Optical unit, imaging device, and imaging system

Abstract

To provide an optical unit capable of, even when a rotational angle of a movable body having an optical module relative to a solid body movably holding the movable body is increased, facilitating movement of the movable body provided at an origin position relative to the solid body while suppressing the deterioration in drive force of a drive mechanism for rotating the movable body relative to the solid body.SOLUTION: In an optical unit, a magnet-side opposed surface 24a of a driving magnet 24 is formed into an arc shape having the rotational center of a movable body as the center of curvature. Effective side part-side opposed surfaces 23d, 23e of effective side parts 23a, 23b of a driving coil 23 curved along the magnet-side opposed surface 24a are substantially orthogonal to a radial direction having the rotational center of the movable body as the center. The driving magnet 24 is magnetized in such a manner that magnetic lines F1, F2 passing through the centers of the effective side part-side opposed surfaces 23d, 23e are substantially orthogonal to the effective side part-side opposed surfaces 23d, 23e when viewed from a Z direction in such a state that the movable body is provided at an origin position.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an optical unit including a movable body having an optical module such as a camera module, and a fixed body that rotatably holds the movable body. The present invention also relates to a photographing apparatus and a photographing system including such an optical unit.

Background Art

[0002] Conventionally, an optical unit with an image stabilization function for correcting the shake of an optical image is known (see, for example, Patent Document 1). The optical unit with an image stabilization function described in Patent Document 1 includes a movable body that holds an optical module, a fixed body that holds the movable body, a magnetic drive mechanism that rotates the movable body with respect to the fixed body, and a plate-shaped spring member that connects the movable body and the fixed body. The magnetic drive mechanism includes a plate-shaped magnet and a coil facing the magnet.

[0003] In the optical unit with an image stabilization function described in Patent Document 1, the fixed body holds the movable body via a gimbal mechanism, and the movable body can rotate with respect to the fixed body about an X-axis direction orthogonal to the optical axis direction of the optical module as a rotation axis direction, and about a Y-axis direction orthogonal to both the optical axis direction and the X-axis direction as a rotation axis direction. The spring member functions to define the posture of the movable body with respect to the fixed body when the magnetic drive mechanism is at rest. When the magnetic drive mechanism is at rest, the movable body is arranged at a predetermined origin position (reference position) with respect to the fixed body by the biasing force of the spring member.

[0004] In the optical unit with an image stabilization function described in Patent Document 1, for example, the opposing surface of the magnet facing the coil is a convex curved surface, and the opposing surface of the coil facing the magnet is a concave curved surface. Therefore, in this optical unit with an image stabilization function, even when the rotation angle of the movable body with respect to the fixed body increases, it is possible to keep the distance between the magnet and the coil constant. As a result, even when the rotation angle of the movable body with respect to the fixed body increases, it is possible to suppress a decrease in the driving force of the magnetic drive mechanism.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the optical unit with an image stabilization function described in Patent Document 1, as described above, even when the rotation angle of the movable body with respect to the fixed body increases, it is possible to suppress a decrease in the driving force of the magnetic drive mechanism. Further, in the case of this optical unit with an image stabilization function, when the magnetic drive mechanism is stopped, the movable body is arranged at the origin position, and the movable body often moves out from the origin position with respect to the fixed body. Therefore, in this optical unit with an image stabilization function, it is preferable that the movable body arranged at the origin position is more easily movable with respect to the fixed body.

[0007] Therefore, an object of the present invention is to provide an optical unit including a movable body having an optical module, a fixed body that rotatably holds the movable body, and a drive mechanism that rotates the movable body with respect to the fixed body, which can suppress a decrease in the driving force of the drive mechanism even when the rotation angle of the movable body with respect to the fixed body increases, and can make the movable body arranged at a predetermined origin position more easily movable with respect to the fixed body. Another object of the present invention is to provide a photographing apparatus and a photographing system including such an optical unit.

Means for Solving the Problems

[0008] In order to solve the above problems, the optical unit of the present invention includes a movable body having an optical module, a fixed body that rotatably holds the movable body, and a drive mechanism that rotates the movable body with respect to the fixed body with a first direction orthogonal to the optical axis of the optical module as the axial direction of rotation. The drive mechanism includes a drive coil wound in a hollow shape and a drive magnet disposed opposite to the drive coil in a radial direction centered on the rotation center of the movable body with respect to the fixed body. The magnet-side opposing surface, which is the opposing surface of the drive magnet facing the drive coil, is formed in an arc shape with the rotation center of the movable body as the center of curvature when viewed from the first direction. The drive coil includes a pair of effective side portions parallel to the first direction and is bent along the magnet-side opposing surface having an arc shape when viewed from the first direction. The pair of effective side portions are arranged at intervals in the circumferential direction centered on the rotation center of the movable body. When viewed from the first direction, the effective-side opposing surface, which is the opposing surface of the effective side portion facing the magnet-side opposing surface, is substantially orthogonal to the radial direction centered on the rotation center of the movable body. The drive magnet is magnetized such that the magnetic field lines passing through the center of the effective-side opposing surface are substantially orthogonal to the effective-side opposing surface when viewed from the first direction with the movable body disposed at a predetermined origin position with respect to the fixed body.

[0009] In the optical unit of the present invention, the magnet-side opposing surface, which is the opposing surface of the drive magnet facing the drive coil, is formed in an arc shape with the rotation center of the movable body as the center of curvature when viewed from the first direction. The drive coil includes a pair of effective side portions parallel to the first direction and is bent along the magnet-side opposing surface having an arc shape when viewed from the first direction. Further, in the present invention, when viewed from the first direction, the effective-side opposing surface, which is the opposing surface of the effective side portion facing the magnet-side opposing surface, is substantially orthogonal to the radial direction centered on the rotation center of the movable body. Therefore, in the present invention, even when the rotation angle of the movable body with respect to the fixed body increases, it is possible to keep the distance between the magnet-side opposing surface of the drive magnet and the effective-side opposing surface of the drive coil constant. Accordingly, in the present invention, even when the rotation angle of the movable body with respect to the fixed body increases, it is possible to suppress a decrease in the driving force of the drive mechanism.

[0010] In the present invention, when the movable body is disposed at a predetermined origin position with respect to the fixed body, when viewed from the first direction, the drive magnet is magnetized such that the magnetic field lines passing through the center of the effective side facing surface that is substantially orthogonal to the radial direction centered on the rotation center of the movable body are substantially orthogonal to the effective side facing surface. Therefore, in the present invention, when a current is supplied to the drive coil in a state where the movable body is disposed at the origin position, it is possible to increase the driving force acting in the tangential direction of the magnet side facing surface of the drive mechanism. Accordingly, in the present invention, it is possible to make it easier to move the movable body disposed at the origin position with respect to the fixed body.

[0011] In the present invention, one of the pair of effective sides is defined as the first effective side, the other effective side is defined as the second effective side, the effective side facing surface of the first effective side is defined as the first effective side facing surface, and the effective side facing surface of the second effective side is defined as the second effective side facing surface. For example, the drive magnet includes a first magnet portion disposed on the first effective side in the circumferential direction centered on the rotation center of the movable body, and a second magnet portion disposed on the second effective side in the circumferential direction centered on the rotation center of the movable body. The magnetic poles of the magnet side facing surface of the first magnet portion and the magnetic poles of the magnet side facing surface of the second magnet portion are different magnetic poles. The first magnet portion is magnetized such that the magnetic field lines passing through the first effective side facing surface are substantially orthogonal to the first effective side facing surface in a state where the movable body is disposed at the origin position with respect to the fixed body. The second magnet portion is magnetized such that the magnetic field lines passing through the second effective side facing surface are substantially orthogonal to the second effective side facing surface in a state where the movable body is disposed at the origin position with respect to the fixed body.

[0012] In this case, even if the shape of the drive magnet is a complex shape, it is possible to magnetize the drive magnet relatively easily as compared with the case where the first magnet portion and the second magnet portion are magnetized such that the magnetic field lines form a radial shape centered on the rotation center of the movable body.

[0013] In the present invention, the optical unit includes, for example, a position holding mechanism for maintaining the state where the movable body is disposed at the origin position.

[0014] In the present invention, for example, the drive magnet is fixed to the movable body, the drive coil is fixed to the fixed body, and is disposed outside the drive magnet in the radial direction centered on the rotation center of the movable body.

[0015] In the present invention, the movable body preferably includes a defining member for defining the rotation center of the movable body. The drive magnet is formed with a positioning recess for positioning the drive magnet with respect to the movable body, and the defining member is formed with an engaging portion that engages with the positioning recess to position the drive magnet with respect to the movable body. With this configuration, since the drive magnet is positioned with respect to the movable body by the direct engagement of the defining member for defining the rotation center of the movable body with the drive magnet, it is possible to suppress displacement of the drive magnet with respect to the rotation center of the movable body. Therefore, even if the distance between the magnet-side facing surface of the drive magnet and the effective-side facing surface of the drive coil is short, it is possible to prevent interference between the magnet-side facing surface and the effective-side facing surface when the movable body rotates with respect to the fixed body.

[0016] In the present invention, for example, the optical module is a camera module, and the positioning recess is formed at the center of the surface of the drive magnet on the movable body side. In this case, it is possible to weaken the magnetic flux at the center portion of the surface of the drive magnet on the movable body side. Therefore, for example, even if the camera module includes a magnetic drive mechanism for autofocus, it is possible to suppress magnetic interference between this magnetic drive mechanism and the drive mechanism of the optical unit.

[0017] In the present invention, on the fixed body, protective wall portions are formed on both sides of the drive coil in the circumferential direction centered on the rotation center of the movable body, and it is preferable that the protective wall portions are arranged on the drive magnet side rather than the drive coil in the radial direction centered on the rotation center of the movable body. With such a configuration, for example, even if an impact is applied to the optical unit, an excessive force acts on the movable body, and the movable body moves relative to the fixed body, it is possible to prevent contact between the drive magnet and the drive coil. Therefore, even if an excessive force acts on the movable body and the movable body moves relative to the fixed body, it is possible to prevent damage to the drive magnet and the drive coil.

[0018] In the present invention, the optical unit includes, for example, an inertial sensor attached to the fixed body, and the drive mechanism rotates the movable body based on the detection result of the inertial sensor. In this case, based on the detection result of the inertial sensor, it becomes possible to rotate the movable body so that the optical module faces in the direction in which the fixed body is tilted.

[0019] The optical unit of the present invention can be used, for example, in an in-vehicle imaging device. In this imaging device, the optical module is a camera module. That is, the optical unit of the present invention can be used, for example, in a drive recorder. In this imaging device (drive recorder), based on the detection result of the inertial sensor, it becomes possible to rotate the movable body so that the optical axis direction of the camera module always faces the traveling direction of the vehicle. Therefore, for example, it becomes possible to acquire an image of the traveling direction of the vehicle while the vehicle is turning at an intersection. As a result, for example, even if a collision accident occurs after the vehicle turns at an intersection, it becomes possible to grasp the situation from a little before the accident occurs to the occurrence of the accident based on the image acquired by the imaging device.

[0020] The optical unit of the present invention can be used, for example, in an in-vehicle imaging device including an inertial sensor disposed outside the optical unit and a control unit to which the inertial sensor and a drive coil are electrically connected. In this imaging device, the optical module is a camera module, and the control unit controls the current supplied to the drive coil based on the detection result of the inertial sensor to rotate a movable body.

[0021] That is, the optical unit of the present invention can be used, for example, in a drive recorder. In this imaging device, based on the detection result of the inertial sensor, it becomes possible to rotate the movable body so that the optical axis direction of the camera module always faces the traveling direction of the vehicle. Therefore, for example, it becomes possible to acquire an image of the traveling direction of the vehicle while the vehicle is turning at an intersection. As a result, for example, even if a collision accident occurs after the vehicle turns at an intersection, it becomes possible to grasp the situation from a little before the accident occurs to the occurrence of the accident based on the image acquired by the imaging device.

[0022] The optical unit of the present invention can be used, for example, in an imaging system including an in-vehicle imaging device having this optical unit and a steering angle detector that detects the steering angle of the vehicle. In this imaging system, the optical module is a camera module, the imaging device includes a control unit to which the steering angle detector and a drive coil are electrically connected, and the control unit controls the current supplied to the drive coil based on the detection result of the steering angle detector to rotate a movable body.

[0023] That is, the optical unit of the present invention can be used, for example, in a photographing system having a drive recorder. In this photographing system, based on the detection result of the steering angle detector, it becomes possible to rotate a movable body so that the optical axis direction of the camera module always faces the traveling direction of the vehicle. Therefore, for example, it becomes possible to acquire an image of the traveling direction of the vehicle while the vehicle is turning at an intersection. As a result, for example, even if a collision accident occurs after the vehicle turns at an intersection, it becomes possible to grasp the situation from a little before the accident occurs to the occurrence of the accident based on the image acquired by the photographing device.

Advantages of the Invention

[0024] As described above, in the present invention, in an optical unit including a movable body having an optical module, a fixed body that rotatably holds the movable body, and a drive mechanism that rotates the movable body with respect to the fixed body, even when the rotation angle of the movable body with respect to the fixed body increases, it becomes possible to suppress a decrease in the driving force of the drive mechanism, and it becomes possible to more easily move the movable body disposed at a predetermined origin position with respect to the fixed body.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0027] (Overall Configuration of the Optical Unit) FIG. 1 is a perspective view of an optical unit 1 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the optical unit 1 shown in FIG. 1. FIG. 3 is a plan view of the state where the cover 19 is removed from the optical unit 1 shown in FIG. 1.

[0028] In the following description, as shown in FIG. 1 and the like, each of the three mutually orthogonal directions is defined as the X direction, the Y direction, and the Z direction, the X direction is the left - right direction, the Y direction is the front - rear direction, and the Z direction is the up - down direction. Also, the X1 - direction side of FIG. 1 and the like, which is one side in the left - right direction, is the "left" side, the X2 - direction side of FIG. 1 and the like, which is the opposite side, is the "right" side, the Y1 - direction side of FIG. 1 and the like, which is one side in the front - rear direction, is the "front" side, the Y2 - direction side of FIG. 1 and the like, which is the opposite side, is the "rear" side, the Z1 - direction side of FIG. 1 and the like, which is one side in the up - down direction, is the "up" side, and the Z2 - direction side of FIG. 1 and the like, which is the opposite side, is the "down" side.

[0029] The optical unit 1 of this embodiment is a small and thin unit mounted on a mobile device such as a smartphone, and includes a camera module 2 having a lens for photography and an imaging device. The optical unit 1 is formed in a substantially rectangular parallelepiped shape that is flat and thin as a whole. The optical unit 1 includes a movable body 3 having the camera module 2, a fixed body 4 (see FIG. 1) that rotatably holds the movable body 3, a drive mechanism 5 that rotates the movable body 3 with respect to the fixed body 4, and two spherical balls 6, 7 that constitute a fulcrum for the rotation of the movable body 3 with respect to the fixed body 4. The camera module 2 of this embodiment is an optical module.

[0030] The optical axis L of the camera module 2 is orthogonal to the vertical direction. The movable body 3 is rotatable with respect to the fixed body 4 with the vertical direction orthogonal to the optical axis L of the camera module 2 as the axial direction of rotation. That is, the movable body 3 is rotatable with respect to the fixed body 4 about an axis L1 having the vertical direction as the axial direction as the center of rotation. The drive mechanism 5 rotates the movable body 3 with respect to the fixed body 4 with the vertical direction as the axial direction of rotation. For example, the drive mechanism 5 rotates the movable body 3 with respect to the fixed body 4 in order to correct the shake of the optical unit 1 during photography. Alternatively, the drive mechanism 5 rotates the movable body 3 with respect to the fixed body 4, for example, in order to perform panoramic photography. The vertical direction (Z direction) of this embodiment is the first direction orthogonal to the optical axis L of the camera module 2. Further, the vertical direction is the thickness direction of the optical unit 1.

[0031] In this embodiment, when a drive coil 23 (described later) that constitutes a part of the drive mechanism 5 is in a non-energized state and the movable body 3 is not rotated with respect to the fixed body 4, and the movable body 3 is disposed at a predetermined origin position (reference position) with respect to the fixed body 4, the direction (optical axis direction) of the optical axis L of the camera module 2 coincides with the front-rear direction. The movable body 3 is rotatable, for example, about 10° to 15° in each of the clockwise direction (hereinafter, this direction is referred to as the "clockwise direction") in FIG. 3 and the counterclockwise direction (hereinafter, this direction is referred to as the "counterclockwise direction") with respect to the origin position as a reference.

[0032] The movable body 3 is formed as a flat rectangular parallelepiped with a small thickness in the vertical direction as a whole. In addition to the camera module 2, the movable body 3 includes a frame 8 to which the camera module 2 is fixed and a magnetic plate 9 fixed to the frame 8. The camera module 2 is formed as a flat rectangular parallelepiped with a small thickness in the vertical direction. The upper surface, lower surface, rear surface, and side surfaces in the left-right direction of the camera module 2 are flat surfaces. The upper surface and the lower surface of the camera module 2 are orthogonal to the vertical direction. When the movable body 3 is disposed at the origin position, the side surfaces in the left-right direction of the camera module 2 are orthogonal to the left-right direction, and the rear surface of the camera module 2 is orthogonal to the front-rear direction.

[0033] The frame 8 is composed of a first frame 10 that covers the side surfaces and the lower surface in the left-right direction of the camera module 2 and a second frame 11 that covers the upper surface of the camera module 2. The first frame 10 and the second frame 11 are formed by bending a thin metal plate into a predetermined shape. The first frame 10 includes two side portions 10a that constitute the side surfaces in the left-right direction of the first frame 10 and a bottom portion 10b that constitutes the bottom surface of the first frame 10. The side portion 10a is formed as a rectangular flat plate. The thickness direction of the side portion 10a coincides with the left-right direction when the movable body 3 is disposed at the origin position.

[0034] The bottom portion 10b is formed as a rectangular flat plate. The thickness direction of the bottom portion 10b coincides with the vertical direction. A through hole 10c that penetrates the bottom portion 10b in the vertical direction is formed at the center of the bottom portion 10b. The through hole 10c is formed as a round hole. A ball 6 is disposed below the bottom portion 10b. The inner diameter of the through hole 10c is smaller than the outer diameter of the ball 6. The upper end portion of the ball 6 is disposed in the through hole 10c.

[0035] The second frame 11 includes an upper surface portion 11a formed in a rectangular flat plate shape, and two protruding portions 11b protruding outward in the left-right direction from the upper surface portion 11a. The thickness direction of the upper surface portion 11a coincides with the up-down direction. The upper surface portion 11a is fixed to the upper end of the first frame 10. A through hole 11c penetrating the upper surface portion 11a in the up-down direction is formed at the center portion of the upper surface portion 11a. The through hole 11c is formed in a round hole shape. A ball 7 is disposed above the upper surface portion 11a. The inner diameter of the through hole 11c is smaller than the outer diameter of the ball 7. The lower end portion of the ball 7 is disposed in the through hole 11c.

[0036] The through hole 11c is disposed at the same position as the through hole 10c in the horizontal direction, and when viewed from the up-down direction, the through hole 11c and the through hole 10c overlap. That is, the ball 6 and the ball 7 are disposed at the same position in the horizontal direction, and when viewed from the up-down direction, the ball 6 and the ball 7 overlap. The center of the ball 6 and the center of the ball 7 are disposed on the axis L1.

[0037] The protruding portion 11b is formed in an L shape in which the tip side portion of the protruding portion 11b bends downward at a right angle. The tip portion of the protruding portion 11b extending downward serves as an engaging portion 11d that engages with a positioning concave portion 24d of a driving magnet 24 described later, which constitutes a part of the driving mechanism 5. The engaging portion 11d is formed in a rectangular flat plate shape. The thickness direction of the engaging portion 11d coincides with the left-right direction when the movable body 3 is disposed at the origin position. The engaging portion 11d is disposed outside the side surface portion 10a in the left-right direction.

[0038] The magnetic plate 9 is composed of a magnetic material having magnetism. The magnetic plate 9 is formed in a rectangular flat plate shape thicker than the side surface portion 10a of the first frame 10 and the like. The magnetic plate 9 is fixed to the outer surface in the left-right direction of the side surface portion 10a. The thickness direction of the magnetic plate 9 coincides with the left-right direction when the movable body 3 is disposed at the origin position.

[0039] As described above, the camera module 2 includes a lens and an imaging device. The imaging device is disposed on the rear end side of the camera module 2, and a subject disposed on the front side of the camera module 2 is photographed by the camera module 2. The camera module 2 includes a circuit board 15 on which the imaging device is mounted. The circuit board 15 constitutes the rear surface of the camera module 2. Further, the camera module 2 of the present embodiment includes a magnetic drive mechanism for autofocus.

[0040] A flexible printed circuit board (FPC) 16 is drawn out from the circuit board 15 that constitutes the rear surface of the camera module 2. The FPC 16 is drawn out rearward from the central portion of the circuit board 15 in the left-right direction. Further, the FPC 16 is drawn out rearward from the central portion of the camera module 2 in the left-right direction and is also drawn out rearward from the central portion of the movable body 3 in the left-right direction. The FPC 16 drawn out rearward from the circuit board 15 is then routed leftward and then routed forward. The front end portion of the FPC 16 is fixed to a case body 18 described later that constitutes the fixed body 4. The FPC 16 is bent in a substantially angular groove shape (substantially U-shaped).

[0041] The fixed body 4 includes a case body 18 that constitutes the left and right side surfaces and the lower surface of the fixed body 4, a cover 19 that constitutes the upper surface of the fixed body 4, and a fixing plate 20 fixed to the case body 18. The case body 18 is formed of a resin material. The cover 19 is formed by bending a thin metal plate into a predetermined shape. The fixing plate 20 is formed of a thin metal plate. Further, the fixing plate 20 is formed in a substantially disc shape. The case body 18 is composed of two side portions 18a that constitute the left and right side surfaces of the case body 18 and a bottom portion 18b that constitutes the lower surface of the case body 18. The movable body 3 is disposed between the two side portions 18a in the left-right direction. Further, the movable body 3 is disposed above the bottom portion 18b.

[0042] On the side surface portion 18a, a through hole 18c penetrating in the left - right direction is formed. Inside the through hole 18c, a drive coil 23 (described later) which constitutes a part of the drive mechanism 5 is disposed. Both side portions of the through hole 18c in the circumferential direction centered on the rotation center of the movable body 3 on the side surface portion 18a serve as protective wall portions 18d for protecting the drive coil 23. That is, the protective wall portions 18d are formed on the fixed body 4.

[0043] Also, on the side surface portion 18a, an abutting surface 18e for positioning the drive coil 23 disposed in the through hole 18c is formed (see FIG. 2). The abutting surface 18e is formed below the through hole 18c. At the front end portion of the side surface portion 18a disposed on the left side, an FPC fixing portion 18f protruding toward the left side is formed. The front end portion of the FPC 16 is fixed to the FPC fixing portion 18f by a double - sided tape or the like.

[0044] The fixing plate 20 is fixed to the central portion of the upper surface of the bottom surface portion 18b. At the center of the fixing plate 20, a ball placement portion 20a for placing the lower end portion of the ball 6 is formed. The ball placement portion 20a is formed in a substantially hemispherical shape swelling downward, and the upper surface of the ball placement portion 20a is a hemispherical concave curved surface recessed downward. The ball 6 is disposed above the ball placement portion 20a.

[0045] The cover 19 is fixed to the upper end portion of the case body 18. The movable body 3 is disposed below the cover 19. At the central portion of the cover 19, a spring portion 19a for biasing the ball 7 is formed. That is, the cover 19 is a leaf spring. The spring portion 19a is slightly cut and raised downward. At the tip portion of the spring portion 19a, a ball placement portion 19b for placing the upper end portion of the ball 7 is formed. The ball placement portion 19b is formed in a substantially hemispherical shape swelling upward, and the lower surface of the ball placement portion 19b is a hemispherical concave curved surface recessed upward. The ball 7 is disposed below the ball placement portion 19b.

[0046] The spring portion 19a biases the ball 7 downward. The ball 7 is in contact with the lower surface of the ball placement portion 19b and the edge of the upper end of the through hole 11c of the second frame 11 with a predetermined contact pressure by the biasing force of the spring portion 19a. Also, as described above, the ball 6 is arranged at the same position as the ball 7 in the horizontal direction, and is in contact with the edge of the lower end of the through hole 10c of the first frame 10 and the upper surface of the ball placement portion 20a with a predetermined contact pressure by the biasing force of the spring portion 19a.

[0047] As described above, the movable body 3 is rotatable with respect to the fixed body 4 about the axis L1 passing through the centers of the balls 6 and 7 as the rotation center. The rotation center of the movable body 3 with respect to the fixed body 4 is defined by the balls 6 and 7, the through hole 10c of the first frame 10, the through hole 11c of the second frame 11, the ball placement portion 19b of the cover 19, and the ball placement portion 20a of the fixing plate 20. The second frame 11 of the present embodiment serves as a defining member for defining the rotation center of the movable body 3, and an engaging portion 11d is formed on the second frame 11 which is the defining member.

[0048] (Configuration of the drive mechanism) FIG. 4 is a plan view showing the movable body 3, the drive magnet 24, and the magnetic plate 25 shown in FIG. 1 extracted. FIG. 5 is a plan view showing the drive coil 23, the drive magnet 24, and the magnetic plate 27 shown in FIG. 2 extracted. FIG. 6 is a plan view for explaining the arrangement relationship between the drive coil 23 and the drive magnet 24 when the movable body 3 rotates with respect to the fixed body 4 shown in FIG. 1. In the following description, the radial direction centered on the rotation center of the movable body 3 with respect to the fixed body 4 is referred to as the "radial direction", and the circumferential direction (circular direction) centered on the rotation center of the movable body 3 with respect to the fixed body 4 is referred to as the "circumferential direction".

[0049] The drive mechanism 5 includes a drive coil 23 wound in a hollow shape, a drive magnet 24 disposed opposite the drive coil 23 in the radial direction, and a magnetic plate 25 to which the drive magnet 24 is fixed. The drive mechanism 5 of this embodiment includes a drive coil 23, a drive magnet 24, and a magnetic plate 25 disposed on each of the left and right sides of the movable body 3. That is, the drive mechanism 5 includes two drive coils 23, two drive magnets 24, and two magnetic plates 25. The drive coil 23, the drive magnet 24, and the magnetic plate 25 are arranged at a 180° pitch with respect to the rotation center of the movable body 3 relative to the fixed body 4.

[0050] The magnetic plate 25 is formed by bending a metal plate made of a magnetic material into a predetermined shape. The magnetic plate 25 includes a fixed portion 25a fixed to the magnetic plate 9 and two inclined portions 25b connected to both ends of the fixed portion 25a in the front-rear direction. The fixed portion 25a is formed in a rectangular flat plate shape. The fixed portion 25a is fixed to the outer surface in the left-right direction of the magnetic plate 9. That is, the fixed portion 25a of the magnetic plate 25 disposed on the right side of the movable body 3 is fixed to the right surface of the magnetic plate 9 disposed on the right side of the frame 8, and the fixed portion 25a of the magnetic plate 25 disposed on the left side of the movable body 3 is fixed to the left surface of the magnetic plate 9 disposed on the left side of the frame 8.

[0051] The inclined portion 25b is formed in a rectangular flat plate shape. The inclined portion 25b connected to the front end of the fixed portion 25a is inclined with respect to the fixed portion 25a so as to face inward in the left-right direction as it goes forward. The inclined portion 25b connected to the rear end of the fixed portion 25a is inclined with respect to the fixed portion 25a so as to face inward in the left-right direction as it goes backward. The two inclined portions 25b are formed symmetrically with respect to the fixed portion 25a.

[0052] The drive magnet 24 is formed in a block shape whose shape when viewed from the vertical direction is substantially crescent-shaped. The drive magnet 24 is fixed to the fixed portion 25a of the magnetic plate 25. That is, the drive magnet 24 is fixed to the movable body 3 via the magnetic plate 25. The upper and lower surfaces of the drive magnet 24 are planes orthogonal to the vertical direction. The outer surface of the drive magnet 24 in the radial direction is the magnet-side opposing surface 24a that faces the drive coil 23.

[0053] The magnet-side opposing surface 24a is formed in a convex curved surface shape. Also, the magnet-side opposing surface 24a is formed in an arc shape having the rotation center of the movable body 3 as the center of curvature when viewed from the vertical direction. That is, the magnet-side opposing surface 24a, which is the opposing surface of the drive magnet 24 facing the drive coil 23, is formed in an arc shape having the rotation center of the movable body 3 as the center of curvature when viewed from the vertical direction. The central angle of the magnet-side opposing surface 24a when viewed from the vertical direction is, for example, about 90°.

[0054] The inner surface of the drive magnet 24 in the radial direction is composed of a planar fixed surface 24b fixed to the fixed portion 25a and planar inclined surfaces 24c connected to both ends of the fixed surface 24b in the front-rear direction. The fixed surface 24b constitutes the central portion of the inner surface of the drive magnet 24 in the radial direction. The fixed surface 24b is fixed to the outer surface of the fixed portion 25a in the left-right direction and is in contact with the outer surface of the fixed portion 25a in the left-right direction. The inclined surface 24c connected to the front end of the fixed surface 24b is inclined with respect to the fixed surface 24b so as to face inward in the left-right direction as it goes forward, and the inclined surface 24c connected to the rear end of the fixed surface 24b is inclined with respect to the fixed surface 24b so as to face inward in the left-right direction as it goes backward.

[0055] The inclined surface 24c connected to the front end of the fixed surface 24b is parallel to the inclined portion 25b connected to the front end of the fixed portion 25a. A slight gap is formed between the inclined surface 24c and the outer surface of the inclined portion 25b. The inclined surface 24c connected to the rear end of the fixed surface 24b is parallel to the inclined portion 25b connected to the rear end of the fixed portion 25a. A slight gap is formed between the inclined surface 24c and the outer surface of the inclined portion 25b. The magnetic plate 25 functions as a back yoke of the drive magnet 24. Note that the magnetic plate 9 functions as a magnetic shield for preventing magnetic interference between the autofocus magnetic drive mechanism of the camera module 2 and the drive mechanism 5.

[0056] At the center of the fixed surface 24b, a positioning recess 24d for positioning the drive magnet 24 with respect to the movable body 3 is formed. That is, the drive magnet 24 is formed with a positioning recess 24d for positioning the drive magnet 24 with respect to the movable body 3, and the positioning recess 24d is formed at the center of the surface of the drive magnet 24 on the side of the movable body 3. The positioning recess 24d is recessed outward in the left-right direction from the fixed surface 24b. The positioning recess 24d is formed in a corner groove shape extending over the entire vertical range of the fixed surface 24b.

[0057] The width of the positioning recess 24d in the optical axis direction of the camera module 2 is slightly wider than the width of the engaging portion 11d of the second frame 11 in the optical axis direction of the camera module 2. The engaging portion 11d is engaged with the positioning recess 24d. In this embodiment, by engaging the engaging portion 11d with the positioning recess 24d, the drive magnet 24 is positioned with respect to the movable body 3. Specifically, by engaging the engaging portion 11d with the positioning recess 24d, the drive magnet 24 is positioned with respect to the movable body 3 in the optical axis direction of the camera module 2. When the movable body 3 is arranged at the origin position, the two drive magnets 24 are arranged symmetrically left and right.

[0058] The drive coil 23 is an air-core coil formed by winding a conducting wire in an air-core shape. The drive coil 23 includes a pair (two) of effective side portions 23a and 23b that are parallel in the vertical direction, a connecting side portion 23c that connects the upper ends of the pair of effective side portions 23a and 23b, and a connecting side portion 23c that connects the lower ends of the pair of effective side portions 23a and 23b. The effective side portions 23a and 23b are portions that contribute to the driving force of the drive mechanism 5. The drive coil 23 is bent along a magnet-side facing surface 24a that has an arc shape when viewed from the vertical direction. Specifically, the drive coil 23 is bent at two locations along the magnet-side facing surface 24a. Also, the drive coil 23 is bent into a substantially V shape.

[0059] The pair of effective side portions 23a and 23b are arranged at intervals in the circumferential direction. The effective side portion 23a constitutes one end portion of the drive coil 23 in the circumferential direction, and the effective side portion 23b constitutes the other end portion of the drive coil 23 in the circumferential direction. In this embodiment, the effective side portion 23a constitutes the clockwise end portion of the drive coil 23, and the effective side portion 23b constitutes the counterclockwise end portion. The effective side portion 23a of this embodiment is the first effective side portion, and the effective side portion 23b is the second effective side portion.

[0060] The drive coil 23 is arranged outside the drive magnet 24 in the radial direction. Also, the drive coil 23 is arranged outside the drive magnet 24 in the left-right direction. The drive coil 23 is arranged in a through hole 18c of the case body 18, and the two drive coils 23 are arranged symmetrically left and right. The inner side surfaces in the left-right direction of the connecting side portion 23c arranged on the lower side are in contact with a contact surface 18e of the case body 18, and the drive coil 23 is positioned in the horizontal direction by the contact surface 18e.

[0061] As described above, both side portions of the through-hole 18c in the circumferential direction are the protective wall portions 18d, and the protective wall portions 18d are disposed on both sides of the drive coil 23 in the circumferential direction. The protective wall portion 18d is disposed inside the drive coil 23 in the radial direction. That is, the protective wall portion 18d is disposed on the drive magnet 24 side rather than the drive coil 23 in the radial direction.

[0062] When viewed from the up-down direction, the central portion of the drive coil 23 in the circumferential direction is in a straight line parallel to the front-back direction. The drive coil 23 is attached to a flexible printed circuit board (FPC) 26. Specifically, the outer surfaces in the left-right direction of the central portion of the drive coil 23 in the circumferential direction are attached to the FPC 26. Also, two drive coils 23 are attached to the common FPC 26. The FPC 26 is fixed to the outer surface and the lower surface in the left-right direction of the case body 18. That is, the drive coil 23 is fixed to the fixed body 4 via the FPC 26. When current is supplied to the drive coil 23, the movable body 3 rotates with respect to the fixed body 4 about the axis L1 as the rotation center.

[0063] The inner surface of the effective side portion 23a in the radial direction is the effective side portion facing surface 23d facing the magnet side facing surface 24a of the drive magnet 24. The inner surface of the effective side portion 23b in the radial direction is the effective side portion facing surface 23e facing the magnet side facing surface 24a. When viewed from the up-down direction, the effective side portion facing surfaces 23d and 23e are substantially orthogonal to the radial direction. That is, when viewed from the up-down direction, the effective side portion facing surfaces 23d and 23e, which are the facing surfaces of the effective side portions 23a and 23b facing the magnet side facing surface 24a, are substantially orthogonal to the radial direction centered on the rotation center of the movable body 3. Also, the effective side portion facing surfaces 23d and 23e are parallel to the tangential direction of the magnet side facing surface 24a. The effective side portion facing surface 23d of the present embodiment is the first effective side portion facing surface, and the effective side portion facing surface 23e is the second effective side portion facing surface.

[0064] The magnet-side facing surface 24a is magnetized with two poles in the circumferential direction. That is, the magnet-side facing surface 24a is magnetized such that the magnetic pole of one side portion of the magnet-side facing surface 24a in the circumferential direction is different from the magnetic pole of the other side portion of the magnet-side facing surface 24a in the circumferential direction, and is polarized into two poles in the circumferential direction. Specifically, the center of the driving magnet 24 in the circumferential direction is the polarization position (magnetization polarization line) 24e, and the magnet-side facing surface 24a is polarized into two poles with the polarization position 24e as the boundary.

[0065] If the portion of the driving magnet 24 arranged on the clockwise side of the polarization position 24e is defined as the first magnet portion 24f, and the portion of the driving magnet 24 arranged on the counterclockwise side of the polarization position 24e is defined as the second magnet portion 24g, then the driving magnet 24 is composed of the first magnet portion 24f and the second magnet portion 24g. That is, the driving magnet 24 is composed of the first magnet portion 24f arranged on the effective side portion 23a side in the circumferential direction and the second magnet portion 24g arranged on the effective side portion 23b side in the circumferential direction, and the magnetic pole of the magnet-side facing surface 24a of the first magnet portion 24f is different from the magnetic pole of the magnet-side facing surface 24a of the second magnet portion 24g. In this embodiment, the magnetic pole of the magnet-side facing surface 24a of the first magnet portion 24f is the N pole, and the magnetic pole of the magnet-side facing surface 24a of the second magnet portion 24g is the S pole.

[0066] The driving magnet 24 is magnetized such that when viewed from the vertical direction with the movable body 3 arranged at the origin position with respect to the fixed body 4, the magnetic force lines F1, F2 (see FIG. 5) passing through the centers of the effective side portion facing surfaces 23d, 23e are substantially perpendicular to the effective side portion facing surfaces 23d, 23e. That is, the first magnet portion 24f is magnetized such that when viewed from the vertical direction with the movable body 3 arranged at the origin position, the magnetic force line F1 passing through the center of the effective side portion facing surface 23d is substantially perpendicular to the effective side portion facing surface 23d, and the second magnet portion 24g is magnetized such that when viewed from the vertical direction with the movable body 3 arranged at the origin position, the magnetic force line F2 passing through the effective side portion facing surface 23e is substantially perpendicular to the effective side portion facing surface 23e. The directions of the magnetic force lines F1, F2 coincide with the radial direction.

[0067] In this embodiment, when viewed from the vertical direction with the movable body 3 disposed at the origin position, the first magnet portion 24f is magnetized such that the magnetic force line F1 passing through the center of the effective side portion facing surface 23d and the magnetic force line F3 (see FIG. 5) passing through a portion of the effective side portion facing surface 23d that is offset from the center are parallel. That is, in the state where the movable body 3 is disposed at the origin position, the first magnet portion 24f is magnetized such that the magnetic force lines F1 and F3 passing through the effective side portion facing surface 23d are substantially orthogonal to the effective side portion facing surface 23d. Further, in this embodiment, the first magnet portion 24f is magnetized such that the magnetic force lines generated by the portion of the first magnet portion 24f that faces the effective side portion facing surface 23d within the rotation range of the movable body 3 are parallel to the magnetic force line F1.

[0068] Similarly, when viewed from the vertical direction with the movable body 3 disposed at the origin position, the second magnet portion 24g is magnetized such that the magnetic force line F2 passing through the center of the effective side portion facing surface 23e and the magnetic force line F4 (see FIG. 5) passing through a portion of the effective side portion facing surface 23e that is offset from the center are parallel. That is, in the state where the movable body 3 is disposed at the origin position, the second magnet portion 24g is magnetized such that the magnetic force lines F2 and F4 passing through the effective side portion facing surface 23e are substantially orthogonal to the effective side portion facing surface 23e. Further, in this embodiment, the second magnet portion 24g is magnetized such that the magnetic force lines generated by the portion of the second magnet portion 24g that faces the effective side portion facing surface 23e within the rotation range of the movable body 3 are parallel to the magnetic force line F2.

[0069] Note that the inclined surface 24c of the first magnet portion 24f is a plane that is substantially orthogonal to the direction of the magnetic force line F1 when passing through the effective side portion facing surface 23d. That is, the inclined surface 24c of the first magnet portion 24f when the movable body 3 is disposed at the origin position is substantially parallel to the effective side portion facing surface 23d. Also, the inclined surface 24c of the second magnet portion 24g is a plane that is substantially orthogonal to the direction of the magnetic force line F2 when passing through the effective side portion facing surface 23e. That is, the inclined surface 24c of the second magnet portion 24g when the movable body 3 is disposed at the origin position is substantially parallel to the effective side portion facing surface 23e.

[0070] In this embodiment, even when the movable body 3 rotates with respect to the fixed body 4 up to the rotation end in the clockwise direction, the polarization position 24e of the drive magnet 24 does not reach the effective side portion 23a in the circumferential direction (see Fig. 6(A)). Also, even when the movable body 3 rotates with respect to the fixed body 4 up to the rotation end in the counterclockwise direction, the polarization position 24e does not reach the effective side portion 23b in the circumferential direction (see Fig. 6(B)). That is, the interval between the pair of effective side portions 23a and 23b in the circumferential direction is set so that the polarization position 24e does not reach the effective side portions 23a and 23b throughout the entire rotation range of the movable body 3.

[0071] On the surface of the FPC 26 where the drive coil 23 is attached, a Hall element (not shown) for detecting the rotation angle of the movable body 3 with respect to the fixed body 4 is mounted. The Hall element is arranged on the inner circumferential side of the drive coil 23 wound in a hollow shape. On the surface of the FPC 26 opposite to the surface where the drive coil 23 is attached (specifically, the outer surface of the FPC 26 in the left-right direction), a flat magnetic plate 27 made of a magnetic material is fixed. The magnetic plate 27 is formed in a rectangular shape. The thickness direction of the magnetic plate 27 coincides with the left-right direction. When viewed from above in the up-down direction with the movable body 3 arranged at the origin position, the center of the magnetic plate 27 in the front-back direction and the polarization position 24e of the drive magnet 24 are arranged at the same position in the circumferential direction.

[0072] The position of the movable body 3 arranged at the origin position is held by the magnetic attractive force generated between the drive magnet 24 and the magnetic plate 27. That is, the drive magnet 24 and the magnetic plate 27 function to maintain the state where the movable body 3 is arranged at the origin position when no current is supplied to the drive coil 23. In this embodiment, a position holding mechanism 28 for maintaining the state where the movable body 3 is arranged at the origin position is constituted by the drive magnet 24 and the magnetic plate 27.

[0073] (Main effects of this embodiment) As described above, in this embodiment, the magnet-side facing surface 24a of the drive magnet 24 is formed in an arc shape with the rotation center of the movable body 3 as the center of curvature when viewed from the vertical direction, and the drive coil 23 is bent along the magnet-side facing surface 24a whose shape is arc-shaped when viewed from the vertical direction. Further, in this embodiment, when viewed from the vertical direction, the effective-side facing surfaces 23d and 23e of the effective sides 23a and 23b of the drive coil 23 are substantially orthogonal to the radial direction. Therefore, in this embodiment, even when the rotation angle of the movable body 3 with respect to the fixed body 4 increases, it is possible to keep the distances between the magnet-side facing surface 24a and the effective-side facing surfaces 23d and 23e constant. Accordingly, in this embodiment, even when the rotation angle of the movable body 3 with respect to the fixed body 4 increases, it is possible to suppress a decrease in the driving force of the drive mechanism 5.

[0074] In this embodiment, the drive magnet 24 is magnetized such that the magnetic force lines F1 and F2 passing through the centers of the effective-side facing surfaces 23d and 23e, which are substantially orthogonal to the radial direction, are substantially orthogonal to the effective-side facing surfaces 23d and 23e when viewed from the vertical direction with the movable body 3 disposed at the origin position with respect to the fixed body 4. Therefore, in this embodiment, when a current is supplied to the drive coil 23 with the movable body 3 disposed at the origin position, it is possible to increase the driving force acting in the tangential direction of the magnet-side facing surface 24a of the drive mechanism 5. Accordingly, in this embodiment, it is possible to make the movable body 3 disposed at the origin position easier to move with respect to the fixed body 4.

[0075] In this embodiment, the first magnet portion 24f is magnetized such that the magnetic field lines generated by the portion of the first magnet portion 24f that faces the effective side portion facing surface 23d within the rotation range of the movable body 3 are parallel to the magnetic field lines F1. Also, in this embodiment, the second magnet portion 24g is magnetized such that the magnetic field lines generated by the portion of the second magnet portion 24g that faces the effective side portion facing surface 23e within the rotation range of the movable body 3 are parallel to the magnetic field lines F2. Therefore, in this embodiment, compared with the case where the first magnet portion 24f and the second magnet portion 24g are magnetized such that the magnetic field lines form a radial shape centered on the rotation center of the movable body 3, even if the shape of the drive magnet 24 is a complex shape, it becomes possible to magnetize the drive magnet 24 relatively easily.

[0076] In this embodiment, an engaging portion 11d is formed on the second frame 11 for defining the rotation center of the movable body 3, which engages with the positioning concave portion 24d of the drive magnet 24 to position the drive magnet 24 with respect to the movable body 3. That is, in this embodiment, a part of the second frame 11 for defining the rotation center of the movable body 3 directly engages with the drive magnet 24, whereby the drive magnet 24 is positioned with respect to the movable body 3. Therefore, in this embodiment, it becomes possible to suppress the displacement of the drive magnet 24 with respect to the rotation center of the movable body 3. Accordingly, in this embodiment, even if the distances between the magnet side facing surface 24a of the drive magnet 24 and the effective side portion facing surfaces 23d, 23e of the drive coil 23 are short, it becomes possible to prevent interference between the magnet side facing surface 24a and the effective side portion facing surfaces 23d, 23e when the movable body 3 rotates with respect to the fixed body 4.

[0077] In this embodiment, the positioning recess 24d is formed at the center of the surface of the drive magnet 24 on the side of the movable body 3. Therefore, in this embodiment, it is possible to weaken the magnetic flux at the center portion of the surface of the drive magnet 24 on the side of the movable body 3. Accordingly, in this embodiment, even if the camera module 2 is provided with a magnetic drive mechanism for autofocus, it is possible to suppress the magnetic interference between this magnetic drive mechanism and the drive mechanism 5. Further, in this embodiment, since the magnetic plate 9 that functions as a magnetic shield is fixed to the outer surfaces in the left-right direction of the first frame 10, it is possible to effectively suppress the magnetic interference between the magnetic drive mechanism for autofocus of the camera module 2 and the drive mechanism 5.

[0078] In this embodiment, the protective wall portions 18d disposed on both sides of the drive coil 23 in the circumferential direction are disposed inside the drive coil 23 in the radial direction. Therefore, in this embodiment, for example, even if an impact is applied to the optical unit 1 and an excessive force acts on the movable body 3 causing the movable body 3 to move relative to the fixed body 4, it is possible to prevent contact between the drive coil 23 and the drive magnet 24. Accordingly, in this embodiment, even if an excessive force acts on the movable body 3 causing the movable body 3 to move relative to the fixed body 4, it is possible to prevent damage to the drive coil 23 and the drive magnet 24.

[0079] (Modification Example 1 of the Use of the Optical Unit) FIGS. 7 and 8 are block diagrams for explaining a modification example of the use of the optical unit 1 shown in FIG. 1.

[0080] In the above-described embodiment, the optical unit 1 is mounted on and used in a mobile device such as a smartphone. However, as shown in FIGS. 7 and 8, the optical unit 1 may be mounted on and used in a drive recorder 35 which is a vehicle-mounted imaging device. In this modification example, the drive recorder 35 includes an inertial sensor 36. The inertial sensor 36 is, for example, a gyro sensor (gyroscope) or an acceleration sensor. Further, the inertial sensor 36 may be a sensor in which a gyro sensor and an acceleration sensor are integrated.

[0081] In the modification example shown in FIG. 7, the optical unit 1 includes an inertial sensor 36. The inertial sensor 36 is attached to the fixed body 4. For example, the inertial sensor 36 is mounted on the FPC 26 and fixed to the fixed body 4 via the FPC 26. In the modification example shown in FIG. 8, the inertial sensor 36 is disposed outside the optical unit 1. For example, the drive recorder 35 includes a fixing member to which the fixed body 4 is fixed, and the inertial sensor 36 is attached to this fixing member. The inertial sensor 36 functions to detect the traveling direction of the vehicle on which the drive recorder 35 is mounted.

[0082] The drive recorder 35 includes a control unit 37 to which the inertial sensor 36 is electrically connected. The output signal of the inertial sensor 36 is input to the control unit 37. The drive coil 23 is also electrically connected to the control unit 37. Specifically, the FPC 26 is electrically connected, and the hall element disposed on the inner peripheral side of the drive coil 23 is also electrically connected to the control unit 37. The control unit 37 controls the drive mechanism 5.

[0083] In the drive recorder 35, the control unit 37 controls the current supplied to the drive coil 23 based on the detection result of the inertial sensor 36 to rotate the movable body 3. That is, the drive mechanism 5 rotates the movable body 3 based on the detection result of the inertial sensor 36. Specifically, the control unit 37 rotates the movable body 3 so as to follow the movement of the vehicle's steering wheel based on the detection result of the inertial sensor 36. More specifically, the control unit 37 rotates the movable body 3 so that the optical axis direction of the camera module 2 always faces the traveling direction of the vehicle based on the detection result of the inertial sensor 36. That is, in this modification example, the drive mechanism 5 rotates the movable body 3 with respect to the fixed body 4 so that the optical axis direction of the camera module 2 always faces the traveling direction of the vehicle. Further, the control unit 37 controls the current supplied to the drive coil 23 based on the detection result of the hall element to rotate the movable body 3.

[0084] In this modified example, based on the detection result of the inertial sensor 36, the movable body 3 is rotated so that the optical axis direction of the camera module 2 always faces the traveling direction of the vehicle. Therefore, for example, it becomes possible to acquire an image of the traveling direction of the vehicle while the vehicle is turning at an intersection. Thus, for example, even if a collision accident occurs after the vehicle turns at an intersection, it becomes possible to grasp the situation from slightly before the accident occurred until the accident occurred based on the image acquired by the drive recorder 35.

[0085] Note that the optical unit 1 shown in FIG. 7 (that is, the optical unit 1 including the inertial sensor 36) may be mounted on and used in a device other than the drive recorder 35. Even in this case, based on the detection result of the inertial sensor 36, it becomes possible to rotate the movable body 3 so that the optical axis direction of the camera module 2 faces the direction in which the fixed body 4 is tilted.

[0086] (Modified Example 2 of the Use of the Optical Unit) FIG. 9 is a block diagram for explaining a modified example of the use of the optical unit 1 shown in FIG. 1.

[0087] When the optical unit 1 is mounted on and used in the drive recorder 35, the drive recorder 35 does not necessarily have to include the inertial sensor 36. In this case, the vehicle on which the drive recorder 35 is mounted is provided with a steering angle detector 38 that detects the steering angle of the vehicle as shown in FIG. 9. The control unit 37 of the drive recorder 35 is electrically connected to the steering angle detector 38 and the drive coil 23. In the example shown in FIG. 9, the drive recorder 35 and the steering angle detector 38 constitute a drive recorder system 39 as a photographing system.

[0088] In this modified example, the control unit 37 controls the current supplied to the drive coil 23 based on the detection result of the steering angle detector 38 to rotate the movable body 3. Specifically, the control unit 37 rotates the movable body 3 based on the detection result of the steering angle detector 38 so that the optical axis direction of the camera module 2 always faces the traveling direction of the vehicle. Also in this modified example, for example, since it becomes possible to acquire an image of the traveling direction of the vehicle while the vehicle is turning at an intersection, even if a collision accident occurs after the vehicle has turned at an intersection, based on the image acquired by the drive recorder 35, it becomes possible to grasp the situation from a little before the accident occurred until the accident occurred.

[0089] (Other embodiments) The above-described embodiments are examples of preferred embodiments of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0090] In the above-described embodiment, the position holding mechanism for maintaining the state in which the movable body 3 is disposed at the origin position may be a spring member such as a leaf spring. When the position holding mechanism is a leaf spring, this leaf spring includes, for example, a fixed portion fixed to the movable body 3, a fixed portion fixed to the fixed body 4, and a plurality of spring portions connecting the fixed portions to each other. Further, in the above-described embodiment, the drive coil 23 may be bent at one location along the magnet-side facing surface 24a, or may be bent at three or more locations. Further, the drive coil 23 may be bent in an arc shape along the magnet-side facing surface 24a.

[0091] In the above-described embodiment, the drive mechanism 5 may include only one drive coil 23 and one drive magnet 24, or may include three or more drive coils 23 and drive magnets 24. Also, in the above-described embodiment, the drive coil 23 may be fixed to the movable body 3, and the drive magnet 24 may be fixed to the fixed body 4. In this case, the drive magnet 24 is disposed outside the drive coil 23 in the radial direction. Also, in this case, the inner surface of the drive magnet 24 in the radial direction serves as the magnet-side opposing surface facing the drive coil 23, and the outer surfaces of the effective side portions 23a, 23b in the radial direction serve as the effective side portion-side opposing surfaces facing the magnet-side opposing surface of the drive magnet 24.

[0092] In the above-described embodiment, the first magnet portion 24f and the second magnet portion 24g may be magnetized so that the magnetic force lines form a radial shape centered on the rotation center of the movable body 3. Also, in the above-described embodiment, the optical unit 1 may include an optical module other than the camera module 2. For example, the optical unit 1 may include, as an optical module, a laser module that emits laser light. Also, the optical unit 1 may include an optical module having optical components such as lenses and prisms.

Description of Reference Numerals

[0093] 1 Optical unit 2 Camera module (optical module) 3 Movable body 4 Fixed body 5 Drive mechanism 11 Second frame (defining member) 11d Engagement portion 18d Protection wall portion 23 Drive coil 23a Effective side portion (first effective side portion) 23b Effective side portion (second effective side portion) 23d Effective side portion-side opposing surface (first effective side portion-side opposing surface) 23e Effective side portion-side opposing surface (second effective side portion-side opposing surface) 24 Drive magnet 24a Magnet-side opposing surface Concave portion for 24d positioning 24f First magnet part 24g Second magnet part 28 Position holding mechanism 35 Drive recorder (imaging device) 36 Inertial sensor 37 Control unit 38 Steering angle detector 39 Imaging system F1, F2 Magnetic field lines (magnetic field lines passing through the center of the opposing surface of the effective side part) F3 Magnetic field line (magnetic field line passing through the opposing surface of the first effective side part) F4 Magnetic field line (magnetic field line passing through the opposing surface of the second effective side part) L Optical axis of the camera module (optical axis of the optical module) Z First direction

Claims

1. A movable body having an optical module, a fixed body that rotatably holds the movable body, and a drive mechanism that rotates the movable body with respect to the fixed body with a first direction orthogonal to the optical axis of the optical module as the axial direction of rotation, wherein the drive mechanism includes a drive coil wound in a hollow shape and a drive magnet disposed to face the drive coil in a radial direction centered on the rotation center of the movable body with respect to the fixed body, wherein a magnet-side facing surface, which is a facing surface of the drive magnet facing the drive coil, is formed in an arc shape having the rotation center of the movable body as the center of curvature when viewed from the first direction, wherein the drive coil includes a pair of effective side portions parallel to the first direction and is bent along the magnet-side facing surface having an arc shape when viewed from the first direction, wherein the pair of effective side portions are arranged at intervals in the circumferential direction centered on the rotation center of the movable body, wherein an effective-side facing surface, which is a facing surface of the effective side portion facing the magnet-side facing surface when viewed from the first direction, is substantially orthogonal to the radial direction centered on the rotation center of the movable body, and wherein the drive magnet is magnetized such that magnetic field lines passing through the center of the effective-side facing surface are substantially orthogonal to the effective-side facing surface when viewed from the first direction in a state where the movable body is disposed at a predetermined origin position with respect to the fixed body. An optical unit characterized by this.

2. Let one of the pair of effective side portions be a first effective side portion, the other effective side portion be a second effective side portion, the effective-side facing surface of the first effective side portion be a first effective-side facing surface, and the effective-side facing surface of the second effective side portion be a second effective-side facing surface. Then, the drive magnet is composed of a first magnet portion disposed on the first effective side portion side in the circumferential direction centered on the rotation center of the movable body and a second magnet portion disposed on the second effective side portion side in the circumferential direction centered on the rotation center of the movable body, wherein the magnetic pole of the magnet-side facing surface of the first magnet portion and the magnetic pole of the magnet-side facing surface of the second magnet portion are different magnetic poles, and wherein the first magnet portion is magnetized such that magnetic field lines passing through the first effective-side facing surface are substantially orthogonal to the first effective-side facing surface in a state where the movable body is disposed at the origin position with respect to the fixed body. The optical unit according to claim 1, wherein the second magnet part is magnetized such that magnetic field lines passing through the second effective side part facing surface are substantially orthogonal to the second effective side part facing surface in a state where the movable body is disposed at the origin position with respect to the fixed body.

3. The optical unit according to claim 1 or 2, further comprising a position holding mechanism for maintaining the state where the movable body is disposed at the origin position.

4. The drive magnet is fixed to the movable body, The drive coil is fixed to the fixed body and is disposed outside the drive magnet in a radial direction centered on the rotation center of the movable body. The optical unit according to any one of claims 1 to 3.

5. The movable body includes a defining member for defining the rotation center of the movable body, The drive magnet is formed with a positioning recess for positioning the drive magnet with respect to the movable body, The optical unit according to claim 4, wherein the defining member is formed with an engaging portion that engages with the positioning recess to position the drive magnet with respect to the movable body.

6. The optical module is a camera module, The optical unit according to claim 5, wherein the positioning recess is formed at the center of the surface of the drive magnet on the side of the movable body.

7. The fixed body is formed with protective wall portions disposed on both sides of the drive coil in a circumferential direction centered on the rotation center of the movable body, The optical unit according to any one of claims 4 to 6, wherein the protective wall portions are disposed on the drive magnet side rather than the drive coil in a radial direction centered on the rotation center of the movable body.

8. Comprising an inertial sensor attached to the fixed body, The drive mechanism rotates the movable body based on a detection result of the inertial sensor. The optical unit according to any one of claims 1 to 7.

9. Comprising the optical unit according to claim 8, An in-vehicle imaging device, wherein the optical module is a camera module.

10. Comprising the optical unit according to any one of claims 1 to 7, an inertial sensor disposed outside the optical unit, and a control unit to which the inertial sensor and the drive coil are electrically connected, The optical module is a camera module. The in-vehicle imaging device is characterized in that the control unit controls the current supplied to the drive coil based on the detection result of the inertial sensor to rotate the movable body.

11. An in-vehicle imaging device having an optical unit according to any one of Claims 1 to 7, and a steering angle detector that detects a steering angle of a vehicle. The optical module is a camera module. The imaging device includes a control unit to which the steering angle detector and the drive coil are electrically connected. The imaging system is characterized in that the control unit controls the current supplied to the drive coil based on the detection result of the steering angle detector to rotate the movable body.

Images