 (second conductive member CM2).As shown in FIG. 10A, the drive device 10 electrically connects the first conductive path CD1, the first wire SA1, the common conductive path CD0, the second wire SA2, and the second conductive path CD2 in series, and supplies current to the first wire SA1 and the second wire SA2, so that a current flows from the first point PT1 to the second point PT2 of the first conductive path CD1 (first conductive member CM1) as shown by an arrow AR61 in FIG. 12A, and a current flows from the second point PT12 to the first point PT11 of the second conductive path CD2 (second conductive member CM2) as shown by an arrow AR62 in FIG. The imaging device 101 is configured to be switchable between a first mode, a second mode in which the first conductive path CD1, the first wire SA1, and the common conductive path CD0 are electrically connected in series and a current is supplied to the first wire SA1 so that a current flows in the first conductive path CD1 (first conductive member CM1) as shown in Fig. 10B, and a third mode in which the second conductive path CD2, the second wire SA2, and the common conductive path CD0 are electrically connected in series and a current is supplied to the second wire SA2 so that a current flows in the second conductive path CD2 (second conductive member CM2) as shown in Fig. 10C. The imaging device 101 is configured to be able to execute a combination of the first mode and at least one of the second mode and the third mode.

[0176] This configuration has the effect of reducing the magnitude of the magnetic field formed around the conductive path for supplying current to the shape memory alloy wire SA, and therefore has the effect of reducing noise in the imaging element caused by the magnetic field formed around the conductive path.

[0177] This is because the magnetic field formed by the current flowing through the first conductive path CD1 is cancelled out by the magnetic field formed by the current flowing through the second conductive path CD2. Specifically, this is because the drive device 10 is configured such that, in the first mode, currents flow in opposite directions through the first conductive path CD1 (first conductive member CM1) and the second conductive path CD2 (second conductive member CM2), which are installed parallel to each other as shown in Fig. 12A, and the magnitude of the current flowing through the first conductive path CD1 (first conductive member CM1) is the same as the magnitude of the current flowing through the second conductive path CD2 (second conductive member CM2).

[0178] Furthermore, the drive device 10 is configured to execute a combined mode that combines the first mode with at least one of the second mode and the third mode, thereby enabling the desired amount of power to be accurately supplied to each of the first wire SA1 and the second wire SA2. The combination of the first mode with at least one of the second mode and the third mode may be a combination of the first mode with the second mode, a combination of the first mode with the third mode, or a combination of the first mode with the second mode and the third mode. In the combined mode that combines at least one of the first mode with the second mode and the third mode, any one of the operation modes may be executed first, or the operation modes may be executed consecutively, or a measurement time slot or a PWM OFF period may be inserted between the operation modes. The combined mode that combines the first mode with at least one of the second mode and the third mode may be executed during one or more drive cycles, or during one or more measurement cycles.

[0179] Furthermore, the driving device 10 may be configured so that the magnitude of the current flowing in the first mode is greater than the magnitude of the current flowing in each of the second and third modes.

[0180] This configuration has the effect of further reducing magnetic fields (induced magnetic fields) that may adversely affect the image quality of the imaging element. This is because, in the first mode, the magnetic fields formed by the current flowing through the first conductive path CD1 (first conductive member CM1) and the magnetic fields formed by the current flowing through the second conductive path CD2 (second conductive member CM2) cancel each other out. Furthermore, when supplying a desired amount of power to the first wire SA1, the larger the magnitude of the current flowing in the first mode, the smaller the magnitude of the current flowing in the second mode executed after the first mode. The smaller the magnitude of the current flowing in the second mode, the smaller the magnetic field formed by the current flowing through the first conductive path CD1 (first conductive member CM1) in the second mode. Similarly, when supplying a desired amount of power to the second wire SA2, the larger the magnitude of the current flowing in the first mode, the smaller the magnitude of the current flowing in the third mode executed after the first mode. The smaller the magnitude of the current flowing in the third mode, the smaller the magnetic field formed by the current flowing through the second conductive path CD2 (second conductive member CM2) in the third mode.

[0181] In addition, the portion connecting the first point PT1 and the second point PT2 on the first conductive path CD1 (first conductive member CM1) and the portion connecting the first point PT11 and the second point PT12 on the second conductive path CD2 (second conductive member CM2) may be embedded in the base member 18.

[0182] This configuration has the effect of further reducing magnetic fields (induced magnetic fields) that may adversely affect the image quality of the imaging element, because the propagation of the magnetic fields formed around the portions of the first conductive member CM1 embedded in the base member 18 and the magnetic fields formed around the portions of the second conductive member CM2 embedded in the base member 18 to the imaging element is at least partially suppressed by the base member 18.

[0183] The first wire SA1 and the second wire SA2 may be arranged to be aligned in a plan view along the optical axis direction (Z-axis direction) as shown in Fig. 4B. The first wire SA1 and the second wire SA2 may be arranged to intersect with each other in a side view along a direction (Y-axis direction) that is approximately perpendicular to the extension direction (X-axis direction) of the first wire SA1 and the second wire SA2 and perpendicular to the optical axis direction (Z-axis direction), as shown in Fig. 4A.

[0184] This configuration has the effect of further reducing the net magnetic field (induced magnetic field) that may adversely affect the image quality of the imaging element. This is because, in the first mode, when current is supplied simultaneously to the first wire SA1 and the second wire SA2 (the state shown in FIG. 7A), the induced magnetic field formed around the first wire SA1 and the induced magnetic field formed around the second wire SA2 cancel each other out.

[0185] 5, the base member 18 may have a rectangular frame shape having a first side 18E1, a second side 18E2, a third side 18E3, and a fourth side 18E4 in a plan view along the optical axis direction (Z-axis direction). As shown in FIG. 12A, the first conductive path CD1 (see FIG. 9) may include a first terminal TM1, and the second conductive path CD2 (see FIG. 9) may include a second terminal TM2. The first terminal TM1 and the second terminal TM2 may be disposed on the third side 18E3, which is one of the first side 18E1, the second side 18E2, the third side 18E3, and the fourth side 18E4. In this case, the portion connecting the first point PT1 and the second point PT2 on the first conductive path CD1 (first conductive member CM1) and the portion connecting the first point PT11 and the second point PT12 on the second conductive path CD2 (second conductive member CM2) may be arranged parallel to the second side portion 18E2, which is another one of the first side portion 18E1, the second side portion 18E2, the third side portion 18E3, and the fourth side portion 18E4.

[0186] This configuration brings about the effect of facilitating the mounting of the imaging element, because a flexible printed circuit board or the like connected to the imaging element can be disposed below the second side portion 18E2 of the base member 18.

[0187] In addition, the control method of the imaging device 101 according to an embodiment of the present invention includes a step in which the control device 20 controls the driving device 10 so that a measurement current is supplied to each of the multiple shape memory alloy wires SA at a timing different from the timing at which the driving current is supplied, and the control device 20 acquires the resistance values of the multiple shape memory alloy wires SA.

[0188] This control method allows the imaging device 101 to more accurately estimate the length of the shape memory alloy wire SA. This is because this control method sets the time for which the measurement current is continuously supplied, regardless of the time for which the driving current is continuously supplied. In other words, this control method sets the time for which the measurement current is continuously supplied to a necessary and sufficient length.

[0189] Furthermore, the control method of the imaging device 101 according to the embodiment of the present invention includes a first mode in which, as shown in FIG. 10A, the first conductive path CD1, the first wire SA1, the common conductive path CD0, the second wire SA2, and the second conductive path CD2 are electrically connected in series to supply current to the first wire SA1 and the second wire SA2, and as shown in FIG. 12A, current flows from the first point PT1 to the second point PT2 of the first conductive path CD1 (first conductive member CM1) and from the second point PT12 to the first point PT11 of the second conductive path CD2 (second conductive member CM2); The method includes a step of causing the driving device 10 to execute a composite mode that combines at least one of a second mode in which the first conductive path CD1, the first wire SA1, and the common conductive path CD0 are electrically connected in series and a current is supplied to the first wire SA1 so that a current flows through the first conductive path CD1, as shown in Figure 10B, and a third mode in which the second conductive path CD2, the second wire SA2, and the common conductive path CD0 are electrically connected in series and a current is supplied to the second wire SA2 so that a current flows through the second conductive path CD2, as shown in Figure 10C.

[0190] This control method allows the imaging device 101 to reduce the magnitude of the magnetic field formed around the conductive path for supplying current to the shape memory alloy wire SA, and therefore the imaging device 101 can reduce noise in the imaging element caused by the magnetic field formed around the conductive path.

[0191] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications and substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, the features described with reference to the above-described embodiments may be combined as appropriate unless technically inconsistent.

[0192] This application claims priority based on Japanese Patent Application No. 2022-005275, filed on January 17, 2022, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0193] 2 Lens holder 2D Movable-side base part 2D1 First movable-side base part 2D2 Second movable-side base part 2P Cylindrical part 2S Protruding part 2S1 First protruding part 2S2 Second protruding part 2T Protruding part 2V Projecting part 4 Cover member 4A Outer wall part 4A1 First side plate part 4A2 Second side plate part 4A3 Third side plate part 4A4 Fourth side plate part 4B Top plate part 4K Opening 4S Storage part 5 Metal member 5F Fixed-side metal member 5F1 First fixed-side terminal plate 5F2 Second fixed-side terminal plate 5F3···Third fixed side terminal plate 5F4···Fourth fixed side terminal plate 5F5···Fifth fixed side terminal plate 5F6···Sixth fixed side terminal plate 5F7···Seventh fixed side terminal plate 5F8···Eighth fixed side terminal plate 5M···Moving side metal member 5M1···First movable side terminal plate 5M2···Second movable side terminal plate 5M3···Third movable side terminal plate 5M4···Fourth movable side terminal plate 6···Leaf spring 6A···First leaf spring 6A1···First part 6A2···Second part 6A3···Third part 6A4···Fourth part 6A5···Fifth part 6AH1···First through hole 6AH2···Second through hole 6AH3···Third through hole 6AH4···Fourth through hole 6AH5···Fifth through hole 6AH6···Sixth through hole 6B···Second leaf spring 6B1···First part 6B2···Second part 6B3···Third part 6B4···Fourth part 6B5···Fifth part 6BH1···First through hole 6BH2···Second through hole 6BH3···Third through hole 6BH4···Fourth through hole 6BH5···Fifth through hole 6BH6···Sixth through hole 10···Driver 10A···First drive unit 10A 10B···Second drive unit 11···High potential source 12···Low potential source 13···Constant current source 18···Base member 18D···Fixed side base part 18D1···First fixed side base part 18D2···Second fixed side base part 18E···Side part 18E1···First side part 18E2···Second side part 18E3···Third side part 18E4···Fourth side part 18K···Opening 18T···Protruding part 18V···Protruding part101: Imaging device AE: Active element AE1: First active element AE2: Second active element AE3: Third active element AE4: Fourth active element AE5: Fifth active element AE6: Sixth active element AE10: Tenth active element AE11: Eleventh active element AE12: Twelfth active element AE13: Thirteenth active element AE14: Fourteenth active element AH: Rectangular hole CD0: Common conductive path CD1: First conductive path CD2: Second conductive path CD3: Third conductive path CD4: Fourth conductive path CM: Conductive member CM1: First conductive member CM2: Second conductive member CM3: Third conductive member CM4: Fourth conductive member CM5...Fifth conductive member CM6...Sixth conductive member CP5...Fifth joint surface CP6...Sixth joint surface CT1...First contact portion CT2...Second contact portion CT3...Third contact portion CT4...Fourth contact portion CT5...Fifth contact portion CT6...Sixth contact portion CT7...Seventh contact portion CT8...Eighth contact portion CT9...Ninth contact portion CT10...Tenth contact portion CT11...Eleventh contact portion CT12...Twelfth contact portion ED1...First connection portion ED2...Second connection portion ED3...Third connection portion ED4...Fourth connection portion FB...Fixed side member J1~J4...Holding portion OA...Optical axis MB...Movable side member FB···Fixed side member MP1···First measurement point MP2···Second measurement point PT1, PT11···First point PT2, PT12···Second point RH···Through hole 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 SD···Joint material TM1···First terminal TM2···Second terminal TM3···Third terminal TM4···Fourth terminal TM5···Fifth terminal TM6···Sixth terminal

Claims

1. A fixed side member, a movable side member movable relative to the fixed side member; a first shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member; a second shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member; a first conductive path electrically connected to one end of the first shape memory alloy wire; a second conductive path electrically connected to one end of the second shape memory alloy wire; a common conductive path electrically connected to the other end of each of the first shape memory alloy wire and the second shape memory alloy wire; a driving device configured to be electrically connected to each of the first conductive path, the second conductive path, and the common conductive path, and capable of supplying current to each of the first shape memory alloy wire and the second shape memory alloy wire to drive each of the first shape memory alloy wire and the second shape memory alloy wire, a portion connecting a first point and a second point on the first conductive path and a portion connecting a first point and a second point on the second conductive path are arranged in parallel to each other on the fixed-side member; An imaging device characterized by:

2. A first point on the first conductive path is juxtaposed to a first point on the second conductive path; a second point on the first conductive path is juxtaposed to a second point on the second conductive path; a first mode in which the first conductive path, the first shape memory alloy wire, the common conductive path, the second shape memory alloy wire, and the second conductive path are electrically connected in series to supply current to the first shape memory alloy wire and the second shape memory alloy wire, so that current flows from a first point to a second point of the first conductive path and from a second point to a first point of the second conductive path; The imaging device according to claim 1 .

3. A second mode is provided in which the first conductive path, the first shape memory alloy wire, and the common conductive path are electrically connected in series to supply current to the first shape memory alloy wire so that current flows through the first conductive path; configured to execute a combination of the first mode and the second mode; The imaging device according to claim 2 .

4. The magnitude of the current flowing in the first mode is greater than the magnitude of the current flowing in the second mode. The imaging device according to claim 3 .

5. a portion connecting the first point and the second point on the first conductive path and a portion connecting the first point and the second point on the second conductive path are embedded in the fixed-side member; The imaging device according to claim 1 .

6. The first shape memory alloy wire and the second shape memory alloy wire are arranged so as to be aligned in a plan view seen along the optical axis direction, and are arranged so as to intersect with each other in a side view seen along a direction that is approximately perpendicular to the extending direction of the first shape memory alloy wire and the second shape memory alloy wire and perpendicular to the optical axis direction. The imaging device according to claim 1 .

7. the fixed-side member has a rectangular frame shape having a first side, a second side, a third side, and a fourth side in a plan view along the optical axis direction, the first conductive path includes a first terminal portion, the second conductive path includes a second terminal portion, the first terminal portion and the second terminal portion are arranged on one of the first side portion, the second side portion, the third side portion, and the fourth side portion; a portion connecting the first point and the second point on the first conductive path and a portion connecting the first point and the second point on the second conductive path are arranged in parallel along another one of the first side portion, the second side portion, the third side portion, and the fourth side portion; The imaging device according to claim 1 .

8. A lens body, An imaging device according to any one of claims 1 to 7; a camera module including:

9. A fixed side member, a movable side member movable relative to the fixed side member; a first shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member; a second shape memory alloy wire having one end fixed to the fixed-side member and the other end fixed to the movable-side member; a first conductive path electrically connected to one end of the first shape memory alloy wire; a second conductive path electrically connected to one end of the second shape memory alloy wire; a common conductive path electrically connected to the other end of each of the first shape memory alloy wire and the second shape memory alloy wire, the first conductive path and the second conductive path are arranged so as to cancel out magnetic fields generated by current flow when electrically connected in series; An imaging device characterized by:

Images