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

Abstract

To reduce driving sound of members when a device is driven by using a piezoelectric element.SOLUTION: A driving device includes: a resonance unit having a pair of arm parts, the resonance unit being resonated by vibration of a piezoelectric element; and a moving unit in contact with the pair of arms, the moving unit relatively moving with respect to the resonance unit in association with vibration of the resonance unit. In the resonance unit and in the moving unit, sites in contact with each other are made of ceramic and the pair of arm parts has a sphere made of ceramic as sites in contact with the moving unit.SELECTED DRAWING: Figure 4A

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 including a flexural displacement member using a piezoelectric element, a friction member provided at the free end of the flexural displacement member, a driven body that abuts against the friction member by a preload mechanism, etc. In this driving device, the friction member and the driven body abut against each other by the preload mechanism, and when the flexural displacement member (piezoelectric element) is driven by applying a voltage to cause the flexural displacement member to be flexibly displaced (vibrated), the driven body moves due to the frictional force between the friction member and the driving member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-63349 A Summary of the Invention [Problem to be solved by the invention]

[0005] As shown in Patent Document 1, in a driving device driven by a piezoelectric element, the driven body moves while the friction member and the driven body are in frictional contact with each other. Therefore, there is a problem that the driving sound generated by the frictionally contacting members is louder than other driving devices, for example, driving devices using a voice coil motor.

[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 reducing the drive noise between components when driving using a piezoelectric element. [Means for solving the problem]

[0007] The drive device according to the present invention comprises: a resonating portion having a pair of arms and resonating with vibration of the piezoelectric element; a moving part that is in contact with the pair of arm parts and moves relatively to the resonating part in response to vibration of the resonating part; Equipped with the resonating portion and the moving portion have portions that come into contact with each other and are made of ceramic, The pair of arms have ceramic spheres as portions that come into contact with the moving portion.

[0008] The optical element driving device according to the present invention comprises: A holder capable of holding an optical element; a housing portion that houses 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, it is possible to reduce the driving noise between members when driving them using a piezoelectric element. [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 4A] 4 is a diagram illustrating a drive unit of the main body of the optical element driving device shown in FIG. 3. [Figure 4B] 4B is a view of the drive unit shown in FIG. 4A as viewed from above in the Z direction. [Figure 5A] 1 is a front view showing an automobile as a camera-mounted device equipped with an in-vehicle camera module. [Figure 5B] FIG. 5B is a perspective view of the automobile shown in FIG. 5A 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 focal point) depending on the type of optical element. Here, the optical path is the path of light formed by the opening 301 of the cover 3, the opening 11 of the holding part 10, or the housing opening 21 of the housing part 20, 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 having a substantially rectangular shape in a plan view from the Z direction. In this embodiment, the cover 3 has a substantially square shape in a plan view. The cover 3 has a substantially circular opening 301 on the upper surface. The lens unit 2 is accommodated in the opening 11 of the holding unit 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 accommodation unit 20 (for example, the bottom 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 housing 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] [Containment section] The accommodating portion 20 has a frame portion 22 with an accommodating opening 21 formed in the center, and the accommodating opening 21 is configured to surround the outer periphery of the holding portion 10 so as to be able to accommodate 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. Accommodation portion 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 in the accommodation unit 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 accommodation unit 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 accommodation part 20. As shown in FIG. 3, the support parts 30A, 30B, and 30C are respectively disposed at three positions dispersed in the circumferential direction on the inner circumferential surface 23 (the 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 accommodating 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 accommodation part 20 so as to be movable in the Z direction.

[0045] In addition, the first groove and the second groove may be provided 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 housing part 20 are usually made of 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 housing 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 holding unit 10 in the Z direction relative to the accommodation unit 20. The driving units 40A, 40B are respectively arranged 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 holding unit 10 in the Z direction by the above-mentioned supporting units 30A, 30B, 30C and driving units 40A, 40B, thereby realizing the AF function.

[0047] As shown in Fig. 3, the frame 22 of the storage unit 20 has four corners 22bA, 22bB, 22bC, and 22bD. In the example shown in Fig. 3, the support unit 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] As the driving units 40A and 40B, ultrasonic motors, which are actuators having piezoelectric elements, are used.

[0049] The driving units 40A and 40B will be described with reference to Fig. 4A and Fig. 4B. Fig. 4A is a diagram for explaining the driving unit 40A of the optical element driving device main body 4 shown in Fig. 3. Fig. 4B is a diagram showing the driving unit 40A shown in Fig. 4A as viewed from above in the Z direction. Note that, although Fig. 4A and Fig. 4B 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, a power transmission unit 43 (a moving unit 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 43. Although not shown here, the power transmission unit 43 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 43. In the driving unit 40A, the resonating unit 42 constitutes an active element, and the power transmission unit 43 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 42a (main body in the present invention) of the resonator 42. Although not shown in the figure, a connection wiring provided on an FPC 51 described later is electrically connected to the piezoelectric element 41, and a voltage is applied to the piezoelectric element 41.

[0052] The resonator 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. The resonator 42 is formed by, for example, laser processing, etching, pressing, or the like of a metal plate.

[0053] The resonating unit 42 has a body portion 42a, a pair of arm portions 42b, a protruding portion 42c, a current-carrying portion 42d, etc. The resonating unit 42 further has a contact member 44, which will be described later.

[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 tip portions which are 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 so that their free ends sandwich the power transmission unit 43. More specifically, the pair of arms 42b are configured so that their free ends abut against an abutment surface 43a of the power transmission unit 43, which will be described later, toward the inside. In this embodiment, as will be described later, the pair of arms 42b are configured to abut against the abutment surface 43a of the power transmission unit 43 via an abutment member 44. Each of the pair of arms 42b has a member accommodating portion (here, a sphere accommodating portion 42e) which is a recessed portion for accommodating the abutment member 44.

[0056] The protruding portion 42c extends in the Z direction from the center of the body portion 42a. A through hole for inserting a rivet or the like is formed in the protruding portion 42c. The protruding portion 42c is fixed to the housing portion 20 side by using a rivet or the like.

[0057] The current-carrying portion 42d extends from the center of the body 42a to the opposite side to the protruding portion 42c. The current-carrying portion 42d is a portion that constitutes a power supply line to the piezoelectric element 41 via the body 42a, and although not shown, is electrically connected to a connection wiring provided on the FPC 51.

[0058] By the above-mentioned electrical connection, a voltage is applied to the piezoelectric element 41 attached to the body portion 42a in the thickness direction, 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.

[0059] Here, the different behaviors are a behavior in which the pair of arm portions 42b advances and retreats the power transmission portion 43 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 43 in the Z direction.

[0060] The power transmission unit 43 has, for example, a rectangular parallelepiped shape having a predetermined length in the Z direction, and has a contact surface 43a that contacts the contact member 44 described later 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 43a, and the power transmission unit 43 functions as a chucking guide for the pair of arm portions 42b. For example, the end portion of the power transmission unit 43 on the upper side (+Z side) in the figure is attached to the outer circumferential surface 13 of the frame portion 12 of the holding unit 10.

[0061] At least the contact surface 43a of the power transmission part 43 or the entire power transmission part 43 is made of ceramic. As the ceramic, for example, zirconia, alumina, etc. can be used. When only the contact surface 43a is made of ceramic, for example, a plate material made of ceramic may be placed on the power transmission part 43 as the contact surface 43a (surface).

[0062] The abutment member 44 is fixed to the sphere receiving portion 42e at the tip end (free end) of the pair of arm portions 42b, and abuts against the abutment surface 43a of the power transmission portion 43. The abutment member 44 is made of ceramic. For example, zirconia, alumina, or the like can be used as the ceramic. Moreover, as one example, the abutment member 44 is a spherical ball member.

[0063] Regarding a conventional ultrasonic motor, referring to FIG. 4A, the tips of a pair of arm portions 42b abut against a contact surface 43a, and as the piezoelectric element 41 vibrates, the tips of the arm portions 42b come into frictional contact with the contact surface 43a, causing the power transmission portion 43 to move.

[0064] In this case, there was a problem that the driving noise generated by the frictional contact between the tip of the arm portion 42b and the contact surface 43a was louder than that of, for example, a voice coil motor. This was because one or both of the members in frictional contact were worn away, and this wear caused the driving noise to become louder. For example, when the members in frictional contact were stainless steel, one or both of the stainless steels were worn away, causing the driving noise to become louder.

[0065] Therefore, in this embodiment, at least the contact surface 43a or the entire power transmission part 43 is made of, for example, ceramic. Also, a contact member 44 is disposed at the tip of the pair of arm parts 42b, and the contact member 44 is made of, for example, ceramic.

[0066] In this way, the contact members 44 and the contact surfaces 43a, which are the mutually contacting portions of the resonating unit 42 and the power transmitting unit 43, are both made of ceramic. This increases the hardness of the contact members 44 and the contact surfaces 43a, respectively, and makes the hardness equal to each other, thereby preventing the members from being scraped against each other, and as a result, the drive noise can be reduced.

[0067] The inventors have confirmed that by making the abutment member 44 and the abutment surface 43a, which are the frictionally contacting members, out of ceramic, the driving noise is reduced by at least 5 to 10 dB compared to a conventional configuration, for example, where the frictionally contacting members are made of stainless steel.

[0068] In addition, in the conventional configuration, the contact forces between the tips of the pair of arm parts 42b and the corresponding contact surfaces 43a were different and the contact directions were not symmetrical due to the machining accuracy of the resonating part 42 and the power transmission part 43 and the positional accuracy during assembly, etc. In other words, there was variation in the contact state between the tips of the pair of arm parts 42b and the corresponding contact surfaces 43a.

[0069] In contrast, in the present embodiment, the abutment member 44 is a spherical ball member. This makes the abutment force between the abutment member 44, which is the tip of the pair of arm portions 42b, and the corresponding abutment surface 43a equal or approximately equal, and also makes the abutment direction symmetrical or approximately symmetrical, thereby suppressing variation in the abutment state. Since variation in the abutment state can be suppressed in this way, assembly of the resonating unit 42, the power transmission unit 43, etc. is also easy.

[0070] With the configuration described above, when a voltage is applied to the piezoelectric element 41 of the driving unit 40A, the piezoelectric element 41 vibrates, 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 43 so as to push it inward, and a driving force generated by the deformation of the pair of arms 42b is transmitted to the power transmission unit 43, and the power transmission unit 43 moves in the Z direction relative to the resonating unit 42. In this way, the driving force of the driving unit 40A is transmitted to the holding unit 10, which moves the holding unit 10 in the Z direction, thereby performing focusing.

[0071] In this embodiment, as described above, the contact member 44 and the contact surface 43a, which are the parts of the resonator unit 42 and the power transmission unit 43 that come into contact with each other, are made of high-hardness ceramic, thereby reducing the driving noise.

[0072] [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.

[0073] 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.

[0074] 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.

[0075] 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 holding unit 10 and the storage unit 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.

[0076] Although not shown, the FPC 51 is provided with connection wiring that is electrically connected to the driving units 40A and 40B.

[0077] 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.

[0078] 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 housing 20 so as to go around the outer circumferential surface 24 substantially once.

[0079] 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.

[0080] [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.

[0081] 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.

[0082] 5A and 5B are diagrams showing an automobile V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). FIG. 5A is a front view of the automobile V, and FIG. 5B 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. 5A and FIG. 5B, 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.

[0083] 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.

[0084] 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.

[0085] 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 housing unit 20 movably in the X direction and the Y direction via an OIS support unit, and an OIS driving unit that drives the housing unit 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 housing unit 20 in the X direction and the Y direction using, for example, the above-mentioned driving unit 40A.

[0086] In the above embodiment, the contact member 44 is a spherical ball member, but the shape is not limited to this and may be other shapes. For example, the contact member 44 may be cylindrical or semi-cylindrical, and the curved surface may be the portion that contacts the contact surface 43a.

[0087] In the above embodiment, the ball housing portion 42e and the abutment member 44 are provided at the tip of the arm portion 42b, but the tip of the arm portion 42b may be coated with ceramic instead of providing the ball housing portion 42e and the abutment member 44. The same applies to the abutment surface 43a of the power transmission portion 43, and the surface of the abutment surface 43a may be coated with ceramic.

[0088] In the above embodiment, the free ends of the pair of arms 42b of the resonator 42 sandwich the power transmission unit 43, but the present invention is not limited to this configuration and may be other configurations as long as the resonator 42 and the power transmission unit 43 abut against each other. For example, the power transmission units 43 may be disposed 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 resonator 42 may have one arm 42b, and the free end of the one arm 42b may abut against the power transmission unit 43.

[0089] In addition, in the above embodiment, the resonating unit 42 is fixed to the accommodating unit 20 side and the power transmission unit 43 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 43 to the accommodating unit 20 side.

[0090] 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]

[0091] 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]

[0092] 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 Storage unit 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 section 42a Torso 42b Arm section 42c protrusion 42d Current carrying part 42e Sphere container 43 Power transmission section 43a Contact surface 44 Contact member 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

Claims

1. a resonating portion having a pair of arms and resonating with vibration of the piezoelectric element; a moving part that is in contact with the pair of arm parts and moves relatively to the resonating part in response to vibration of the resonating part; Equipped with the resonating portion and the moving portion have portions that come into contact with each other and are made of ceramic, The pair of arms each have a ceramic sphere as a portion that comes into contact with the moving portion. Drive unit.

2. The moving part is entirely made of ceramic. The drive device according to claim 1 .

3. the moving part has a surface that comes into contact with the resonating part and is made of ceramic; The drive device according to claim 1 .

4. The pair of arms each have a sphere receiving portion that receives the sphere. The drive device according to claim 1 .

5. A holder capable of holding an optical element; a housing portion that houses 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.

6. The optical element driving device according to claim 5 , an imaging unit that captures an object image using the optical element; Equipped with Camera module.

7. A camera-equipped device that is an information device or a transport device, A camera module according to claim 6; an image processing unit that processes image information obtained by the camera module; Equipped with Camera-equipped device.

Images