Piezoelectric drive device and camera module

Abstract

To prevent the structure of piezoelectric drive devices from becoming overly complex. [Solution] The piezoelectric drive device 101 includes a biasing member 7 that biases the piezoelectric drive unit PD toward the receiving member RC, and a guide mechanism GM that guides the movement of the movable side member MB. The guide mechanism GM includes a guide shaft member 4 and a guided portion 2G. The guide shaft member 4 includes a first guide shaft member 41 and a second guide shaft member 42. The guided portion 2G includes a first guided portion 2G1 that is slidable on the first guide shaft member 41, and a second guided portion 2G2 that is slidable on the second guide shaft member 42. Each of the first guided portion 2G1 and the second guided portion 2G2 is configured to be pressed against the first guide shaft member 41 and the second guide shaft member 42 by the biasing force of the biasing member 7.

Description

Technical Field

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

Background Art

[0002] Conventionally, there is known a lens driving unit (piezoelectric driving device) that moves a lens carrier (movable member) guided by a ball bearing by a piezoelectric driving unit pressed against the lens carrier (movable member) side by two lateral springs (coil springs) (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] However, since the above-described device uses balls, the structure may become complicated.

[0005] Therefore, it is desirable to provide a piezoelectric driving device capable of suppressing the complication of the structure.

Means for Solving the Problems

[0006] A piezoelectric drive device according to an embodiment of the present disclosure comprises: a fixed side member; a movable side member movable relative to the fixed side member; a piezoelectric drive unit provided on one side member, which is one of the movable side member and the fixed side member, and configured to have a piezoelectric element; a receiving member provided on the other side member, which is the other of the movable side member and the fixed side member, and in contact with the piezoelectric drive unit; a biasing member that biases the piezoelectric drive unit toward the receiving member; and a guide mechanism that guides the movement of the movable side member accompanying the movement of the piezoelectric element, wherein the piezoelectric drive device is configured such that the movable side member moves in a first direction relative to the fixed side member by the piezoelectric drive unit, and the biasing member comprises: a fixed part fixed to the one side member, and the piezoelectric The guide mechanism comprises a support portion for supporting the drive portion and an elastically deformable elastic deformation portion provided between the fixed portion and the support portion, and the guide mechanism is configured to include a guide shaft member provided on the fixed side member and a guided portion provided on the movable side member, the guide shaft member includes a first guide shaft member and a second guide shaft member extending in the first direction and arranged to face each other with the movable side member in between, the guided portion includes a first guided portion that can slide on the first guide shaft member and a second guided portion that can slide on the second guide shaft member, and each of the first guided portion and the second guided portion is configured to be pressed against the first guide shaft member and the second guide shaft member by the biasing force of the biasing member. [Effects of the Invention]

[0007] The piezoelectric drive device described above can suppress structural complexity. [Brief explanation of the drawing]

[0008] [Figure 1] This is an exploded perspective view of a camera module including a piezoelectric drive device according to an embodiment of the present disclosure. [Figure 2] Figure 1 is an exploded perspective view of the piezoelectric drive device shown. [Figure 3] Figure 1 is a front perspective view of the holding member, biasing member, magnet, piezoelectric drive unit, receiving member, and magnetic sensor that constitute the piezoelectric drive device shown. [Figure 4] Figure 1 is a rear perspective view of the holding member, biasing member, magnet, piezoelectric drive unit, receiving member, and magnetic sensor that constitute the piezoelectric drive device shown. [Figure 5] Figure 1 is a cross-sectional view of the piezoelectric drive device shown. [Figure 6] This figure shows the piezoelectric elements and contact members that constitute the piezoelectric drive device shown in Figure 1. [Figure 7] This figure shows the movement of the piezoelectric drive device shown in Figure 1. [Figure 8] Figure 1 is a three-view drawing of the biasing member that constitutes the piezoelectric drive device shown. [Figure 9] Figure 1 is a front view of the biasing member that constitutes the piezoelectric drive device. [Figure 10] Figure 1 is a three-view drawing of the biasing member, piezoelectric element, and contact member that constitute the piezoelectric drive device shown. [Figure 11] Figure 1 is a three-view drawing of the holding member and biasing member that constitute the piezoelectric drive device shown. [Figure 12] Figure 1 is a perspective view of the holding member, biasing member, piezoelectric element, and contact member that constitute the piezoelectric drive device shown. [Figure 13] Figure 1 is a cross-sectional view of the lens holding member, base member, and guide shaft member that constitute the piezoelectric drive device shown. [Figure 14] Figure 1 is a cross-sectional view of the piezoelectric drive device shown. [Figure 15] Figure 1 is a cross-sectional view of the piezoelectric drive device shown. [Figure 16] Figure 1 is a cross-sectional view of the piezoelectric drive device shown. [Figure 17] Figure 1 is a perspective view of the components that make up the piezoelectric drive device shown. [Figure 18] Figure 1 is a perspective view of the components that make up the piezoelectric drive device shown. [Figure 19] This is a perspective view of a piezoelectric drive device according to another embodiment of the present disclosure. [Figure 20] Figure 19 is a top view of the lens holding member, guide shaft member, piezoelectric element, and contact member that constitute the piezoelectric drive device shown.

Best Mode for Carrying Out the Invention

[0009] Hereinafter, referring to FIGS. 1 to 5, a piezoelectric driving device 101 according to an embodiment of the present disclosure will be described. FIG. 1 is an exploded perspective view of a camera module CM which is an example of an optical device including the piezoelectric driving device 101. FIG. 2 is an exploded perspective view of the piezoelectric driving device 101. FIGS. 3 and 4 are perspective views of a holding member 6, a biasing member 7, a magnet MG, a piezoelectric driving unit PD, a receiving member RC, and a magnetic sensor SR that constitute the piezoelectric driving device 101. Specifically, FIG. 3 is a front perspective view, and FIG. 4 is a rear perspective view. Also, the upper diagrams in FIGS. 3 and 4 are assembled perspective views, and the lower diagrams in FIGS. 3 and 4 are exploded perspective views. FIG. 5 is a cross-sectional view of the piezoelectric driving device 101. Specifically, the upper diagram in FIG. 5 is a view when looking at the cross-section of the piezoelectric driving device 101 in a virtual plane parallel to the XY plane including the cutting line CL1 shown in FIG. 1 from the Z1 side. Also, the lower diagram in FIG. 5 is an enlarged view of a range R1 surrounded by a broken line in the upper diagram of FIG. 5.

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

[0011] The camera module CM is composed of a piezoelectric drive device 101, a lens body LS which is an example of an optical element OE, and an imaging element IS mounted on a substrate (not shown) so as to face the lens body LS. The piezoelectric drive device 101 has an outer shape of a substantially rectangular parallelepiped and is attached on the substrate on which the imaging element IS is mounted. Note that the optical element OE may be a mirror, a prism, a diffraction grating, a light-emitting element, a light-receiving element, an imaging element, an optical filter, etc. Also, the optical element OE may be a combination of multiple types of elements. Further, when the optical element OE is an element other than the lens body LS, the imaging element IS may be omitted.

[0012] In the illustrated example, as shown in FIG. 2, the piezoelectric drive device 101 includes a fixed-side member FB and a movable-side member MB. Specifically, the fixed-side member FB that supports the movable-side member MB includes a cover member 1, a base member 3, and a guide shaft member ④, and the movable-side member MB includes a lens holding member 2 and is slidably supported in a moving direction (Z-axis direction) parallel to the optical axis direction by the guide shaft member 4. The optical axis direction includes the direction of the optical axis OA regarding the lens body LS held by the lens holding member 2 and a direction parallel to the optical axis OA. The lens body LS is, for example, a cylindrical lens barrel provided with at least one lens. Also, the movable-side member MB is configured to be moved in a predetermined moving direction with respect to the fixed-side member FB by the force generated by the piezoelectric drive unit PD.

[0013] The cover member 1 is a component that forms part of the housing HS and is configured to cover the upper and side portions of the movable side member MB. In the illustrated example, as shown in Figure 2, the cover member 1 has a substantially rectangular cylindrical outer peripheral wall portion 1A and a flat, rectangular annular top plate portion 1B. Specifically, the outer peripheral wall portion 1A includes first side plate portions 1A1 to fourth side plate portions 1A4. The first side plate portion 1A1 and the third side plate portion 1A3 face each other, and the second side plate portion 1A2 and the fourth side plate portion 1A4 face each other. Furthermore, the second side plate portion 1A2 and the fourth side plate portion 1A4 extend perpendicularly to the first side plate portion 1A1 and the third side plate portion 1A3. That is, the first side plate portion 1A1 and the third side plate portion 1A3 extend perpendicularly to the second side plate portion 1A2 and the fourth side plate portion 1A4. The top plate portion 1B has a substantially circular opening 1K formed in the central part. Furthermore, the cover member 1 is manufactured by punching and drawing processes on a metal plate. However, the cover member 1 may be made of other materials such as synthetic resin.

[0014] The base member 3 is a component that constitutes a part of the housing HS. In the illustrated example, the base member 3 is made of synthetic resin. However, the base member 3 may be made of metal. Specifically, as shown in Figure 2, the base member 3 has a substantially rectangular cylindrical outer peripheral wall portion 3A and a rectangular annular bottom plate portion 3B. Specifically, the outer peripheral wall portion 3A includes first side plate portions 3A1 to fourth side plate portions 3A4. The first side plate portion 3A1 and the third side plate portion 3A3 face each other, and the second side plate portion 3A2 and the fourth side plate portion 3A4 face each other. Also, the second side plate portion 3A2 and the fourth side plate portion 3A4 extend perpendicularly to the first side plate portion 3A1 and the third side plate portion 3A3. That is, the first side plate portion 3A1 and the third side plate portion 3A3 extend perpendicularly to the second side plate portion 3A2 and the fourth side plate portion 3A4. The bottom plate portion 3B has a roughly circular opening 3K in its central part. Additionally, a notch 3C for receiving the retaining member 6 is formed at the left front corner of the outer peripheral wall portion 3A. Specifically, a first notch 3C1 is formed in the first side plate portion 3A1, and a second notch 3C2 is formed in the second side plate portion 3A2. The base member 3 is joined to the cover member 1 by adhesive or the like, and together with the cover member 1, constitutes the housing HS.

[0015] The guide shaft member 4 is configured to guide (support so that it can move) the movable side member MB (lens holding member 2) in the vertical direction relative to the fixed side member FB (base member 3). In the illustrated example, the guide shaft member 4 is a substantially cylindrical member made of metal, which is fitted into a housing recess 3R formed on the inside of the outer peripheral wall portion 3A of the base member 3 and fixed to the base member 3 by adhesive AD6 (see Figure 13). Specifically, the guide shaft member 4 includes a first guide shaft member 41 and a second guide shaft member 42 having the same structure, and the housing recess 3R includes a first housing recess 3R1 into which the first guide shaft member 41 is fitted, and a second housing recess 3R2 into which the second guide shaft member 42 is fitted.

[0016] The lens holding member 2 is configured to hold the optical element OE. In the illustrated example, the lens holding member 2 is formed by injection molding of a synthetic resin such as liquid crystal polymer (LCP). The lens holding member 2 is configured to hold the lens body LS by fixing the lens body LS inside a substantially cylindrical tubular portion 2C with adhesive. The lens holding member 2 also has a guided portion 2G that protrudes radially outward from the outer circumferential surface of the tubular portion 2C and receives the guide shaft member 4. Specifically, the guided portion 2G includes a first guided portion 2G1 having a U-shaped concave portion CS in plan view that receives the first guide shaft member 41, and a second guided portion 2G2 having a flat surface portion FS in plan view that receives the second guide shaft member 42. In this embodiment, "plan view" means viewing the member or part in question along the first direction (Z-axis direction). The same applies hereafter.

[0017] Stopper portions 2S are provided on the upper and lower end surfaces of the cylindrical portion 2C of the lens holding member 2. In the illustrated example, as shown in Figure 2, the upper end surface of the cylindrical portion 2C is provided with three upper stopper portions 2SU formed to contact the lower surface (ceiling surface) of the top plate portion 1B of the cover member 1 when the lens holding member 2 moves in the Z1 direction. Similarly, the lower end surface of the cylindrical portion 2C is provided with three lower stopper portions 2SD (see Figure 14) formed to contact the upper surface (inner bottom surface) of the bottom plate portion 3B of the base member 3 when the lens holding member 2 moves in the Z2 direction.

[0018] Furthermore, a recess 2U for housing the receiving member RC and a recess 2V for housing the magnet MG are formed on the outer circumferential surface of the cylindrical portion 2C of the lens holding member 2. The magnet MG and magnetic sensor SR are components for detecting the position of the movable side member MB. The magnet MG constitutes a part of the movable side member MB. In the illustrated example, the magnet MG is a permanent magnet magnetized to two poles along the Z-axis direction. The magnetic sensor SR is composed of a Hall element and is configured to detect the position of the movable side member MB, including the magnet MG, by measuring the output voltage of the Hall element, which changes according to the magnitude of the magnetic field from the magnet MG that the Hall element receives. However, the magnetic sensor SR may be configured to detect the position of the movable side member MB using a magnetoresistive element such as a giant magnetoresistive effect (GMR) element, a semiconductor magnetoresistive (SMR) element, an anisotropic magnetoresistive (AMR) element, or a tunnel magnetoresistive (TMR) element.

[0019] The receiving member RC is the member that receives the driving force generated by the piezoelectric drive unit PD. In the illustrated example, the receiving member RC is a substantially cylindrical member made of metal and constitutes the movable side member MB.

[0020] The holding member 6 is configured to hold the piezoelectric drive unit PD. In the illustrated example, the holding member 6 is one of the fixed-side members FB and is formed by injection molding of a synthetic resin such as liquid crystal polymer (LCP). As shown in Figure 5, the holding member 6, while holding the biasing member 7 and the piezoelectric drive unit PD, is inserted into the notch 3C of the base member 3 from the Z1 side and fixed to the base member 3 by adhesive AD4 (see lower diagram in Figure 5).

[0021] The biasing member 7 is configured to bias the piezoelectric drive unit PD relative to the receiving member RC in order to bring the piezoelectric drive unit PD into contact with the receiving member RC. In the illustrated example, the biasing member 7 is made of a leaf spring member formed by press working on a rolled metal plate, and is fixed to the holding member 6 via a fixing portion 7F, as shown in Figures 3 and 4. Specifically, the fixing portion 7F includes a left fixing portion 7FL and a right fixing portion 7FR, as shown in Figures 3 and 4. The biasing member 7 may be configured to generate an elastic restoring force that tries to bring the left fixing portion 7FL and the right fixing portion 7FR closer together when it is attached to the holding member 6. Furthermore, the fixing portion 7F of the biasing member 7 is fixed to the base member 3 and the holding member 6 by adhesive AD4 (see lower diagram in Figure 5) applied to the base member 3 and the holding member 6 when the holding member 6 is attached to the base member 3.

[0022] The piezoelectric drive unit PD is configured to move the movable side member MB (lens holding member 2) along a predetermined direction of movement. In the illustrated example, 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 flexible wiring board 10. The piezoelectric drive unit PD is configured to be biased by a biasing member 7, which is held by a holding member 6, and pressed against a receiving member RC.

[0023] Specifically, the piezoelectric element 8 is configured to realize bending vibration in response to the applied voltage. In the illustrated example, the piezoelectric element 8 extends in the Y-axis direction along the rotation axis 8X, as shown in Figures 3 and 4. The piezoelectric element 8 is also configured to realize bending vibration having two nodes (nodes ND). When bending vibration occurs, the two node ND sections hardly vibrate. In Figures 3 and 4, for clarity, a cross pattern is drawn at the positions of the nodes ND on the piezoelectric element 8. The positions of the nodes ND on the piezoelectric element 8 include the position of the first node ND1 and the position of the second node ND2. The positions of the nodes ND correspond to positions at a predetermined distance from the end of the piezoelectric element 8. The predetermined distance is, for example, approximately one-quarter of the total length of the piezoelectric element 8.

[0024] The flexible wiring board 10 is a flexible wiring board containing conductive patterns and is configured to electrically connect an external power source and a piezoelectric element 8. In the illustrated example, the flexible wiring board 10 is configured to allow voltage to be applied to the piezoelectric element 8. Specifically, the flexible wiring board 10 includes a left unfolding section 10L, a right unfolding section 10R, a connecting section 10C (lower connecting section 10CD and upper connecting section 10CU) connecting the left unfolding section 10L and the right unfolding section 10R, an extension section 10E extending in the Z1 direction from the center of the lower connecting section 10CD, and a connecting section 10J extending from the extension section 10E and joined to the piezoelectric element 8. As shown in the upper diagram of Figure 3, a capacitor CD, a resistor RS, and a driver integrated circuit DR are mounted on the left unfolding section 10L. The right unfolding section 10R is the part used for connecting to external equipment, and a terminal section used for connecting to external equipment is provided at the lower end of the right unfolding section 10R. Furthermore, as shown in the upper diagram of Figure 4, a capacitor CD, a resistor RS, a magnetic sensor SR, and a thermistor TM are mounted in the right-hand unfolding section 10R.

[0025] Furthermore, the piezoelectric element 8 extends along the rotation axis 8X and is bonded to the proximal (X2 side) surface of the flexible wiring board 10 by adhesive AD1. "Proximal side" means the side closer to the receiving member RC compared to the "distal side". In the illustrated example, as shown in Figure 3, the piezoelectric element 8 has electrodes ED at each of the four corners of the distal (X1 side) surface. The four electrodes ED of the piezoelectric element 8 are then bonded via adhesive AD1 to four connection parts PT (see Figure 4) formed on the proximal surface of the joint part 10J of the flexible wiring board 10.

[0026] In the illustrated example, the adhesive AD1 is an anisotropic conductive film that is heated and pressurized while placed between the piezoelectric element 8 and the flexible wiring board 10, and fixed to both the piezoelectric element 8 and the flexible wiring board 10. As a result, the four electrodes ED of the piezoelectric element 8 and the four connection points PT, which are part of the conductive pattern of the flexible wiring board 10, are electrically connected individually. However, the adhesive AD1 may be a conductive adhesive or solder, etc.

[0027] Furthermore, in the illustrated example, the flexible wiring board 10 has conductive patterns formed on both sides, and an insulating film covering the conductive patterns is provided on both sides, except for exposed parts such as the connection part PT. In addition, an insulating protective film is provided on the parts that come into contact with the biasing member 7 and the parts that come into contact with the piezoelectric element 8 to ensure more reliable insulation.

[0028] The piezoelectric drive unit PD is configured to be biased toward X2 by a biasing member 7 attached to a holding member 6 fixed to the base member 3, and pressed against the receiving member RC. In the illustrated example, as shown in Figures 3 and 4, the biasing member 7 is configured to contact the distal (X1 side) surface of the joint 10J of the flexible wiring board 10 at positions corresponding to each of the two nodes ND formed during bending vibration of the piezoelectric element 8 (positions of the end face 7E of the protruding plate portion 7P). In the illustrated example, the end face 7E of the biasing member 7 and the joint 10J of the flexible wiring board 10 are joined by an adhesive AD2 (see Figure 10).

[0029] In the illustrated example, the biasing member 7, as shown in Figures 3, 4, and 8, has a plate-shaped base portion 7M positioned opposite the distal surface of the piezoelectric drive unit PD, and a protruding plate portion 7P that is bent from the edge of the base portion 7M in the extending direction (Y-axis direction) of the piezoelectric element 8 and protrudes toward the proximal surface side (X2 side) of the piezoelectric drive unit PD. Specifically, the protruding plate portion 7P includes a right protruding plate portion 7PR that is bent in an L-shape from the right edge of the base portion 7M and protrudes toward the X2 side, and a left protruding plate portion 7PL that is bent in an L-shape from the left edge of the base portion 7M and protrudes toward the X2 side.

[0030] Furthermore, the protruding plate portion 7P has a support projection 7Q that protrudes toward the piezoelectric drive unit PD in the Z-axis direction. In the illustrated example, as shown in Figure 8, the support projection 7Q includes a left support projection 7QL formed on the left protruding plate portion 7PL and a right support projection 7QR formed on the right protruding plate portion 7PR. The left support projection 7QL includes a lower left support projection 7QLD and an upper left support projection 7QLU, and the right support projection 7QR includes a lower right support projection 7QRD and an upper right support projection 7QRU. Specifically, each of the support projections 7Q (lower left support projection 7QLD, upper left support projection 7QLU, lower right support projection 7QRD, and upper right support projection 7QRU) is formed to extend (project) in a direction perpendicular to the extending direction (Y-axis direction) of the piezoelectric element 8 (Z-axis direction). Furthermore, the positions where each of the support protrusions 7Q is positioned are preferably the positions corresponding to the nodes ND of the piezoelectric element 8, as shown in the rear view of Figure 10, and specifically, they are spaced apart from each other in the extending direction (Y-axis direction) of the piezoelectric element 8.

[0031] As shown in Figures 3 and 4, the piezoelectric drive unit PD is attached to the biasing member 7 such that the distal surface (X1 side surface) of the joint portion 10J of the flexible wiring board 10 is in contact with the end surface 7E of the protruding plate portion 7P of the biasing member 7. Specifically, the piezoelectric drive unit PD is attached to the biasing member 7 such that the left end surface 7EL and the right end surface 7ER of the biasing member 7 are in contact with the positions corresponding to the first section ND1 and the second section ND2 of the piezoelectric element 8 on the joint portion 10J, respectively. In other words, the piezoelectric drive unit PD is attached to the biasing member 7 such that the biasing member 7 is not in contact with the portion of the distal surface (X1 side surface) of the joint portion 10J that does not correspond to the first section ND1 and the second section ND2 of the piezoelectric element 8, respectively.

[0032] Next, the movement of the piezoelectric drive unit PD will be explained with reference to Figure 6. Figure 6 is a diagram showing the piezoelectric element 8 and contact member 9 that constitute the piezoelectric drive unit PD. In Figure 6, the flexible wiring board 10 is omitted from the illustration for clarity. Specifically, the top diagram in Figure 6 is a perspective view of the piezoelectric element 8 and contact member 9, the second, third, and fourth diagrams from the top in Figure 6 are top views of the piezoelectric element 8 and contact member 9 viewed along the Z-axis, and the fifth, sixth, and seventh diagrams from the top in Figure 6 are front views of the piezoelectric element 8 and contact member 9 viewed along the X-axis. Note that in Figure 6, the curved shape of the piezoelectric drive unit PD is exaggerated for ease of understanding.

[0033] In the illustrated example, the piezoelectric element 8 has two parts (a first part 81 and a second part 82) aligned along the Z-axis direction, and each of these two parts has two electrodes ED to which a voltage can be applied individually. Specifically, the first part 81 has a first electrode ED1 and a second electrode ED2, and the second part 82 has a first electrode ED11 and a second electrode ED12. In Figure 6, for clarity, the first part 81 is marked with a dot pattern and the second part 82 is marked with a diagonal line pattern.

[0034] The piezoelectric drive unit PD can bend and vibrate the piezoelectric element 8 (piezoelectric drive unit PD) so that, for example, the trajectory traced by the center point CP, which is a predetermined point on the piezoelectric element 8 (piezoelectric drive unit PD), is a circular orbit centered on the rotation axis 8X, when the voltage to the first part 81 and the voltage to the second part 82 are applied individually at appropriate timings. Note that the circular motion may also be elliptical motion. In other words, the piezoelectric element 8 can achieve movement (circular or elliptical motion) such that the center point CP traces a circle. In the illustrated example, the center point CP of the piezoelectric element 8 is the center of gravity of the piezoelectric element 8. However, the center point CP may be located within the contact member 9 fixed to the piezoelectric element 8, because the contact member 9 also moves in a circular motion together with the piezoelectric element 8. Furthermore, by applying voltage to the first part 81 and the second part 82 respectively at appropriate timings, the piezoelectric drive unit PD can switch the direction of movement (direction of rotation) of the center point CP following the circular orbit between clockwise and counterclockwise when viewed from one side in the direction along the rotation axis 8X. Furthermore, the circle (circular orbit) traced by the center point CP does not need to be a perfect circle; it only needs to be roughly circular, and may even be elliptical.

[0035] In the top diagram of Figure 6, the dashed arrow drawn around the piezoelectric element 8 represents an example of bending vibration of the piezoelectric element 8 (circular motion in which the piezoelectric element 8 rotates counterclockwise around the rotation axis 8X while bending). Although not shown by the arrow, the piezoelectric element 8 can also rotate clockwise around the rotation axis 8X while bending.

[0036] The contact member 9 is attached to the piezoelectric element 8 and configured to contact the receiving member RC. In the illustrated example, the contact member 9 is bonded to the surface of one side of the piezoelectric element 8 (proximal side, X2 side) by adhesive so as to cover the entire surface of that side. The contact member 9 is made of a metal such as titanium copper or stainless steel and is configured with an appropriate thickness so as to be able to perform bending vibration (circular motion) along with the bending vibration (circular motion) of the piezoelectric element 8. In the illustrated example, the contact member 9 is a friction plate made of stainless steel. The contact member 9 extends in the same direction as the piezoelectric element 8 and has the same length as the piezoelectric element 8. The contact member 9 is configured to contact the movable side member MB (receiving member RC) at its center in the direction of its extension. Specifically, the contact member 9 is configured to contact the movable side member MB (receiving member RC) 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, in the illustrated example, the contact surface 9S of the contact member 9, on the side that contacts the movable side member MB (proximal side, X2 side), is a convex curved surface that is convex toward the X2 side. That is, the contact surface 9S is configured to form a surface having a single convex portion.

[0037] The reason for bringing the metal movable side member MB (receiving member RC) into contact with the metal contact member 9 is to avoid wear of the movable side member MB (receiving member RC) due to contact between the synthetic resin movable side member MB (receiving member RC) and the metal contact member 9. However, as long as contact between the movable side member MB (receiving member RC) and the contact member 9 is achieved, the length of the contact member 9 in the direction along the rotation axis 8X does not have to be the same as the length of the piezoelectric element 8 in the direction along the rotation axis 8X. For example, the length of the contact member 9 in the direction along the rotation axis 8X may be smaller than the length of the piezoelectric element 8 in the direction along the rotation axis 8X. However, it is preferable that the length of the contact member 9 in the extending direction (direction along the rotation axis 8X) is equal to or greater than the length of the piezoelectric element 8.

[0038] When the first electrode ED1 is connected to a high potential and the second electrode ED2 is connected to a low potential so that the first part 81 contracts, and when the first electrode ED11 is connected to a high potential and the second electrode ED12 is connected to a low potential so that the second part 82 contracts, the piezoelectric element 8 and the contact member 9 each bend so that they are convex to the proximal side, as shown in the second figure from the top. Hereinafter, the state of the piezoelectric drive unit PD when the piezoelectric element 8 and the contact member 9 each are convex to the proximal side will also be referred to as the "proximal convex state".

[0039] Furthermore, if the first electrode ED1 and the second electrode ED2 are connected to the same potential so that the first portion 81 does not expand or contract, or if the application of voltage to the first electrode ED1 and the second electrode ED2 is stopped, and the first electrode ED11 and the second electrode ED12 are connected to the same potential so that the second portion 82 does not expand or contract, or if the application of voltage to the first electrode ED11 and the second electrode ED12 is stopped, then, as shown in the third and sixth figures from the top, the piezoelectric element 8 and the contact member 9 will each extend in a straight line. Hereinafter, the state of the piezoelectric drive unit PD when the piezoelectric element 8 and the contact member 9 are each extended in a straight line will also be referred to as the "neutral state". The state when the application of voltage is stopped will also be referred to as the "initial state".

[0040] Furthermore, when the first electrode ED1 is connected to a low potential and the second electrode ED2 is connected to a high potential so that the first portion 81 extends, and when the first electrode ED11 is connected to a low potential and the second electrode ED12 is connected to a high potential so that the second portion 82 extends, the piezoelectric element 8 and the contact member 9 each bend so that they are convex distally, as shown in the fourth figure from the top. Hereinafter, the state of the piezoelectric drive unit PD when the piezoelectric element 8 and the contact member 9 each are convex distally will also be referred to as the "distal convex state".

[0041] Furthermore, when the first electrode ED1 is connected to a low potential and the second electrode ED2 is connected to a high potential so that the first portion 81 expands, and when the first electrode ED11 is connected to a high potential and the second electrode ED12 is connected to a low potential so that the second portion 82 contracts, the piezoelectric element 8 and the contact member 9 each bend so that they are convex upwards in the figure, as shown in the fifth figure from the top. Hereinafter, the state of the piezoelectric drive unit PD when the piezoelectric element 8 and the contact member 9 each are convex upwards in the figure will also be referred to as the "upward convex state".

[0042] Furthermore, when the first electrode ED1 is connected to a high potential and the second electrode ED2 is connected to a low potential so that the first portion 81 contracts, and when the first electrode ED11 is connected to a low potential and the second electrode ED12 is connected to a high potential so that the second portion 82 stretches, the piezoelectric element 8 and the contact member 9 each bend so that they are convex downwards in the figure, as shown in the seventh figure from the top. Hereinafter, the state of the piezoelectric drive unit PD when the piezoelectric element 8 and the contact member 9 each are convex downwards in the figure will also be referred to as the "convex downward state".

[0043] Furthermore, when a voltage is applied between the first electrode ED1 (first electrode ED11) and the second electrode ED2 (second electrode ED12) to stretch or contract the first portion 81 (second portion 82) in its extending direction, the contact member 9 fixed to one side of the piezoelectric element 8 does not change its dimensions in its extending direction. Therefore, the piezoelectric drive unit PD deforms to the state described above. In addition, the flexible wiring board 10 fixed to the other side of the piezoelectric element 8 can deform to follow the shape change of the piezoelectric element 8.

[0044] Furthermore, in the illustrated example, the piezoelectric drive unit PD is configured such that the first electrode ED1 is connected to a high potential and the second electrode ED2 is connected to a low potential so that the first portion 81 contracts, and the first electrode ED1 is connected to a low potential and the second electrode ED2 is connected to a high potential so that the first portion 81 expands. However, it may also be configured such that the first electrode ED1 is connected to a low potential and the second electrode ED2 is connected to a high potential so that the first portion 81 contracts, and the first electrode ED1 is connected to a high potential and the second electrode ED2 is connected to a low potential so that the first portion 81 expands. The same applies to the second portion 82.

[0045] Next, referring to Figure 7, the relationship between the bending vibration (circular motion) of the piezoelectric drive unit PD and the motion of the movable side member MB (receiving member RC) will be explained. Figure 7 is a right side view of the movable side member MB (receiving member RC) and the piezoelectric drive unit PD. Specifically, the left side of Figure 7 shows the movable side member MB (receiving member RC) in its initial position, the center side of Figure 7 shows the movable side member MB (receiving member RC) when it has moved above its initial position, and the right side of Figure 7 shows the movable side member MB (receiving member RC) when it has moved below its initial position. The initial position of the movable side member MB (receiving member RC) is, for example, the position of the movable side member MB (receiving member RC) when it is in the center of its range of motion in the Z-axis direction. In Figure 7, for clarity, a dot pattern is applied to the receiving member RC, and a cross pattern is applied to adhesives AD2 and AD3. Furthermore, in the central and right diagrams of Figure 7, the flexible wiring board 10 is omitted from the illustration for clarity.

[0046] The piezoelectric drive device 101 repeatedly changes the state of the piezoelectric drive unit PD in the order of proximal convex state, upper convex state, distal convex state, lower convex state, proximal convex state, ..., thereby translating the movable side member MB (receiving member RC) upward (towards Z1), as shown by arrow AR1 in the central diagram of Figure 7.

[0047] Furthermore, the piezoelectric drive device 101 can repeatedly change the state of the piezoelectric drive unit PD in the order of proximal convex state, downward convex state, distal convex state, upward convex state, proximal convex state, ..., thereby translating the movable side member MB (receiving member RC) downward (towards Z2), as shown by arrow AR2 in the right-hand figure.

[0048] Next, the details of the biasing member 7 will be described with reference to Figures 8 and 9. Figure 8 is a three-view drawing (top view, left side view, and right side view) of the biasing member 7, and Figure 9 is a front view of the biasing member 7.

[0049] The biasing member 7 is made of a metal plate rolled in a predetermined rolling direction (Y-axis direction). In the illustrated example, the biasing member 7 is configured to be symmetrical in a plan view, as shown in the upper view (top view) of Figure 8, and symmetrical in a front view, as shown in Figure 9. Specifically, the biasing member 7 is configured so that its left end and right end are separated in the rolling direction (Y-axis direction) perpendicular to the first direction (Z-axis direction). The biasing member 7 also has a fixed part 7F fixed to the fixed side member FB (holding member 6), a support part 7S located between the left end and the right end that supports the piezoelectric drive part PD, an elastically deformable elastic deformation part 7G provided between the fixed part 7F and the support part 7S, 20 bend parts 7N provided between the left end and the right end, and 10 inclined parts 7T provided between two adjacent bend parts 7N. Each of the 20 bent sections 7N is bent such that the bending axis 7X is approximately perpendicular to the rolling direction (Y-axis direction). The bending axis 7X is an axis that extends parallel to the bending line, and the bending line is a line that represents the position where the punch used in the bending process makes contact.

[0050] As shown in Figure 8, the support portion 7S has a flat plate-shaped base portion 7M that faces the distal (X1 side) surface of the piezoelectric drive unit PD, and two protruding plate portions 7P that face each other spaced apart in the rolling direction (Y-axis direction) with the base portion 7M in between, and protrude from the base portion 7M toward the piezoelectric drive unit PD side (X2 side). As shown in Figure 9, the base portion 7M is configured such that its plate surface extends along the YZ plane.

[0051] As shown in Figure 8, the two protruding plate portions 7P include a right protruding plate portion 7PR which is bent in an L-shape from the right edge of the base portion 7M and protrudes toward the X2 side, and a left protruding plate portion 7PL which is bent in an L-shape from the left edge of the base portion 7M and protrudes toward the X2 side.

[0052] The fixing portion 7F includes a left fixing portion 7FL provided at the left end of the biasing member 7 and a right fixing portion 7FR provided at the right end of the biasing member 7.

[0053] As shown in Figure 8, the elastic deformation portion 7G includes a left elastic deformation portion 7GL provided between the left fixing portion 7FL and the left protruding plate portion 7PL of the support portion 7S, and a right elastic deformation portion 7GR provided between the right fixing portion 7FR and the right protruding plate portion 7PR of the support portion 7S. Specifically, as shown in Figure 9, the left elastic deformation portion 7GL includes an upper left elastic deformation portion 7GLU provided between the upper end of the left fixing portion 7FL and the upper end of the left protruding plate portion 7PL of the support portion 7S, a lower left elastic deformation portion 7GLD provided between the lower end of the left fixing portion 7FL and the lower end of the left protruding plate portion 7PL of the support portion 7S, and a left central elastic deformation portion 7GLC extending in the Z-axis direction and connecting the upper left elastic deformation portion 7GLU and the lower left elastic deformation portion 7GLD. Furthermore, the right elastic deformation portion 7GR includes an upper right elastic deformation portion 7GRU provided between the upper end of the right fixing portion 7FR and the upper end of the right protruding plate portion 7PR of the support portion 7S, a lower right elastic deformation portion 7GRD provided between the lower end of the right fixing portion 7FR and the lower end of the right protruding plate portion 7PR of the support portion 7S, and a right central elastic deformation portion 7GRC extending in the Z-axis direction and connecting the upper right elastic deformation portion 7GRU and the lower right elastic deformation portion 7GRD.

[0054] Furthermore, as shown in Figure 9, an opening 7H is formed in the biasing member 7. The opening 7H includes a first opening 7H1 and a second opening 7H2. Specifically, the first opening 7H1 includes a first left opening 7H1L ​​and a first right opening 7H1R, and the second opening 7H2 includes a second left opening 7H2L and a second right opening 7H2R.

[0055] The 20 bent sections 7N include the first bent section 7N1 to the sixth bent section 7N6, as shown in Figure 8. Specifically, the first bent section 7N1 includes the first left bent section 7NL1 and the first right bent section 7NR1; the second bent section 7N2 includes the second left bent section 7NL2 and the second right bent section 7NR2; the third bent section 7N3 includes the third left bent section 7NL3 and the third right bent section 7NR3; the fourth bent section 7N4 includes the fourth left bent section 7NL4 and the fourth right bent section 7NR4; the fifth bent section 7N5 includes the fifth left bent section 7NL5 and the fifth right bent section 7NR5; and the sixth bent section 7N6 includes the sixth left bent section 7NL6 and the sixth right bent section 7NR6.

[0056] Typically, the bending process is carried out sequentially from the tip side (fixing part 7F side) of the biasing member 7. In the illustrated example, the bending process is carried out in the order of the first bend 7N1, the second bend 7N2, the third bend 7N3, the fourth bend 7N4, the fifth bend 7N5, and the sixth bend 7N6.

[0057] More specifically, as shown in Figure 9, the first left bend 7NL1 includes the first lower left bend 7NLD1 and the first upper left bend 7NLU1, and the first right bend 7NR1 includes the first lower right bend 7NRD1 and the first upper right bend 7NRU1. The second left bend 7NL2 includes the second lower left bend 7NLD2 and the second upper left bend 7NLU2, and the second right bend 7NR2 includes the second lower right bend 7NRD2 and the second upper right bend 7NRU2. The third left bend 7NL3 includes the third lower left bend 7NLD3 and the third upper left bend 7NLU3, and the third right bend 7NR3 includes the third lower right bend 7NRD3 and the third upper right bend 7NRU3. Furthermore, the fourth left bend 7NL4 includes the fourth lower left bend 7NLD4 and the fourth upper left bend 7NLU4, and the fourth right bend 7NR4 includes the fourth lower right bend 7NRD4 and the fourth upper right bend 7NRU4.

[0058] Furthermore, as shown in Figure 8, each of the 20 bent sections 7N has a corresponding bending axis 7X. Specifically, the first to sixth bent sections 7N1 to 7N6 each have a first bending axis 7X1 to 7X6. Specifically, the first bending axis 7X1 includes a first left bending axis 7XL1 and a first right bending axis 7XR1, the second bending axis 7X2 includes a second left bending axis 7XL2 and a second right bending axis 7XR2, the third bending axis 7X3 includes a third left bending axis 7XL3 and a third right bending axis 7XR3, the fourth bending axis 7X4 includes a fourth left bending axis 7XL4 and a fourth right bending axis 7XR4, the fifth bending axis 7X5 includes a fifth left bending axis 7XL5 and a fifth right bending axis 7XR5, and the sixth bending axis 7X6 includes a sixth left bending axis 7XL6 and a sixth right bending axis 7XR6.

[0059] More specifically, as shown in Figure 9, the first left bending axis 7XL1 includes the first lower left bending axis 7XLD1 and the first upper left bending axis 7XLU1, and the first right bending axis 7XR1 includes the first lower right bending axis 7XRD1 and the first upper right bending axis 7XRU1. Furthermore, the second left bending axis 7XL2 includes the second lower left bending axis 7XLD2 and the second upper left bending axis 7XLU2, and the second right bending axis 7XR2 includes the second lower right bending axis 7XRD2 and the second upper right bending axis 7XRU2. Furthermore, the third left bending axis 7XL3 includes the third lower left bending axis 7XLD3 and the third upper left bending axis 7XLU3, and the third right bending axis 7XR3 includes the third lower right bending axis 7XRD3 and the third upper right bending axis 7XRU3. Furthermore, the fourth left bending axis 7XL4 includes the fourth lower left bending axis 7XLD4 and the fourth upper left bending axis 7XLU4, and the fourth right bending axis 7XR4 includes the fourth lower right bending axis 7XRD4 and the fourth upper right bending axis 7XRU4.

[0060] Furthermore, as shown in Figure 8, the inclined portion 7T is the portion where the plate surface is inclined with respect to the X-axis and Y-axis, respectively, and includes a left inclined portion 7TL and a right inclined portion 7TR. Specifically, the left inclined portion 7TL includes a first left inclined portion 7TL1, a second left inclined portion 7TL2, and a third left inclined portion 7TL3, and the right inclined portion 7TR includes a first right inclined portion 7TR1, a second right inclined portion 7TR2, and a third right inclined portion 7TR3. Preferably, the inclined portion 7T is configured to have a width (length along the rolling direction) that is three times or more the thickness of the plate.

[0061] More specifically, as shown in Figure 9, the first left inclined section 7TL1 includes the first upper left inclined section 7TLU1 and the first lower left inclined section 7TLD1, and the first right inclined section 7TR1 includes the first upper right inclined section 7TRU1 and the first lower right inclined section 7TRD1. Furthermore, the second left inclined section 7TL2 includes the second upper left inclined section 7TLU2 and the second lower left inclined section 7TLD2, and the second right inclined section 7TR2 includes the second upper right inclined section 7TRU2 and the second lower right inclined section 7TRD2.

[0062] Next, with reference to Figure 10, the positional relationship between the biasing member 7, the piezoelectric element 8, and the contact member 9 will be explained. Figure 10 is a three-view drawing (top view, rear view, and left side view) of the biasing member 7, the piezoelectric element 8, and the contact member 9. In Figure 10, a cross pattern is applied to adhesives AD2 and AD3 for clarity.

[0063] Specifically, as shown in the lower left view (left side view) of Figure 10, the piezoelectric element 8 is bonded to the joint portion 10J (see Figure 3) of the flexible wiring board 10 by adhesive AD1 (see Figure 3) on its distal (X1) side surface, and the distal (X1) side surface (not shown in Figure 10) of the joint portion 10J is bonded to the end face 7E of the protruding plate portion 7P of the biasing member 7 by adhesive AD2.

[0064] Furthermore, the piezoelectric element 8 is joined to the contact member 9 by an adhesive (not shown) on its proximal side (X2 side), and the upper (Z1 side) and lower (Z2 side) surfaces of the contact member 9 are joined to the support projection 7Q of the protruding plate portion 7P of the biasing member 7 by adhesive AD3.

[0065] More specifically, the piezoelectric element 8 and the contact member 9 are attached to the biasing member 7 such that, on the upper (Z1 side) and lower (Z2 side) surfaces of the contact member 9, positions Pb (see Figure 3) corresponding to each of the two nodes ND in the piezoelectric element 8 face the support protrusions 7Q of the biasing member 7. In the illustrated example, as shown in Figure 3, positions Pb include, on the upper (Z1 side) surface of the contact member 9, position Pb1 corresponding to the first node ND1; on the upper (Z1 side) surface of the contact member 9, position Pb2 corresponding to the second node ND2; on the lower (Z2 side) surface of the contact member 9, position Pb11 corresponding to the first node ND1; and on the lower (Z2 side) surface of the contact member 9, position Pb12 corresponding to the second node ND2. The piezoelectric element 8 and the contact member 9 are attached to the biasing member 7 such that, as shown in the lower right view (rear view) of Figure 10, position Pb1 faces the upper left support protrusion 7QLU, position Pb2 faces the upper right support protrusion 7QRU, position Pb11 faces the lower left support protrusion 7QLD, and position Pb12 faces the lower right support protrusion 7QRD. In other words, the contact member 9 is supported by the biasing member 7 at two points on its upper surface and two points on its lower surface. The biasing member 7 and the contact member 9 are joined together by adhesive AD3 at two points on their upper surface and two points on their lower surface.

[0066] Next, the positional relationship between the retaining member 6 and the biasing member 7 will be explained with reference to Figure 11. Figure 11 is a three-view drawing (top view, front view, and left side view) of the retaining member 6 and the biasing member 7. For clarity, a dot pattern is added to the retaining member 6 in Figure 11.

[0067] Specifically, the holding member 6 is a member for holding the biasing member 7 to which the piezoelectric drive unit PD is attached, and has a substantially rectangular annular frame portion 6E. The frame portion 6E has a lower side portion 6ED, a left side portion 6EL, a right side portion 6ER, and an upper side portion 6EU. The left side portion 6EL has a left engaging portion 6FL that protrudes outward (to the left) so as to engage with the left fixing portion 7FL of the biasing member 7, and the right side portion 6ER has a right engaging portion 6FR that protrudes outward (to the right) so as to engage with the right fixing portion 7FR of the biasing member 7.

[0068] More specifically, the left engaging portion 6FL is configured to pass through the second left opening 7H2L, formed between the first upper left inclined portion 7TLU1 and the first lower left inclined portion 7TLD1 of the biasing member 7, from the inside to the outside, and to engage with the inner end (front end) of the left fixing portion 7FL when the biasing member 7 is attached to the holding member 6. Similarly, the right engaging portion 6FR is configured to pass through the second right opening 7H2R, formed between the first upper right inclined portion 7TRU1 and the first lower right inclined portion 7TRD1 of the biasing member 7, from the inside to the outside, and to engage with the inner end (front end) of the right fixing portion 7FR when the biasing member 7 is attached to the holding member 6.

[0069] Furthermore, the biasing member 7, as a leaf spring member, may be configured to exert a restoring force when attached to the retaining member 6, such that the left fixing portion 7FL and the right fixing portion 7FR move closer together. In this case, the biasing member 7 attached to the retaining member 6 can generate a force that prevents the biasing member 7 from falling off the retaining member 6.

[0070] Furthermore, the holding member 6 has protrusions 6P formed to sandwich the piezoelectric element 8 and the contact member 9 from above and below, respectively. Specifically, the protrusions 6P include a left protrusion 6PL located to the left of the support portion 7S of the biasing member 7, and a right protrusion 6PR located to the right of the support portion 7S of the biasing member 7. The left protrusion 6PL includes an upper left protrusion 6PLU located above the piezoelectric element 8 and the contact member 9, and a lower left protrusion 6PLD located below the piezoelectric element 8 and the contact member 9. Similarly, the right protrusion 6PR includes an upper right protrusion 6PRU located above the piezoelectric element 8 and the contact member 9, and a lower right protrusion 6PRD located below the piezoelectric element 8 and the contact member 9.

[0071] Next, with reference to Figure 12, the positional relationship between the holding member 6, the biasing member 7, and the piezoelectric drive unit PD (piezoelectric element 8 and contact member 9) will be explained. Figure 12 is a perspective view of the holding member 6, the biasing member 7, the piezoelectric element 8, and the contact member 9. Specifically, the upper part of Figure 12 is a perspective view of the holding member 6, the biasing member 7, the piezoelectric element 8, and the contact member 9 viewed from the upper right front, and the lower part of Figure 12 is a perspective view of the holding member 6, the biasing member 7, the piezoelectric element 8, and the contact member 9 viewed from the upper left rear. Note that in Figure 12, a dot pattern is added to the holding member 6 for clarity, and the flexible wiring board 10 is not shown.

[0072] Specifically, the biasing member 7 is attached to the holding member 6 with the piezoelectric drive unit PD attached by adhesives AD2 and AD3. In the illustrated example, the biasing member 7 is attached to the holding member 6 with the protruding portion 6P inserted through the first opening 7H1 and the engaging portion 6F inserted through the second opening 7H2.

[0073] In this state, as shown in the upper diagram of Figure 12, the upper left elastic deformation portion 7GLU is positioned between the upper side portion 6EU and the upper left protrusion portion 6PLU, the lower left elastic deformation portion 7GLD is positioned between the lower side portion 6ED and the lower left protrusion portion 6PLD, the upper right elastic deformation portion 7GRU is positioned between the upper side portion 6EU and the upper right protrusion portion 6PRU, and the lower right elastic deformation portion 7GRD is positioned between the lower side portion 6ED and the lower right protrusion portion 6PRD. Furthermore, the support portion 7S is positioned between the left protrusion portion 6PL and the right protrusion portion 6PR, and between the upper side portion 6EU and the lower side portion 6ED.

[0074] Furthermore, in the illustrated example, the holding member 6 and the biasing member 7 are assembled such that the rear end surface BE of the right engaging portion 6FR and the front end surface FE of the right fixing portion 7FR are in contact (see the upper diagram in Figure 12), and the rear end surface BE of the left engaging portion 6FL and the front end surface FE of the left fixing portion 7FL are in contact (see the lower diagram in Figure 12), while other parts do not come into contact with each other.

[0075] Then, the retaining member 6 to which the biasing member 7 is attached is fixed to the base member 3 by adhesive AD4, as shown in the lower diagram of Figure 5. Specifically, the base member 3, the retaining member 6, and the biasing member 7 are fixed together by adhesive AD4 applied to the recess 3S (see lower diagram of Figure 5) provided in the base member 3, thereby integrating the recess 3S, the engaging portion 6F, and the fixing portion 7F.

[0076] Next, the details of the guide mechanism GM will be explained with reference to Figures 13 to 16. Figure 13 is a cross-sectional view of the lens holding member 2, the base member 3, and the guide shaft member 4. Specifically, the upper part of Figure 13 is an enlarged view of the area R2 enclosed by the dashed line in the upper part of Figure 5, and the lower part of Figure 13 is an enlarged view of the area R3 enclosed by the dashed line in the upper part of Figure 5. Figures 14 to 16 are cross-sectional views of the piezoelectric drive device 101. Specifically, Figure 14 is a view of the cross-section of the piezoelectric drive device 101 from the X1 side in a virtual plane perpendicular to the XY plane including the virtual line L2 shown in Figure 5. Figure 15 is a view of the cross-section of the piezoelectric drive device 101 from the Y2 side in a virtual plane perpendicular to the XY plane including the cutting line CL2 shown in Figure 5. Figure 16 is a view of the cross-section of the piezoelectric drive device 101 from the Y2 side in a virtual plane perpendicular to the XY plane including the cutting line CL3 shown in Figure 5. Note that in Figure 15, the left concave groove 41GL, which is actually invisible, is represented by a dotted line for the sake of clarity. Similarly, in Figure 16, the left concave groove 42GL, which is actually invisible, is represented by a dotted line for the sake of clarity.

[0077] The guide mechanism GM is a mechanism that guides the movement of the movable side member MB relative to the fixed side member FB. In the illustrated example, the guide mechanism GM is a mechanism that guides the movement of the lens holding member 2 along the optical axis direction relative to the base member 3, and is composed of the guided portion 2G of the lens holding member 2, the columnar portion 30 (first columnar portion 31 and second columnar portion 32) of the base member 3, and the guide axis member 4. Specifically, the guide mechanism GM includes a first guide mechanism GM1 composed of a first guided portion 2G1, a first columnar portion 31, and a first guide axis member 41, and a second guide mechanism GM2 composed of a second guided portion 2G2, a second columnar portion 32, and a second guide axis member 42.

[0078] As shown in Figure 2, the columnar portion 30 is formed to protrude upward from the bottom plate portion 3B at the corner of the base member 3. Specifically, the first columnar portion 31, which is one of the columnar portions 30, is formed on the inside of the right corner of the base member 3, and the second columnar portion 32, which is the other of the columnar portions 30, is formed on the inside of the left corner of the base member 3. In addition, the columnar portion 30 has a housing recess 3R for receiving the guide shaft member 4. Specifically, the first columnar portion 31 has a first housing recess 3R1 for receiving the first guide shaft member 41, and the second columnar portion 32 has a second housing recess 3R2 for receiving the second guide shaft member 42. The guide shaft member 4 is inserted into the housing recess 3R with the lens holding member 2 fitted inside the base member 3, and is then fixed to the base member 3 by adhesive AD6 injected into the housing recess 3R. Furthermore, the lens holding member 2 moves towards X1 when the guide shaft member 4 is inserted into the housing recess 3R. As a result, the lens holding member 2 can press the receiving member RC, which is mounted in the recess 2U, against the piezoelectric drive unit PD (contact surface 9S of the contact member 9), which is supported by the biasing member 7. In other words, the biasing member 7 can press the piezoelectric drive unit PD (contact surface 9S of the contact member 9) against the receiving member RC.

[0079] Specifically, as shown in the upper diagram of Figure 13, the first columnar portion 31 has a pair of convex portions 31P (left convex portion 31PL and right convex portion 31PR) facing each other along the Y-axis direction at the X1 side opening of the first receiving recess 3R1. The pair of convex portions 31P are configured to interlock with a pair of recessed groove portions 41G (left recessed groove portion 41GL and right recessed groove portion 41GR) formed on the first guide shaft member 41.

[0080] As shown in Figure 2, the pair of grooves 41G are formed to extend along the extending direction (Z-axis direction) of the first guide shaft member 41, over a length of approximately two-thirds of the total length of the first guide shaft member 41. More specifically, as shown in Figure 14, the pair of grooves 41G are formed to extend over the range HT1R on the Y1 side and Y2 side surfaces of the first guide shaft member 41, respectively.

[0081] Similarly, as shown in the lower diagram of Figure 13, the second columnar portion 32 has a pair of convex portions 32P (left convex portion 32PL and right convex portion 32PR) facing each other along the Y-axis direction at the X1 side opening of the second accommodating recess 3R2. The pair of convex portions 32P are configured to interlock with a pair of recessed grooves 42G (left recessed groove portion 42GL and right recessed groove portion 42GR) formed in the second guide shaft member 42.

[0082] As shown in Figure 2, the pair of grooves 42G are formed to extend along the extending direction (Z-axis direction) of the second guide shaft member 42, over a length of approximately two-thirds of the total length of the second guide shaft member 42. More specifically, as shown in Figure 14, the pair of grooves 42G are formed to extend over the range HT1L on the Y1 side and Y2 side surfaces of the second guide shaft member 42, respectively.

[0083] In the illustrated example, the first guide shaft member 41 and the second guide shaft member 42 have approximately the same diameter, as shown in Figure 13, and are formed to have approximately the same length in the Z-axis direction, as shown in Figure 14. Furthermore, the range HT1R corresponding to the length of the pair of grooves 41G and the range HT1L corresponding to the length of the pair of grooves 42G are approximately the same size.

[0084] The guide shaft member 4, inserted into the housing recess 3R, contacts the guided portion 2G of the lens holding member 2, pushing the lens holding member 2 toward X1. Specifically, as shown in the upper diagram of Figure 13, the first guide shaft member 41 contacts the concave portion CS of the first guided portion 2G1 at two contact portions 41C (left contact portion 41CL and right contact portion 41CR) in a plan view. Note that in the upper diagram of Figure 13, a cross pattern is added to the contact portion 41C for clarity.

[0085] More specifically, as shown in Figure 15, the concave portion CS has an upper concave portion CSU formed at the upper end of the first guided portion 2G1 and a lower concave portion CSD formed at the lower end of the first guided portion 2G1. The left contact portion 41CL has an upper left contact portion 41CLU that contacts the upper concave portion CSU and a lower left contact portion 41CLD that contacts the lower concave portion CSD.

[0086] Each of the four contact portions 41C (top, bottom, left, and right) is formed to extend over a range HT2 in the Z-axis direction. Specifically, each of the left contact portions 41CL is formed to extend over a range HT2L in the Z-axis direction. More specifically, the upper left contact portion 41CLU is formed to extend over a range HT2LU in the Z-axis direction, and the lower left contact portion 41CLD is formed to extend over a range HT2LD in the Z-axis direction. In the illustrated example, ranges HT2LD and HT2LU are approximately the same size. The same applies to the right contact portion 41CR, although it is not shown in the illustration.

[0087] With this configuration, the first guide mechanism GM1, which includes the first guided portion 2G1 and the first guide shaft member 41, can position the lens holding member 2. Specifically, the first guide shaft member 41 can prevent the lens holding member 2 from moving towards the X2 side, the Y1 side, and the Y2 side, respectively, through its four contact portions 41C.

[0088] Furthermore, as shown in the lower diagram of Figure 13, the second guide shaft member 42 contacts the planar portion FS of the second guided portion 2G2 at one contact portion 42C in a plan view. Note that in the lower diagram of Figure 13, a cross pattern is added to the contact portion 42C for clarity.

[0089] More specifically, the planar portion FS has an upper planar portion FSU formed at the upper end of the second guided portion 2G2, and a lower planar portion FSD formed at the lower end of the second guided portion 2G2, as shown in Figure 16. The contact portion 42C has an upper contact portion 42CU that contacts the upper planar portion FSU, and a lower contact portion 42CD that contacts the lower planar portion FSD.

[0090] Each of the two upper and lower contact portions 42C is formed to extend over a range HT2 in the Z-axis direction. Specifically, the upper contact portion 42CU is formed to extend over a range HT2U in the Z-axis direction, and the lower contact portion 42CD is formed to extend over a range HT2D in the Z-axis direction. In the illustrated example, ranges HT2D and HT2U are approximately the same size.

[0091] With this configuration, the second guide mechanism GM2, which includes the second guided portion 2G2 and the second guide shaft member 42, can allow movement of the lens holding member 2 in the Y-axis direction while suppressing movement of the lens holding member 2 toward the X2 side. Therefore, this configuration has the effect of absorbing tolerances in the components constituting the piezoelectric drive device 101.

[0092] Next, the assembly method of the piezoelectric drive device 101 will be described with reference to Figures 17 and 18. Figures 17 and 18 are perspective views of the components constituting the piezoelectric drive device 101. Specifically, the upper part of Figure 17 is a perspective view of the base member 3, the middle part of Figure 17 is a perspective view of the base member 3 with the holding member 6, biasing member 7, and piezoelectric drive unit PD attached, and the lower part of Figure 17 is a perspective view of the base member 3 with the lens holding member 2 further attached. Furthermore, the upper part of Figure 18 is a perspective view of the base member 3 with the guide shaft member 4 further attached, and the lower part of Figure 18 is a perspective view of the base member 3 with the cover member 1 further attached, i.e., a perspective view of the piezoelectric drive device 101. Note that in Figures 17 and 18, newly attached components are marked with a dot pattern for clarity.

[0093] First, as shown in the center view of Figure 17, the retaining member 6, the biasing member 7, and the piezoelectric drive unit PD are attached to the base member 3. Specifically, the piezoelectric drive unit PD is attached to the biasing member 7, the biasing member 7 with the piezoelectric drive unit PD attached is attached to the retaining member 6, and the retaining member 6 with the biasing member 7 attached is attached to the base member 3. Then, the base member 3 (recess 3S), the retaining member 6 (engaging part 6F), and the biasing member 7 (fixing part 7F) are integrally fixed together by adhesive AD4 (see Figure 5).

[0094] Subsequently, as shown in the lower diagram of Figure 17, the lens holding member 2 is attached to the base member 3 before the guide shaft member 4 is attached. Specifically, the lens holding member 2, with the magnet MG and receiving member RC attached, is housed inside the outer peripheral wall portion 3A of the base member 3.

[0095] Subsequently, as shown in the upper diagram of Figure 18, the guide shaft member 4 is inserted between the lens holding member 2 and the base member 3. Specifically, the first guide shaft member 41 is inserted from top to bottom so as to receive the two convex portions 31P formed on the first columnar portion 31 into the two recessed portions 41G, as shown in the upper diagram of Figure 13. Similarly, the second guide shaft member 42 is inserted from top to bottom so as to receive the two convex portions 32P formed on the second columnar portion 32 into the two recessed portions 42G, as shown in the lower diagram of Figure 13. At this time, the lens holding member 2 is pushed by the guide shaft member 4 and moves towards X1, as indicated by the arrow AR3 in the upper diagram of Figure 18. This is to secure space for receiving the guide shaft member 4 between the guided portion 2G of the lens holding member 2 and the columnar portion 30 of the base member 3. For this reason, the receiving member RC fixed to the lens holding member 2 is pressed against the contact member 9 of the piezoelectric drive unit PD. As a result, the biasing member 7 can press the contact member 9 of the piezoelectric drive unit PD against the receiving member RC.

[0096] Subsequently, as shown in the lower diagram of Figure 18, the cover member 1 is attached to the base member 3. In the illustrated example, the inner surface of the cover member 1 and the outer surfaces of the base member 3 and the flexible wiring board 10 are joined together with an adhesive (not shown).

[0097] Next, with reference to Figures 19 and 20, another example of the piezoelectric drive device 101 configuration will be described. Figure 19 is a perspective view of another example of the piezoelectric drive device 101 configuration. Specifically, the upper part of Figure 19 (the figure above the block arrow) is an exploded perspective view, and the lower part of Figure 19 (the figure below the block arrow) is an assembled perspective view. Figure 20 is a top view of the lens holding member 2, guide shaft member 4, piezoelectric element 8, and contact member 9 that constitute the piezoelectric drive device 101 shown in Figure 19. In Figure 20, for clarity, a dot pattern is applied to the guide shaft member 4 and a cross pattern is applied to the contact portion 42C.

[0098] The piezoelectric drive device 101 shown in Figure 19 differs from the piezoelectric drive device 101 shown in Figure 1, mainly in that the guide shaft member 4 penetrates the cover member 1 and the base member 3 and is fixed to the cover member 1 and the base member 3. In the piezoelectric drive device 101 shown in Figure 1, the guide shaft member 4 is fixed to the base member 3 without penetrating the cover member 1 and the base member 3. Specifically, in the piezoelectric drive device 101 shown in Figure 19, the guide shaft member 4 is inserted through a through hole 1H formed in the top plate portion 1B of the cover member 1 and a through hole 3H formed in the bottom plate portion 3B of the base member 3.

[0099] Furthermore, the piezoelectric drive device 101 shown in Figure 19 differs from the piezoelectric drive device 101 shown in Figure 1 in that the lens holding member 2 has a through portion 2T formed in the guided portion 2G as shown in Figure 20.

[0100] Specifically, in the piezoelectric drive device 101 shown in Figure 19, the lens holding member 2 has a first through-hole 2T1 formed in the first guided portion 2G1 and a second through-hole 2T2 formed in the second guided portion 2G2, as shown in Figure 20. The first through-hole 2T1 is a substantially circular through-hole through which the first guide shaft member 41 is inserted, and includes a substantially circular concave portion CS in plan view. The second through-hole 2T2 is a notch with an outward-opening opening through which the second guide shaft member 42 is inserted, and includes two planar portions FS.

[0101] The first guide shaft member 41 is positioned so as to be slidable in contact with the concave portion CS of the first guided portion 2G1 at its outer contact portion 41C, which is an annular portion in plan view. The second guide shaft member 42 is positioned so as to be in contact with each of the two planar portions FS that are arranged opposite each other in the X-axis direction at its two contact portions 42C.

[0102] Furthermore, the first guide shaft member 41 and the second guide shaft member 42 are positioned to face each other in a plan view along the first direction (Z-axis direction), with a virtual line L1 connecting the center of the receiving member RC and the central axis (optical axis OA) of the movable side member MB (lens holding member 2) in between.

[0103] Furthermore, the first guided portion 2G1 has a concave portion CS that accommodates at least a part of the first guide shaft member 41, and the second guided portion 2G2 has two planar portions FS that extend substantially parallel to the imaginary line L2 connecting the first guide shaft member 41 and the second guide shaft member 42 in a plan view along the first direction (Z-axis direction). The two planar portions FS are configured to slide on the second guide shaft member 42.

[0104] With this configuration, the first guide mechanism GM1, which includes the first guided portion 2G1 and the first guide shaft member 41, can position the lens holding member 2. Specifically, the first guide shaft member 41 can prevent the lens holding member 2 from moving to the X1 side, X2 side, Y1 side, and Y2 side by its annular contact portion 41C in plan view.

[0105] Furthermore, this configuration allows the second guide mechanism GM2, which includes the second guided portion 2G2 and the second guide shaft member 42, to allow movement of the lens holding member 2 in the Y-axis direction while suppressing movement of the lens holding member 2 in the X-axis direction. Therefore, this configuration has the effect of absorbing tolerances in the components constituting the piezoelectric drive device 101.

[0106] As described above, the piezoelectric drive device 101 according to the embodiment of this disclosure, as shown in Figure 2, comprises a fixed side member FB, a movable side member MB that is movable relative to the fixed side member FB, a piezoelectric drive unit PD provided on one side member which is one of the movable side member MB and the fixed side member FB (in the example shown in Figure 2, the fixed side member FB), and having a piezoelectric element 8, a receiving member RC provided on the other side member which is the other of the movable side member MB and the fixed side member FB (in the example shown in Figure 2, the movable side member MB), and in contact with the piezoelectric drive unit PD, and a biasing member 7 that biases the piezoelectric drive unit PD toward the receiving member RC, and is configured such that the movable side member MB moves relative to the fixed side member FB in a first direction (Z-axis direction). As shown in Figure 8, the biasing member 7 is made of a metal plate rolled in a predetermined rolling direction (Y-axis direction), with one end (left end) and the other end (right end) separated in the rolling direction (Y-axis direction) intersecting the first direction (Z-axis direction). It has a fixing part 7F provided at each of the one end (left end) and the other end (right end) and fixed to one side member (fixed side member FB), a support part 7S located between the one end (left end) and the other end (right end) and supporting the piezoelectric drive part PD, an elastically deformable elastic deformation part 7G provided between the fixing part 7F and the support part 7S, and a plurality (20) of bend parts 7N provided between the one end (left end) and the other end (right end), and each of the plurality (20) of bend parts 7N is bent such that the bending axis 7X is substantially perpendicular (approximately orthogonal) to the rolling direction (Y-axis direction), as shown in Figure 9.

[0107] This configuration has the effect of suppressing the occurrence of cracks or fractures during bending, even when the biasing member 7, which acts as a leaf spring member, has increased hardness due to repeated rolling, because the bending direction is in the Goodway direction (perpendicular to the rolling direction). Therefore, this configuration has the effect of improving the ease of manufacturing of the piezoelectric drive device 101. Furthermore, since this configuration has a cantilevered structure in which both ends of the leaf spring member are fixed, it has the effect of realizing a twist-resistant structure with multiple bends between one end and the other, that is, a structure that can properly support the piezoelectric drive unit PD even when the piezoelectric element 8 is in motion.

[0108] Furthermore, the bent portion 7N is preferably bent by an obtuse angle bend such that the angle formed between the two portions connected by the bent portion 7N is obtuse. In the illustrated example, as shown in the top view of Figure 8, the bent portion 7N is bent such that the angle formed between the two portions connected by the bent portion 7N is approximately 135 degrees.

[0109] This configuration has the effect of making the biasing member 7 less susceptible to springback or cracks compared to the case where the biasing member 7 is formed by an acute-angle bend so that the angle formed between the two parts connected by the bent portion 7N is acute. Furthermore, this configuration has the effect of suppressing the occurrence of cracks or fractures when bending occurs. In addition, this configuration has the effect of allowing the leaf spring member to be bent approximately vertically by two or more bent portions 7N.

[0110] Furthermore, the biasing member 7 preferably has a first flat plate portion (base portion 7M), a second flat plate portion (right protruding plate portion 7PR), and a third flat plate portion (third right inclined portion 7TR3) located between the first and second flat plate portions, as shown in Figure 8. The plane along the surface of the first flat plate portion (base portion 7M) and the plane along the surface of the second flat plate portion (right protruding plate portion 7PR) are substantially perpendicular to each other, the plane along the surface of the first flat plate portion (base portion 7M) and the plane along the surface of the third flat plate portion (third right inclined portion 7TR3) are inclined to each other, and the plane along the surface of the second flat plate portion (right protruding plate portion 7PR) and the plane along the surface of the third flat plate portion (third right inclined portion 7TR3) are inclined to each other. Furthermore, the first flat plate section (base section 7M) and the third flat plate section (third right-sloping section 7TR3) are connected by the first bent section 7N (sixth right-bent section 7NR6), and the second flat plate section (right protruding plate section 7PR) and the third flat plate section (third right-sloping section 7TR3) are connected by the second bent section 7N (fifth right-bent section 7NR5). The first bent section 7N (sixth right-bent section 7NR6) and the second bent section 7N (fifth right-bent section 7NR5) are included in a plurality (20) of bent sections 7N.

[0111] This configuration offers the advantage of being less susceptible to springback or cracking compared to a configuration where a portion of the leaf spring member is bent nearly vertically by a single bending section. Furthermore, this configuration suppresses the occurrence of cracks or fractures during bending. Additionally, this configuration allows the leaf spring member to be bent nearly vertically by two or more bending sections 7N.

[0112] Furthermore, the support portion 7S of the biasing member 7 preferably has a flat plate-shaped base portion 7M facing the piezoelectric drive unit PD, and two protruding plate portions 7P that face each other spaced apart in the rolling direction (Y-axis direction) with the base portion 7M in between, and extend from the base portion 7M toward the piezoelectric drive unit PD side (X2 side), as shown in Figure 8. The plate surface of the base portion 7M is oriented in the first direction (Z-axis direction), and the base portion 7M constitutes the first flat plate portion, while each of the two protruding plate portions 7P (left protruding plate portion 7PL and right protruding plate portion 7PR) constitutes the second flat plate portion.

[0113] This configuration has the effect of allowing the piezoelectric drive unit PD to be supported by the support part 7S, which has increased rigidity.

[0114] Furthermore, the piezoelectric drive unit PD is preferably fixed to the end face 7E of the protruding plate portion 7P, as shown in the lower diagram of Figure 5. In the illustrated example, the piezoelectric drive unit PD (joint portion 10J of the flexible wiring board 10) is fixed to the end face 7E by adhesive AD2, as shown in Figure 10.

[0115] This configuration allows the piezoelectric drive unit PD to be supported by the narrow area of ​​the end face 7E, resulting in the effect of being less likely to be hindered in the movement of the piezoelectric drive unit PD.

[0116] Furthermore, the biasing member 7 is preferably provided between the fixed portion 7F and the protruding plate portion 7P, with the plate surface of the fixed portion 7F being substantially parallel to the plate surface of the protruding plate portion 7P, as shown in Figure 8. The biasing member 7 has an elastically deformable portion 7G extending in a direction along the rolling direction (Y-axis direction), at least two bent portions 7N (third bent portion 7N3 and fourth bent portion 7N4) that constitute a plurality (20) of bent portions 7N between one end of the elastically deformable portion 7G and the protruding plate portion 7P, and at least two other bent portions 7N (first bent portion 7N1 and second bent portion 7N2) that constitute a plurality (20) of bent portions 7N between the other end of the elastically deformable portion 7G and the fixed portion 7F. The fixed portion 7F extends in the same direction as the extending direction (X-axis direction) of the protruding plate portion 7P from the outer bent portion (first bent portion 7N1) located on the side furthest from the elastically deformable portion 7G among the at least two other bent portions 7N (first bent portion 7N1 and second bent portion 7N2).

[0117] This configuration, in which the biasing member 7 as a leaf spring member has a stepped shape, increases the torsional rigidity of the biasing member 7, that is, makes the biasing member 7 less prone to twisting, and has the effect of being able to properly transmit the motion of the piezoelectric drive unit PD (piezoelectric element 8) to the receiving member RC.

[0118] Furthermore, preferably, as shown in Figure 9, multiple (two) elastic deformation portions 7G are provided spaced apart in the first direction (Z-axis direction). An opening 7H (first right opening 7H1R) is formed between the two elastic deformation portions 7G (upper right elastic deformation portion 7GRU and lower right elastic deformation portion 7GRD) that are spaced apart in the first direction (Z-axis direction).

[0119] This configuration has the effect of allowing a desired spring constant to be obtained by adjusting the width dimension (length in the Z-axis direction) of the elastically deformable section 7G.

[0120] Furthermore, the fixed-side member FB preferably has a housing HS that is substantially rectangular when viewed from the first direction (Z-axis direction), as shown in Figure 1. The piezoelectric drive unit PD and the biasing member 7 are provided on the fixed-side member FB (base member 3) at the portion corresponding to the corner (front corner) of the housing HS, as shown in Figure 5. The receiving member RC is provided on the movable-side member MB (lens holding member 2). In the illustrated example, the receiving member RC is fixed to the lens holding member 2 by adhesive AD5 applied to a recess 2U provided in the cylindrical portion 2C of the lens holding member 2, as shown in the lower part of Figure 5.

[0121] This configuration improves space efficiency within the housing HS, which in turn enables miniaturization of the piezoelectric drive unit 101.

[0122] Furthermore, as shown in Figure 2, the piezoelectric drive device 101 according to the embodiment of this disclosure comprises a fixed side member FB, a movable side member MB that is movable relative to the fixed side member FB, a piezoelectric drive unit PD provided on one side member which is one of the movable side member MB and the fixed side member FB (in the example shown in Figure 2, the fixed side member FB), and having a piezoelectric element 8, a receiving member RC provided on the other side member which is the other of the movable side member MB and the fixed side member FB (in the example shown in Figure 2, the movable side member MB), and in contact with the piezoelectric drive unit PD, a biasing member 7 that biases the piezoelectric drive unit PD toward the receiving member RC, and a guide mechanism GM that guides the movement of the movable side member MB accompanying the movement of the piezoelectric element 8, and is configured such that the movable side member MB moves in a first direction (Z-axis direction) relative to the fixed side member FB by the piezoelectric drive unit PD. The biasing member 7 has a fixing portion 7F provided at one end (left end) and the other end (right end) and fixed to one side member (fixed side member FB), a support portion 7S located between the one end (left end) and the other end (right end) and supporting the piezoelectric drive unit PD, and an elastically deformable elastic deformation portion 7G provided between the fixing portion 7F and the support portion 7S. The guide mechanism GM is composed of a guide shaft member 4 provided on the fixed side member FB and a guided portion 2G provided on the movable side member MB (lens holding member 2). The guide shaft member 4 includes a first guide shaft member 41 and a second guide shaft member 42 that extend in a first direction (Z-axis direction) and are arranged to face each other with the movable side member MB (lens holding member 2) in between. The guided portion 2G includes a first guided portion 2G1 that can slide on the first guide shaft member 41 and a second guided portion 2G2 that can slide on the second guide shaft member 42. Furthermore, the first guided portion 2G1 and the second guided portion 2G2 are configured to be pressed against the first guide shaft member 41 and the second guide shaft member 42 by the biasing force of the biasing member 7.

[0123] This configuration, by utilizing the guide shaft member 4, has the effect of suppressing the complexity of the guide mechanism GM compared to a configuration using balls. Furthermore, this configuration has the effect of improving the ease of assembly (manufacturability) of the piezoelectric drive device 101 compared to a configuration using balls.

[0124] Furthermore, the receiving member RC preferably extends in the first direction (Z-axis direction), as shown in Figure 2. The first guide shaft member 41 and the second guide shaft member 42 are positioned opposite each other in a plan view along the first direction (Z-axis direction), with a virtual line L1 connecting the center of the receiving member RC and the central axis (optical axis OA) of the movable side member MB (lens holding member 2), as shown in Figure 5.

[0125] This configuration has the effect of guiding the movement of the movable side member MB in a balanced and stable manner.

[0126] Furthermore, the fixed-side member FB (cover member 1 and base member 3) preferably includes a housing HS having a substantially rectangular outer shape in a plan view along the first direction (Z-axis direction), as shown in Figure 1. The housing HS has a first corner portion CN1 and a third corner portion CN3 located on one diagonal in a plan view along the first direction (Z-axis direction), and a second corner portion CN2 and a fourth corner portion CN4 located on the other diagonal, as shown in the upper part of Figure 5. The guide mechanism GM includes a first guide mechanism GM1 and a second guide mechanism GM2. The piezoelectric drive unit PD is located inside the first corner portion CN1, as shown in the lower part of Figure 5. The first guide mechanism GM1, which includes a first guide shaft member 41 and a first guided portion 2G1, is located inside the second corner portion CN2, and the second guide mechanism GM2, which includes a second guide shaft member 42 and a second guided portion 2G2, is located inside the fourth corner portion CN4.

[0127] This configuration improves space efficiency within the housing HS compared to a configuration where the guide mechanism GM is located at a position other than the corner, and consequently enables miniaturization of the piezoelectric drive unit 101. Furthermore, this configuration allows for more stable guidance of the movement of the movable side member MB compared to a configuration where the guide mechanism GM is located at a position other than the corner.

[0128] Preferably, as shown in Figure 5, the first guided portion 2G1 has a concave portion CS that accommodates at least a part of the first guide shaft member 41, and the second guided portion 2G2 has a planar portion FS that extends substantially parallel to the imaginary line L2 connecting the first guide shaft member 41 and the second guide shaft member 42 in a plan view along the first direction (Z-axis direction). The planar portion FS is configured to slide on the second guide shaft member 42.

[0129] This configuration has the effect of allowing the movable side member MB (lens holding member 2) to be positioned by the first guide shaft member 41 and the first guided portion 2G1. Furthermore, this configuration has the effect that even if there is a slight deviation (tolerance) in the dimensions of members such as the lens holding member 2, the second guide mechanism GM2 can absorb the effects of that deviation.

[0130] Furthermore, the planar portion FS is preferably provided on the second guided portion 2G2 at two positions spaced apart in the first direction (Z-axis direction), as shown in Figure 16. Specifically, the planar portion FS includes an upper planar portion FSU and a lower planar portion FSD spaced apart in the first direction (Z-axis direction).

[0131] This configuration has the effect of reducing the sliding resistance between the second guide shaft member 42 and the second guided portion 2G2 compared to a configuration in which the planar portion FS is connected without being divided into upper and lower parts.

[0132] Preferably, the movable side member MB (lens holding member 2) is made of synthetic resin, and the first guide shaft member 41 and the second guide shaft member 42 are each made of metal.

[0133] This configuration has the advantage of enabling smoother sliding of the movable side member MB (lens holding member 2) compared to the case where the first guide shaft member 41 and the second guide shaft member 42 are each made of synthetic resin. This is because it enables sliding between the synthetic resin and the metal.

[0134] Preferably, as shown in Figure 2, the fixed-side member FB includes the base member 3, and each of the first guide shaft member 41 and the second guide shaft member 42 is formed in a substantially cylindrical shape and has at least two recessed grooves 41G and 42G extending in the first direction (Z-axis direction). Then, as shown in Figure 14, the first guide shaft member 41 and the second guide shaft member 42 are fixed to the base member 3 by adhesive AD6 (see Figure 13) with the convex portions 31P and 32P erected on the base member 3 interlocking with the recessed grooves 41G and 42G.

[0135] This configuration has the advantage of allowing the first guide shaft member 41 and the second guide shaft member 42 to be easily attached to the base member 3.

[0136] Preferably, as shown in Figure 13, the grooves 41G and 42G are located in different positions in the circumferential direction from the contact portions 41C and 42C that contact the guided portion 2G. Preferably, as shown in Figures 15 and 16, the range HT2 of the contact portions 41C and 42C in the first direction (Z-axis direction) and the range HT1 of the grooves 41G and 42G in the first direction (Z-axis direction) overlap in at least a portion. In the illustrated example, as shown in Figure 15, the range HT2LD of the lower left contact portion 41CLD and the range HT1R of the left groove portion 41GL overlap in the first direction (Z-axis direction), and as shown in Figure 16, the range HT2D of the lower contact portion 42CD and the range HT1L of the left groove portion 42GL overlap in the first direction (Z-axis direction).

[0137] This configuration allows for longer lengths of the recessed grooves 41G and 42G in the Z-axis direction compared to a configuration without overlap, resulting in the effect of stabilizing engagement with the convex portions 31P and 32P of the base member 3.

[0138] Furthermore, preferably, the receiving member RC is made of metal, and the contact member 9 of the piezoelectric drive unit PD that contacts the receiving member RC is also made of metal.

[0139] This configuration has the effect of suppressing the generation of foreign matter such as wear particles compared to configurations in which synthetic resins are in contact with each other, or configurations in which synthetic resin is in contact with metal.

[0140] Preferred embodiments of the present disclosure have been described in detail above. However, the present invention is not limited to the embodiments described above. Various modifications or 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 conflict technically.

[0141] For example, in the above embodiment, the piezoelectric drive unit PD is provided on the fixed side member FB and the receiving member RC is provided on the movable side member MB, but the piezoelectric drive unit PD may be provided on the movable side member MB and the receiving member RC may be provided on the fixed side member FB.

[0142] Furthermore, in the above-described embodiment, the bent portion 7N is bent such that the angle formed between the two parts connected by the bent portion 7N is approximately 135 degrees (a portion of the biasing member 7 is bent by approximately 45 degrees). In this case, for example, the base portion 7M and the protruding plate portion 7P of the support portion 7S of the biasing member 7 are formed to be perpendicular to each other by two obtuse angle bends (also called 45-degree bends). However, the bent portion 7N may also be bent such that the angle formed between the two parts connected by the bent portion 7N is approximately 150 degrees (a portion of the biasing member 7 is bent by approximately 30 degrees). In this case, for example, the base portion 7M and the protruding plate portion 7P of the support portion 7S of the biasing member 7 are formed to be perpendicular to each other by three obtuse angle bends (also called 30-degree bends). [Explanation of Symbols]

[0143] 1. Cover member 1A. Outer wall section 1A1. First side plate section 1A2. Second side plate section 1A3. Third side plate section 1A4. Fourth side plate section 1B. Top plate section 1K. Opening 2. Lens holding member 2C. Cylindrical section 2G. Guided section 2G1. First guided section 2G2. Second guided section 2S. Stopper section 2SD. Lower stopper section 2SU. Upper stopper section 2U. Recess 2V. Recess 3. Base member 3A. Outer wall section 3A1. First side plate section 3A2. Second side plate section 3A3. Third side plate section 3A4. Fourth side plate section 3B. Bottom plate section 3C... Notch 3C1... First notch 3C2... Second notch 3K... Opening 3R... Receiving recess 3R1... First receiving recess 3R2... Second receiving recess 3S... Recess 4... Guide shaft member 6... Holding member 6E... Frame 6ED... Lower side 6EL... Left side 6ER... Right side 6EU... Upper side 6F... Engaging part 6FL... Left engaging part 6FR... Right engaging part 6P... Protrusion 6PL... Left protrusion 6PLD... Lower left protrusion 6PLU... Upper left protrusion 6PR... Right protrusion 6PRD... Lower right protrusion 6PRU... Upper right protrusion 7... Biasing member 7E...End face 7EL...Left end face 7ER...Right end face 7F...Fixed part 7FL...Left fixed part 7FR...Right fixed part 7G...Elastic deformation part 7GL...Left elastic deformation part 7GLC...Left central elastic deformation part 7GLD...Left lower elastic deformation part 7GLU...Left upper elastic deformation part 7GR...Right elastic deformation part 7GRC...Right central elastic deformation part 7GRD...Right lower elastic deformation part 7GRU...Right upper elastic deformation part 7H...Opening 7H1...First opening 7H1L...First left opening 7H1R...First right opening 7H2...Second opening 7H2L...Second left opening 7H2R...Second right opening 7M...Base part 7N...Bending part 7N1...First bend section 7NL1...First left bend section 7NLD1...First lower left bend section 7NLU1...First upper left bend section 7NR1...First right bend section 7NRD1...First lower right bend section 7NRU1...First upper right bend section 7N2...Second bend section 7NL2...Second left bend section 7NLD2...Second lower left bend section7NLU2...Second upper left bend 7NR2...Second right bend 7NRD2...Second lower right bend 7NRU2...Second upper right bend 7N3...Third bend 7NL3...Third left bend 7NLD3...Third lower left bend 7NLU3...Third upper left bend 7NR3...Third right bend 7NRD3...Third lower right bend 7NRU3...Third upper right bend 7N4...Fourth bend 7NL4...Fourth left bend 7NLD4...Fourth lower left bend 7NLU4...Fourth upper left bend 7NR4...Fourth right bend 7NRD4...Fourth lower right bend 7NRU4...Fourth upper left bend 7N5...Fifth bend 7NL5...5th left bend section 7NR5...5th right bend section 7N6...6th bend section 7NL6...6th left bend section 7NR6...6th right bend section 7P...Protruding plate section 7PL...Left protruding plate section 7PR...Right protruding plate section 7Q...Support projection section 7QL...Left support projection section 7QLD...Lower left support projection section 7QLU...Upper left support projection section 7QR...Right support projection section 7QRD...Lower right support projection section 7QRU...Upper right support projection section 7S...Support section 7T...Inclined section 7TL...Left inclined section 7TL1...1st left inclined section 7TLD1...1st lower left inclined section 7TLU1...1st upper left inclined section 7TL2...2nd left inclined section 7TLD2...Second lower left inclined section 7TLU2...Second upper left inclined section 7TL3...Third left inclined section 7TR...Right inclined section 7TR1...First right inclined section 7TRD1...First lower right inclined section 7TRU1...First upper right inclined section 7TR2...Second right inclined section 7TRD2...Second lower right inclined section 7TRU2...Second upper right inclined section 7TR3...Third right inclined section 7X...Bending axis 7X1...First bending axis 7XL1...First left bending axis 7XLD1...First lower left bending axis 7XLU1...First upper left bending axis 7XR1...First right bending axis 7XRD1...First lower right bending axis 7XRU1...First upper right bending axis 7X2...Second bending axis 7XL2...Second left bending axis 7XLD2...Second lower left bending axis 7XLU2...Second upper left bending axis 7XR2...Second right bending axis 7XRD2...Second lower right bending axis 7XRU2...Second upper right bending axis 7X3...Third bending axis 7XL3...Third left bending axis 7XLD3...Third lower left bending axis 7XLU3...Third upper left bending axis7XR3...3rd right bending axis 7XRD3...3rd right-down bending axis 7XRU3...3rd right-up bending axis 7X4...4th bending axis 7XL4...4th left bending axis 7XLD4...4th left-down bending axis 7XLU4...4th left-up bending axis 7XR4...4th right bending axis 7XRD4...4th right-down bending axis 7XRU4...4th right-up bending axis 7X5...5th bending axis 7XL5...5th left bending axis 7XR5...5th right bending axis 7X6...6th bending axis 7XL6...6th left bending axis 7XR6...6th right bending axis 8...Piezoelectric element 8X...Rotation axis 9...Contact member 9S...Contact surface 10...Flexible wiring board 10C...Connection part 10CD...Lower connection part 10CU...Upper connection part 10E...Extension part 10J...Joint part 10L...Left extension part 10R...Right extension part 30...Columnar part 31...First columnar part 32...Second columnar part 41...First guide shaft member 41C...Contact part 41CL...Left contact part 41CLD...Lower left contact part 41CLU...Upper left contact part 41CR...Right contact part 41G...Recessed groove part 41GL...Left recessed groove part 41GR...Right recessed groove part 42...Second guide shaft member 42C...Contact part 42CD...Lower contact part 42CU...Upper contact part 42G...Recessed groove part 42GL...Left groove 42GR...Right groove 81...1st part 82...2nd part 101...Piezoelectric drive device AD1~AD6...Adhesive BE...Rear end surface CD...Capacitor CM...Camera module CN...Corner CN1...1st corner CN2...2nd corner CN3...Third corner CN4...Fourth corner CP...Center point CS...Concave portion CSD...Lower concave portion CSU...Upper concave portion DR...Driver integrated circuit ED...Electrode ED1, ED11...1st electrode ED2, ED12...Second electrode FB...Fixed side member FE...Front end surface FS...Flat surface FSD...Lower plane part FSU...Upper plane part GM...Guiding mechanism GM1...First guide mechanism GM2...Second guide mechanism HS...Housing IS...Image sensor LS...Lens MB...Movable side member MG...Magnet ND...Section ND1...First section ND2...Second section OA...Optical axis OE...Optical elementPb, Pb1, Pb2, Pb11, Pb12... Position PD... Piezoelectric drive unit PT... Connection unit RC... Receiving member RS... Resistor SR... Magnetic sensor TM... Thermistor

Claims

1. Fixed side member and A movable side member that is movable relative to the fixed side member, A piezoelectric drive unit is provided on one of the movable side member and the fixed side member, and is configured to have a piezoelectric element. A receiving member is provided on the other side member, which is the other of the movable side member and the fixed side member, and contacts the piezoelectric drive unit, A biasing member that biases the piezoelectric drive unit toward the receiving member, The system includes a guide mechanism that guides the movement of the movable side member accompanying the movement of the piezoelectric element, A piezoelectric drive device configured such that the movable side member moves in a first direction relative to the fixed side member by the piezoelectric drive unit, The biasing member has a fixing portion fixed to the one-side member, a support portion that supports the piezoelectric drive unit, and an elastically deformable elastic deformation portion provided between the fixing portion and the support portion. The guide mechanism is configured to include a guide shaft member provided on the fixed side member and a guided portion provided on the movable side member, The guide shaft member includes a first guide shaft member and a second guide shaft member that extend in the first direction and are arranged to face each other with the movable side member in between, The guided portion includes a first guided portion that is slidable on the first guide shaft member, and a second guided portion that is slidable on the second guide shaft member. Each of the first guided portion and the second guided portion is configured to be pressed against the first guide shaft member and the second guide shaft member by the biasing force of the biasing member. A piezoelectric drive device characterized by the following features.

2. The receiving member extends in the first direction, The first guide shaft member and the second guide shaft member are arranged to face each other in a plan view along the first direction, with a virtual line connecting the center of the receiving member and the central axis of the movable side member in between. The piezoelectric drive device according to claim 1.

3. The fixed side member includes a housing having a substantially rectangular outer shape in plan view. The housing has a first corner and a third corner located on one diagonal in a plan view, and a second corner and a fourth corner located on the other diagonal, The aforementioned guidance mechanism includes a first guidance mechanism and a second guidance mechanism, The piezoelectric drive unit is located inside the first corner portion. The first guide mechanism, which includes the first guide shaft member and the first guided portion, is positioned inside the second corner portion. The second guide mechanism, which includes the second guide shaft member and the second guided portion, is located inside the fourth corner. The piezoelectric drive device according to claim 2.

4. The first guided portion has a concave portion that accommodates at least a part of the first guide shaft member, The second guided portion has a planar portion that extends substantially parallel to the imaginary line connecting the first guide shaft member and the second guide shaft member in a plan view along the first direction, The planar portion is configured to slide on the second guide shaft member. A piezoelectric drive device according to any one of claims 1 to 3.

5. The planar portion is provided on the second guided portion at two positions spaced apart in the first direction. The piezoelectric drive device according to claim 4.

6. The movable side member is made of synthetic resin, The first guide shaft member and the second guide shaft member are made of metal. A piezoelectric drive device according to any one of claims 1 to 3.

7. The aforementioned fixed side member includes a base member, Each of the first guide shaft member and the second guide shaft member is formed in a substantially cylindrical shape and has at least two recessed grooves extending in the first direction. The first guide shaft member and the second guide shaft member are fixed to the base member in a state where the convex portion erected on the base member and the concave groove portion are interlocked. The piezoelectric drive device according to claim 5.

8. The groove portion is provided in a position different from the contact portion that contacts the guided portion in the circumferential direction. The range of the contact portion in the first direction and the range of the groove portion in the first direction overlap in at least a portion. The piezoelectric drive device according to claim 7.

9. The receiving member is made of metal, The contact member of the piezoelectric drive unit that contacts the receiving member is made of metal. The piezoelectric drive device according to claim 1.

10. A piezoelectric drive device according to claim 1, A lens body fixed to the aforementioned movable side member, The lens body has an image sensor facing it, Camera module.

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