Optical element driving device, camera module, and camera-equipped device

Abstract

This optical element driving device comprises: a movable part; a driving part that has an ultrasonic motor including a laminate in which a plurality of piezoelectric elements are laminated, and that drives the movable part in a prescribed direction; and a shaft part that extends in the prescribed direction and that is disposed oppositely from the laminate, wherein the driving part has two contact parts that contact the laminate and the shaft part and that are disposed on the laminate so as to sandwich the shaft part.

Description

Optical element driving device, camera module, and camera-mounted device

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

[0002] Conventionally, camera modules mounted on thin camera-equipped devices such as smartphones are known, and some of these camera modules include an optical element driving device with a zoom function that enlarges or reduces the image of a subject.

[0003] For example, Patent Document 1 discloses a configuration including a fixed lens onto which light from a subject is incident, two movable lenses onto which light bent by the fixed lens is incident, and a lens drive unit that moves the two movable lenses in the direction of the optical axis.

[0004] Furthermore, from the viewpoint of miniaturizing the optical element driving device, the use of an ultrasonic motor including a piezoelectric element as a drive source for the movable lens has been considered. For example, a compound resonance type ultrasonic motor in which multiple piezoelectric elements are stacked is known (see, for example, Patent Document 2). Such an ultrasonic motor can move the movable lens by simultaneously generating two types of resonance (flexural resonance and expansion / contraction resonance).

[0005] JP 2018-36416 A JP 2011-186073 A

[0006] However, such an ultrasonic motor requires a part on the optical element driving device side that receives the vibrations of the ultrasonic motor, so a configuration is desired in which the part that receives the vibrations and the ultrasonic motor are in stable contact with each other.

[0007] An object of the present invention is to provide an optical element driving device, a camera module, and a camera-mounted device that are capable of bringing an ultrasonic motor into stable contact with a portion that receives vibrations from the ultrasonic motor.

[0008] The optical element driving device of the present invention comprises: a movable part that houses an optical element; a driving part that has an ultrasonic motor including a laminate in which a plurality of plate-like elements including piezoelectric elements are stacked, and drives the movable part in a predetermined direction; and a shaft part that extends in the predetermined direction and is arranged opposite the laminate, wherein the driving part has two contact parts that contact the laminate and the shaft part and are arranged on the laminate so as to sandwich the shaft part.

[0009] A camera module according to the present invention comprises: the optical element driving device; an element section including an optical element held by the movable section; and an imaging section that captures a subject image formed by the element section.

[0010] A camera-equipped device according to the present invention is an information device or transportation device, and includes the camera module described above, and an imaging control unit that processes image information obtained by the camera module.

[0011] According to the present invention, stable contact can be achieved between the ultrasonic motor and the portion that receives the vibration of the ultrasonic motor.

[0012] 1 is a diagram showing a smartphone equipped with a camera module. FIG. 2 is a diagram showing a smartphone equipped with a camera module. FIG. 3 is a diagram showing a simplified view of a camera module according to a first embodiment of the present invention. FIG. 4 is a diagram showing a simplified side view of a camera module according to the first embodiment. FIG. 5 is a perspective view showing a portion of a drive unit and a shaft unit. FIG. 6 is a perspective view showing a portion of a drive unit. FIG. 7 is a cross-sectional view of a contact portion of a drive unit and a shaft unit. FIG. 8 is a diagram showing the contact portion and the shaft unit from the negative side in the X direction. FIG. 9 is a perspective view of a housing unit provided in a camera module according to a second embodiment. FIG. 10 is an exploded perspective view of the housing unit. FIG. 11 is a perspective view showing a pressurizing portion of a biasing unit. FIG. 12 is a diagram showing a contact portion between a pressurizing portion and an ultrasonic motor. FIG. 13 is a cross-sectional view showing a contact portion between a shaft unit and a rolling unit. FIG. 14 is a diagram showing a guide holding unit. FIG. 15 is a diagram showing a holding portion of a rolling unit of a guide holding unit. FIG. 16 is a diagram showing a guide support unit. FIG. 17 is a diagram for explaining the operation of the second embodiment. FIG. 18 is a diagram showing a shaft unit according to a modified example. FIG. 19 is a diagram showing a car equipped with a camera module. FIG. 19 is a diagram showing a car equipped with a camera module.

[0013] A first embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 2 is a diagram showing a simplified configuration of a camera module 1 according to the first embodiment of the present invention. Fig. 3 is a diagram showing a simplified configuration of the camera module 1 according to the first embodiment as viewed from the side.

[0014] The camera module 1 is mounted on a thin camera-mounted device such as a smartphone M (see FIGS. 1A and 1B), a mobile phone, a digital camera, a notebook computer, a tablet terminal, a portable game console, or an in-vehicle camera.

[0015] In describing the structure of camera module 1 of this embodiment, a Cartesian coordinate system (X, Y, Z) is used. The same Cartesian coordinate system (X, Y, Z) is also used in the figures described below. When actually capturing an image with a camera-mounted device, camera module 1 is mounted so that the X direction is the left-right direction, the Y direction is the up-down direction, and the Z direction is the front-back direction, for example. Light from a subject enters camera module 1 from the +Z direction side, bends from the incident portion, and is guided to the +Y direction side. By reducing the thickness of camera module 1 in the Z direction, the camera-mounted device can be made thinner.

[0016] As shown in FIG. 2, the camera module 1 includes a housing 10 , a reflection drive unit 20 , a lens unit 30 , an imaging unit 40 , a lens drive unit 60 , a shaft unit 80 , and a drive control unit 100 .

[0017] The drive control unit 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU reads a program corresponding to the processing content from the ROM, loads it into the RAM, and centrally controls the lens drive unit 60 in cooperation with the loaded program. In this way, the drive control unit 100 drives the lens unit 30 housed in the housing 10. As a result, the camera module 1 performs stepless optical zoom and autofocus. The housing 10, the lens drive unit 60, the shaft unit 80, and the drive control unit 100 correspond to the "optical element drive device" of the present invention.

[0018] 3, in the camera module 1, incident light L1 is incident on the housing 10 via a reflection drive unit 20. The reflection drive unit 20 has a reflection housing 21, a mirror 22, and a reflection drive control unit 23. In the example shown in FIGS. 2 and 3, the reflection housing 21 is disposed adjacent to the end of the housing 10 on the negative side in the Y direction. The mirror 22 is provided inside the reflection housing 21, and reflects the incident light L1 toward the housing 10 as reflected light L2. The reflection drive control unit 23 includes a CPU, ROM, RAM, etc., and controls the orientation of the mirror 22.

[0019] Furthermore, mirror 22 according to this embodiment has two rotation axes (not shown) extending in the X and Y directions. In reflection drive unit 20, mirror 22 rotates around these rotation axes under the control of reflection drive control unit 23. This provides camera module 1 with an image stabilization function (OIS (Optical Image Stabilization) function) that optically corrects shake (vibration) that occurs during image capture to reduce image distortion.

[0020] The reflected light L2 incident on the housing 10 is output to the imaging unit 40 via the lens unit 30 housed in the housing 10 .

[0021] The imaging unit 40 is disposed on the outer surface on the positive side in the Y direction of the housing 10, and is configured so that reflected light L2 is incident thereon via the lens unit 30. The imaging unit 40 has an imaging element, a substrate, etc. (not shown).

[0022] The imaging element is configured by, for example, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, etc. The imaging element is mounted on a substrate and electrically connected to wiring on the substrate via bonding wires. The imaging element captures an image of a subject formed by the lens unit 30 and outputs an electrical signal corresponding to the subject image.

[0023] A printed wiring board (not shown) is electrically connected to the substrate of the imaging unit 40, and power is supplied to the imaging element and an electrical signal of the subject image captured by the imaging element is output via this printed wiring board. The electrical signal is output to an imaging control unit 200 provided in the camera-mounted device. The imaging control unit 200 includes a CPU, ROM, RAM, etc., and processes image information obtained by the camera module 1. The imaging control unit 200 may be mounted on the camera-mounted device, but may also be built into the camera module 1.

[0024] The housing 10 houses the lens unit 30, the lens driving unit 60, and the shaft unit 80, and has, for example, a rectangular parallelepiped shape as a whole.

[0025] The lens unit 30 is provided in an area within the housing 10 through which the reflected light L2 from the reflection drive unit 20 passes. The lens unit 30 has a first lens unit 31, a second lens unit 32, a third lens unit 33, and a fourth lens unit 34 arranged side by side in the Y direction. Each of the first lens unit 31, the second lens unit 32, the third lens unit 33, and the fourth lens unit 34 houses a lens. The lens corresponds to the "optical element" of the present invention.

[0026] The first lens unit 31 is disposed on the most upstream side in the incident direction of the reflected light L2 (direction toward the positive side of the Y direction), and is fixed to the housing 10 .

[0027] The second lens unit 32 is disposed downstream of the first lens unit 31 in the incident direction, and is held by a frame of the lens driving unit 60. The second lens unit 32 is movable in the Y direction by the lens driving unit 60.

[0028] The third lens unit 33 is disposed downstream of the second lens unit 32 in the incident direction, and is held by a frame of the lens driving unit 60. The third lens unit 33 is movable in the Y direction by the lens driving unit 60.

[0029] The second lens unit 32 and the third lens unit 33 may be configured, for example, so that their movement in the Y direction is guided by a guide shaft extending in the Y direction, or they may be configured to be movable on rails extending in the Y direction.

[0030] The fourth lens unit 34 is disposed on the most downstream side in the incident direction and is fixed to the housing 10 .

[0031] The lenses in the first to fourth lens units 31 to 34 may be assembled into the housing 10 when the optical element driving device is manufactured, or they may be assembled into the housing 10 when the camera module 1 is manufactured from the lens driving unit 60.

[0032] The lens driving units 60 are provided corresponding to the second lens unit 32 and the third lens unit 33, respectively, and independently move either the corresponding second lens unit 32 or the corresponding third lens unit 33 under the control of the drive control unit 100. The lens driving units 60 are respectively arranged in the area between the lens unit and the side wall on the positive side in the X direction of the housing 10, and in the area between the lens unit and the side wall on the negative side in the X direction of the housing 10. In other words, one lens driving unit 60 is provided on each side of the optical axis of the housing 10.

[0033] In this embodiment, the lens driving unit 60 on the + side in the X direction drives the second lens unit 32 in the Y direction, and the lens driving unit 60 on the - side in the X direction drives the third lens unit 33 in the Y direction. In other words, the lens driving units 60 on the + side and - side in the X direction correspond to the "driving unit" of the present invention.

[0034] In this embodiment, the lens drivers 60 have substantially the same shape, and therefore, in the following description, unless otherwise specified, only the lens driver 60 corresponding to the second lens unit 32 will be described, and a description of the lens driver 60 corresponding to the third lens unit 33 will be omitted. Furthermore, in this embodiment, the lens drivers 60 are arranged symmetrically in the X and Y directions, and therefore the relationship between the positive and negative directions in the lens driver 60 corresponding to the third lens unit 33 is opposite to the relationship between the positive and negative directions in the lens driver 60 corresponding to the second lens unit 32. Furthermore, in the following description, the second lens unit 32 and the third lens unit 33 will be referred to as movable lenses.

[0035] 4 and 5, the lens driving unit 60 has an ultrasonic motor 61 and a contact unit 62, and is disposed opposite the shaft unit 80. The lens driving unit 60 also includes a frame that supports the movable lens, a magnet unit for detecting the position of the frame, and the like. The configurations of the frame, magnet unit, and the like are similar to known configurations.

[0036] The ultrasonic motor 61 has a compound resonance configuration and is fixed to the frame or the like of the lens driving unit 60. The ultrasonic motor 61 is composed of a laminate 63 in which a plurality of piezoelectric elements each composed of a rectangular plate-shaped element are stacked. As shown in Fig. 6, among the piezoelectric elements that make up the laminate 63, the first piezoelectric elements 63A in the first and second layers from the positive side in the X direction have through holes formed therein.

[0037] Furthermore, the second piezoelectric element 63B other than the first piezoelectric element 63A having the through hole formed therein includes an electrode portion. The electrode portion is connected to an electrode terminal (not shown) that is connected to a substrate (not shown) provided on the housing 10. This causes electricity to flow through the second piezoelectric element 63B, generating vibrations. Specifically, the second piezoelectric element 63B is configured to simultaneously generate two types of vibrations: vibration in the Y direction (bending resonance) and vibration in the X direction (stretching resonance).

[0038] Furthermore, the first piezoelectric element 63A having the through-hole formed therein does not include an electrode portion and serves as a dummy element that is not used for driving.

[0039] The space defined by the through-hole of the first piezoelectric element 63A and the second piezoelectric element 63B in the third layer from the positive side in the X direction constitutes a housing portion 63C.

[0040] The accommodation portions 63C are spaces for accommodating the contact portions 62, and four accommodation portions 63C are provided in the first piezoelectric element 63A (see also FIG. 5). The four accommodation portions 63C are located at positions corresponding to the four vertices of a rectangle whose center is the center point of the first piezoelectric element 63A.

[0041] The stack 63 is also arranged so that the surface on the side of the accommodating portion 63C is positioned on the positive side of the X direction, and so that the short sides of the rectangle formed by the four accommodating portions 63C are parallel to the Z direction.

[0042] The contact portion 62 is a spherical member made of, for example, a metal such as ceramic, and is housed in each housing portion 63C so as to be in contact with the laminate 63 (the second piezoelectric element 63B of the third layer) and the shaft portion 80. The contact portion 62 is adhered inside the housing portion 63C with, for example, an adhesive.

[0043] A total of four contact portions 62 are provided corresponding to the four accommodation portions 63C. Of the four contact portions 62, two contact portions 62 aligned in the Z direction are also referred to as a contact portion group. In this embodiment, a contact portion 62 is accommodated in each of the four accommodation portions 63C arranged as described above, so two contact portion groups are arranged aligned in the Y direction.

[0044] The shaft portion 80 is an axial member extending in the Y direction and is supported by the housing 10 so as to face the laminated body 63. The shaft portion 80 holds the movable lens via a frame that supports the movable lens. The position of the central axis of the shaft portion 80 in the Z direction is a position sandwiched between two contact portions 62 of each contact portion group (see also FIG. 7 ). In other words, the two contact portions 62 are arranged on the laminated body 63 so as to sandwich the shaft portion 80 therebetween.

[0045] Specifically, the two contact portions 62 are arranged in an area overlapping with the shaft portion 80 when viewed from the X direction, and are arranged at positions symmetrical with respect to the central axis of the shaft portion 80. As a result, the two contact portions 62 are arranged so that the contact pressures (forces in the X direction and Z direction components) with the shaft portion 80 are equal to each other.

[0046] When the second piezoelectric element 63B is energized, two types of vibrations are generated simultaneously, causing vibrations in the contact portion 62 that trace an elliptical locus tilted in an oblique direction (a direction having an X-direction component and a Y-direction component). This vibration causes a frictional force in the oblique direction to act between the contact portion 62 and the shaft portion 80, making it possible to apply a thrust force from the ultrasonic motor 61 to the frame that moves it in the direction of the optical axis (Y-direction). This makes it possible to move the movable lens in the Y-direction.

[0047] In the present embodiment configured as described above, there are two contact portions 62 that contact the laminate 63 and the shaft portion 80 and are arranged on the laminate 63 so as to sandwich the shaft portion 80. This allows stable contact between the two contact portions 62 and the shaft portion 80, and therefore allows stable movement of the movable lens along the direction in which the shaft portion 80 extends (Y direction).

[0048] For example, if a part (such as a plate) that receives vibrations from the contact part is provided on the side wall of the housing, the contact position of the contact part may shift due to disturbances, making it difficult to stably move the movable lens. Therefore, it becomes necessary to accurately manage the mounting angle of the plate, etc.

[0049] In contrast, in this embodiment, two contact portions 62 are provided to sandwich the shaft portion 80, so that the contact positions of the contact portions 62 are less likely to shift, allowing the movable lens to move stably.

[0050] Furthermore, since multiple contact groupings each consisting of two contact portions 62 are arranged in line in the Y direction (predetermined direction), the contact position of the contact portion 62 is less likely to shift, further improving the stable movement of the movable lens.

[0051] Furthermore, the laminate 63 has a housing portion 63C that houses the contact portion 62 at the portion facing the shaft portion 80, so that it is possible to accurately position the contact portion 62. As a result, it is possible to achieve accurate contact with the shaft portion 80, and in turn, it is possible to further improve the stable movement of the movable lens.

[0052] Furthermore, since the laminate 63 includes the first piezoelectric element 63A having a through hole formed therein and the second piezoelectric element 63B having an electrode portion, the laminate 63 can be integrally formed of piezoelectric elements.

[0053] Furthermore, since the contact portion 62 is configured to be spherical, the contact surface of the contact portion 62 with the shaft portion 80 is configured to be spherical. This allows the contact portion 62 and the shaft portion 80 to come into smooth contact with each other compared to a configuration in which the contact surface is angular, making it possible to make the shaft portion 80 less susceptible to wear.

[0054] Next, a second embodiment of the present invention will be described. As shown in Fig. 8, a housing 10 according to the second embodiment is provided with a lens unit 30, a lens driving unit 60, a shaft unit 80, and a housing unit 90 that houses a portion of the lens driving unit 60 and the shaft unit 80. The configurations of the lens driving unit 60 and the shaft unit 80 are the same as those in the first embodiment.

[0055] As shown in FIG. 9 , the housing portion 90 includes a case 91 , an electrode portion 92 , a biasing portion 93 , a rolling portion 94 , and a guide portion 95 .

[0056] The case 91 is a portion of the housing 90 that houses the lens driving unit 60 and part of the shaft unit 80, and is configured in a box shape that opens to the negative side in the X direction. The case 91 also houses part of the electrode unit 92, the rolling unit 94, and the guide unit 95.

[0057] Holes 91A through which the shaft portion 80 is passed are formed in the side walls on both sides in the Y direction of the case 91. Furthermore, mounting portions 91B for mounting the biasing portions 93 are provided on both sides of the hole 91A in the case 91 in the Z direction.

[0058] The electrode unit 92 is an electrode for supplying electricity to the ultrasonic motor 61, and has a first electrode 92A, a connection unit 92B, and a second electrode 92C. The first electrode 92A is an electrode that contacts a substrate (not shown) of the camera module 1. The connection unit 92B is a portion that connects the first electrode 92A and the second electrode 92C. The first electrode 92A and the connection unit 92B are disposed on the outside of the case 91 (see FIG. 8 ).

[0059] The second electrode 92C is an electrode that comes into contact with the negative surface in the X direction of the second piezoelectric element 63B of the ultrasonic motor 61, and is a part of the electrode unit 92 that is disposed in the case 91. A hole 92D is formed in the center of the second electrode 92C.

[0060] The biasing portion 93 is an elastic body (for example, a spring) for biasing the ultrasonic motor 61 toward the shaft portion 80. The biasing portion 93 has a main body portion 93A, a mounted portion 93B, and a pressurizing portion 93C.

[0061] Main body portion 93A is disposed so as to cover the opening of case 91. As shown in Figures 9 and 10A, attached portions 93B are configured to extend from both ends of main body portion 93A in the Y direction toward the positive side in the X direction, and are provided at positions corresponding to attachment portion 91B of case 91. Holes 93D are formed in attached portions 93B, and attachment portion 91B is hooked into holes 93D (see also Figure 8), thereby attaching biasing portion 93 to case 91.

[0062] 10A and 10B , the pressure applying portion 93C is a portion for applying pressure to the ultrasonic motor 61, and is provided so as to protrude from the center of the surface on the positive side in the X direction of the main body portion 93A. The pressure applying portion 93C is located at a position corresponding to the hole 92D of the second electrode 92C, and is passed through the hole 92D to come into contact with the second piezoelectric element 63B of the ultrasonic motor 61. This makes it possible for the pressure applying portion 93C to apply pressure to the ultrasonic motor 61, and ultimately to urge the ultrasonic motor 61 toward the shaft portion 80.

[0063] 9 and 11 , the rolling portion 94 is made up of a plurality of rollable ball members 94A that are arranged to sandwich the shaft portion 80 between the rolling portion 94 and the contact portion 62. The rolling portion 94 has a total of 22 ball members 94A. The plurality of ball members 94A are arranged in two groups (ball groups). The two ball groups are arranged to sandwich the shaft portion 80 from both sides in the Z direction, and some of the ball members 94A in each ball group are arranged in positions that allow them to come into contact with the shaft portion 80.

[0064] The guide portion 95 guides the rolling of the rolling portion 94 and includes a guide holding portion 951 and a guide support portion 952 .

[0065] The guide holding portion 951 is a holding portion for the plurality of ball members 94A of the guide portion 95, and is disposed so as to cover the plurality of ball members 94A from the negative side in the X direction. As shown in Figures 11 and 12, the portion of the guide holding portion 951 on the negative side in the X direction that corresponds to the shaft portion 80 is a recessed portion 951A that is recessed so as to fit along the shaft portion 80.

[0066] 13, an elliptical guide recess 951B extending in the Y direction is formed on the positive side in the X direction of the guide holding portion 951. Two guide recesses 951B are provided so as to sandwich the portion corresponding to recess 951A from both sides in the Z direction. A group of balls of the rolling portion 94 is arranged in each guide recess 951B.

[0067] The guide recess 951B is configured such that its length in the X direction is long enough to accommodate two ball members 94A, and its length in the Y direction is long enough to accommodate multiple (approximately six) ball members 94A.

[0068] 11 and 12 , a hole 951C is formed in the guide recess 951B in a portion corresponding to the recess 951A. The ball member 94A at the position corresponding to the hole 951C is disposed so as to protrude toward the shaft portion 80 beyond the wall surface of the recess 951A. Therefore, this hole 951C allows the ball member to come into contact with the shaft portion 80. In other words, the guide recess 951B is configured to include a region R1 where the ball member 94A faces the shaft portion 80, and a region R2 where the ball member 94A does not face the shaft portion 80.

[0069] 11 and 14, the guide support portion 952 is disposed on the positive side in the X direction of the guide holding portion 951 so as to support the rolling portion 94. A partition portion 953 is provided in a portion of the guide support portion 952 corresponding to the guide recess 951B, which separates the plurality of ball members 94A of the ball group into two rows.

[0070] The partition portion 953 is arranged to separate the guide recess 951B into a region R1 where the ball member 94A faces the shaft portion 80 and a region R2 where the ball member 94A does not face the shaft portion 80. This allows the multiple ball members to roll along the ellipse of the guide recess 951B.

[0071] By configuring the guide portion 95 in this manner, when the driving force from the ultrasonic motor 61 is transmitted to the shaft portion 80 and a force is applied to the shaft portion 80 to move in the Y direction, the ball member in contact with the shaft portion 80 rolls in the Y direction.

[0072] 15 , when a force is applied to the shaft portion 80 to move in the direction of arrow A, a rolling force acts on the inner ball members 94A of the ball groups in the rolling portion 94 in the direction along arrow A. As a result, a rolling force also acts on the ball members 94A that do not contact the shaft portion 80, as they are pressed by the ball members 94A that roll when in contact with the shaft portion 80. As a result, the multiple ball members 94A of the ball group revolve within the guide recess 951B. In other words, the guide recess 951B is configured so that the multiple ball members 94A roll while revolving.

[0073] 15, in rolling portion 94, the balls on the negative side in the Z direction rotate in the direction of arrow B1, and the balls on the positive side in the Z direction rotate in the direction of arrow B2. Note that when a force is applied to shaft portion 80 to move in the direction opposite to arrow A, the rotation direction of each ball group in rolling portion 94 becomes the opposite direction to that in the example shown in FIG.

[0074] According to the second embodiment configured as described above, the shaft portion 80 is sandwiched between the rolling portion 94 and the contact portion 62, so that it is possible to reduce the frictional resistance of the surface of the shaft portion 80 facing the rolling portion 94. As a result, it is possible to make the movement of the movable lens smoother.

[0075] Furthermore, the guide portion 95 guides the rolling of the rolling portion 94, so that the rolling of the rolling portion 94 can be made smooth.

[0076] Furthermore, since the plurality of ball members 94A rolls around the guide portion of the guide part 95, there is no need to ensure the stroke of the ball members 94A in accordance with the drive amount (movement amount) of the shaft part 80. As a result, the configuration can be made compact.

[0077] Furthermore, the partition portion 953 separates the ball members 94A into a region R1 where the ball members 94A face the shaft portion 80 and a region R2 where the ball members 94A do not face the shaft portion 80, so that the multiple ball members 94A can be rotated accurately within the guide recess 951B.

[0078] In the second embodiment, the shaft portion 80 is configured to be cylindrical, but the present invention is not limited to this, and it does not have to be configured to be cylindrical.

[0079] 16, the shaft portion 80 may be configured to have a D-shape in cross section. Specifically, a surface 80A of the shaft portion 80 facing the contact portion 62 is configured to be flat. A surface 80B of the shaft portion 80 facing the rolling portion 94 is configured to be arc-shaped.

[0080] Incidentally, if the shaft portion 80 is configured in a cylindrical shape, the contact surface with the contact portion 62 of the ultrasonic motor 61 is an arcuate surface, and therefore the shaft portion 80 may rotate due to contact with the contact portion 62. When the shaft portion 80 rotates, there is a possibility that wear powder, which tends to accumulate in the sliding portions of the shaft portion 80, may fly off.

[0081] In contrast, the surface 80A of the shaft portion 80 facing the contact portion 62 is flat, which can prevent the shaft portion 80 from rotating due to contact with the contact portion 62. As a result, it is possible to prevent the scattering of wear powder caused by the rotation of the shaft portion 80.

[0082] In the second embodiment, the guide portion 95 has the partition portion 953, but the present invention is not limited to this. For example, the partition portion 953 may not be provided as long as the guide portion 95 can guide the rolling of the ball member 94A, for example, by forming a groove in the guide support portion 952 that allows the ball member 94A to rotate.

[0083] Furthermore, in the second embodiment described above, the guide portion 95 is configured so that a plurality of ball members 94A rotates around it, but the present invention is not limited to this, and the configuration does not have to be such that a plurality of ball members 94A rotates around it.

[0084] In the above embodiment, two contact groupings are provided, but the present invention is not limited to this, and three or more contact groupings may be provided, or only one contact group may be provided.

[0085] Furthermore, in the above embodiment, the number of first piezoelectric elements 63A in which through holes (accommodation sections 63C) are formed is two, but the present invention is not limited to this, and for example, the number of first piezoelectric elements in which through holes are formed can be adjusted appropriately depending on the depth of the accommodation section.

[0086] Furthermore, in the above embodiment, the contact portion 62 is housed in the housing portion 63C, but the present invention is not limited to this, and for example, the contact portion 62 may be bonded to the surface of the piezoelectric element in the first layer of the laminate 63. In this case, the piezoelectric element in the first layer does not have to be a dummy element.

[0087] Furthermore, in the above embodiment, the laminate is composed of a first piezoelectric element and a second piezoelectric element, but the present invention is not limited to this, and the laminate may be composed of elements other than piezoelectric elements.

[0088] Furthermore, in the above embodiment, the contact surface of the contact portion with the shaft portion is configured to be spherical, but the present invention is not limited to this, and it does not have to be configured to be spherical.

[0089] Furthermore, in the above embodiment, the drive control unit, the reflection drive control unit, and the imaging control unit are provided separately, but the present invention is not limited to this, and at least two of the drive control unit, the reflection drive control unit, and the imaging control unit may be configured as a single control unit.

[0090] Furthermore, for example, in the above embodiment, a smartphone, which is a camera-equipped mobile terminal, has been described as an example of a camera-equipped device equipped with the camera module 1. However, the present invention can be applied to a camera-equipped device having a camera module and an image processing unit that processes image information obtained by the camera module. Camera-equipped devices include information devices and transportation equipment. Information devices include, for example, camera-equipped mobile phones, laptop computers, tablet terminals, portable game consoles, web cameras, drones, and camera-equipped in-vehicle devices (e.g., backup monitor devices and drive recorder devices). Transportation equipment includes, for example, automobiles and drones.

[0091] 17A and 17B are diagrams showing an automobile V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). FIG. 17A is a front view of the automobile V, and FIG. 17B is a rear perspective view of the automobile V. The automobile V is equipped with the camera module 1 described in the embodiment as the in-vehicle camera module VC. As shown in FIGS. 8A and 8B , 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 backup monitoring, drive recorders, collision avoidance control, autonomous driving control, etc.

[0092] Furthermore, the above-described embodiments are merely examples of specific embodiments of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be embodied in various forms without departing from the gist or main features of the present invention. For example, the shapes, sizes, numbers, and materials of the components described in the above-described embodiments are merely examples, and can be modified as appropriate.

[0093] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2023-222348, filed on December 28, 2023, are incorporated herein by reference in their entirety.

[0094] The optical element driving device according to the present invention is useful as an optical element driving device, a camera module, and a camera-mounted device that can stably contact an ultrasonic motor with a portion that receives vibrations from the ultrasonic motor.

[0095] REFERENCE SIGNS LIST 1 camera module, 10 housing, 20 reflection drive unit, 21 reflection housing, 22 mirror, 23 reflection drive control unit, 30 lens unit, 31 first lens unit, 32 second lens unit, 33 third lens unit, 34 fourth lens unit, 40 imaging unit, 60 lens drive unit, 61 ultrasonic motor, 62 contact unit, 63 laminated body, 63A first piezoelectric element, 63B second piezoelectric element, 63C storage unit, 80 shaft unit, 90 storage unit, 91 case, 91A hole, 91B mounting unit, 92 electrode unit, 92A first electrode, 92B connection unit, 92C second electrode, 92D hole, 93 energizing unit, 93A main body unit, 93B mounted unit, 93C Pressurized portion, 93D hole, 94 rolling portion, 94A ball member, 95 guide portion, 951 guide holding portion, 951A recess, 951B guide recess, 951C hole, 952 guide support portion, 953 partition portion

Claims

1. An optical element driving device comprising: a movable part that houses an optical element; a drive part having an ultrasonic motor including a laminate in which a plurality of plate-like elements including piezoelectric elements are stacked, and that drives the movable part in a predetermined direction; and a shaft part extending in the predetermined direction and arranged opposite the laminate, wherein the drive part has two contact parts that contact the laminate and the shaft part and are arranged on the laminate so as to sandwich the shaft part.

2. The optical element driving device according to claim 1, wherein a plurality of contact groups each made up of the two contact portions are arranged in the predetermined direction.

3. The optical element driving device according to claim 1, wherein the laminate has a housing portion for housing the contact portion at a portion facing the shaft portion.

4. The optical element driving device according to claim 3, wherein a through hole is formed in at least a surface layer of the laminate, and at least a part of the housing portion is a space portion of the through hole.

5. The optical element driving device according to claim 4, wherein the laminate includes a first piezoelectric element having the through hole formed therein, and a second piezoelectric element including an electrode portion.

6. The optical element driving device according to claim 1, wherein the contact surface of the contact portion with the shaft portion is configured to be spherical.

7. The optical element driving device according to claim 1, further comprising a rollable rolling portion arranged to sandwich the shaft portion between the rolling portion and the contact portion.

8. The optical element driving device according to claim 7, further comprising a guide portion for guiding the rolling of said rolling portion.

9. An optical element driving device as described in claim 8, wherein the rolling portion has a plurality of ball members, and the guide portion of the guide portion for the plurality of ball members includes an area where the ball members face the shaft portion, and is configured so that the plurality of ball members roll while rotating.

10. The optical element driving device according to claim 9, wherein the guide portion has a partition portion configured to separate an area where the ball member faces the shaft portion from an area where the ball member does not face the shaft portion.

11. The optical element driving device according to claim 7, wherein a surface of the shaft portion facing the contact portion is configured to be flat, and a surface of the shaft portion facing the rolling portion is configured to be arcuate.

12. A camera module comprising: an optical element driving device according to claim 1; an element section including an optical element held by the movable section; and an imaging section that captures a subject image formed by the element section.

13. A camera-equipped device which is an information device or a transport device, comprising: a camera module according to claim 12; and an imaging control unit which processes image information obtained by the camera module.

Images