Drive device, camera module, and camera-equipped device

Abstract

This drive device has: a movable part made of a magnetic material; an ultrasonic motor including a laminate in which a plurality of plate-shaped elements including a piezoelectric element are stacked; and a contact part that contacts the laminate and the movable part, and is provided with a drive part that drives the movable part in a predetermined direction, and a magnet part that is arranged at a position other than between the laminate and the movable part and is magnetized to bias the movable part toward the contact part.

Description

Drive Device, Camera Module, and Camera-Mounted Device

[0001] The present invention relates to a drive device, a camera module, and a camera-mounted device.

[0002] Conventionally, a camera module mounted on a thin camera-mounted device such as a smartphone is known. Such a camera module is known to include a drive device having a zoom function for enlarging or reducing a subject image.

[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 the light bent by the fixed lens is incident, and a lens driving unit that moves the two movable lenses in the direction of the optical axis.

[0004] Further, from the perspective of miniaturizing the drive 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 composite resonance type ultrasonic motor in which a plurality of piezoelectric elements are laminated is known (see, for example, Patent Document 2). Such an ultrasonic motor can move a movable lens by simultaneously generating two types of resonances (flexural resonance and longitudinal resonance).

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

[0006] By the way, in such an ultrasonic motor, in order to appropriately transmit the vibration of the ultrasonic motor to the movable part, it is preferable to stabilize the contact state between the part (contact part) that transmits the vibration of the ultrasonic motor to the movable part and the movable part. Further, in order to stabilize the contact state between the contact part and the movable part, for example, a configuration in which the movable part is pressed toward the contact part from the side opposite to the contact part side can be considered. However, with such a configuration, the frictional resistance between the part that presses the movable part and the movable part increases, and as a result, there is a possibility that the operation of the movable part cannot be made smooth.

[0007] An object of the present invention is to provide a drive device, a camera module, and a camera-mounted device capable of stabilizing the contact state between a contact part and a movable part and making the operation of the movable part smooth.

[0008] The drive device according to the present invention comprises: a movable part made of a magnetic material; an ultrasonic motor including a laminate in which a plurality of plate-shaped elements including a piezoelectric element are stacked; a drive unit having a contact part that contacts the laminate and the movable part, and driving the movable part in a predetermined direction; and a magnet part disposed at a position other than between the laminate and the movable part, and magnetized to bias the movable part toward the contact part.

[0009] The camera module according to the present invention comprises the above-mentioned drive device, an element unit including an optical element held in the movable part, and an imaging unit that captures an image of a subject formed by the element unit.

[0010] The camera-mounted device according to the present invention is a camera-mounted device which is an information device or a transport device, and comprises the above-mentioned camera module and an imaging control unit which processes image information obtained by the camera module.

[0011] According to the present invention, the contact state between the contact part and the movable part can be stabilized.

[0012] This is a diagram showing a smartphone equipped with a camera module. This is a diagram showing a smartphone equipped with a camera module. This is a simplified diagram showing a camera module according to an embodiment of the present invention. This is a simplified diagram showing a side view of the camera module according to this embodiment. This is a perspective view showing the lens drive unit and shaft unit. This is an exploded perspective view of the lens drive unit. This is a perspective view of the case. This is a cross-sectional view of the contact portion of the drive unit and shaft unit. This is a view of the contact portion and shaft unit from the - side in the X direction. This is a diagram showing the electrode portion arranged on the yoke. This is a diagram for explaining the positional relationship between the ultrasonic motor, electrode portion, magnet portion and yoke. This is a diagram showing the arrangement of the yoke in the case. This is a diagram for explaining the magnetic circuit formed by the shaft portion, magnet portion and yoke. This is a diagram showing an automobile equipped with a camera module. This is a diagram showing an automobile equipped with a camera module.

[0013] Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. Figure 2 is a simplified diagram showing a camera module 1 according to the first embodiment of the present invention. Figure 3 is a simplified diagram showing a side view of the camera module 1 according to the first embodiment.

[0014] Camera module 1 is mounted on thin camera-equipped devices such as smartphones M (see Figures 1A and 1B), mobile phones, digital cameras, notebook computers, tablet devices, portable game consoles, and in-car cameras.

[0015] In describing the structure of the camera module 1 in this embodiment, we will use a Cartesian coordinate system (X, Y, Z). The same Cartesian coordinate system (X, Y, Z) will also be used in the figures described later. When the camera module 1 is actually mounted on the camera-mounted device, for example, 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. Light from the subject enters the camera module 1 from the Z-direction + side, bends from the entry point, and is guided to the Y-direction + side. By reducing the thickness of the camera module 1 in the Z direction, the camera-mounted device can be made thinner.

[0016] As shown in Figure 2, the camera module 1 comprises 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), ROM (Read Only Memory), RAM (Random Access Memory), etc. The CPU reads a program corresponding to the processing content from the ROM, loads it into the RAM, and works in cooperation with the loaded program to centrally control the lens drive unit 60. As a result, the drive control unit 100 drives the lens unit 30 housed in the housing 10. Consequently, the camera module 1 performs stepless optical zoom and autofocus. The housing 10, lens drive unit 60, shaft unit 80, and drive control unit 100 correspond to the "drive device" of the present invention.

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

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

[0020] The reflected light L2 that enters the housing 10 is output to the imaging unit 40 via the lens unit 30 housed within the housing 10.

[0021] The imaging unit 40 is positioned on the outer surface of the housing 10 on the positive side in the Y direction, and is configured to receive reflected light L2 through the lens unit 30. The imaging unit 40 includes an image sensor and a substrate (not shown).

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

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

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

[0025] The lens section 30 is located in a region within the housing 10 through which the reflected light L2 from the reflection drive unit 20 passes. The lens section 30 has a first lens unit 31, a second lens unit 32, a third lens unit 33, and a fourth lens unit 34 arranged 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.

[0026] The first lens unit 31 is positioned at the upstream end in the incident direction of reflected light L2 (towards the positive side of the Y direction) and is fixed to the housing 10.

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

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

[0029] The second lens unit 32 and the third lens unit 33 may be configured to be guided to move in the Y direction by a guide axis extending in the Y direction, or they may be configured to be movable on a rail extending in the Y direction.

[0030] The fourth lens unit 34 is positioned at the downstream end 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 to the housing 10 during the manufacturing of the drive unit, or they may be assembled to the housing 10 when the camera module 1 is manufactured from the lens drive unit 60.

[0032] The lens drive unit 60 is provided in correspondence with the second lens unit 32 and the third lens unit 33, respectively, and independently moves either the corresponding second lens unit 32 or the third lens unit 33 under the control of the drive control unit 100 described above. The lens drive unit 60 is positioned in the area between the positive side wall of the housing 10 in the X direction and the lens unit, and in the area between the negative side wall of the housing 10 in the X direction and the lens unit. In other words, one lens drive unit 60 is provided on each side of the optical axis in the housing 10.

[0033] In this embodiment, the lens drive unit 60 on the positive side in the X direction drives the second lens unit 32 in the Y direction, and the lens drive unit 60 on the negative side in the X direction drives the third lens unit 33 in the Y direction.

[0034] Since each lens drive unit 60 has substantially the same shape in this embodiment, unless otherwise specified, the following description will only describe the lens drive unit 60 corresponding to the second lens unit 32, and the description of the lens drive unit 60 corresponding to the third lens unit 33 will be omitted. Also, since each lens drive unit 60 is arranged symmetrically in the X and Y directions in this embodiment, the relationship between the positive and negative directions in the lens drive unit 60 corresponding to the third lens unit 33 is the opposite of the relationship between the positive and negative directions in the lens drive unit 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] As shown in Figure 4, the lens drive unit 60 is positioned opposite the shaft unit 80. The shaft unit 80 is an axial member extending in the Y direction and is supported by the housing 10. The shaft unit 80 is made of a magnetic material and holds the movable lens via a frame that supports the movable lens. The lens drive unit 60 drives the movable lens in the Y direction by driving the shaft unit 80 in the Y direction. The shaft unit 80 corresponds to the "movable part" of the present invention.

[0036] The lens drive unit 60 includes a case 61, an ultrasonic motor 62, a contact portion 63, an electrode portion 64, a magnet portion 65, and a yoke 66.

[0037] As shown in Figure 5, the case 61 is a case for housing the ultrasonic motor 62, the contact portion 63, the electrode portion 64, the magnet portion 65, and the yoke 66. The case 61 consists of four side walls that surround the ultrasonic motor 62, the contact portion 63, the electrode portion 64, the magnet portion 65, and the yoke 66.

[0038] As shown in Figure 6, of the four side walls of the case 61, two placement sections 611 for positioning the yoke 66 are provided at the X-side ends of the two side walls on both sides in the Z direction. In addition, of the four side walls of the case 61, recesses 612 are formed at the X-side ends of the two side walls on both sides in the Y direction for positioning the convex portion 664 of the yoke 66.

[0039] As shown in FIGS. 4 and 5, the ultrasonic motor 62 has a composite resonance structure and is disposed within the case 61. The ultrasonic motor 62 is composed of a laminate 621 formed by stacking a plurality of piezoelectric elements each formed of a rectangular plate-like element. As shown in FIG. 7, a through-hole is formed in the first piezoelectric element 621A of the first layer from the + side in the X direction among the piezoelectric elements constituting the laminate 621.

[0040] Further, the second piezoelectric element 621B other than the first piezoelectric element 621A in which the through-hole is formed includes an electrode. Among the plurality of second piezoelectric elements 621B, the first second piezoelectric element 621B from the - side in the X direction is arranged to contact the electrode portion 64 (see also FIG. 10).

[0041] As a result, the electrode of the second piezoelectric element 621B is connected to the electrode portion 64, so that when the second piezoelectric element 621B is energized by the electrode portion 64, vibration is generated. Specifically, two types of vibrations, namely, vibration in the Y direction (flexural resonance) and vibration in the X direction (tensile-compressive resonance), are simultaneously generated in the second piezoelectric element 621B.

[0042] Further, the first piezoelectric element 621A in which the through-hole is formed does not include an electrode and serves as a dummy element not used for driving.

[0043] The space portion formed by the through-hole portion of the first piezoelectric element 621A and the second piezoelectric element 621B constitutes the accommodating portion 621C.

[0044] The accommodating portion 621C is a space for accommodating the contact portion 63 and is provided in four in the first piezoelectric element 621A. The four accommodating portions 621C are located at positions corresponding to the four vertices of a rectangle centered on the center point of the first piezoelectric element 621A (see also FIG. 8).

[0045] Further, the laminate 621 is arranged such that the surface on the accommodating portion 621C side is located on the + side in the X direction, and the short sides of the rectangle formed by the four accommodating portions 621C are arranged to be parallel to the Z direction.

[0046] As shown in FIGS. 7 and 8, the contact portion 63 is, for example, a spherical member made of a metal such as ceramic, and is housed in each housing portion 621C so as to contact the laminate 621 (the second piezoelectric element 621B in the housing portion 621C) and the shaft portion 80. The contact portion 63 is adhered in the housing portion 621C by, for example, an adhesive or the like.

[0047] A total of four contact portions 63 are provided corresponding to the four housing portions 621C. Of the four contact portions 63, two contact portions 63 arranged in the Z direction are also referred to as a contact portion group. In the present embodiment, since the contact portion 63 is housed in each of the four housing portions 621C arranged as described above, two contact portion groups are arranged side by side in the Y direction.

[0048] Further, the position of the central axis of the shaft portion 80 in the Z direction is a position sandwiched by the two contact portions 63 of each contact portion group. In other words, the two contact portions 63 are arranged on the laminate 621 so as to sandwich the shaft portion 80 in the Z direction.

[0049] Specifically, the two contact portions 63 are arranged in a range overlapping the shaft portion 80 when viewed from the X direction, and are arranged at symmetric positions sandwiching the axis of the central axis of the shaft portion 80. Thereby, the two contact portions 63 are arranged so that the contact pressure (forces in the X direction component and the Z direction component) with the shaft portion 80 becomes equal to each other.

[0050] As shown in FIG. 9, the electrode portion 64 is an electrode for energizing the ultrasonic motor 62, and includes a first electrode 64A, a connection portion 64B, and a second electrode 64C. The first electrode 64A is an electrode that contacts a substrate (not shown) of the camera module 1. The connection portion 64B is a portion that connects the first electrode 64A and the second electrode 64C.

[0051] As shown in FIGS. 9 and 10, the second electrode 64C is an electrode that contacts the - side surface in the X direction of the second piezoelectric element 621B of the ultrasonic motor 62, and is a portion arranged in the case 61 in the electrode portion 64. Further, the first electrode 64A and the connection portion 64B are arranged outside the case 61 through the concave portion 612 of the case 61.

[0052] When the second piezoelectric element 621B is energized via the electrode portion 64, two types of vibrations are generated simultaneously, causing vibrations in the contact portion 63 that trace an elliptical trajectory tilted in an oblique direction (a direction having X-direction components and Y-direction components). Due to these vibrations, an oblique frictional force acts between the contact portion 63 and the shaft portion 80, making it possible to impart thrust from the ultrasonic motor 62 to the frame in the direction of the optical axis (Y-direction). This makes it possible to move the movable lens in the Y-direction via the shaft portion 80.

[0053] The magnet section 65 consists of two magnets 651 that are magnetized to bias a shaft section 80, which is made of a magnetic material, toward the contact section 63, thereby biasing the shaft section 80 toward the contact section 63 (the negative side in the X direction). Each of the two magnets 651 is positioned on the yoke 66 so as to face the shaft section 80 in the X direction. Each of the two magnets 651 is configured as a rectangular parallelepiped with a length in the Z direction and a thickness in the X direction that is approximately the same as that of the laminate 621.

[0054] In this way, the arrangement of the magnet portion 65 allows the shaft portion 80 to be attracted towards the magnet portion 65 side (the negative side in the X direction) by magnetic force. As a result, the shaft portion 80 and the contact portion 63 can be brought into contact under pre-pressurized conditions, thereby stabilizing the contact state between the shaft portion 80 and the contact portion 63.

[0055] The two magnets 651 are positioned in the Y direction so as to sandwich the ultrasonic motor 62. A gap is left between each magnet 651 and the ultrasonic motor 62 so that the vibrating laminate 621 and the magnet 651 do not interfere with each other.

[0056] With each magnet 651 arranged in this manner, the shaft portion 80 can be attracted from both sides in the Y direction of the laminate 621 by each magnet 651. As a result, the pressure between the shaft portion 80 and the contact portion 63 is suppressed from being biased to one side in the Y direction, and consequently, the pressure can be made uniform throughout the entire Y direction.

[0057] The yoke 66 is positioned on the opposite side of the shaft portion 80 from the two magnets 651, thereby covering the openings of the four side walls of the case 61 from the X-side (see also Figure 11). The yoke 66 is rectangular in shape and has a length approximately equal to the sum of the lengths of the two magnets 651 and the laminate 621 in the Y-direction.

[0058] On the positive side of the yoke 66 in the X direction, there are arrangement sections 661 for arranging two magnets 651. The arrangement sections 661 are provided at each of the four corners of the rectangle of the yoke 66 and protrude more than the other surfaces 662 of the yoke 66.

[0059] Furthermore, the second electrode 64C of the electrode portion 64 described above is positioned on the surface 662 of the yoke 66 other than the arrangement portion 661. The connection portion 64B of the electrode portion 64 is positioned so that it passes between the two arrangement portions 661 on the negative side in the Y direction of the four arrangement portions 661.

[0060] Furthermore, as shown in Figure 11, a recess 663 is provided on the negative side of the yoke 66 in the X direction. The recesses 663 are located at the locations corresponding to the four placement sections 611 of the case 61 described above. By placing each recess 663 at each placement section 611, the yoke 66 is positioned in the case 61.

[0061] Each of the end faces on both sides of the yoke 66 in the Y direction is provided with a protrusion 664. The protrusions 664 are positioned to correspond to the recesses 612 of the case 61 and are designed to engage with the recesses 612 when the yoke 66 is installed on the case 61.

[0062] With the yoke 66 positioned in this way, as shown in Figure 12, the shaft portion 80, the two magnets 651, and the yoke 66 surround the ultrasonic motor 62. Since each of the shaft portion 80, the two magnets 651, and the yoke 66 is a magnetic material, a magnetic circuit M is formed surrounding the ultrasonic motor 62. In other words, the yoke 66 forms a magnetic circuit M between the shaft portion 80 and the two magnets 651. The magnetic circuit M is a magnetic path formed by combining the shaft portion 80, the two magnets 651, and the yoke 66.

[0063] This makes it easier for the magnetic flux generated from the magnet 651 to pass through the magnetic circuit M, thus suppressing the generation of magnetic flux outside the magnetic circuit M, that is, outside the camera module 1. In other words, in this embodiment, by providing the yoke 66, the magnetic flux directed in unwanted directions can be reduced, so that the shaft portion 80 can be efficiently attracted to the magnet 651.

[0064] According to this embodiment configured as described above, the shaft portion 80 can be attracted to the magnet portion 65 by the magnetic force of the magnet portion 65. As a result, the shaft portion 80 and the contact portion 63 can be brought into contact under pressure, thereby stabilizing the contact state between the shaft portion 80 and the contact portion 63.

[0065] By the way, in order to stabilize the contact state between the contact portion 63 and the shaft portion 80, one could consider a configuration in which the shaft portion is pressed toward the contact portion from the opposite side of the contact portion. However, with this configuration, the frictional resistance between the part pressing the shaft portion and the shaft portion increases, which may prevent the shaft portion from moving smoothly.

[0066] In contrast, in this embodiment, the magnetic force of the magnet portion 65 can bias the shaft portion 80 toward the contact portion 63, so there is no part that presses against the shaft portion 80. In other words, there is no part that contacts the surface of the shaft portion 80 opposite to the contact portion 63, so the above-mentioned frictional resistance does not occur. As a result, the operation of the shaft portion 80 can be made smoother.

[0067] In other words, in this embodiment, the contact state between the contact portion 63 and the shaft portion 80 can be stabilized, and the operation of the shaft portion 80 can be made smoother.

[0068] Furthermore, since the two magnets 651 are positioned to sandwich the ultrasonic motor 62, the shaft portion 80 can be attracted from both sides of the laminate 621 in the Y direction by the magnets 651. As a result, the pressure between the shaft portion 80 and the contact portion 63 is suppressed from being biased to one side in the Y direction, and consequently, the pressure can be made uniform throughout the entire Y direction.

[0069] Furthermore, since the yoke 66 forms a magnetic circuit M between the shaft portion 80 and the two magnets 651, the magnetic flux generated from the magnets 651 can easily pass through the magnetic circuit M. As a result, the magnetic flux directed in unwanted directions outside the magnetic circuit M can be reduced, allowing the shaft portion 80 to be efficiently attracted to the magnets 651.

[0070] In the above embodiment, the magnet section 65 had two magnets 651, but the present invention is not limited to this. For example, the number of magnets 651 may be two or more, as long as at least two magnets 651 are arranged to sandwich the laminate 621.

[0071] Furthermore, although the above embodiment had two magnets 651 in the magnet section 65, the present invention is not limited to this, and may have a configuration with, for example, one magnet.

[0072] Furthermore, in the above embodiment, the two magnets 651 (magnet portion 65) were arranged so as to sandwich the laminate 621, but the present invention is not limited to this. For example, the magnet portion may be positioned anywhere (for example, on the negative side of the X direction from the laminate 621) as long as it is not between the laminate 621 and the shaft portion 80.

[0073] Furthermore, although a yoke 66 was provided in the above embodiment, the present invention is not limited thereto, and a yoke may not be provided.

[0074] Furthermore, although the above embodiment provided two contact groups, the present invention is not limited thereto, and may provide three or more contact groups, or only one contact group.

[0075] Furthermore, although the contact portion 63 was housed in the housing portion 621C in the above embodiment, the present invention is not limited thereto, and for example, it may be bonded to the surface of the first layer piezoelectric element of the laminate 621. In this case, the first layer piezoelectric element does not have to be a dummy element.

[0076] Furthermore, although the laminate in the above embodiment was composed of a first piezoelectric element and a second piezoelectric element, the present invention is not limited thereto and may include elements other than piezoelectric elements.

[0077] Furthermore, in the above embodiment, the contact surface between the contact portion and the shaft portion was configured in a spherical shape, but the present invention is not limited to this, and it does not have to be configured in a spherical shape.

[0078] Furthermore, although the above embodiment provided separate drive control units, reflection drive control units, and imaging control units, the present invention is not limited thereto, and at least two of the drive control units, reflection drive control units, and imaging control units may be composed of a single control unit.

[0079] Furthermore, for example, in the above embodiment, a smartphone, which is a mobile terminal with a camera, was described as an example of a camera-mounted device equipped with a camera module 1. However, 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. Camera-mounted devices include information equipment and transportation equipment. Information equipment includes, for example, mobile phones with cameras, notebook computers, tablet terminals, portable game consoles, webcams, drones, and in-vehicle devices with cameras (e.g., rearview monitors, drive recorders). Transportation equipment includes, for example, automobiles and drones.

[0080] Figures 13A and 13B show a vehicle V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). Figure 13A is a front view of the vehicle V, and Figure 13B is a rear perspective view of the vehicle V. The vehicle V is equipped with the camera module 1 described in the embodiment as the in-vehicle camera module VC. As shown in Figures 13A and 13B, the in-vehicle camera module VC can be mounted, for example, on the windshield facing forward or on the rear gate facing backward. This in-vehicle camera module VC is used for purposes such as a backup monitor, a drive recorder, collision avoidance control, and autonomous driving control.

[0081] Furthermore, the above embodiments are merely examples of how the present invention may be implemented, and the technical scope of the present invention should not be interpreted as being limited by them. In other words, the present invention can be implemented in various forms without departing from its gist or its main features. For example, the shape, size, number, and material of each part described in the above embodiments are merely examples and can be modified as appropriate.

[0082] The drive device according to the present invention is useful as a drive device, camera module, and camera mounting device that can stabilize the contact state between the contact part and the movable part.

[0083] All disclosures in the specification, drawings, and abstract contained in the Japanese application No. 2024-219721, filed on 16 December 2024, are incorporated herein by reference.

[0084] 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 Case, 62 Ultrasonic motor, 63 Contact unit, 64 Electrode unit, 64A First electrode, 64B Connection unit, 64C Second electrode, 65 Magnet unit, 66 Yoke, 80 Shaft unit, 611 Arrangement unit, 612 Recess, 621 Laminate, 621A First piezoelectric element, 621B Second piezoelectric element, 621C Housing unit, 651 Magnet, 661 Arrangement unit, 662 Surface, 663 Recess 664 Convex part

Claims

1. A drive device comprising: a movable part made of a magnetic material; an ultrasonic motor including a laminate in which a plurality of plate-shaped elements including a piezoelectric element are stacked; a drive unit having a contact part that contacts the laminate and the movable part, and driving the movable part in a predetermined direction; and a magnet part disposed at a position other than between the laminate and the movable part, and magnetized to bias the movable part toward the contact part.

2. The drive device according to claim 1, wherein the magnet portion has at least two magnets arranged so as to sandwich the laminate.

3. The drive device according to claim 2, further comprising a yoke that is positioned on the opposite side of the movable part from the at least two magnets, thereby forming a magnetic circuit between the movable part and the at least two magnets.

4. A camera module comprising: a drive device according to claim 1; an element unit including an optical element held by the movable part; and an imaging unit for capturing an image of a subject formed by the element unit.

5. A camera-mounted device which is an information device or a transport device, comprising: a camera module as described in claim 4; and an imaging control unit for processing image information obtained by the camera module.

Images