Lens holder drive device

Abstract

A lens holder driving device (101) comprises: a first lens holder (3A) capable of holding a first lens body (LS1); a second lens holder (3B) capable of holding a second lens body (LS2); a first movable side member (MB1) including the first lens holder (3A); a second movable side member (MB2) including the second lens holder (3B); a first piezoelectric driving part (PD1) that moves the first lens holder (3A) in an optical axis direction by the movement of a first piezoelectric element (8A); and a second piezoelectric driving part (PD2) that moves the second lens holder (3B) in the optical axis direction by the movement of a second piezoelectric element (8B). The second movable side member (MB2) is included in the first movable side member (MB1), and is movable in the optical axis direction with respect to the first lens holder (3A). The first piezoelectric driving part (PD1) is provided in a fixed side member (FB), and the second piezoelectric driving part (PD2) is provided in the second movable side member (MB2).

Description

Technical Field

[0001] This disclosure relates to a lens holder driving device.

Background Art

[0002] Conventionally, a lens driving device that can separately move a first movable part holding a first movable lens and a second movable part holding a second movable lens in the optical axis direction is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above lens driving device, for example, since the first movable lens (zoom lens) and the second movable lens (focus lens) move separately in the optical axis direction, there is a possibility that the time required for focusing becomes long during zooming in or out.

[0005] Therefore, it is desired to provide a lens holder driving device that can move two lens holders more efficiently.

Means for Solving the Problems

[0006] A lens holder driving device according to an embodiment of the present invention comprises: a fixed side member; a first lens holder capable of holding a first lens body; a second lens holder capable of holding a second lens body arranged to have the same optical axis as the first lens body; a first movable side member including the first lens holder; a second movable side member including the second lens holder; a first piezoelectric driving unit comprising a first piezoelectric element, which moves the first movable side member in the optical axis direction by the movement of the first piezoelectric element; and a second piezoelectric driving unit comprising a second piezoelectric element, which moves the second movable side member in the optical axis direction by the movement of the second piezoelectric element, wherein the second movable side member is included in the first movable side member and is movable in the optical axis direction relative to the first lens holder, and the first piezoelectric driving unit comprises the fixed side member Material The second piezoelectric drive unit is provided, and the second movable side Material Established The first movable side member has a first receiving member that extends in the optical axis direction and receives the movement of the first piezoelectric drive unit, the first piezoelectric drive unit is biased toward the first receiving member by a first biasing member provided on the fixed side member, and the first lens holder has a second receiving member that extends in the optical axis direction and receives the movement of the second piezoelectric drive unit, the second piezoelectric drive unit is biased toward the second receiving member by a second biasing member provided on the second movable side member. ru. [Effects of the Invention]

[0007] The lens holder drive device described above can move the two lens holders more efficiently. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a perspective view of the lens holder drive mechanism. [Figure 1B] This is an exploded perspective view of the lens holder drive mechanism. [Figure 2] This is a schematic diagram of the camera module. [Figure 3] This is an exploded perspective view of the lens holder drive mechanism with the cover removed. [Figure 4] This is an exploded perspective view of the first movable side member. [Figure 5A] This is a perspective view of the first movable side member supported by the shaft member. [Figure 5B] This is a perspective view of the first lens holder driven by the first piezoelectric drive unit. [Figure 5C]This is a perspective view of the second lens holder, which is driven by the second piezoelectric drive unit. [Figure 6A] This is a perspective view of a piezoelectric drive unit that is pressed against a shaft member by a biasing member. [Figure 6B] This is an exploded perspective view of the biasing member and the piezoelectric drive unit. [Figure 7] This is a perspective view of the first biasing member attached to the base member. [Figure 8] Front view of the lens holder. [Figure 9] This figure shows an example of the positional relationship between a magnetic sensor, a magnetic field generating member, and a circuit board. [Modes for carrying out the invention]

[0009] Hereinafter, a lens holder drive device 101 according to an embodiment of the present invention will be described with reference to the drawings. Figure 1A is a perspective view of the lens holder drive device 101. Figure 1B is an exploded perspective view of the lens holder drive device 101. Figure 2 is a schematic diagram of a camera module CM in a portable device with a camera on which the lens holder drive device 101 is mounted.

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

[0011] The lens holder driving device 101 is configured to be able to move the lens body LS along the optical axis OA of the lens body LS.

[0012] The lens body LS is an example of an optical member and is composed of one or more lenses. Typically, the lens body LS is a cylindrical lens barrel provided with at least one lens, and is configured such that its central axis line is along the optical axis OA. In the illustrated example, the lens body LS has a first lens body LS1 including a zoom lens and a second lens body LS2 including a focus lens.

[0013] The lens holder driving device 101 is configured to be able to move the lens body LS along the optical axis direction by a piezoelectric driving unit PD (see FIG. 4) housed in the housing HS. The optical axis direction includes the direction of the optical axis OA of the lens body LS and the direction parallel to the optical axis OA. Specifically, as shown by the double arrows AR1 in FIGS. 1B and 2 respectively, the lens holder driving device 101 can move the first lens body LS1 along the optical axis direction, and as shown by the double arrows AR2, can move the second lens body LS2 along the optical axis direction. That is, the lens holder driving device 101 can move the first lens body LS1 and the second lens body LS2 simultaneously along the optical axis direction, and can move the second lens body LS2 along the optical axis direction with respect to the first lens body LS1. Note that the optical axis of the first lens body LS1 and the optical axis of the second lens body LS2 are located on the same straight line (on the optical axis OA).

[0014] As shown in FIG. 1A, the housing HS is a part of the fixed-side member FB and includes a cover member 1 and a base member 2. The cover member 1 includes an upper cover member 1U, a rear cover member 1B, and a lower cover member 1D as shown in FIG. 1B.

[0015] The cover member 1 is configured to cover a part of the base member 2. In the illustrated example, the upper cover member 1U and the lower cover member 1D are made of metal. However, the upper cover member 1U and the lower cover member 1D may be made of synthetic resin. The rear cover member 1B is a printed circuit board on which the image sensor IS is mounted.

[0016] As shown in FIG. 2, the lens holder driving device 101 is used in a camera module CM such as a periscope-type camera module. In the example shown in FIG. 2, the camera module CM mainly includes a mirror MR, a lens body LS, a lens holder driving device 101, an image sensor IS, etc. The mirror MR may be a prism. In the example shown in FIG. 2, the mirror MR is configured to provide a flat reflecting surface.

[0017] Typically, as shown in FIG. 2, the lens holder driving device 101 is disposed at a position farther from the subject than the mirror MR, and is configured to cause the light LT from the subject reflected by the mirror MR to reach the image sensor IS through the lens body LS.

[0018] Next, referring to FIG. 3, the internal configuration of the lens holder driving device 101 will be described. FIG. 3 is an exploded perspective view of the lens holder driving device 101 with the cover member 1 removed. Specifically, FIG. 3 is a perspective view of the base member 2, the shaft member 5, the outer circuit board 11, the biasing member 13, the image sensor holder HD, the fixed lens holder LH, the first movable side member MB1, and the piezoelectric driving unit PD.

[0019] The base member 2 is a member that constitutes a part of the housing HS. In the illustrated example, the base member 2 is made of synthetic resin, but it may be made of metal.

[0020] Specifically, the base member 2 has a roughly rectangular cylindrical outer wall portion 2A that defines the housing portion 2S. The outer wall portion 2A includes first side plate portions 2A1 to fourth side plate portions 2A4. The first side plate portion 2A1 and the third side plate portion 2A3 face each other, and the second side plate portion 2A2 and the fourth side plate portion 2A4 face each other. Furthermore, the second side plate portion 2A2 and the fourth side plate portion 2A4 extend perpendicularly to the first side plate portion 2A1 and the third side plate portion 2A3. That is, the first side plate portion 2A1 and the third side plate portion 2A3 extend perpendicularly to the second side plate portion 2A2 and the fourth side plate portion 2A4. The first side plate portion 2A1 has a first aperture OP1 for receiving light LT from the subject reflected by the mirror MR. Similarly, the third side plate portion 2A3 has a second aperture OP2 for allowing light LT to reach the image sensor IS. The cover member 1 is joined to the base member 2 by an adhesive or the like, and together with the base member 2, constitutes the housing HS.

[0021] Furthermore, as shown in Figure 3, the base member 2 is fitted with a first biasing member 13A, an image sensor holder HD configured to hold the image sensor IS, and a fixed lens holder LH configured to hold the fixed lens FL. The fixed lens FL is also called the front lens. The fixed lens holder LH is attached to the first aperture OP1, and the image sensor holder HD is attached to the outside of the second aperture OP2. In addition, the first movable side member MB1 and the outer circuit board 11 are housed in the housing section 2S of the base member 2.

[0022] The axial member 5 includes a first axial member 5A having an axis (first axis 5AX) parallel to the optical axis OA, and a second axial member 5B having an axis (second axis 5BX) parallel to the optical axis OA. Therefore, the first axial member 5A and the second axial member 5B extend in the direction of the optical axis parallel to each other. In the illustrated example, the axial member 5 is configured such that one end is inserted through a through hole 2T (see Figure 3) formed in the first side plate portion 2A1 of the base member 2, and the other end is fitted into a recess 2R formed on the inner surface of the third side plate portion 2A3 of the base member 2. However, the axial member 5 may also be configured such that one end is fitted into a recess formed on the inner surface of the first side plate portion 2A1 of the base member 2, and the other end is inserted through a through hole formed in the third side plate portion 2A3 of the base member 2. Furthermore, the shaft member 5 may be fixed to the base member 2 (first side plate portion 2A1 and third side plate portion 2A3) with adhesive. Also, the first shaft member 5A and the second shaft member 5B may be made of a magnetic metal.

[0023] The piezoelectric drive unit PD is configured to receive power and move the lens holder 3 in the optical axis direction relative to the base member 2. In the illustrated example, the piezoelectric drive unit PD includes a first piezoelectric drive unit PD1 that moves the first movable side member MB1 in the optical axis direction relative to the base member 2, and a second piezoelectric drive unit PD2 that moves the second movable side member MB2 in the optical axis direction relative to the first lens holder 3A. Specifically, the piezoelectric drive unit PD is configured to operate in accordance with the applied voltage (voltage applied to the piezoelectric element 8) controlled by the drive circuit. The drive circuit may be mounted on the external circuit board 11 or located outside the housing HS. In the illustrated example, the drive circuit is located outside the housing HS.

[0024] The first movable side member MB1 includes a first lens holder 3A, a movable side axis member 7, a first lens body LS1, and a second movable side member MB2. The second movable side member MB2 constitutes a part of the first movable side member MB1. Specifically, the second movable side member MB2 includes a second lens holder 3B, a second lens body LS2, and a second biasing member 13B. The first movable side member MB1 is configured to be moved in the optical axis direction by a first piezoelectric drive unit PD1 while being guided by a first axis member 5A and a second axis member 5B. The second movable side member MB2 is configured to be moved in the optical axis direction by a second piezoelectric drive unit PD2 while being guided by the first axis member 5A.

[0025] Here, the details of the first movable side member MB1 will be explained with reference to Figures 4 and 5A to 5C. Figure 4 is an exploded perspective view of the first movable side member MB1. In Figure 4, for clarity, the relationship in which one member is assembled to another member is shown by dashed arrows. Also in Figure 4, the members constituting the first movable side member MB1 are enclosed by a dashed line, and the members constituting the second movable side member MB2 are enclosed by a dashed line. Figure 5A is a perspective view of the first movable side member MB1 supported by the shaft member 5. Figure 5B is a perspective view of the first lens holder 3A driven by the first piezoelectric drive unit PD1. Figure 5C is a perspective view of the second lens holder 3B driven by the second piezoelectric drive unit PD2.

[0026] The first lens holder 3A is a component formed by injection molding of a synthetic resin such as liquid crystal polymer (LCP), and as shown in Figure 4, it has a first holding portion 31A that holds the first lens body LS1 and a first bearing portion 32A that receives the shaft member. The first bearing portion 32A has a first left bearing portion 32AL that receives the first shaft member 5A and a first right bearing portion 32AR that receives the second shaft member 5B and the movable side shaft member 7.

[0027] The second lens holder 3B is a component formed by injection molding of a synthetic resin such as liquid crystal polymer (LCP), and as shown in Figure 4, it has a second holding portion 31B that holds the second lens body LS2 and a second bearing portion 32B that receives the shaft member. The second bearing portion 32B has a second left bearing portion 32BL that receives the first shaft member 5A and a second right bearing portion 32BR that receives the movable side shaft member 7.

[0028] More specifically, the first right bearing portion 32AR has a first through hole TH1 capable of receiving the second shaft member 5B, two substantially semicircular first notches CT1 opening to the right (in the Y2 direction), and three substantially semicircular second notches CT2 opening to the right (in the Y2 direction) capable of receiving the movable side shaft member 7. The first left bearing portion 32AL has a substantially semicircular third notch groove CT3 opening to the left (in the Y1 direction) capable of receiving the first shaft member 5A. The second right bearing portion 32BR has two substantially V-shaped fourth notches CT4 opening to the right (in the Y2 direction) capable of receiving the movable side shaft member 7. The second left bearing portion 32BL has a substantially semicircular fifth notch groove CT5 opening to the left (in the Y1 direction) capable of receiving the first shaft member 5A.

[0029] A magnet 4 is attached to the second left bearing portion 32BL of the second lens holder 3B. The magnet 4 is a component positioned to suppress play in the second lens holder 3B on the first shaft member 5A.

[0030] The magnet 4 is configured to utilize the magnetic attraction force acting between the magnet 4 and the first shaft member 5A to press a portion of the second left bearing portion 32BL of the second lens holder 3B against the upper surface of the first shaft member 5A from above.

[0031] Furthermore, at least a portion of the second right bearing portion 32BR of the second lens holder 3B is positioned within the space formed in the first right bearing portion 32AR of the first lens holder 3A, as shown in Figure 5A. Therefore, a third opening OP3 (see Figure 4) that penetrates in the Y-axis direction is formed in the first right bearing portion 32AR.

[0032] Next, the piezoelectric drive unit PD will be described with reference to Figures 6A and 6B. Figure 6A is a perspective view of the piezoelectric drive unit PD pressed against the movable shaft member 7 by the biasing member 13, and Figure 6B is an exploded perspective view of the biasing member 13 and the piezoelectric drive unit PD.

[0033] The piezoelectric drive unit PD is configured to move the lens holder 3 along the optical axis. In this embodiment, the piezoelectric drive unit PD is an example of a friction drive unit utilizing the drive system disclosed in U.S. Patent No. 7,786,648, and includes a piezoelectric element 8, a contact member 9, and a circuit board 10.

[0034] The piezoelectric drive unit PD is configured to be biased inward (towards the optical axis OA) by a biasing member 13 and pressed against the movable side shaft member 7, which acts as a receiving member RV. In the illustrated example, the biasing member 13 for pressing the piezoelectric drive unit PD against the receiving member RV is made of a metal plate and is configured to contact the circuit board 10 attached to the outer surface (the side farther from the optical axis OA) of the piezoelectric element 8 at portions (inner edge BE) corresponding to each of the two nodes ND (see Figure 6B) formed during the bending vibration (circular motion described later) of the piezoelectric element 8. The bond between the biasing member 13 and the piezoelectric drive unit PD is achieved, for example, by an adhesive.

[0035] Specifically, the piezoelectric drive unit PD includes a first piezoelectric drive unit PD1 that moves the first lens holder 3A along the optical axis direction relative to the base member 2, and a second piezoelectric drive unit PD2 that moves the second lens holder 3B along the optical axis direction relative to the first lens holder 3A. The first piezoelectric drive unit PD1 includes a first piezoelectric element 8A, a first contact member 9A, and a first circuit board 10A, and the second piezoelectric drive unit PD2 includes a second piezoelectric element 8B, a second contact member 9B, and a second circuit board 10B.

[0036] The biasing member 13 includes a first biasing member 13A and a second biasing member 13B. The first biasing member 13A is attached to the base member 2 as shown in Figures 3 and 7 and is configured to press the first piezoelectric drive unit PD1 against the first receiving member RV1. The second biasing member 13B is attached to the second lens holder 3B as shown in Figure 4 and is configured to press the second piezoelectric drive unit PD2 against the second receiving member RV2.

[0037] The movable shaft member 7 is a shaft member fixed to the first lens holder 3A and is configured to function as a receiving member RV (first receiving member RV1 and second receiving member RV2). The movable shaft member 7 is fixed with adhesive to three second notch grooves CT2 provided in the first right bearing portion 32AR of the first lens holder 3A.

[0038] As shown in Figure 6B, the first piezoelectric element 8A extends in the Z-axis direction, which is perpendicular to the optical axis direction (X-axis direction), and is configured to realize bending vibration (circular motion) with two nodes ND. That is, when bending vibration occurs, the portions of the two nodes ND hardly vibrate. Specifically, the first piezoelectric element 8A has a two-layer structure stacked in the Y-axis direction, consisting of a first layer that realizes the first bending vibration on the XZ plane and a second layer that realizes the second bending vibration on the YZ plane. The first piezoelectric drive unit PD1 can cause the first piezoelectric element 8A to bend and vibrate (circular motion) when the voltage is applied to the piezoelectric elements constituting the first layer and the voltage is applied to the piezoelectric elements constituting the second layer individually at appropriate timings, such that the trajectory traced by the midpoint of the first piezoelectric element 8A becomes a circular orbit centered on the first rotation axis 8AX when viewed from above. That is, the first piezoelectric element 8A can realize a movement (circular motion) in which its midpoint traces a circle. In the example shown in Figure 6B, the first rotation axis 8AX is parallel to the Z axis. Furthermore, the first piezoelectric drive unit PD1 can switch the direction of movement (rotation direction) of the midpoint following the circular orbit between clockwise and counterclockwise when viewed from the Z1 side, by applying voltage at the appropriate timing. By switching the rotation direction, the first piezoelectric drive unit PD1 can switch the direction of movement of the first lens holder 3A along the optical axis direction. Note that the circle (circular orbit) traced by the midpoint of the first piezoelectric element 8A does not need to be a perfect circle (true circle), but only needs to be roughly circular.

[0039] In Figure 6B, the arrows drawn around the first piezoelectric element 8A represent bending vibration of the first piezoelectric element 8A (circular motion in which the first piezoelectric element 8A bends and rotates clockwise around the first rotation axis 8AX as viewed from the Z1 side). In this case, the first movable side member MB1, including the first receiving member RV1 (movable side shaft member 7) that is in contact with the first contact member 9A of the first piezoelectric drive unit PD1, moves backward (in the X2 direction). Although not shown by the arrows, the first piezoelectric element 8A can also rotate counterclockwise around the first rotation axis 8AX as viewed from the Z1 side while bending. In this case, the first movable side member MB1, including the first receiving member RV1 (movable side shaft member 7) that is in contact with the first contact member 9A of the first piezoelectric drive unit PD1, moves forward (in the X1 direction).

[0040] In other words, the first lens holder 3A to which the first receiving member RV1 (movable side shaft member 7) is attached is moved backward (in the X2 direction) when the rotation direction of the midpoint of the first piezoelectric element 8A is clockwise when viewed from above, and is moved forward (in the X1 direction) when the rotation direction of the midpoint of the first piezoelectric element 8A is counterclockwise. In the illustrated example, the midpoint of the first piezoelectric element 8A is the point where the amplitude of the first bending vibration is maximum (corresponding to the antinode of the first bending vibration) and also the point where the amplitude of the second bending vibration is maximum (corresponding to the antinode of the second bending vibration).

[0041] The first contact member 9A is attached to the first piezoelectric element 8A and configured to contact the first receiving member RV1 (movable side shaft member 7). In the illustrated example, the first contact member 9A is bonded to the inner surface of the first piezoelectric element 8A by adhesive so as to cover the entire inner surface of the first piezoelectric element 8A (the Y1 side, which is the side facing the optical axis OA). The first contact member 9A is made of a metal such as stainless steel and is configured with an appropriate thickness so that it can perform bending vibration (circular motion) in response to the bending vibration (circular motion) of the first piezoelectric element 8A. In the illustrated example, the first contact member 9A is a friction plate made of stainless steel. The first contact member 9A extends in the Z-axis direction, which is the same direction as the extension direction of the first piezoelectric element 8A. The inner surface of the central part of the first contact member 9A (the Y1 side surface) is configured to contact the first receiving member RV1 (movable side shaft member 7). Specifically, the first contact member 9A is configured to contact the first receiving member RV1 (movable side shaft member 7) at the point where the amplitude of the bending vibration (circular motion) is maximum (the point corresponding to the antinode of the bending vibration). Furthermore, the surface of the first contact member 9A that contacts the first receiving member RV1 (movable side shaft member 7) (Y1 side) is a convex curved surface that is convex toward the Y1 side.

[0042] The movable shaft member 7 is typically made of a metal such as stainless steel. In the illustrated example, the movable shaft member 7 is a cylindrical rod made of stainless steel that extends in the direction of the optical axis. Note that the length dimension of the first contact member 9A in the Z-axis direction may differ from the length dimension of the first piezoelectric element 8A, as long as contact between the first contact member 9A and the movable shaft member 7 is achieved. In the illustrated example, the length dimension of the first contact member 9A and the length dimension of the first piezoelectric element 8A in the Z-axis direction are approximately the same.

[0043] The first circuit board 10A is a board including a conductive pattern and is configured to electrically connect the external power supply (drive circuit) and the first piezoelectric element 8A through the outer circuit board 11. In the illustrated example, the first circuit board 10A is a flexible printed circuit board and includes a connector portion 10C, a piezoelectric element fixing portion 10P, and a curved portion 10W.

[0044] The outer circuit board 11 (see Figure 3) is a substrate containing conductive patterns and is configured to electrically connect the external power supply to the circuit board 10 (first circuit board 10A and second circuit board 10B). In the illustrated example, the outer circuit board 11 is a flexible printed circuit board and has a magnetic sensor 6 (first magnetic sensor 6A), a first connector CN1, and a second connector CN2 mounted on it.

[0045] Specifically, as shown in Figure 3, the outer surface (Y2 side) of the connector portion 10C of the first circuit board 10A is connected to the outer circuit board 11 through the first connector CN1. Furthermore, as shown in Figure 6B, the inner surface (Y1 side) of the piezoelectric element fixing portion 10P of the first circuit board 10A is bonded to the first piezoelectric element 8A by an anisotropic conductive adhesive or an anisotropic conductive adhesive film.

[0046] The second piezoelectric element 8B has the same configuration as the first piezoelectric element 8A. Specifically, the second piezoelectric element 8B extends in the Z-axis direction and is configured to realize bending vibration (circular motion) with two nodes ND. That is, when bending vibration occurs, the portions of the two nodes ND hardly vibrate. Furthermore, the second piezoelectric element 8B has a two-layer structure stacked in the Y-axis direction, consisting of a first layer that realizes the first bending vibration on the XZ plane and a second layer that realizes the second bending vibration on the YZ plane. The second piezoelectric drive unit PD2 can cause the second piezoelectric element 8B to bend and vibrate (circular motion) such that the trajectory traced by the midpoint of the second piezoelectric element 8B is a circular orbit centered on the second rotation axis 8BX when viewed from above, when the voltage is applied to the piezoelectric elements constituting the first layer and the voltage is applied to the piezoelectric elements constituting the second layer at appropriate timings. In other words, the second piezoelectric element 8B can realize movement (circular motion) such that its midpoint traces a circle. Note that in the example shown in Figure 6B, the second rotation axis 8BX is parallel to the Z-axis. Furthermore, the second piezoelectric drive unit PD2 can switch the direction of movement (rotation direction) of the midpoint following the circular orbit between clockwise and counterclockwise when viewed from the Z1 side, by applying voltage at the appropriate timing. This switching of the rotation direction allows the second piezoelectric drive unit PD2 to switch the direction of movement of the second lens holder 3B along the optical axis. Note that the circle (circular orbit) traced by the midpoint of the second piezoelectric element 8B does not need to be a perfect circle (true circle), but only needs to be roughly circular.

[0047] In Figure 6B, the arrows drawn around the second piezoelectric element 8B represent bending vibration of the second piezoelectric element 8B (circular motion in which the second piezoelectric element 8B bends and rotates clockwise around the second rotation axis 8BX as viewed from the Z1 side). In this case, the second piezoelectric drive unit PD2, including the second contact member 9B that is in contact with the second support member RV2 (movable side shaft member 7), moves forward (in the X1 direction). Although not shown by the arrows, the second piezoelectric element 8B can also rotate counterclockwise around the second rotation axis 8BX as viewed from the Z1 side while bending. In this case, the second piezoelectric drive unit PD2, including the second contact member 9B that is in contact with the second support member RV2 (movable side shaft member 7), moves backward (in the X2 direction).

[0048] In other words, the second lens holder 3B to which the second piezoelectric drive unit PD2 is attached is moved forward (in the X1 direction) when the rotation direction of the midpoint of the second piezoelectric element 8B is clockwise when viewed from above, and is moved backward (in the X2 direction) when the rotation direction of the midpoint of the second piezoelectric element 8B is counterclockwise. In the illustrated example, the midpoint of the second piezoelectric element 8B is the point where the amplitude of the first bending vibration is maximum (corresponding to the antinode of the first bending vibration) and also the point where the amplitude of the second bending vibration is maximum (corresponding to the antinode of the second bending vibration).

[0049] The second contact member 9B is attached to the second piezoelectric element 8B and configured to contact the second receiving member RV2 (movable side shaft member 7). In the illustrated example, the second contact member 9B is bonded to the inner surface of the second piezoelectric element 8B by adhesive so as to cover the entire inner surface of the second piezoelectric element 8B (the Y1 side, which is the side facing the optical axis OA). The second contact member 9B is made of a metal such as stainless steel and is configured with an appropriate thickness so that it can perform bending vibration (circular motion) in response to the bending vibration (circular motion) of the second piezoelectric element 8B. In the illustrated example, the second contact member 9B is a friction plate made of stainless steel. The second contact member 9B extends in the Z-axis direction, which is the same direction as the extension direction of the second piezoelectric element 8B. The inner surface of the central part of the second contact member 9B (the Y1 side surface) is configured to contact the second receiving member RV2 (movable side shaft member 7). Specifically, the second contact member 9B is configured to contact the second support member RV2 (movable side shaft member 7) at the point where the amplitude of the bending vibration (circular motion) is maximum (corresponding to the antinode of the bending vibration). Furthermore, the surface of the second contact member 9B that contacts the second support member RV2 (movable side shaft member 7) (Y1 side) is a convex curved surface that is convex toward the Y1 side.

[0050] Furthermore, as long as contact between the second contact member 9B and the movable shaft member 7 is achieved, the length dimension of the second contact member 9B in the Z-axis direction may differ from the length dimension of the second piezoelectric element 8B. In the illustrated example, the length dimension of the second contact member 9B and the length dimension of the second piezoelectric element 8B in the Z-axis direction are approximately the same.

[0051] The second circuit board 10B is a board containing a conductive pattern and is configured to electrically connect the external power supply and the second piezoelectric element 8B through the outer circuit board 11. In the illustrated example, the second circuit board 10B is a flexible printed circuit board and includes a connector portion 10C, a piezoelectric element fixing portion 10P, a sensor fixing portion 10S, and a curved portion 10W.

[0052] Specifically, as shown in Figure 3, the second circuit board 10B has its outer surface (Y2 side) of the connector portion 10C connected to the outer circuit board 11 through the second connector CN2. The second circuit board 10B is also configured to deform (bend) in accordance with the movement of the second lens holder 3B in the optical axis direction, thereby moving the position of the curved portion 10W and allowing voltage to be applied to the second piezoelectric element 8B. More specifically, the curved portion 10W moves backward in accordance with the backward movement (X2 direction) of the second lens holder 3B and moves forward in accordance with the forward movement (X1 direction) of the second lens holder 3B. Furthermore, as shown in Figure 6B, the second circuit board 10B is configured so that the inner surface (Y1 side) of the piezoelectric element fixing portion 10P is bonded to the second piezoelectric element 8B by an anisotropic conductive adhesive or an anisotropic conductive adhesive film. In addition, the second circuit board 10B is configured so that the sensor fixing portion 10S is located below (Z2 side) the second biasing member 13B. The second circuit board 10B is configured such that the magnetic sensor 6 (second magnetic sensor 6B) is mounted on the lower (Z2 side) surface of the sensor fixing part 10S. In the illustrated example, the upper (Z1 side) surface of the sensor fixing part 10S is fixed with adhesive to the lower (Z2 side) surface of the second biasing member 13B.

[0053] In the illustrated example, the biasing member 13 is composed of a leaf spring member. Specifically, as shown in Figure 7, the first biasing member 13A has a fixing portion 13F fixed to the fourth side plate portion 2A4 of the base member 2, a support portion 13S that supports the first piezoelectric drive unit PD1, and an elastically deformable elastic deformation portion 13E provided between the fixing portion 13F and the support portion 13S. Figure 7 is a perspective view of the first biasing member 13A attached to the base member 2. Note that in Figure 7, a dot pattern is applied to the first biasing member 13A for clarity.

[0054] As shown in Figure 7, the first biasing member 13A is fixed to the base member 2 via a fixing portion 13F so that the support portion 13S and the elastically deformable portion 13E do not come into contact with the base member 2. Specifically, the fixing portions 13F provided at both ends of the elastically deformable portion 13E are attached to the fourth side plate portion 2A4 of the base member 2 by fitting into grooves 2G formed on the inner surface of the fourth side plate portion 2A4.

[0055] More specifically, the fixing portion 13F of the first biasing member 13A includes a front fixing portion 13FF and a rear fixing portion 13FB (see Figure 6B), and the support portion 13S includes an upper support portion 13SU and a lower support portion 13SD. The elastic deformation portion 13E includes an upper elastic deformation portion 13EU and a lower elastic deformation portion 13ED provided between the front fixing portion 13FF and the rear fixing portion 13FB. The front fixing portion 13FF and the rear fixing portion 13FB have the same shape and size, the upper support portion 13SU and the lower support portion 13SD have the same shape and size, and the upper elastic deformation portion 13EU and the lower elastic deformation portion 13ED have the same shape and size. In other words, the first biasing member 13A is configured to be plane-symmetric with respect to a plane of symmetry parallel to the YZ plane (a plane that divides the first biasing member 13A into front and rear halves). Furthermore, the first biasing member 13A is configured to be symmetrical with respect to another plane of symmetry parallel to the XY plane (a plane that divides the first biasing member 13A vertically).

[0056] The support portion 13S of the first biasing member 13A is bent in an L-shape from the elastically deformable portion 13E and is configured to protrude on the side where the first lens holder 3A is located (Y1 side). A recess RS (see Figure 6B) is formed at the tip of the support portion 13S. The recess RS is a recess that is open on the side where the first lens holder 3A is located (Y1 side). Specifically, the recess RS is formed at the tips of the upper support portion 13SU and the lower support portion 13SD, respectively, to be the same shape and size. As shown in Figure 6A, the first piezoelectric drive unit PD1 is partially positioned within the recess RS and is fixed to the support portion 13S with adhesive while in contact with the inner edge BE (see Figure 6B) of the recess RS.

[0057] More specifically, as shown in Figure 6B, the recess RS has a front edge and a rear edge that face each other with the inner edge BE in between. The first piezoelectric drive unit PD1 is positioned between the front edge and the rear edge, as shown in Figure 6A.

[0058] The contact point between the inner edge BE of the recess RS and the first piezoelectric drive unit PD1 corresponds to the position of node ND of the first piezoelectric element 8A that realizes bending vibration (circular motion). The position of node ND includes the positions of the first node ND1 and the second node ND2. In Figure 6B, a cross pattern is added to the position of node ND for clarity.

[0059] The position where the inner edge BE of the recess RS and the first piezoelectric drive unit PD1 come into contact (position of node ND) corresponds to a position at a predetermined distance from the end of the first piezoelectric drive unit PD1 in the Z-axis direction. The predetermined distance is, for example, approximately one-quarter of the total length of the piezoelectric drive unit PD.

[0060] The first piezoelectric drive unit PD1 and the support unit 13S are fixed together by adhesive. Specifically, the first piezoelectric drive unit PD1 (first circuit board 10A) and the support unit 13S of the first biasing member 13A are fixed together by adhesive at the inner edge BE of the recess RS. In the illustrated example, the adhesive is an ultraviolet-curing adhesive. However, the adhesive may be other types of adhesives such as moisture-curing or thermosetting adhesives.

[0061] As shown in Figure 6B, the elastically deformable portion 13E of the first biasing member 13A has a portion extending forward (in the X1 direction) from the support portion 13S and a portion extending backward (in the X2 direction) from the support portion 13S. Specifically, the upper elastically deformable portion 13EU has a portion extending forward from the upper support portion 13SU and a portion extending backward from the upper support portion 13SU, and the lower elastically deformable portion 13ED has a portion extending forward from the lower support portion 13SD and a portion extending backward from the lower support portion 13SD. Furthermore, the extension direction of the elastically deformable portion 13E is along the optical axis direction.

[0062] As shown in Figure 5C, the second biasing member 13B is fixed to the right end (Y2 side end) of the second right bearing portion 32BR of the second lens holder 3B via a fixing portion 13F, so that the support portion 13S and the elastic deformation portion 13E do not come into contact with the second lens holder 3B.

[0063] Specifically, the fixing portion 13F of the second biasing member 13B includes an upper fixing portion 13FU and a lower fixing portion 13FD, as shown in Figure 6B, and the support portion 13S includes an upper support portion 13SU and a lower support portion 13SD. The elastic deformation portion 13E includes a front elastic deformation portion 13EF and a rear elastic deformation portion 13EB provided between the fixing portion 13F and the support portion 13S. The upper fixing portion 13FU and the lower fixing portion 13FD have the same shape and size, the upper support portion 13SU and the lower support portion 13SD have the same shape and size, and the front elastic deformation portion 13EF and the rear elastic deformation portion 13EB have the same shape and size. In other words, the second biasing member 13B is configured to be symmetrical with respect to a plane of symmetry parallel to the YZ plane (a plane that divides the second biasing member 13B into front and rear halves). Furthermore, the second biasing member 13B is configured to be symmetrical with respect to another plane of symmetry parallel to the XY plane (a plane that divides the second biasing member 13B vertically).

[0064] The support portion 13S of the second biasing member 13B is bent in an L-shape from the elastically deformable portion 13E and is configured to protrude on the side where the second lens holder 3B is located (Y1 side). A recess RS (see Figure 6B) is formed at the tip of the support portion 13S. The recess RS is a recess that is open on the side where the second lens holder 3B is located (Y1 side). Specifically, the recess RS is formed at the tips of the upper support portion 13SU and the lower support portion 13SD, respectively, to be the same shape and size. As shown in Figure 6A, the second piezoelectric drive unit PD2 is partially positioned within the recess RS and is fixed to the support portion 13S with adhesive while in contact with the inner edge BE (see Figure 6B) of the recess RS.

[0065] More specifically, as shown in Figure 6B, the recess RS has a front edge and a rear edge that face each other with the inner edge BE in between. The second piezoelectric drive unit PD2 is positioned between the front edge and the rear edge, as shown in Figure 6A.

[0066] The contact points between the inner edge BE of the recess RS and the second piezoelectric drive unit PD2 correspond to the positions of nodes ND of the second piezoelectric element 8B that realize bending vibration (circular motion). The positions of nodes ND include the positions of the third node ND3 and the fourth node ND4. In Figure 6B, a cross pattern is added to the positions of nodes ND for clarity.

[0067] The position where the inner edge BE of the recess RS and the second piezoelectric drive unit PD2 come into contact (position of node ND) corresponds to a position at a predetermined distance from the end of the second piezoelectric drive unit PD2 in the Z-axis direction. This predetermined distance is, for example, approximately one-quarter of the total length of the piezoelectric drive unit PD.

[0068] The second piezoelectric drive unit PD2 and the support unit 13S are fixed together by adhesive. Specifically, the second piezoelectric drive unit PD2 (second circuit board 10B) and the support unit 13S (second biasing member 13B) are fixed together by adhesive at the inner edge BE of the recess RS. In the illustrated example, the adhesive is an ultraviolet-curing adhesive. However, the adhesive may be other types of adhesives such as moisture-curing or thermosetting adhesives.

[0069] As shown in Figure 6B, the elastic deformation portion 13E of the second biasing member 13B has a front elastic deformation portion 13EF extending forward (in the X1 direction) from the support portion 13S and a rear elastic deformation portion 13EB extending backward (in the X2 direction) from the support portion 13S. The elastic deformation portion 13E also includes a portion extending along the optical axis direction.

[0070] Fixing portions 13F are provided at both ends of the elastically deformable portion 13E. The fixing portions 13F are attached by sandwiching the upper and lower ends of the second right bearing portion 32BR of the second lens holder 3B, as shown in Figures 4 and 5C.

[0071] In the illustrated example, the fixing portion 13F of the second biasing member 13B includes an upper fixing portion 13FU and a lower fixing portion 13FD. The second biasing member 13B is configured to sandwich the right end of the second right bearing portion 32BR of the second lens holder 3B between the upper fixing portion 13FU and the lower fixing portion 13FD. The fixing of the second biasing member 13B to the second right bearing portion 32BR may be achieved by adhesive, or reinforced with adhesive material.

[0072] Next, the first movable side member MB1 will be described with reference to Figure 8. Figure 8 is a front view of the lens holder 3. Specifically, the upper part of Figure 8 is a front view of the first lens holder 3A guided by the shaft member 5, and the lower part of Figure 8 is a front view of the second lens holder 3B guided by the shaft members (first shaft member 5A and movable side shaft member 7).

[0073] The shaft member 5 includes a first shaft member 5A and a second shaft member 5B. The movable shaft member 7, which acts as a receiving member RV, is positioned away from the virtual plane VP, as shown in the upper diagram of Figure 8. Specifically, the movable shaft member 7 is positioned so that its axis 7X is not on the virtual plane VP. In the illustrated example, the movable shaft member 7 is configured such that its axis 7X is parallel to the virtual plane VP. The virtual plane VP is a virtual plane that includes the axes of the first shaft member 5A (first axis 5AX) and the second shaft member 5B (second axis 5BX), which are parallel to each other. In the illustrated example, the movable shaft member 7 is positioned offset above (towards Z1) the virtual plane VP. However, the movable shaft member 7 may also be positioned offset below (towards Z2) the virtual plane VP. The movable shaft member 7 (axis 7X) is configured to be parallel to the first shaft member 5A (first axis 5AX).

[0074] This configuration has the effect of suppressing play in the first lens holder 3A. In the illustrated example, the force (force F1, represented by the dotted arrow) exerted by the first biasing member 13A on the first receiving member RV1 (movable side shaft member 7) attached to the first lens holder 3A toward the Y1 side generates a torque (torque TQ1, represented by the dashed arrow) that attempts to rotate the first lens holder 3A around the axis of the second shaft member 5B (second shaft 5BX). Torque TQ1 acts to press the first left bearing portion 32AL of the first lens holder 3A against the first shaft member 5A from above. In addition to torque TQ1, the first lens holder 3A is also subjected to a torque (weight torque) due to its own weight that attempts to rotate it around the axis of the second shaft member 5B (second shaft 5BX). Furthermore, the first biasing member 13A is configured such that the magnitude of the torque TQ1 brought about by the force F1 is greater than the magnitude of the self-weight torque. Therefore, no matter what position the lens holder drive device 101 is in (even if it is upside down), the combined torque obtained by combining the torque TQ1 and the self-weight torque always acts to press the first left bearing portion 32AL of the first lens holder 3A against the first shaft member 5A. In other words, not only when the torque TQ1 and the self-weight torque are in the same direction, but even when the torque TQ1 and the self-weight torque are in opposite directions, the combined torque always acts to press the first left bearing portion 32AL of the first lens holder 3A against the first shaft member 5A. As a result, regardless of the orientation of the lens holder drive device 101 (even if it is upside down), the first left bearing portion 32AL of the first lens holder 3A and the first shaft member 5A are always in contact, and the occurrence of play between the first left bearing portion 32AL and the first shaft member 5A is suppressed. The same applies to play between the first right bearing portion 32AR and the second shaft member 5B of the first lens holder 3A.

[0075] As shown in the lower diagram of Figure 8, magnet 4 is positioned away from the virtual plane VP. Specifically, magnet 4 is positioned not on the virtual plane VP. In the illustrated example, magnet 4 is positioned offset above (towards Z1) the virtual plane VP. However, magnet 4 may also be positioned offset below (towards Z2) the virtual plane VP.

[0076] This configuration has the effect of suppressing play in the second lens holder 3B. In the illustrated example, the magnetic attractive force (force F2, represented by the dotted arrow) acting between the magnet 4 and the first shaft member 5A generates a torque (torque TQ2, represented by the dashed arrow) that attempts to rotate the second lens holder 3B around the axis (axis 7X) of the movable shaft member 7. Torque TQ2 acts to press the second left bearing portion 32BL of the second lens holder 3B against the first shaft member 5A from above. In addition to torque TQ2, the second lens holder 3B is also subjected to a torque (weight torque) caused by its own weight that attempts to rotate it around the axis (axis 7X) of the movable shaft member 7. The magnet 4 is configured such that the magnitude of the torque TQ2 generated by force F2 is greater than the magnitude of the weight torque. Therefore, regardless of the orientation of the lens holder drive device 101 (even if it is upside down), the combined torque obtained by combining the torque TQ2 and the self-weight torque always acts to press the second left bearing portion 32BL of the second lens holder 3B against the first shaft member 5A. In other words, not only when the torque TQ2 and the self-weight torque are in the same direction, but even when the torque TQ2 and the self-weight torque are in opposite directions, the combined torque always acts to press the second left bearing portion 32BL of the second lens holder 3B against the first shaft member 5A. As a result, regardless of the orientation of the lens holder drive device 101 (even if it is upside down), the second left bearing portion 32BL of the second lens holder 3B and the first shaft member 5A are always in contact, and the occurrence of play between the second left bearing portion 32BL and the first shaft member 5A is suppressed.

[0077] Next, the position detection mechanism DT will be described with reference to Figure 9. Figure 9 is a diagram showing an example of the positional relationship between the magnetic sensor 6, the magnetic field generating member MG, the second circuit board 10B, and the outer circuit board 11. Specifically, the upper left diagram of Figure 9 is a perspective view of the magnetic sensor 6, the magnetic field generating member MG, the second circuit board 10B, and the outer circuit board 11; the upper right diagram of Figure 9 is an enlarged perspective view of the magnetic field generating member MG; the lower left diagram of Figure 9 is a left side view of the magnetic sensor 6, the magnetic field generating member MG, the second circuit board 10B, and the outer circuit board 11; and the lower right diagram of Figure 9 is a front view of the magnetic sensor 6, the magnetic field generating member MG, the second circuit board 10B, and the outer circuit board 11.

[0078] The position detection mechanism DT is a mechanism for detecting the position of the lens holder 3 and includes a magnetic sensor 6 and a magnetic field generating member MG.

[0079] The magnetic field generating member MG is a member configured to generate a magnetic field, and is a permanent magnet or electromagnet, etc. In the illustrated example, the magnetic field generating member MG is a permanent magnet with multi-pole magnetization on both sides, and is fixed to the first right bearing portion 32AR of the first lens holder 3A. In the upper right diagram of Figure 9, for the sake of clarity, a cross pattern is applied to the north pole portion of the magnetic field generating member MG, and a dot pattern is applied to the south pole portion of the magnetic field generating member MG.

[0080] The magnetic sensor 6 is configured to detect the magnetic field generated by the magnetic field generating member MG. In the illustrated example, the magnetic sensor 6 is composed of a giant magnetoresistive effect (GMR) element and is configured to measure a voltage value that changes according to the magnitude of the magnetic field generated by the magnetic field generating member MG that the magnetic sensor 6 receives, and to output the measured voltage value to the drive circuit. The drive circuit is configured to detect the position of the magnetic sensor 6 or the lens holder 3 to which the magnetic field generating member MG is attached, based on the output of the magnetic sensor 6. The magnetic sensor 6 is configured to output a larger voltage value as the north pole portion approaches and a smaller voltage value as the south pole portion approaches. However, the magnetic sensor 6 may also be configured to output a smaller voltage value as the north pole portion approaches and a larger voltage value as the south pole portion approaches. Furthermore, the magnetic sensor 6 may be configured to detect the position of the lens holder 3 using other magnetoresistive elements such as a semiconductor magnetoresistive (SMR) element, anisotropic magnetoresistive (AMR) element, or tunnel magnetoresistive (TMR) element, or it may be configured to detect the position of the lens holder 3 using a Hall element or the like.

[0081] In the illustrated example, the position detection mechanism DT includes a first position detection mechanism DT1 for detecting the position of the first lens holder 3A and a second position detection mechanism DT2 for detecting the position of the second lens holder 3B. The magnetic sensor 6 includes a first magnetic sensor 6A mounted on the outer circuit board 11 and a second magnetic sensor 6B mounted on the sensor fixing portion 10S of the second circuit board 10B. The magnetic field generating member MG is configured such that its lower half functions as a first magnetic field generating member MG1 corresponding to the first magnetic sensor 6A, and its upper half functions as a second magnetic field generating member MG2 corresponding to the second magnetic sensor 6B. The first position detection mechanism DT1 includes the first magnetic sensor 6A and the first magnetic field generating member MG1, and the second position detection mechanism DT2 includes the second magnetic sensor 6B and the second magnetic field generating member MG2. Note that the first magnetic field generating member MG1 and the second position detection mechanism DT2 may be separate and independent members.

[0082] As the first movable side member MB1 moves along the optical axis direction, the first magnetic field generating member MG1, which is fixed to the first right bearing portion 32AR of the first lens holder 3A, moves relative to the first magnetic sensor 6A, which is fixed to the base member 2 (outer circuit board 11).

[0083] The drive circuit acquires the voltage value output by the first magnetic sensor 6A at predetermined control cycles, and based on the change in this voltage value, it derives the relative position of the first lens holder 3A with respect to the base member 2 as the current position of the first lens holder 3A. Then, while confirming the current position of the first lens holder 3A, the drive circuit controls the voltage applied to the first piezoelectric element 8A of the first piezoelectric drive unit PD1, thereby moving the first lens holder 3A to the desired position.

[0084] Similarly, when the second movable side member MB2 moves relative to the first lens holder 3A along the optical axis direction, the second magnetic sensor 6B, which is fixed to the sensor fixing portion 10S of the second circuit board 10B, moves relative to the second magnetic field generating member MG2, which is fixed to the first right bearing portion 32AR of the first lens holder 3A.

[0085] The drive circuit acquires the voltage value output by the second magnetic sensor 6B at predetermined control cycles, and based on the change in this voltage value, it derives the relative position of the second lens holder 3B with respect to the first lens holder 3A as the current position of the second lens holder 3B. Then, while confirming the current position of the second lens holder 3B, the drive circuit controls the voltage applied to the second piezoelectric element 8B of the second piezoelectric drive unit PD2, thereby moving the second lens holder 3B to the desired position.

[0086] With this configuration, the lens holder drive device 101 can move the first lens body LS1 and the second lens body LS2 integrally in the optical axis direction by the first piezoelectric drive unit PD1. Furthermore, the lens holder drive device 101 can move the second lens body LS2 relative to the first lens body LS1 in the optical axis direction by the second piezoelectric drive unit PD2. As a result, the lens holder drive device 101 can increase or decrease the distance between the first lens body LS1 and the second lens body LS2 while moving them in the same direction at approximately the same speed.

[0087] As described above, the lens holder driving device 101 according to an embodiment of the present invention, as shown in Figure 3, comprises a fixed side member FB, a first lens holder 3A capable of holding a first lens body LS1, a second lens holder 3B capable of holding a second lens body LS2 arranged to have the same optical axis as the first lens body LS1, an axis member that guides each of the first lens holder 3A and the second lens holder 3B so as to be movable in the optical axis direction, a first movable side member MB1 including the first lens holder 3A, a second movable side member MB2 including the second lens holder 3B, a first piezoelectric driving unit PD1 comprising a first piezoelectric element 8A which moves the first movable side member MB1 in the optical axis direction by the movement of the first piezoelectric element 8A, and a second piezoelectric driving unit PD2 comprising a second piezoelectric element 8B which moves the second movable side member MB2 in the optical axis direction by the movement of the second piezoelectric element 8B. The second movable side member MB2 is included in the first movable side member MB1 and is movable in the optical axis direction relative to the first lens holder 3A. That is, the second movable side member MB2 is a part of the first movable side member MB1 and can be moved in the optical axis direction not only by the second piezoelectric drive unit PD2 but also by the first piezoelectric drive unit PD1. The first piezoelectric drive unit PD1 is provided on the fixed side member FB or the first lens holder 3A so that the second lens holder 3B can move in the optical axis direction together with the first lens holder 3A relative to the fixed side member FB. The second piezoelectric drive unit PD2 is provided on the second movable side member MB2 or the first lens holder 3A so that the second lens holder 3B can move in the optical axis direction relative to the first lens holder 3A.

[0088] This configuration allows the lens holder drive device 101 to move the first lens holder 3A and the second lens holder 3B together (simultaneously) in the optical axis direction. For example, when zooming in or out, the lens holder drive device 101 can move the first lens body LS1 (zoom lens) and the second lens body LS2 (focus lens) while maintaining the distance between them, i.e., in a focused state. Therefore, the lens holder drive device 101 can shorten the time required for focusing after zooming in or out. Furthermore, in predetermined cases, such as when the subject distance changes slightly, the lens holder drive device 101 can move the second lens body LS2 (focus lens) independently without moving the first lens body LS1 (zoom lens).

[0089] In the example shown in Figure 3, the first piezoelectric drive unit PD1 is provided on the fixed-side member FB (base member 2). Specifically, the first movable-side member MB1 has a first receiving member RV1 that extends in the direction of the optical axis and receives the motion (force generated by the motion) of the first piezoelectric drive unit PD1. The first piezoelectric drive unit PD1 is biased toward the first receiving member RV1 by a first biasing member 13A provided on the fixed-side member FB (base member 2). This mechanism has the effect of simplifying the configuration of the lens holder drive device 101.

[0090] Furthermore, the fixed-side member FB may have an axial member 5 (first axial member 5A and second axial member 5B) extending in the optical axis direction that guides the first movable-side member MB1 so as to be movable in the optical axis direction. In this case, the first receiving member RV1 may be provided at a position offset from the virtual plane VP passing through the centers of the first axial member 5A and the second axial member 5B, as shown in Figure 8.

[0091] This configuration allows the lens holder drive device 101 to suppress play in the first lens holder 3A when moving it in the optical axis direction. This is because the lens holder drive device 101 can continuously press the first lens holder 3A against the shaft member 5 by continuously pressing the first piezoelectric drive unit PD1 against the first receiving member RV1 with the first biasing member 13A.

[0092] In the illustrated example, the second piezoelectric drive unit PD2 is provided on the second movable side member MB2 (second lens holder 3B). In this case, the first lens holder 3A may have a second receiving member RV2 that extends in the direction of the optical axis and receives the motion (force generated by the motion) of the second piezoelectric drive unit PD2, as shown in Figure 4. The second piezoelectric drive unit PD2 may be biased toward the second receiving member RV2 by a second biasing member 13B provided on the second movable side member MB2 (second lens holder 3B). This mechanism has the effect of simplifying the configuration of the lens holder drive device 101 because both the first receiving member RV1 and the second receiving member RV2 are provided on the first lens holder 3A.

[0093] The first support member RV1 and the second support member RV2 may be composed of the same shaft member (movable side shaft member 7), as shown in Figure 3. In other words, the movable side shaft member 7 may be used for both the first support member RV1 and the second support member RV2.

[0094] This configuration has the effect of reducing the number of parts. Furthermore, this configuration allows for miniaturization of the lens holder drive device 101. However, the first receiving member RV1 and the second receiving member RV2 may be composed of two separate, independent shaft members.

[0095] Furthermore, as described above, the fixed-side member FB may have an axial member 5 (first axial member 5A and second axial member 5B) extending in the optical axis direction that guides the first movable-side member MB1 so as to be movable in the optical axis direction. In this case, the second movable-side member MB2 (second lens holder 3B) may be guided so as to be movable in the optical axis direction relative to the first movable-side member MB1 (first lens holder 3A) by one of the first axial member 5A and the second axial member 5B and another axial member (movable-side axial member 7). In the example shown in the lower part of Figure 8, the second movable-side member MB2 (second lens holder 3B) is guided so as to be movable in the optical axis direction relative to the first lens holder 3A by the first axial member 5A and the movable-side axial member 7.

[0096] In this configuration, the movement of the second movable side member MB2 is guided by two shaft members, which has the effect of ensuring proper guidance of the second movable side member MB2. If the movement of the second movable side member MB2 were guided by three shaft members, it could hinder the movement of the second movable side member MB2. Furthermore, since this configuration is realized with a total of three shaft members (first shaft member 5A, second shaft member 5B, and movable side shaft member 7), it has the effect of simplifying the configuration of the lens holder drive device 101. In addition, since this configuration is realized with a total of three shaft members, it has the effect of enabling miniaturization of the lens holder drive device 101.

[0097] One of the first axis member 5A and the second axis member 5B may be positioned opposite the other of the first axis member 5A and the second axis member 5B, as well as another axis member (movable side axis member 7), with the second lens body LS2 in between. In the example shown in the lower part of Figure 8, the first axis member 5A is positioned opposite the second axis member 5B and the movable side axis member 7, with the second lens body LS2 in between.

[0098] This configuration has the effect of appropriately guiding the movement of the first lens holder 3A and the second lens holder 3B in the optical axis direction, because the distance between the two axial members used for guidance can be increased.

[0099] Furthermore, at least one of the first shaft member 5A and the second shaft member 5B that guide the movement of the second movable side member MB2, and another shaft member (movable side shaft member 7), may be a magnetic metal member. The second movable side member MB2 may also be provided with a magnet 4. In this case, the magnet 4 and the magnetic metal member may be arranged so that an attractive force acts between the magnet 4 and the magnetic metal member. In the example shown in the lower part of Figure 8, the first shaft member 5A is a magnetic metal member, and the magnet 4 and the first shaft member 5A are arranged so that an attractive force acts between the magnet 4 and the first shaft member 5A.

[0100] This configuration has the effect of suppressing the looseness of the second movable member MB2 when it moves along the optical axis direction.

[0101] Furthermore, one of the first shaft member 5A and the second shaft member 5B may be a magnetic metal member. In this case, the magnet 4 may be provided on the side opposite the second piezoelectric drive unit PD2, with the second lens body LS2 in between. In the example shown in the lower part of Figure 8, the first shaft member 5A is a magnetic metal member, and the magnet 4 is provided on the side opposite the second piezoelectric drive unit PD2, with the second lens body LS2 in between.

[0102] This configuration improves the ease of assembly of the lens holder drive device 101. In this configuration, the second piezoelectric drive unit PD2 and the magnet 4 are arranged far apart from each other, making the assembly of the second piezoelectric drive unit PD2 and the magnet 4 to the second movable side member MB2 less complicated.

[0103] The first movable side member MB1 (first lens holder 3A) may be provided with a magnetic field generating member MG. In this case, the fixed side member FB may be provided with a first magnetic sensor 6A for detecting the magnetic field of the magnetic field generating member MG, and the second movable side member MB2 may be provided with a second magnetic sensor 6B for detecting the magnetic field of the magnetic field generating member MG.

[0104] In this configuration, the magnetic field generating member MG is shared by the first magnetic sensor 6A for detecting the relative position of the first lens holder 3A with respect to the base member 2, and by the second magnetic sensor 6B for detecting the relative position of the second movable side member MB2 (second lens holder 3B) with respect to the first lens holder 3A. Therefore, this configuration has the effect of simplifying the configuration of the lens holder drive device 101. Furthermore, this configuration has the effect of reducing the number of parts.

[0105] Preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications and substitutions can be applied to the embodiments described above without departing from the scope of the present invention. Furthermore, each of the features described with reference to the embodiments described above may be combined as appropriate, as long as they do not contradict the technical invention.

[0106] For example, in the above embodiment, when the lens holder 3 moves in the optical axis direction, the first lens holder 3A and the second lens holder 3B are provided with parts that function as guided parts, which are guided by the axis members 5 (first axis member 5A and second axis member 5B) (first through hole TH1, first notch groove CT1, third notch groove CT3, and fifth notch groove CT5). However, the parts that function as guided parts may also be provided in the first lens body LS1 and the second lens body LS2.

[0107] This application claims priority based on Japanese Patent Application No. 2022-128149, filed on 10 August 2022, and the entire contents of that Japanese Patent Application are incorporated herein by reference. [Explanation of symbols]

[0108] 1. Cover member 1B. Rear cover member 1D. Lower cover member 1U. Upper cover member 2. Base member 2A. Outer wall section 2A1. First side plate section 2A2. Second side plate section 2A3. Third side plate section 2A4. Fourth side plate section 2R. Recess 2S. Housing section 2T. Through hole 3. Lens holder 3A. First lens holder 3B. Second lens holder 4. Magnet 5. Axis member 5A. First axis member 5AX. First axis 5B. Second axis member 5BX. Second axis 6. Magnetic sensor 6A. First magnetic sensor 6B. Second magnetic sensor 7. Movable side axis member 7X... Axis 8... Piezoelectric element 8A... First piezoelectric element 8AX... First rotation axis 8B... Second piezoelectric element 8BX... Second rotation axis 9... Contact member 9A... First contact member 9B... Second contact member 10... Circuit board 10A... First circuit board 10B... Second circuit board 10C... Connector part 10P... Piezoelectric element fixing part 10S... Sensor fixing part 10W... Curved part 11... Outer circuit board 13... Biasing member 13A... First biasing member 13B... Second biasing member 13E... Elastic deformation part 13EB... Rear elastic deformation part 13ED... Lower elastic deformation part 13EF... Front elastic deformation part 13EU...Upper elastic deformation part 13F...Fixed part 13FB...Rear fixed part 13FD...Lower fixed part 13FF...Front fixed part 13FU...Upper fixed part 13S...Support part 13SD...Lower support part 13SU...Upper support part 31A...First holding part 31B...Second holding part 32A...First bearing part 32AL...First left bearing part 32AR...First right bearing part 32B...Second bearing part 32BL...Second left bearing part 32BR...Second right bearing part 101...Lens holder drive device BE...Inner edge part CM...Camera module CT1...First notch groove CT2...Second notch groove CT3...Third notch groove CT4...Fourth notch groove CT5...Fifth notch groove DT...Position detection mechanism DT1...First position detection mechanism DT2...Second position detection mechanism FB...Fixed side member HD...Image sensor holder HS...Housing IS...Image sensorLH... Fixed lens holder LS... Lens body LS1... First lens body LS2... Second lens body LT... Optical element MB1... First movable side member MB2... Second movable side member MG... Magnetic field generating member MG1... First magnetic field generating member MG2... Second magnetic field generating member MR... Mirror ND... Node ND1... First node ND2... Second node ND3... Third node ND4... Fourth node OA... Optical axis OP1... First aperture OP2... Second aperture OP3... Third aperture PD... Piezoelectric drive unit PD1... First piezoelectric drive unit PD2... Second piezoelectric drive unit RS... Recess RV... Receiving member RV1... First receiving member RV2... Second receiving member TH1... First through hole

Claims

1. Fixed side member and A first lens holder capable of holding the first lens body, A second lens holder capable of holding a second lens body arranged to have the same optical axis as the first lens body, The first movable side member including the first lens holder, The second movable side member including the second lens holder, A first piezoelectric drive unit is configured to have a first piezoelectric element, and moves the first movable side member in the optical axis direction by the movement of the first piezoelectric element, A lens holder driving device comprising a second piezoelectric drive unit configured to have a second piezoelectric element, which moves the second movable side member in the optical axis direction by the movement of the second piezoelectric element, The second movable side member is included in the first movable side member and is movable in the optical axis direction relative to the first lens holder. The first piezoelectric drive unit is provided on the fixed side member, The second piezoelectric drive unit is provided on the second movable side member, The first movable side member has a first receiving member that extends in the direction of the optical axis and receives the movement of the first piezoelectric drive unit, The first piezoelectric drive unit is biased toward the first receiving member by a first biasing member provided on the fixed side member. The first lens holder has a second receiving member that extends in the optical axis direction and receives the movement of the second piezoelectric drive unit, The second piezoelectric drive unit is biased toward the second receiving member by a second biasing member provided on the second movable side member. A lens holder driving device characterized by the following features.

2. The first receiving member and the second receiving member are made of the same shaft member. The lens holder driving device according to claim 1.

3. The fixed side member has a first axis member and a second axis member extending in the optical axis direction that guide the first movable side member so as to be movable in the optical axis direction, The second movable side member is guided by one of the first and second axis members and the axis member so as to be movable in the optical axis direction relative to the first lens holder. The lens holder driving device according to claim 2.

4. One of the first and second axis members is positioned opposite the other of the first and second axis members, as well as each of the axis members, with the second lens body in between. The lens holder driving device according to claim 3.

5. At least one of the first and second shaft members that guide the movement of the second movable side member, and the shaft member, is a magnetic metal member. The second movable side member is provided with a magnet. An attractive force acts between the magnet and the magnetic metal member. The lens holder driving device according to claim 3 or claim 4.

6. One of the first shaft member and the second shaft member is the magnetic metal member, The magnet is provided on the side opposite to the second piezoelectric drive unit, with the second lens body in between. The lens holder driving device according to claim 5.

7. The first movable side member is provided with a magnetic field generating member. The fixed side member is provided with a first magnetic sensor for detecting the magnetic field of the magnetic field generating member. The second movable side member is provided with a second magnetic sensor for detecting the magnetic field of the magnetic field generating member. A lens holder driving device according to any one of claims 1 to 4.

8. A fixed side member and A first lens holder capable of holding the first lens body, A second lens holder capable of holding a second lens body arranged to have the same optical axis as the first lens body, The first movable side member including the first lens holder, The second movable side member including the second lens holder, A first piezoelectric drive unit is configured to have a first piezoelectric element, and moves the first movable side member in the optical axis direction by the movement of the first piezoelectric element, A lens holder driving device comprising a second piezoelectric drive unit configured to have a second piezoelectric element, which moves the second movable side member in the optical axis direction by the movement of the second piezoelectric element, The second movable side member is included in the first movable side member and is movable in the optical axis direction relative to the first lens holder. The first piezoelectric drive unit is provided on the fixed side member or the first lens holder, The second piezoelectric drive unit is provided on the second movable side member or the first lens holder, The first movable side member is provided with a magnetic field generating member. The fixed side member is provided with a first magnetic sensor for detecting the magnetic field of the magnetic field generating member. The second movable side member is provided with a second magnetic sensor for detecting the magnetic field of the magnetic field generating member. A lens holder driving device characterized by the following features.

9. The first piezoelectric drive unit is provided on the fixed side member, The first movable side member has a first receiving member that extends in the direction of the optical axis and receives the movement of the first piezoelectric drive unit, The first piezoelectric drive unit is biased toward the first receiving member by a first biasing member provided on the fixed side member. The lens holder driving device according to claim 8.

10. The fixed side member has a first axis member and a second axis member extending in the optical axis direction that guide the first movable side member so as to be movable in the optical axis direction, The first receiving member is provided at a position offset from a virtual plane passing through the centers of the first shaft member and the second shaft member, The lens holder driving device according to claim 1 or 9.

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