Driving device, optical element driving device, camera module, and camera-mounted device

Abstract

To efficiently transmit vibrations from a piezoelectric element to a resonating portion.SOLUTION: A driving device includes a piezoelectric element that vibrates when a voltage is applied, a resonating portion that resonates with the vibration of the piezoelectric element to move a member that comes into contact with it, and a conductive resin that seals the gap between the piezoelectric element and the resonating portion, and the resonating portion has a housing portion that can house the conductive resin.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a driving device, an optical element driving device, a camera module, and a camera-mounted device. [Background technology]

[0002] 2. Description of the Related Art In camera modules mounted on camera-mounted devices such as smartphones and drones, driving devices such as ultrasonic motors using piezoelectric elements have been proposed as driving devices for driving optical elements.

[0003] For example, Patent Document 1 discloses a driving device in which an active element is composed of a resonator (resonating portion) and a piezoelectric element that vibrates the resonator, and the active element drives a passive element by the vibration action of the active element. In the driving device disclosed in Patent Document 1, the piezoelectric element and the resonator are bonded with a conductive adhesive having a conductive material such as a metal ball. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2008-503995 Summary of the Invention [Problem to be solved by the invention]

[0005] As shown in Patent Document 1, the piezoelectric element and the resonator are bonded by a conductive adhesive containing a conductive material. Such conductive adhesives tend to have larger constituent particles than non-conductive adhesives because they contain a conductive material. Therefore, it is difficult to reduce the thickness between the piezoelectric element and the resonator. The thickness between the piezoelectric element and the resonator affects the vibration transmission between the piezoelectric element and the resonator, and when the thickness between the piezoelectric element and the resonator becomes thick, it is difficult to efficiently transmit the vibration from the piezoelectric element to the resonator.

[0006] An object of the present invention is to provide a drive device, an optical element drive device, a camera module, and a camera-mounted device that are capable of efficiently transmitting vibrations from a piezoelectric element to a resonating portion. [Means for solving the problem]

[0007] The drive device according to the present invention comprises: A piezoelectric element that vibrates when a voltage is applied; a resonating section that resonates with the vibration of the piezoelectric element to move a member that comes into contact with the resonating section; a conductive resin that fixes the piezoelectric element and the resonator unit; Equipped with The resonator unit includes: It is a recess The storage section On the opposing surfaces of the resonator, Yes death, The piezoelectric elements are fixed to the opposing surfaces by the conductive resin filled in the housing portion. .

[0008] The optical element driving device according to the present invention comprises: A holder capable of holding an optical element; a base that accommodates the holding portion so as to be movable in an optical path direction of the optical element; The drive device that drives the holding portion; Equipped with.

[0009] The camera module according to the present invention comprises: The optical element driving device; an imaging unit that captures an object image using the optical element; Equipped with.

[0010] The camera-mounted device according to the present invention comprises: A camera-equipped device that is an information device or a transport device, The camera module; an image processing unit that processes image information obtained by the camera module; Equipped with. Effect of the Invention

[0011] According to the present invention, vibrations from the piezoelectric element can be efficiently transmitted to the resonating portion. [Brief description of the drawings]

[0012] [Figure 1A] 1 is a front view showing a smartphone equipped with a camera module according to an embodiment of the present invention. [Figure 1B] FIG. 1B is a rear view of the smartphone shown in FIG. 1A. [Diagram 2] FIG. 2 is a perspective view showing a camera module and an imaging unit. [Diagram 3] 2 is a plan view of an optical element driving device main body of the optical element driving device of the camera module. FIG. [Figure 4] 4 is a diagram showing a resonance portion that constitutes a drive unit of the main body of the optical element driving device shown in FIG. 3. [Diagram 5] 5 is a diagram showing a state in which a piezoelectric element is attached to the resonance portion shown in FIG. 4. [Figure 6] 6 is a perspective view of the piezoelectric element and the resonating portion shown in FIG. 5. [Figure 7] FIG. 4 is a perspective view showing a drive unit shown in FIG. [Figure 8] FIG. 8 is a side view showing the drive unit shown in FIG. [Figure 9A] 1 is a front view showing an automobile as a camera-mounted device equipped with an in-vehicle camera module. [Figure 9B] FIG. 9B is a perspective view of the automobile shown in FIG. 9A as seen obliquely from the rear side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] [Smartphone] 1A and 1B are diagrams showing a smartphone M (an example of a camera-mounted device) equipped with a camera module A according to the present embodiment, in which Fig. 1A is a front view of the smartphone M and Fig. 1B is a rear view of the smartphone M.

[0015] The smartphone M has a dual camera consisting of two rear cameras OC1 and OC2. In this embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0016] The camera module A has an AF function and can automatically adjust the focus when photographing a subject. The camera module A may also have an image stabilization function (hereinafter referred to as the "OIS function": Optical Image Stabilization). The OIS function optically corrects shake (vibration) that occurs during shooting, making it possible to shoot images without blurring.

[0017] [Camera module] Fig. 2 is a perspective view showing a camera module A and an imaging unit 5. Fig. 3 is a plan view of an optical element driving device main body 4 of the optical element driving device 1 of the camera module A shown in Fig. 2. As shown in Figs. 2 and 3, in this embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. Also, in the drawings described later, an orthogonal coordinate system (X, Y, Z) is used for explanation.

[0018] For example, when a photograph is taken with a smartphone M, the camera module A is mounted so that the X direction is the up-down direction (or left-right direction), the Y direction is the left-right direction (or up-down direction), and the Z direction is the front-rear direction. That is, the Z direction is the optical axis direction of the optical axis OA of the lens unit 2 shown in Fig. 2, and in Fig. 2, the upper side (+Z side) is the light receiving side in the optical axis direction, and the lower side (-Z side) is the image forming side in the optical axis direction.

[0019] In the following description, the optical axis OA is used, but the optical axis direction of the optical axis OA may be referred to as the optical path direction or the focal direction (the direction for adjusting the focus) depending on the type of optical element. Here, the light path is the path of light formed by the opening 301 of the cover 3 described later, the opening 11 of the holding part 10 described later, or the accommodation opening 21 of the base 20 described later, and the direction in which this optical path extends (the penetrating direction of each opening) is the optical path direction.

[0020] 2 and 3, the camera module A includes an optical element driving device 1 that realizes an AF function, a lens unit 2 formed by housing a lens in a cylindrical lens barrel, and an imaging unit 5 that captures a subject image formed by the lens unit 2. In other words, the optical element driving device 1 is a so-called lens driving device that drives the lens unit 2 as an optical element.

[0021] The optical element driving device 1 of this embodiment is configured so that its length in the Z direction is shorter than its lengths in the X direction and Y direction, taking into consideration that it will be mounted on the above-mentioned camera module A, etc., and is configured to be low-profile when the Z direction is the height direction.

[0022] [cover] In the optical element driving device 1, the optical element driving device main body 4 is covered on the outside with a cover 3. The cover 3 is a covered square cylinder that is approximately rectangular in plan view when viewed from the Z direction. In this embodiment, the cover 3 has an approximately square shape in plan view. The cover 3 has an approximately circular opening 301 on the upper surface. The lens unit 2 is accommodated in the opening 11 of the holding part 10 of the optical element driving device main body 4, faces the outside from the opening 301 of the cover 3, and is configured to protrude toward the light receiving side beyond the opening surface of the cover 3 as it moves in the Z direction. The inner wall of the cover 3 is fixed to the base 20 (for example, the bottom part 22a described later) of the optical element driving device main body 4 by, for example, adhesion, and accommodates the optical element driving device main body 4.

[0023] The cover 3 has a member for blocking electromagnetic waves from the outside of the optical element driving device 1 and from the inside of the cover 3, for example a shielding member made of a magnetic material.

[0024] [Imaging unit] The imaging unit 5 is disposed on the imaging side of the optical element driving device 1. The imaging unit 5 has, for example, an image sensor board 501, an imaging element 502 mounted on the image sensor board 501, and a control unit 503. The imaging element 502 is configured with, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, or the like, and captures an image of a subject formed by the lens unit 2.

[0025] The control unit 503 is formed of, for example, a control IC, and performs driving control of the entire optical element driving device 1. The optical element driving device 1 is mounted on the image sensor substrate 501 and is mechanically and electrically connected thereto. The control unit 503 may be provided in the image sensor substrate 501, or in a camera-mounted device (in this embodiment, a smartphone M) on which the camera module A is mounted.

[0026] 2, the lens unit 2 is driven in the Z direction by the optical element driving device 1 with respect to the image sensor board 501 whose position is fixed, thereby forming an image of the subject on the imaging element 502, but for example, the imaging element 502 may be driven in the Z direction. In this case, the lens unit 2 is fixed to the cover 3, and the imaging element 502, which is an optical element, is driven in the Z direction by the optical element driving device 1, thereby forming an image of the subject on the imaging element 502.

[0027] [Optical element driving device body] The optical element driving device main body 4 is a main body portion of the optical element driving device 1 that drives the lens unit 2, which is an optical element, in the Z direction. For convenience of explanation, the following description will be given on the assumption that the optical element driving device 1 drives the lens unit 2, but as described above, the optical element driving device 1 may also drive the imaging element 502.

[0028] As shown in FIG. 3, the optical element driving device main body 4 includes a holding portion 10, a base portion 20, support portions 30A, 30B, and 30C, driving portions 40A and 40B, a substrate portion 50, and the like.

[0029] [Holding part] The holder 10 has a frame 12 with an opening 11 formed in the center, and the opening 11 is configured to be able to hold the lens unit 2 inside. For example, the opening 11 is configured to be able to hold the lens unit 2 on its inner peripheral surface by forming an attachment groove or the like on its inner peripheral surface. In this way, the holder 10 holds the lens unit 2 by surrounding the outer periphery of the lens unit 2.

[0030] An outer peripheral surface 13 on the outer periphery side of frame portion 12 is supported at multiple points (three points as an example in FIG. 3) by supports 30A, 30B, and 30C extending along the Z direction so as to be movable in the Z direction.

[0031] Furthermore, the outer circumferential surface 13 is held at a plurality of locations (two locations in FIG. 3, for example) by drive units 40A and 40B, and the holder 10 is movable in the Z direction by the drive units 40A and 40B.

[0032] Magnets 14A, 14B for detecting the position in the Z direction are provided at multiple locations (two locations in FIG. 3 as an example) on the outer circumferential surface 13. Position detection sensors 54A, 54B, which will be described later, are provided facing the magnets 14A, 14B, respectively.

[0033] Although the opening 11 is formed in a cylindrical shape to correspond to the cylindrical lens portion 2, the shape of the opening 11 can be changed to an appropriate shape to correspond to the shape of the lens portion 2.

[0034] Furthermore, when the optical element driving device 1 drives the imaging element 502, the holding portion 10 does not need to have an opening 11, that is, the holding portion 10 does not need to be a frame portion. In that case, for example, the imaging element 502 may be held on the upper surface (light receiving surface) of the holding portion 10.

[0035] [base] The base 20 has a frame 22 with a storage opening 21 formed in the center, and the storage opening 21 is configured to surround the outer periphery of the holding portion 10 so as to be able to store the holding portion 10 inside.

[0036] Support portions 30A, 30B, and 30C are provided at a plurality of locations on inner circumferential surface 23, which is the inside of accommodation opening 21. Base 20 supports holding portion 10 by support portions 30A, 30B, and 30C so as to be movable in the Z direction.

[0037] Further, driving units 40A, 40B are provided at a plurality of locations on the inner circumferential surface 23. The driving units 40A, 40B provided on the base 20 move the holding unit 10 in the Z direction. The holding unit 10 functions as a movable unit driven by the driving units 40A, 40B, and the base 20 functions as a fixed unit relative to the holding unit 10.

[0038] In a plan view, the inner circumferential surface 23 is formed to correspond to the shape of the outer circumferential surface 13 of the holding part 10. In Fig. 3, the shapes of the outer circumferential surface 13 of the holding part 10 and the inner circumferential surface 23 of the accommodation opening 21 are merely examples and can be appropriately changed depending on, for example, the arrangement of the support parts 30A, 30B, 30C and the drive parts 40A, 40B, etc.

[0039] The frame 22 has a bottom 22a and a side wall 22b. The inner wall of the cover 3 described above is fixed to the bottom 22a by, for example, adhesion. The substrate 50 is attached along the outer circumferential surface 24, which is the outer circumferential side of the side wall 22b.

[0040] [Support part] The support parts 30A, 30B, and 30C support the holding part 10 movably in the Z direction relative to the base part 20. As shown in FIG. 3, the support parts 30A, 30B, and 30C are respectively disposed at three positions distributed in the circumferential direction on the inner circumferential surface 23 (outer circumferential surface 13).

[0041] Although detailed illustration is omitted, support portions 30A, 30B, and 30C have a first groove portion provided on the outer peripheral surface 13 of holding portion 10, a second groove portion provided on the inner peripheral surface 23 of base portion 20, and a rolling member (e.g., a ball member, etc.) that is sandwiched between the first groove portion and the second groove portion and can roll.

[0042] In the supports 30A, 30B, and 30C, the first groove and the second groove extend in the Z direction and are disposed to face each other. A rolling member is rollably sandwiched between the first groove and the second groove thus disposed.

[0043] One or more rolling members are disposed between the first groove and the second groove. When multiple rolling members are disposed between the first groove and the second groove, tilt of the holder 10 can be more stably suppressed. In this case, the multiple rolling members are arranged in a line along the Z direction, and are held by a retainer (not shown) so that the distance between them is kept constant and they can be positioned in the Z direction.

[0044] The support parts 30A, 30B, and 30C thus configured support the holding part 10 relative to the base part 20 so as to be movable in the Z direction.

[0045] In addition, the first groove and the second groove may be fitted with a rail-shaped member made of a metal material or the like, on which the rolling member can roll. The holding part 10 and the base part 20 are usually made of a resin or the like, and the rolling member is usually made of a material such as ceramic or alloy. Therefore, by providing the first groove and the second groove with a rail-shaped member made of a metal material or the like harder than the holding part 10 and the base part 20, the first groove and the second groove are less likely to deform even when subjected to a pressing force from the rolling member. With this configuration, the support parts 30A, 30B, and 30C can stably support the holding part 10 so as to be movable in the Z direction.

[0046] [Drive unit] The driving units 40A, 40B drive the holder 10 in the Z direction relative to the base 20. The driving units 40A, 40B are disposed at two dispersed positions in the circumferential direction on the inner circumferential surface 23 (outer circumferential surface 13), as shown in Fig. 3. The optical element driving device main body 4 can drive the lens unit 2 together with the holder 10 in the Z direction by the above-mentioned supports 30A, 30B, 30C and driving units 40A, 40B, thereby achieving the AF function.

[0047] The frame 22 of the base 20 has four corners 22bA, 22bB, 22bC, and 22bD, as shown in Fig. 3. In the example shown in Fig. 3, the support 30A is disposed at the corner 22bA, and therefore the drive units 40A and 40B are disposed at corners 22bB and 22bC, which are different from the corner 22bA and are positioned point-symmetrically about the optical axis OA in a plan view. By disposing them in this way, the holder 10 can be moved stably even if the weight of the optical element such as the lens unit 2 increases.

[0048] An ultrasonic motor, which is an actuator having a piezoelectric element, is used as the driving units 40A and 40B. The driving units 40A and 40B will be described with reference to FIGS.

[0049] Fig. 4 is a diagram showing the resonating unit 42 constituting the driving unit 40A of the optical element driving device main body 4 shown in Fig. 3. Fig. 5 is a diagram showing a state in which a piezoelectric element 41 is attached to the resonating unit 42 shown in Fig. 4. Fig. 6 is a perspective view of the piezoelectric element 41 and the resonating unit 42 shown in Fig. 5. Fig. 7 is a perspective view showing the driving unit 40A shown in Fig. 3. Fig. 8 is a side view showing the driving unit 40A shown in Fig. 7. Although Figs. 4 to 8 show the driving unit 40A, the driving unit 40B has the same configuration as the driving unit 40A, and detailed illustration and description thereof will be omitted.

[0050] The driving unit 40A has a piezoelectric element 41, a resonating unit 42, an electrode unit 43, a power transmission unit 44 (a moving member in the present invention), and the like. A driving force generated in the resonating unit 42 by resonating with the vibration of the piezoelectric element 41 is transmitted to the power transmission unit 44. Although not shown here, the power transmission unit 44 is fixed to the holding unit 10 side, and the driving force by the resonating unit 42 is transmitted to the holding unit 10 via the power transmission unit 44. In the driving unit 40A, the resonating unit 42 constitutes an active element, and the power transmission unit 44 constitutes a passive element.

[0051] The piezoelectric element 41 is, for example, a plate-like element made of a ceramic material, and generates vibrations, for example, vibrations at a vibration frequency in the ultrasonic range, when a high-frequency voltage is applied. Two piezoelectric elements 41 are arranged so as to sandwich the body part 42a of the resonance part 42 therebetween. Although not shown in the figure, a connection wiring provided on an FPC 51 described later is electrically connected to the piezoelectric element 41 via an electrode part 43 described later and the like, so that a voltage is applied to the piezoelectric element 41.

[0052] The resonating unit 42 is formed from a plate member made of a conductive material, and resonates with the vibration of the piezoelectric element 41 to convert the vibration motion into linear motion, thereby moving the power transmission unit 44 that comes into contact with it. The resonating unit 42 is formed by, for example, laser processing, etching, pressing, or the like of a metal plate.

[0053] The resonator 42 includes a body 42a, a pair of arms 42b, a current-carrying portion 42c, a protrusion 42d, and the like.

[0054] The body portion 42a is a substantially rectangular portion having two piezoelectric elements 41 bonded to the front and back thereof. Vibrations generated by the piezoelectric elements 41 are transmitted to the pair of arm portions 42b via the body portion 42a.

[0055] The pair of arms 42b extend in the +Z direction from both sides of the body 42a to the free ends of the respective arms 42b. The pair of arms 42b have symmetrical shapes and are deformed symmetrically in resonance with the vibration of the piezoelectric element 41. The pair of arms 42b are formed such that their free ends sandwich the power transmission unit 44. More specifically, the pair of arms 42b are configured such that their free ends abut inward against abutment surfaces 44a of the power transmission unit 44 described later.

[0056] The current-carrying portion 42c extends from the body portion 42a in the -Z direction, and is disposed at an end position of the resonating portion 42. The current-carrying portion 42c constitutes a power supply line to the piezoelectric element 41 via the body portion 42a, and although not shown, is electrically connected to a connection wiring provided on the FPC 51.

[0057] The protruding portion 42d extends from the body portion 42a in the +Z direction and is disposed at a position close to the center of the resonating portion 42. A through hole 42e for inserting a rivet or the like is formed in the protruding portion 42d. The protruding portion 42d is fixed to the base portion 20 side by using a rivet or the like inserted into the through hole 42e.

[0058] The electrode portion 43 has a pair of terminal portions 43a and a connecting portion 43b that connects the pair of terminal portions 43a to each other. The pair of terminal portions 43a are electrically connected to the outer surfaces of the two piezoelectric elements 41. The electrode portion 43 is a portion that constitutes a power supply line to the piezoelectric elements 41, and although not shown, a connection wiring provided on the FPC 51 is electrically connected to the electrode portion 43.

[0059] In the electrode portion 43, each terminal portion 43a has a recess 43a1 formed in its center and a through hole 43a2 formed in the center of the recess 43a1. The terminal portion 43a is electrically connected to the outer surface of the piezoelectric element 41 by solder, and is electrically connected to the outer surface of the piezoelectric element 41 via the through hole 43a2 by melting and hardening the solder in the recess 43a1. The solder can be melted in a short time by, for example, a laser, which can suppress the thermal influence on the piezoelectric element 41 and the conductive resin described below.

[0060] The terminal portion 43a may be electrically connected to the outer surface of the piezoelectric element 41 by a conductive resin, which will be described later, instead of by soldering.

[0061] By the electrical connection between the current-carrying portion 42c and the electrode portion 43, a voltage is applied to the piezoelectric element 41 attached to the body portion 42a, and vibration occurs. The resonating portion 42 has at least two resonant frequencies, and deforms in a different manner for each resonant frequency. In other words, the overall shape of the resonating portion 42 is set so that it deforms in a different manner for the two resonant frequencies.

[0062] Here, the different behaviors are a behavior in which the pair of arm portions 42b advances and retreats the power transmission portion 44 in the Z direction. Therefore, by vibrating the resonating portion 42 at a desired resonant frequency, the pair of arm portions 42b can advance or retreat the power transmission portion 44 in the Z direction.

[0063] The power transmission unit 44 has, for example, a rectangular parallelepiped shape having a predetermined length in the Z direction, and has a contact surface 44a with which the arm portions 42b contact at a portion facing the pair of arm portions 42b. As described above, the pair of arm portions 42b are configured to contact the contact surface 44a, and the power transmission unit 44 functions as a chucking guide for the pair of arm portions 42b. For example, the end of the power transmission unit 44 on the right side (+Z side) in the figure is attached to the outer circumferential surface 13 of the frame portion 12 of the holding unit 10.

[0064] The piezoelectric element 41 is attached to the body portion 42a using an adhesive, and a conductive adhesive is used to electrically connect the piezoelectric element 41 and the resonating portion 42. As the conductive adhesive, for example, a conductive resin such as silver epoxy or epoxy containing metal balls can be used.

[0065] Since the conductive adhesive contains silver particles, metal balls, etc., the constituent particles are large, and compared to a non-conductive adhesive, it is difficult to reduce the thickness between the piezoelectric element 41 and the resonating unit 42. Since the thickness between the piezoelectric element 41 and the resonating unit 42 affects the vibration transmission between the piezoelectric element 41 and the resonating unit 42, it is desirable to reduce this thickness as much as possible.

[0066] Therefore, in this embodiment, the housing portion 45 is provided in the body portion 42a. The housing portion 45 is formed in the body portion 42a to which the piezoelectric element 41 is attached. Recess In the present embodiment, as an example, the accommodation portion 45 is a recess. Also, as an example, the accommodation portion 45 is formed on the inner side of the piezoelectric element 41 so as to be different from the position where the terminal portion 43a is connected to the outer surface of the piezoelectric element 41 in a plan view of the resonator portion 42 and the piezoelectric element 41. To The storage section 45 is disposed .SoThe container portion 45 is filled with a conductive resin R, which is an adhesive having electrical conductivity.

[0067] The accommodation section 45 is filled with conductive resin R, and the piezoelectric element 41 and the resonating section 42 are bonded together to fix them in place. Therefore, even if the bonding is performed using conductive resin R whose constituent particles are relatively large, the thickness between the piezoelectric element 41 and the resonating section 42 can be reduced.

[0068] Furthermore, in the body portion 42a, a non-conductive adhesive is applied to the region 42a1 other than the housing portion 45, and the piezoelectric element 41 is attached to the body portion 42a. In this manner, since the non-conductive adhesive is applied to the region 42a1 other than the housing portion 45, the thickness between the piezoelectric element 41 and the resonating portion 42 can be reduced.

[0069] When using the conductive resin R and the non-conductive adhesive, the conductive resin R and the non-conductive adhesive may be cured simultaneously or separately depending on the shapes and structures of the piezoelectric element 41 and the resonance unit 42. After the inner surface of the piezoelectric element 41 is fixed to the resonance unit 42 in this manner, the terminal portion 43a of the electrode portion 43 is electrically connected by solder to the outer surface of the piezoelectric element 41 on the opposite side.

[0070] Since the piezoelectric element 41 is bonded to the body portion 42a in the above manner, it is possible to reduce the thickness between the piezoelectric element 41 and the resonating portion 42. The efficiency of transmission of vibration from the piezoelectric element 41 to the resonating portion 42 improves as the thickness between the piezoelectric element 41 and the resonating portion 42 decreases. Therefore, in this embodiment in which the conductive resin R is accommodated in the accommodation portion 45, it is possible to efficiently transmit vibration from the piezoelectric element 41 to the resonating portion 42.

[0071] Here, as an example, two housing portions 45 are provided on each of both sides of the resonator 42, but the number of housing portions 45 can be changed as appropriate. Also, the inner peripheral surface 45a of the housing portion 45 has a curved shape and is circular in a plan view, but the shape can also be changed as appropriate.

[0072] The number, shape, etc. of the housing sections 45 can be changed as appropriate, but in any case, it is preferable that the entire area of ​​the housing section 45 is filled with the conductive resin R. If air remains in the housing section 45, the air will expand in the housing section 45 blocked by the piezoelectric element 41 when the conductive resin R is thermally cured, which may hinder the adhesion and electrical connection between the piezoelectric element 41 and the resonator section 42.

[0073] For this reason, in this embodiment, a communication portion 46 is provided in the body portion 42a, which communicates the accommodation portion 45 with a space outside the region of the resonating portion 42 to which the piezoelectric element 41 is fixed. The communication portion 46 is a groove that extends from the accommodation portion 45 to the end of the resonating portion 42.

[0074] If air remains in the accommodation portion 45 and expands inside the accommodation portion 45 blocked by the piezoelectric element 41 when the conductive resin R is thermally cured, the communication portion 46 serves as an escape route for the air. Therefore, the conductive resin R can be thermally cured without impairing the adhesion or electrical connection between the piezoelectric element 41 and the resonance portion 42. Here, since the communication portion 46 extends to the end of the resonance portion 42, the air from the accommodation portion 45 can be reliably discharged to the outside even if the fixed position of the piezoelectric element 41 is misaligned.

[0075] Furthermore, if the amount of conductive resin R injected into the accommodation portion 45 is greater than the capacity that can be accommodated in the accommodation portion 45, the communication portion 46 guides the excess conductive resin R to the communication portion 46. If the communication portion 46 is not present and the amount of conductive resin R injected into the accommodation portion 45 is greater than the above-mentioned capacity, there is a possibility that the thickness between the piezoelectric element 41 and the resonance portion 42 cannot be reduced. In contrast, the communication portion 46 guides the excess conductive resin R to the communication portion 46, so that the capacity of the conductive resin R in the accommodation portion 45 becomes an appropriate amount, and the thickness between the piezoelectric element 41 and the resonance portion 42 can be reduced.

[0076] Here, the communication portion 46 extends from the accommodating portion 45 to the end of the resonating portion 42, but it does not have to extend to the end of the resonating portion 42 as long as it can communicate with the space outside the area where the piezoelectric element 41 is fixed, that is, as long as air can be exhausted from the accommodating portion 45 to the outside.

[0077] Furthermore, if the inner circumferential surface 45a has a shape with corners in a plan view, the conductive resin R may not spread without leaving any gaps, and in that case, air may remain in the gaps. As described above, the air remaining in the gaps may expand when the conductive resin R is thermally cured, and may impede the adhesion and electrical connection between the piezoelectric element 41 and the resonator unit 42.

[0078] Therefore, in this embodiment, the inner circumferential surface 45a of the housing portion 45 is formed to be circular in a plan view. Since the inner circumferential surface 45a is circular in a plan view, the injected conductive resin R spreads without any gaps and comes into contact with the inner circumferential surface 45a without leaving any air. As a result, the conductive resin R fills the entire area of ​​the housing portion 45, so that the conductive resin R contained in the housing portion 45 can reliably bond and electrically connect the piezoelectric element 41 and the resonator portion 42.

[0079] The shape of the containing portion 45 does not have to be circular in plan view, and may be, for example, elliptical, as long as the injected conductive resin R spreads out without any gaps.

[0080] With the above-described configuration, in the driving sections 40A and 40B, the thickness between the piezoelectric element 41 and the resonating section can be reduced, and vibration from the piezoelectric element 41 can be efficiently transmitted to the resonating section .

[0081] When a voltage is applied to the piezoelectric elements 41 of the driving units 40A and 40B, the piezoelectric elements 41 vibrate, the resonating unit 42 deforms in a manner corresponding to the frequency, and the pair of arms 42b also deform in a manner corresponding to the frequency. The pair of arms 42b abut against the power transmission unit 44 so as to push it inward, and the driving force generated by the deformation of the pair of arms 42b is transmitted to the power transmission unit 44, and the power transmission unit 44 moves in the Z direction relative to the resonating unit 42. In this way, the driving force of the driving units 40A and 40B is transmitted to the holding unit 10, which moves the holding unit 10 in the Z direction, thereby performing focusing.

[0082] [Board section] The substrate unit 50 has a circuit for driving the driving units 40A and 40B. The substrate unit 50 has an FPC (Flexible Printed Circuit) 51, a driver IC 52, position detection sensors 54A and 54B, and the like.

[0083] The FPC 51 is a flexible substrate, and is configured by laminating thin insulating layers such as resin films and metal layers such as copper foils. Although not shown in the figure, the metal layers are formed as circuits of signal lines and power lines, and the driving units 40A and 40B, the driver IC 52, the position detection sensors 54A and 54B, etc. are electrically connected.

[0084] The driver IC 52 is an IC that controls a drive signal that drives the drive units 40A and 40B. The driver IC 52 outputs a drive signal based on, for example, detection signals detected by the position detection sensors 54A and 54B, and the output drive signal is output to the drive units 40A and 40B.

[0085] The position detection sensors 54A, 54B are, for example, magnetic sensors such as Hall elements. The position detection sensors 54A, 54B detect the strength of the magnetic force of the magnets 14A, 14B arranged opposite to each other, thereby acquiring the relative position of the holder 10 and the base 20 in the Z direction, and outputting the relative position as a detection signal. Here, two position detection sensors 54A, 54B are provided, but only one position detection sensor may be provided, and in this case, only one magnet may be arranged opposite to each other.

[0086] Although not shown, the FPC 51 is provided with connection wiring that is electrically connected to the driving units 40A and 40B.

[0087] Furthermore, the FPC 51 may have an inductor that boosts the voltage (input voltage) of the drive signal input from the driver IC 52 and outputs the boosted voltage to each of the drive units 40A and 40B.

[0088] The FPC 51 is a single long board in order to mount the driver IC 52 and the position detection sensors 54A and 54B described above on the FPC 51. The FPC 51 is disposed along the outer circumferential surface 24 of the frame 22 of the base 20 so as to go around the outer circumferential surface 24 substantially once.

[0089] In order to arrange the FPC 51 along the outer peripheral surface 24, for example, the outer peripheral surface 24 at the corner 22bA is formed in an arc shape in a plan view. This allows the FPC 51 to be arranged in close contact with the outer peripheral surface 24 at the corner 22bA. This eliminates the need to increase the size of the cover 3 arranged outside the FPC 51, making it possible to miniaturize the entire device and reduce costs.

[0090] [Variation 1] In the above embodiment, as an example, the piezoelectric element 41 was attached to the body portion 42a of the resonator portion 42 using conductive resin R and a non-conductive adhesive, but the piezoelectric element 41 may be attached to the body portion 42a using only conductive resin R without using a non-conductive adhesive.

[0091] In this case, only the conductive resin R is applied to the piezoelectric element 41 or the body portion 42a, and the piezoelectric element 41 is pressed against the body portion 42a, or the body portion 42a is pressed against the piezoelectric element 41. If more conductive resin R than is necessary for adhesion is applied, the excess conductive resin R can be accommodated in the above-mentioned accommodation portion 45, and therefore an appropriate amount of conductive resin R is interposed between the piezoelectric element 41 and the body portion 42a in the above-mentioned region 42a1, and therefore the thickness between the piezoelectric element 41 and the resonating portion 42 can be reduced.

[0092] [Other embodiments] The present invention is not limited to the above-described embodiment, and can be modified without departing from the spirit and scope of the present invention.

[0093] For example, in the above embodiment, the smartphone M has been described as an example, but the present invention can be applied to a camera-mounted device having a camera module and an image processing unit that processes image information obtained by the camera module. The camera-mounted device includes information devices and transport equipment. Information devices include, for example, camera-equipped mobile phones, notebook computers, tablet terminals, portable game consoles, web cameras, camera-equipped in-vehicle devices (for example, rear monitor devices, drive recorder devices), and the like. Transport equipment includes, for example, automobiles, drones, and the like.

[0094] 9A and 9B are diagrams showing an automobile V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). FIG. 9A is a front view of the automobile V, and FIG. 9B is a rear perspective view of the automobile V. The automobile V is equipped with the camera module A described in the above embodiment as the in-vehicle camera module VC. As shown in FIG. 9A and FIG. 9B, the in-vehicle camera module VC is attached, for example, to the windshield facing forward or to the rear gate facing backward. This in-vehicle camera module VC is used for a back monitor, a drive recorder, a collision avoidance control, an automatic driving control, etc.

[0095] In the above embodiment, the optical element driving device 1 that drives the lens unit 2 as an optical element has been described, but the optical element to be driven may be an optical element other than a lens, such as a mirror or a prism, or an optical element such as the imaging element 502. In this case, the shape of the opening 11 of the holder 10 may be changed according to the shape of the optical element to be attached, or may be eliminated in some cases.

[0096] Furthermore, in the above embodiment, the optical element driving device 1 has an AF function, but it may have not only the AF function but also a function for moving the lens unit 2 in the Z direction, such as a zoom function.

[0097] In the above embodiment, the optical element driving device 1 having the AF function has been described as an example, but the optical element driving device 1 may have an OIS function. When the optical element driving device 1 has the OIS function, the optical element driving device 1 has a base that supports the base 20 movably in the X direction and the Y direction via an OIS support unit, and an OIS driving unit that drives the base 20 in the X direction and the Y direction relative to the base. In this case, the OIS driving unit may be configured to drive the base 20 in the X direction and the Y direction using, for example, the above-mentioned driving unit 40A.

[0098] In the above embodiment, the free ends of the pair of arms 42b of the resonating unit 42 sandwich the power transmission unit 44, but the present invention is not limited to this configuration and may be other configurations as long as the resonating unit 42 and the power transmission unit 44 abut against each other. For example, the power transmission units 44 may be arranged on the outer sides of the pair of arms 42b, and the free ends of the pair of arms 42b may abut against each other in the outward direction. Alternatively, the resonating unit 42 may have one arm 42b, and the free end of the one arm 42b may abut against the power transmission unit 44.

[0099] Furthermore, in the above embodiment, the resonating unit 42 is fixed to the base 20 side and the power transmission unit 44 is fixed to the holding unit 10 side, but it is also possible to fix the resonating unit 42 to the holding unit 10 side and the power transmission unit 44 to the base 20 side.

[0100] The above describes the embodiment of the present invention. Note that the above description is an example of a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto. In other words, the description of the configuration of the above device and the shape of each part are examples, and it is clear that various modifications and additions to these examples are possible within the scope of the present invention. [Industrial Applicability]

[0101] The optical element driving device and camera module of the present invention are useful when installed in camera-mounted devices such as smartphones, mobile phones, digital cameras, notebook computers, tablet terminals, portable game consoles, in-vehicle cameras, and drones. [Explanation of symbols]

[0102] 1 Optical element driving device 2 Lens section 3 Cover 4. Optical element driving device main body 5. Imaging unit 10 Holding part 11 Opening 12 Frame section 13 Outer surface 14A, 14B Magnets 20 base 21 Storage opening 22 Frame section 23 Inner surface 24 Outer surface 30A, 30B, 30C support part 40A, 40B Drive unit 41 Piezoelectric element 42 Resonance part 42a Torso 42b Arm section 42c Current carrying part 42d Protrusion 43 Electrode part 44 Power transmission section 44a Contact surface 45 Storage unit 46 Communication part 50 Circuit Board 51 FPC 52 Driver IC 54A, 54B Position detection sensor 301 Opening 501 Image sensor board 502 Image sensor 503 Control Unit R Conductive resin

Claims

1. A piezoelectric element that vibrates when a voltage is applied; a resonating section that resonates with the vibration of the piezoelectric element to move a moving member that comes into contact with the resonating section; a conductive resin that fixes the piezoelectric element and the resonator unit; Equipped with The resonator has a recessed housing portion on each of opposing surfaces of the resonator, The piezoelectric elements are fixed to the opposing surfaces by the conductive resin filled in the housing portion. Drive unit.

2. the resonating unit has a communication portion on each of the opposing surfaces, the communication portion communicating the accommodation portion with a space outside a region where the piezoelectric element is fixed; The drive device according to claim 1 .

3. The communication portion extends from the housing portion to an end of the resonator along each of the opposing surfaces. The drive device according to claim 2.

4. The storage portion has a curved inner circumferential surface. The drive device according to claim 1 .

5. An electrode portion that applies a voltage to the piezoelectric element, The electrode portion is connected to the side opposite to the side where the piezoelectric element is fixed to the resonance portion. The drive device according to claim 1 .

6. A holder capable of holding an optical element; a base that accommodates the holding portion so as to be movable in an optical path direction of the optical element; A drive device according to claim 1 , which drives the holding portion; and Equipped with Optical element driving device.

7. The optical element driving device according to claim 6 , an imaging unit that captures an object image using the optical element; Equipped with Camera module.

8. A camera-equipped device that is an information device or a transport device, A camera module according to claim 7; an image processing unit that processes image information obtained by the camera module; Equipped with Camera-equipped device.

Images