JP7624330B2 - Optical device, actuator and portable information terminal - Google Patents

Description

The present invention relates to an optical device, an actuator, a portable information terminal having an optical device, and a portable information terminal having an actuator.

Devices such as smartphones and wearable cameras are provided with optical devices that include an optical module such as a camera module. Optical devices provided in smartphones and the like also incorporate an image stabilization function that reduces image distortion by rotating the optical module in response to changes in posture. Optical devices with this image stabilization function are provided with an actuator that is made up of a gimbal, a permanent magnet, an electromagnetic coil, etc., that is, an actuator that rotates the optical module (see Patent Documents 1 and 2).

Chinese Patent Publication No. 111416925 Chinese Patent Publication No. 111510598

However, in order to improve the image stabilization function of an optical device, it is necessary to increase the rotational force of the optical module (rotating object) by the actuator, in other words, to increase the rotational force of the holder member that holds the optical module.

The objective of the present invention is to increase the rotational force of the holder member.

An optical device according to one embodiment rotates an optical module by a predetermined angle, and includes a holder member that holds the optical module, and a case member in which the holder member is housed. The optical device includes a support mechanism that is attached to the holder member and the case member and supports the holder member rotatably relative to the case member . The optical device includes a drive mechanism including a coil provided in the case member, and a permanent magnet provided in the holder member facing the coil . A first arc is included in the contour of a cross-sectional profile of the permanent magnet along the short direction, on the side facing the coil. A second arc is included in the contour of a cross-sectional profile of the permanent magnet along the long direction , on the side facing the coil.

An actuator according to one embodiment rotates a rotating object by a predetermined angle, and includes a holder member that holds the rotating object, and a case member in which the holder member is housed. The actuator includes a support mechanism that is attached to the holder member and the case member and supports the holder member rotatably relative to the case member . The actuator includes a drive mechanism including a coil provided in the case member and a permanent magnet provided in the holder member facing the coil . A first arc is included in the contour of a cross-sectional profile of the permanent magnet along a short direction on the side facing the coil. A second arc is included in the contour of a cross-sectional profile of the permanent magnet along a long direction on the side facing the coil.

The portable information terminal of one embodiment has the optical device.

In one embodiment, the portable information terminal has the actuator.

The cross-sectional contour of the permanent magnet includes an arc on the side facing the coil. This increases the thrust acting on the permanent magnet and increases the rotational force of the holder member.

1 is a perspective view showing an optical device according to an embodiment of the present invention; FIG. 2 is an exploded perspective view showing the optical device. FIG. 2A is a perspective view showing a holder assembly, and FIG. 2B is an exploded perspective view showing the holder assembly. FIG. 2A is a perspective view showing a case assembly, and FIG. 2B is an exploded perspective view showing the case assembly. FIG. 2 is a plan view showing a part of the optical device with the stopper plate removed. FIG. 2 is a perspective view showing a portion of the holder assembly and a gimbal attached thereto. FIG. 2 is a diagram showing the positional relationship between a permanent magnet and an electromagnetic coil. FIG. 2 is a plan view showing a part of the optical device. 9 is a cross-sectional view showing the optical device taken along line X1-X1 in FIG. 8. 9 is a cross-sectional view showing the optical device taken along line X1-X1 in FIG. 8. 3A is a front view, a plan view, and a right side view showing a permanent magnet. FIG. 12A is a perspective view showing a permanent magnet, (B) is a cross-sectional view showing a permanent magnet along line 12B-12B in FIG. 11, and (C) is a cross-sectional view showing a permanent magnet along line 12C-12C in FIG. 11. 13A is a plan view showing the holder assembly and the electromagnetic coil, and FIG. 13B is a cross-sectional view of the holder assembly and the electromagnetic coil taken along line X2-X2 in FIG. 13A. 14 is an enlarged cross-sectional view showing a portion of the holder assembly and the electromagnetic coil shown in FIG. 13(B). FIG. 11A and 11B are a front view, a plan view, and a right side view showing a permanent magnet of Example 2. 16A is a perspective view showing a permanent magnet, (B) is a cross-sectional view showing the permanent magnet along line 16B-16B in FIG. 15, and (C) is a cross-sectional view showing the permanent magnet along line 16C-16C in FIG. 15. 13A to 13C are a front view, a plan view, and a right side view showing a permanent magnet of Example 3. 18A is a perspective view showing a permanent magnet, (B) is a cross-sectional view showing the permanent magnet along line 18B-18B in FIG. 17, and (C) is a cross-sectional view showing the permanent magnet along line 18C-18C in FIG. 17. FIG. 2 is a plan view showing a holder assembly with a permanent magnet and an electromagnetic coil. 13A to 13C are a front view, a plan view, and a right side view showing a permanent magnet of Example 3. 21A is an oblique view showing a permanent magnet, (B) is a cross-sectional view showing a permanent magnet along line 21B-21B in FIG. 20, and (C) is a cross-sectional view showing a permanent magnet along line 21C-21C in FIG. 20. 1 is a perspective view showing a portable information terminal according to an embodiment of the present invention;

The following describes in detail an embodiment of the present invention with reference to the drawings. In the following description, identical or substantially identical configurations and elements are designated by the same reference numerals and will not be described repeatedly.

[Overall configuration of optical device]
FIG. 1 is a perspective view showing an optical device 10 according to an embodiment of the present invention. As shown in FIG. 1, the optical device 10 has a camera module 12 including a lens 11 and an image sensor. As described later, the optical device 10 is provided with an image stabilization mechanism 50 that functions as an actuator. By providing the image stabilization mechanism 50, which will be described later, to the optical device 10, the camera module (optical module, rotating object) 12 can be tilted in any direction, that is, rotated at a predetermined angle, as indicated by an arrow α. The optical device 10 shown in the figure is a device mounted on a portable information terminal such as a smartphone, a tablet PC, or a notebook PC.

In FIG. 1, the Z-axis direction indicates the optical axis direction of the camera module 12, the X-axis direction indicates the rotation axis direction of the yawing, and the Y-axis direction indicates the rotation axis direction of the pitching. Also, point C1 where the X, Y, and Z axes intersect represents the rotation center of the holder frame 16, which will be described later. For convenience of drawing, in FIG. 1, the X, Y, and Z axes are shown at a position away from the rotation center of the holder frame 16.

Figure 2 is an exploded perspective view of the optical device 10. As shown in Figure 2, the optical device 10 has a case frame (case member) 15 equipped with electromagnetic coils 13 and 14, a holder frame (holder member) 16 housed in the case frame 15, and a camera module 12 held by the holder frame 16. The case frame 15 and the holder frame 16 are connected via a gimbal 17, and the holder frame 16 is rotatably supported by the case frame 15 via the gimbal 17. Furthermore, a stopper plate 18 is attached to one end surface 15a of the case frame 15, and a bottom cover 19 is attached to the other end surface 15b of the case frame 15.

[Holder assembly]
3A is a perspective view showing a holder assembly 20 composed of a holder frame 16 and a camera module 12, and FIG. 3B is an exploded perspective view showing the holder assembly 20. As shown in FIG. 3B, the holder frame 16 formed in a rectangular frame shape has a pair of holder walls 21a, 21b facing each other and a pair of holder walls 21c, 21d facing each other. A magnet mounting groove 22a is formed in the holder wall 21a, and a magnet mounting groove 22b is formed in the holder wall 21c. A permanent magnet 23 is attached to the magnet mounting groove 22a, and a permanent magnet 24 is attached to the magnet mounting groove 22b. A yoke (magnetic member) 23a is provided on the permanent magnet 23, and a yoke (magnetic member) 24a is provided on the permanent magnet 24. The yokes 23a, 24a are preferably formed using a magnetic material with a high saturation magnetic flux density. For example, the yokes 23a, 24a can be made of a magnetic material such as pure iron, permalloy, carbon steel, etc. The permanent magnets 23, 24, together with the electromagnetic coils 13, 14, etc., constitute a drive mechanism 52 which is a part of the image stabilization mechanism 50.

A bearing mounting groove 25a is formed in the corner 25 that connects the holder walls 21a and 21c, and a bearing mounting groove 26a is formed in the corner 26 that connects the holder walls 21b and 21d. A holder bearing 27 is attached to the bearing mounting groove 25a, and a holder bearing 28 is attached to the bearing mounting groove 26a. The holder bearings 27 and 28 have bearing main bodies 27a and 28a made of sheet metal, and balls 27b and 28b fixed to the bearing main bodies 27a and 28a by welding or the like. In this way, the holder bearings 27 and 28 are arranged diagonally on the rectangular holder frame 16. The holder bearings 27 and 28, together with the gimbal 17 and case bearings 42 and 43 described later, constitute a support mechanism 51, which is part of the image stabilization mechanism 50.

3(A) and (B), the housing 30 of the camera module 12 is fitted inside the holder frame 16, and the camera module 12 is held by the holder frame 16. The camera module 12 has a housing 30 that houses the lens 11 and an autofocus mechanism (not shown), an electronic circuit board 31 provided at the bottom of the housing 30, and a flexible cable 32 connected to the electronic circuit board 31. The flexible cable 32 has a shape that is bent multiple times. This allows the flexible cable 32 to easily deform and follow the rotational movement of the camera module 12, even if the camera module 12 rotates and a load is applied to the flexible cable 32. An image sensor such as a CCD (not shown) is mounted on the electronic circuit board 31 of the camera module 12.

[Case Assembly]
4A is a perspective view showing a case assembly 33 composed of a case frame 15 and electromagnetic coils 13 and 14, and FIG. 4B is an exploded perspective view showing the case assembly 33. As shown in FIG. 4B, the case frame 15 formed in a rectangular frame shape has a pair of case walls 34a and 34b facing each other, a pair of case walls 34c and 34d facing each other, and a cable housing portion 35 extending outward from the case wall 34b. A coil housing hole 36a is formed in the case wall 34a, and a coil housing hole 36b is formed in the case wall 34c. The electromagnetic coil (coil) 13 is housed in the coil housing hole 36a, and the electromagnetic coil (coil) 14 is housed in the coil housing hole 36b. The electromagnetic coils 13 and 14 are provided on a wiring board 37 bent into a substantially L-shape, and magnetic sensors 38 and 39 for detecting the rotational position of the holder frame 16 are attached to the wiring board 37. The electromagnetic coils 13 and 14 , together with the permanent magnets 23 and 24 , etc., constitute a drive mechanism 52 which is a part of the image stabilization mechanism 50 .

A bearing mounting groove 40a is formed at a corner 40 connecting the case walls 34a and 34d, and a bearing mounting groove 41a is formed at a corner 41 connecting the case walls 34b and 34c. A case bearing 42 is mounted in the bearing mounting groove 40a , and a case bearing 43 is mounted in the bearing mounting groove 41a. The case bearings 42 and 43 have bearing main bodies 42a and 43a made of sheet metal, and balls 42b and 43b fixed to the bearing main bodies 42a and 43a by welding or the like. In this way, the case bearings 42 and 43 are arranged diagonally in the rectangular case frame 15. The case bearings 42 and 43, together with the gimbal 17 and the holder bearings 27 and 28, constitute a support mechanism 51, which is a part of the image stabilization mechanism 50.

[Image stabilization mechanism (support mechanism and drive mechanism)]
<Support mechanism>
Next, the support mechanism 51 constituting a part of the image stabilization mechanism 50 will be described. As shown in FIG. 3, the holder bearings 27 and 28 are arranged diagonally in the rectangular holder frame 16. Also, as shown in FIG. 4, the case bearings 42 and 43 are arranged diagonally in the rectangular case frame 15. Furthermore, as shown in FIG. 2, the gimbal 17 connecting the case frame 15 and the holder frame 16 has an annular main body 61 having an opening 62 through which the tip 12a of the camera module 12 protrudes, and a plurality of arm portions 63 to 66 extending from the annular main body 61 toward the holder bearings 27 and 28 and the case bearings 42 and 43. Also, recesses 63a to 66a that engage with the balls 27b, 28b, 42b, and 43b of the bearings 27, 28, 42, and 43 are formed in the arm portions 63 to 66 of the gimbal 17.

As shown in FIG. 2, the arms 63, 64 of the gimbal 17 are attached to the holder bearings 27, 28 of the holder frame 16, and the recesses 63a, 64a of the arms 63, 64 rotatably engage with the balls 27b, 28b of the holder bearings 27, 28. The arms 65, 66 of the gimbal 17 are attached to the case bearings 42, 43 of the case frame 15, and the recesses 65a, 66a of the arms 65, 66 rotatably engage with the balls 42b, 43b of the case bearings 42, 43. In this way, the gimbal 17 is attached to the case frame 15 and the holder frame 16, and the holder frame 16 is rotatably supported by the case frame 15 via the gimbal 17.

Figure 5 is a plan view showing a part of the optical device 10 with the stopper plate 18 removed. Also, Figure 6 is a perspective view showing a part of the holder assembly 20 and the gimbal 17 attached thereto. As shown in Figures 5 and 6, the holder frame 16 that holds the camera module 12 is supported rotatably around the rotation axis A1 and the rotation axis A2 with respect to the case frame 15 that is fixed to a smartphone or the like. That is, by connecting the case frame 15 and the holder frame 16 via the gimbal 17 with two degrees of freedom, the holder frame 16 and the camera module 12 held therein can be rotated in any direction relative to the case frame 15 (arrow α). That is, the holder frame 16 is supported rotatably on the case frame 15 via the gimbal 17 with the intersection of the rotation axes A1 and A2 as the rotation center C1.

The rotation axis A1 is a rotation axis that connects the contact points between the balls 27b, 28b of the holder bearings 27, 28 and the recesses 63a, 64a of the arm portions 63, 64 of the gimbal 17, and the rotation axis A2 is a rotation axis that connects the contact points between the balls 42b, 43b of the case bearings 42, 43 and the recesses 65a, 66a of the arm portions 65, 66 of the gimbal 17. The optical axis Oa of the camera module 12 intersects with the rotation center C1, which is the intersection of the rotation axes A1, A2. In other words, the holder frame 16 is rotatable relative to the case frame 15 with the intersection of the rotation axes A1, A2 and the optical axis Oa as the rotation center C1.

<Drive mechanism>
Next, a description will be given of the drive mechanism 52 constituting a part of the image stabilization mechanism 50. First, as shown in Fig. 6, the permanent magnets 23, 24 are magnetized so that different magnetic poles appear on the surface on one side and the other side in the short direction of the permanent magnets 23, 24. For example, when the upper surfaces of the permanent magnets 23, 24 are magnetized to the N pole, the lower surfaces of the permanent magnets 23, 24 are magnetized to the S pole. Note that the dashed lines shown in Fig. 6 are imaginary lines indicating the boundaries of the magnetized regions of the permanent magnets 23, 24.

Figure 7 is a diagram showing the positional relationship between the permanent magnets 23, 24 and the electromagnetic coils 13, 14. As shown in Figure 7, the permanent magnet 23 of the holder frame 16 faces the electromagnetic coil 13 of the case frame 15, and the permanent magnet 24 of the holder frame 16 faces the electromagnetic coil 14 of the case frame 15. In this way, the electromagnetic coils 13, 14 and the permanent magnets 23, 24 that constitute the drive mechanism 52 face each other, so that the rotational position of the holder frame 16 can be controlled by controlling the energization state of the electromagnetic coils 13, 14.

In other words, by switching the current flow direction of the electromagnetic coil 13, the direction of the thrust force acting on the permanent magnet 23 (F1a, F1b) can be switched, and by switching the current flow direction of the electromagnetic coil 14, the direction of the thrust force acting on the permanent magnet 24 (F2a, F2b) can be switched. Furthermore, by controlling the current flowing through the electromagnetic coil 13, the magnitude of the thrust force F1a (or F1b) acting on the permanent magnet 23 can be controlled, and by controlling the current flowing through the electromagnetic coil 14, the magnitude of the thrust force F2a (or F2b) acting on the permanent magnet 24 can be controlled.

In this way, by controlling the direction and magnitude of the thrust acting on the permanent magnets 23, 24 of the holder frame 16, the holder frame 16 can be rotated around the rotation axes A1, A2. Therefore, the camera module 12 held by the holder frame 16 can be tilted in any direction, that is, rotated at a predetermined angle. In other words, the camera module 12 held by the holder frame 16 can be rotated around the X-axis, which is the rotation axis of yawing, and around the Y-axis, which is the rotation axis of pitching. The current control of the electromagnetic coils 13, 14 can be performed, for example, based on the detection signal of a gyro sensor. In other words, the controller (not shown) that performs the current control of the electromagnetic coils 13, 14 can detect a change in the attitude of the optical device 10, i.e., the case frame 15, by the gyro sensor, as an example of rotation control, and rotate the holder frame 16 relative to the case frame 15 to cancel this change in attitude.

The mechanical upper limit of the rotation angle (hereinafter referred to as the tilt angle) of the holder frame 16 is determined by the stopper 15s of the case frame 15. Here, FIG. 8 is a plan view showing a part of the optical device 10. FIG. 9 is a cross-sectional view showing the optical device 10 along the line X1-X1 in FIG. 8, and FIG. 10 is a cross-sectional view showing the optical device 10 along the line X1-X1 in FIG. 8. FIG. 9 shows the holder frame 16 rotated in the direction of the arrow D1, and FIG. 10 shows the holder frame 16 rotated in the direction of the arrow D2.

9, when the holder frame 16 rotates largely in the direction of the arrow D1, the lower end of the holder wall 21a contacts the stopper 15s of the case frame 15, and further rotation of the holder frame 16 is restricted. Also, as shown in FIG. 10, when the holder frame 16 rotates largely in the direction of the arrow D2, the lower end of the holder wall 21b contacts the stopper 15s of the case frame 15, and further rotation of the holder frame 16 is restricted. The rotation range of the holder frame 16 by controlling the current supply to the electromagnetic coils 13 and 14 is set to a range in which the holder frame 16 does not contact the stopper 15s. Also, in the above description, the tilt angle of the holder frame 16 is restricted by contacting the holder frame 16 with the stopper 15s of the case frame 15, but this is not limited to this. For example, the tilt angle of the holder frame 16 may be limited by contacting the holder frame 16 with a stopper plate 18.

[Permanent Magnet (Example 1)]
FIG. 11 is a front view, a plan view, and a right side view showing the permanent magnets 23, 24. FIG. 12(A) is a perspective view showing the permanent magnets 23, 24, FIG. 12(B) is a cross-sectional view showing the permanent magnets 23, 24 along line 12B-12B in FIG. 11, and FIG. 12(C) is a cross-sectional view showing the permanent magnets 23, 24 along line 12C-12C in FIG. 11. The short side direction shown in FIG. 11 is the short side direction of the permanent magnets 23, 24 shown in the front view, and is a direction parallel to the optical axis Oa of the optical module. The longitudinal direction shown in FIG. 11 is the long side direction of the permanent magnets 23, 24 shown in the front view, and is a direction perpendicular to the short side direction. Furthermore, the thickness direction shown in FIG. 11 is the thickness direction of the permanent magnets 23, 24 shown in the right side view.

As shown in Fig. 11 and Fig. 12(A), the permanent magnets 23, 24 have an arc surface 70 formed on one surface in the thickness direction, and a flat surface 71 formed on the other surface in the thickness direction. That is, in the permanent magnets 23, 24, the surface facing the electromagnetic coils 13, 14 is constituted by the arc surface 70, and the surface to which the yokes 23a, 24a are attached is constituted by the flat surface 71. Also, as shown in Fig. 12(B), among the cross-sectional contours along the short side direction of the permanent magnets 23, 24, the contour 72 on the side facing the electromagnetic coils 13, 14 is constituted by an arc 73. On the other hand, as shown in Fig. 12(C), among the cross-sectional contours along the longitudinal direction of the permanent magnets 23, 24, the contour 74 on the side facing the electromagnetic coils 13, 14 is constituted by a straight line 75. Note that Fig. 12(B) shows the cross-sectional contour at the center of the longitudinal direction of the permanent magnet 24, but similar cross-sectional contours are also present at other parts in the longitudinal direction.

Here, FIG. 13(A) is a plan view showing the holder assembly 20 and the electromagnetic coils 13, 14, and FIG. 13(B) is a cross-sectional view of the holder assembly 20 and the electromagnetic coil 14 taken along line X2-X2 in FIG. 13(A). Also, FIG. 14 is a cross-sectional view showing an enlarged portion of the holder assembly 20 and the electromagnetic coil 13 shown in FIG. 13(B). Note that the internal structure of the camera module 12 is omitted in FIGS. 13(B) and 14.

As shown in FIG. 13B and FIG. 14, the contour 72 of the cross-sectional contour along the short side of the permanent magnet 23, which faces the electromagnetic coil 13, includes an arc 73 with the center of curvature at the rotation center C1 of the holder frame body 16. In other words, the contour 72 of the cross-sectional contour along the short side of the permanent magnet 23, which faces the electromagnetic coil 13, includes an arc 73 with a radius of curvature R1. In other words, as shown in FIG. 13A, the surface of the permanent magnet 23 facing the electromagnetic coil 13 includes an arc surface (rotation surface) 70 with the axis of the virtual straight line L1 passing through the rotation center C1 of the holder frame body 16. In addition, the virtual straight line L1 passing through the rotation center C1 is perpendicular to the optical axis Oa of the camera module 12.

In this way, among the cross-sectional contours along the short side direction of the permanent magnets 23, 24, the contour 72 on the side facing the electromagnetic coils 13, 14 includes an arc 73. In addition, the surface of the permanent magnets 23, 24 facing the electromagnetic coils 13, 14 includes an arc surface 70. As a result, as shown in the enlarged portions of Figures 9 and 10, even when the holder frame 16 rotates relative to the case frame 15, the gaps G1, G2 between the permanent magnet 23 and the electromagnetic coil 13 can be kept approximately constant. In other words, even when the permanent magnets 23, 24 move up and down as the holder frame 16 rotates, excessive approach of the permanent magnets 23, 24 to the electromagnetic coils 13, 14 can be avoided.

This allows the design to narrow the gap between the electromagnetic coils 13, 14 and the permanent magnets 23, 24, and increases the thrust acting on the permanent magnets 23, 24. Furthermore, because the gap between the electromagnetic coils 13, 14 and the permanent magnets 23, 24 can be narrowed, the thickness dimension, i.e., the volume, of the permanent magnets 23, 24 can be increased, and the magnetic force can be increased. In this way, the thrust acting on the permanent magnets 23, 24, i.e., the holder frame 16, can be increased, and the rotational force of the holder frame 16 can be increased, thereby expanding the tilt angle of the camera module 12.

In addition, when the camera module 12 and the holder frame 16 rotate, the distance between the permanent magnets 23, 24 and the electromagnetic coils 13, 14 is kept substantially constant, so that the thrust acting on the permanent magnets 23, 24 can be stabilized. This stabilizes the rotational movement of the holder frame 16, so that the so-called linearity when controlling the tilt angle by energizing the electromagnetic coils 13, 14 can be improved, and the tilt angle of the holder frame 16 and the camera module 12 can be controlled with high precision.

Furthermore, as shown by symbols M1 and M2 in Figs. 11 and 14, the upper and lower corners of the permanent magnets 23, 24 are rounded. This makes it possible to avoid contact between the permanent magnets 23, 24 and the electromagnetic coils 13, 14 even when the tilt angle of the holder frame 16 is increased, thereby achieving a further increase in the tilt angle of the holder frame 16. In the illustrated example, the corners of the permanent magnets 23, 24 are rounded, but this is not limited thereto, and the corners of the permanent magnets 23, 24 may be formed with an inclined surface. In other words, the corners of the permanent magnets 23, 24 may be subjected to so-called R chamfering or so-called C chamfering.

In this embodiment, the center of curvature of the arc 73 of the permanent magnets 23 and 24 coincides with the center of rotation C1 of the holder frame 16, and the imaginary straight line L1, which is the axis of the arc surface 70, passes through the center of rotation C1 of the holder frame 16, but this is not limited to the above. For example, in another embodiment, the center of curvature of the arc 73 may be made to almost coincide with the center of rotation C1, and the imaginary straight line L1, which is the axis of the arc surface 70, may pass near the center of rotation C1. That is, as shown in FIG. 9 and FIG. 10, if the distances G1 and G2 between the permanent magnet 23 and the electromagnetic coil 13 can be kept almost constant, it is possible to allow the center of curvature of the arc 73 to be shifted from the center of rotation C1, and it is possible to allow the axis of the arc surface 70 to be shifted from the center of rotation C1.

[Permanent Magnet (Example 2)]
In the examples shown in Figs. 11 and 12, the surfaces of the permanent magnets 23 and 24 facing the electromagnetic coil 13 are configured by one arc surface 70, but this is not limited thereto. Here, Fig. 15 is a front view, a plan view, and a right side view showing a permanent magnet 80 of the second embodiment. Also, Fig. 16(A) is a perspective view showing the permanent magnet 80, Fig. 16(B) is a cross-sectional view showing the permanent magnet 80 along line 16B-16B in Fig. 15, and Fig. 16(C) is a cross-sectional view showing the permanent magnet 80 along line 16C-16C in Fig. 15. The short side direction shown in Fig. 15 is the short side direction of the permanent magnet 80 shown in the front view, and is a direction parallel to the optical axis Oa of the camera module 12. Also, the longitudinal direction shown in Fig. 15 is the long side direction of the permanent magnet 80 shown in the front view, and is a direction perpendicular to the short side direction. Furthermore, the thickness direction shown in Fig. 15 is the thickness direction of the permanent magnet 80 shown in the right side view.

As shown in Figures 15 and 16(A), in the permanent magnet 80, arc surfaces 81, 82 and a plane 83 are formed on one surface in the thickness direction, and a plane 84 is formed on the other surface in the thickness direction. In other words, the surface facing the electromagnetic coil 13 includes a first arc surface 81 located on one side of the short side of the permanent magnet, a second arc surface 82 located on the other side of the short side of the permanent magnet, and a plane 83 located between the first arc surface 81 and the second arc surface 82. In this way, in the permanent magnet 80, the surface facing the electromagnetic coil 13 is composed of the arc surfaces 81, 82 and the plane 83, and the surface to which the yoke 23a is attached is composed of the plane 84.

As shown in FIG. 16(B), of the cross-sectional contours along the short side of the permanent magnet 80, a contour 85 on the side facing the electromagnetic coil 13 (14) is composed of arcs 81a, 82a and a straight line 83a. On the other hand, as shown in FIG. 16(C), of the cross-sectional contours along the long side of the permanent magnet 80, a contour 86 on the side facing the electromagnetic coil 13 (14) is composed of a straight line 87. Note that FIG. 16(B) shows the cross-sectional contour at the center of the permanent magnet 80 in the long direction, but similar cross-sectional contours are also seen in other parts in the long direction.

Also, like the permanent magnet 23 shown in FIG. 13, the arcs 81a, 82a included in the contour 85 of the cross-sectional contour along the short side of the permanent magnet 80 that faces the electromagnetic coil 13 (14) are arcs defined with the rotation center C1 of the holder frame 16 as the center of curvature, that is, arcs with a radius of curvature R1. Furthermore, like the permanent magnet 23 shown in FIG. 13, the arc surfaces 81, 82 included in the surface of the permanent magnet 80 that faces the electromagnetic coil 13 (14) are surfaces of revolution with the imaginary straight line L1 that passes through the rotation center C1 of the holder frame 16 as its axis.

In this way, among the cross-sectional contours along the short side direction of the permanent magnet 80, the contour 85 on the side facing the electromagnetic coil 13 (14) includes the arcs 81a and 82a. In addition, the surface of the permanent magnet 80 facing the electromagnetic coil 13 (14) includes the arc surfaces 81 and 82. As a result, similar to the permanent magnets 23 and 24 described above, even when the holder frame 16 rotates relative to the case frame 15, the distance between the permanent magnet 80 and the electromagnetic coil 13 (14) can be kept almost constant. Therefore, the thrust acting on the permanent magnet 80, i.e., the holder frame 16, can be increased, and the tilt angle of the camera module 12 can be expanded by increasing the rotational force of the holder frame 16. Furthermore, in the permanent magnet 80, the surface facing the electromagnetic coil 13 is composed of not only the arc surfaces 81 and 82 but also the plane 83. This makes it easier to handle the permanent magnet 80 during the manufacturing process.

[Permanent Magnet (Example 3)]
In the examples shown in Figs. 11 and 12, the contour 72 of the cross-sectional contour along the short side direction of the permanent magnets 23 and 24 includes an arc 73 on the side facing the electromagnetic coils 13 and 14, but is not limited to this. Here, Fig. 17 is a front view, a plan view, and a right side view showing a permanent magnet 90 of Example 3. Also, Fig. 18(A) is a perspective view showing the permanent magnet 90, Fig. 18(B) is a cross-sectional view showing the permanent magnet 90 along line 18B-18B in Fig. 17, and Fig. 18(C) is a cross-sectional view showing the permanent magnet 90 along line 18C-18C in Fig. 17. The short side direction shown in Fig. 17 is the short side direction of the permanent magnet 90 shown in the front view, and is a direction parallel to the optical axis Oa of the camera module 12. Also, the longitudinal direction shown in Fig. 17 is the longitudinal direction of the permanent magnet 90 shown in the front view, and is a direction perpendicular to the short side direction. Furthermore, the thickness direction shown in FIG. 17 is the thickness direction of the permanent magnet 90 shown in the right side view.

As shown in Fig. 17 and Fig. 18(A), the permanent magnet 90 has an arc surface 91 formed on one surface in the thickness direction, and a flat surface 92 formed on the other surface in the thickness direction. That is, in the permanent magnet 90, the surface facing the electromagnetic coil 13 (14) is constituted by the arc surface 91, and the surface to which the yoke 23a is attached is constituted by the flat surface 92. Also, as shown in Fig. 18(B), among the cross-sectional contours along the short side direction of the permanent magnet 90, the contour 93 on the side facing the electromagnetic coil 13 (14) is constituted by a straight line 94. On the other hand, as shown in Fig. 18(C), among the cross-sectional contours along the long side direction of the permanent magnet 90, the contour 95 on the side facing the electromagnetic coil 13 (14) is constituted by an arc 91a. Note that Fig. 18(C) shows the cross-sectional contour at the center of the short side direction of the permanent magnet 90, but similar cross-sectional contours are also seen in other parts in the short side direction.

Here, FIG. 19 is a plan view showing the holder assembly 20 equipped with the permanent magnet 90 and the electromagnetic coils 13 and 14. As shown in FIG. 19, the contour 95 of the cross-sectional contour along the longitudinal direction of the permanent magnet 90 facing the electromagnetic coil 13 includes an arc 91a with a center C2 set at a position outside the holder frame 16 as the center of curvature. In other words, the contour 95 of the cross-sectional contour along the longitudinal direction of the permanent magnet 90 facing the electromagnetic coil 13 includes an arc 91a with a radius of curvature R2. In other words, as shown in FIG. 13(A), the surface of the permanent magnet 90 facing the electromagnetic coil 13 includes an arc surface (surface of rotation) 91 with an axis of a virtual straight line L2 passing through a predetermined center C2. The virtual straight line L2 passing through the center C2 is parallel to the optical axis Oa of the camera module 12.

In this way, the contour 95 of the cross-sectional contour along the longitudinal direction of the permanent magnet 90 includes an arc 91a on the side facing the electromagnetic coil 13. In addition, the surface of the permanent magnet 90 facing the electromagnetic coil 13 includes an arc surface 91. As a result, as shown by the arrow β in FIG. 19, even if the holder frame 16 is shaken due to the bending of the gimbal 17, the distance between the permanent magnet 90 and the electromagnetic coil 13 (14) can be kept almost constant. In this way, even if the holder frame 16 is shaken, interference between the permanent magnet 90 and the electromagnetic coil 13 (14) can be avoided. In addition, if the holder frame 16 is structured to rotate around the optical axis, it goes without saying that an arc surface with the optical axis Oa passing through the center of rotation C1 as its axis may be formed on the surface of the permanent magnet 90.

[Permanent Magnet (Example 4)]
In the examples shown in Figs. 11 and 12, the contour 72 of the cross-sectional contour along the short side direction of the permanent magnets 23 and 24 includes an arc 73 on the side facing the electromagnetic coils 13 and 14, but is not limited to this. Here, Fig. 20 is a front view, a plan view, and a right side view showing the permanent magnet 100 of the third embodiment. Also, Fig. 21(A) is a perspective view showing the permanent magnet 100, Fig. 21(B) is a cross-sectional view showing the permanent magnet 100 along the line 21B-21B in Fig. 20, and Fig. 21(C) is a cross-sectional view showing the permanent magnet 100 along the line 21C-21C in Fig. 20. The short side direction shown in Fig. 20 is the short side direction of the permanent magnet 100 shown in the front view, and is a direction parallel to the optical axis Oa of the camera module 12. Also, the longitudinal direction shown in Fig. 20 is the longitudinal direction of the permanent magnet 100 shown in the front view, and is a direction perpendicular to the short side direction. Furthermore, the thickness direction shown in FIG. 20 is the thickness direction of the permanent magnet 100 shown in the right side view.

As shown in Figures 20 and 21(A), the permanent magnet 100 has arcuate surfaces 101 and 102 formed on one surface in the thickness direction, and a flat surface 103 formed on the other surface in the thickness direction. That is, in the permanent magnet 100, the surface facing the electromagnetic coil 13 (14) is constituted by the arcuate surfaces 101 and 102, and the surface to which the yoke 23a is attached is constituted by the flat surface 103. Also, as shown in Figure 21(B), among the cross-sectional contours of the permanent magnet 100 along the short side direction, a contour 104 on the side facing the electromagnetic coils 13 and 14 is constituted by a circular arc (first circular arc) 101a. Furthermore, as shown in Figure 21(C), among the cross-sectional contours of the permanent magnet 100 along the long side direction, a contour 105 on the side facing the electromagnetic coil 13 (14) is constituted by a circular arc (second circular arc) 102a.

Also, similar to the permanent magnet 23 shown in FIG. 13, the arc 101a included in the contour 104 on the side facing the electromagnetic coil 13 (14) among the cross-sectional contours along the short side of the permanent magnet 100 is an arc defined with the rotation center C1 of the holder frame 16 as the center of curvature, that is, an arc with a radius of curvature R1. Also, similar to the permanent magnet 90 shown in FIG. 17, the arc 102a included in the contour 105 on the side facing the electromagnetic coil 13 (14) among the cross-sectional contours along the long side of the permanent magnet 100 is an arc defined with the predetermined center C2 as the center of curvature, that is, an arc with a radius of curvature R2. Furthermore, similar to the permanent magnet 23 shown in FIG. 13, the arc surface 101 included in the surface of the permanent magnet 100 facing the electromagnetic coil 13 (14) is a surface of rotation with the virtual straight line L1 passing through the rotation center C1 of the holder frame 16 as its axis. Also, similar to the permanent magnet 90 shown in FIG. 17, the arc surface 102 included in the surface of the permanent magnet 100 facing the electromagnetic coil 13 (14) is a surface of revolution about an imaginary straight line L2 that passes through a predetermined center C2.

In this way, among the cross-sectional contours along the short side of the permanent magnet 100, the contour 104 on the side facing the electromagnetic coil 13 (14) includes the arc 101a, and among the cross-sectional contours along the long side of the permanent magnet 100, the contour 105 on the side facing the electromagnetic coil 13 (14) includes the arc 102a. In addition, the surface of the permanent magnet 100 facing the electromagnetic coil 13 (14) includes an arc surface. As a result, as with the permanent magnets 23 and 24 described above, even when the holder frame 16 rotates relative to the case frame 15, the distance between the permanent magnet 100 and the electromagnetic coil 13 (14) can be kept almost constant. Therefore, the thrust acting on the permanent magnet 100, i.e., the holder frame 16, can be increased, and the tilt angle of the camera module 12 can be expanded by increasing the rotational force of the holder frame 16.

Furthermore, as shown by the arrow β in FIG. 19, even if the holder frame 16 vibrates due to bending of the gimbal 17, the distance between the permanent magnet 100 and the electromagnetic coil 13 (14) can be kept almost constant. In this way, even if the holder frame 16 vibrates, interference between the permanent magnet 100 and the electromagnetic coil 13 (14) can be avoided. It goes without saying that if the holder frame 16 is structured to rotate around the optical axis, an arc surface with the optical axis Oa passing through the center of rotation C1 as its axis may be formed on the surface of the permanent magnet 100.

[Portable information terminal]
Fig. 22 is a perspective view showing a portable information terminal 200 according to an embodiment of the present invention. As shown in Fig. 10, the portable information terminal 200, which is a smartphone, is provided with the optical device 10 described above. As described above, the optical device 10 is equipped with an image stabilization mechanism (actuator) 50, and when capturing a moving image or a still image using the portable information terminal 200, a clear moving image or a still image can be obtained by rotating the camera module 12. Note that the portable information terminal 200 is not limited to the smartphone shown in the figure, and may be a tablet PC, a notebook PC, or the like.

The present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the present invention. For example, the camera module 12 may be supported so as to be rotatable only in either the yawing direction or the pitching direction. Also, the camera module 12 may be supported so as to be rotatable in the yawing direction, the pitching direction, and a third direction (e.g., the rolling direction). Also, although the camera module 12 is shown as an example of an optical module, the present invention is not limited to this.

In the above description, the optical device 10 is incorporated into a portable information terminal 200 such as a smartphone, but this is not limited thereto, and the optical device 10 may be incorporated into, for example, a wearable camera. Also, in the above description, the image stabilization mechanism 50 that rotates the camera module 12 as a rotating object is given as an example of an actuator, but this is not limited thereto. For example, the present invention may be applied to an actuator that rotates a weight member (rotating object) such as a weight attached to the holder frame 16.

In the above description, the two permanent magnets 23, 24 assembled to the holder frame 16 are formed to have the same shape, but this is not limited to this, and the shapes of the permanent magnets 23 and 24 may be different from each other. In addition, in the above description, the arc surface 70 is formed on the surface of the permanent magnets 23, 24 facing the electromagnetic coils 13, 14, but this is not limited to this, and the surface of the permanent magnets 23, 24 facing the electromagnetic coils 13, 14 may be formed to have a spherical surface. In addition to forming an arc surface or a spherical surface on the surface of the permanent magnets 23, 24 facing the electromagnetic coils 13, 14, other curved surfaces or flat surfaces may be formed in a composite manner.

In the illustrated example, air-core coils wound with electric wire are used as the electromagnetic coils (coils) 13 and 14, but this is not limited to this. For example, in other embodiments, other types of coils may be used, such as board coils made of a printed circuit board on which conductors are printed.

10...optical device, 11...lens, 12...camera module (optical module, rotating object), 12a...tip, 13, 14...electromagnetic coil (coil), 15...case frame (case member), 15a...one end surface, 15b...other end surface, 15s...stopper, 16...holder frame, 17...gimbal, 18...stopper plate, 19...bottom cover, 20...holder assembly, 21a-21d...holder wall, 22a, 22b...magnet mounting groove, 23, 24...permanent magnet, 23a, 24a...yoke (magnetic member), 25, 26...corner portion, 25a, 26a...bearing mounting groove, 27, 28...holder bearing, 27a, 28a...bearing body portion, 27b, 28b...ball, 30...housing, 31...electronic circuit board, 32...flexible cable, 33...case assembly, 34a to 34d...case wall, 35...cable housing portion, 36a, 36b...coil housing hole, 37...wiring board, 38, 39...magnetic sensor, 40, 41...corner portion, 40a, 41a...bearing mounting groove, 42, 43...case bearing, 42a, 43a...bearing body portion, 42 b, 43b...ball, 50...image stabilization mechanism (actuator), 51...support mechanism, 52...driving mechanism, 61...annular main body, 62...opening, 63-66...arm portion, 63a-66a...recess, 70...arc surface (rotation surface), 71...plane, 72...contour (cross-sectional contour), 73...arc, 74...contour, 75...straight line, 80...permanent magnet, 81...arc surface (first arc surface), 81a...arc, 82...arc surface (second arc surface), 82a...arc, 83...plane, 83a...straight line, 84...plane, 85...contour (cross-sectional contour), 8 6...Contour, 87...Straight line, 90...Permanent magnet, 91...Circular surface (surface of rotation), 91a...Circular arc, 92...Plane, 93...Contour, 94...Straight line, 95...Contour (cross-sectional contour), 100...Permanent magnet, 101, 102...Circular surface (surface of rotation), 101a, 102a...Circular arc, 103...Plane, 104, 105...Contour (cross-sectional contour), 200...Portable information terminal, Oa...Optical axis, A1, A2...Rotation axis, C1...Center of rotation, C2...Center, L1, L2...Virtual straight line, R1, R2...Radius of curvature, F1a, F2a...Thrust, G1, G2...Spacing

Claims (9)

An optical device for rotating an optical module by a predetermined angle,
a holder member for holding the optical module;
a case member in which the holder member is housed;
a support mechanism attached to the holder member and the case member and configured to rotatably support the holder member relative to the case member;
a drive mechanism including a coil provided in the case member and a permanent magnet provided in the holder member opposite to the coil;
having
a first arc is included in a cross-sectional contour of the permanent magnet along a short side direction on a side facing the coil,
A second arc is included in a cross-sectional contour of the permanent magnet along a longitudinal direction on a side facing the coil.
Optical device. The center of curvature of the first arc is the center of rotation of the holder member.
2. The optical device of claim 1. a surface of the permanent magnet facing the coil includes an arc surface including the first arc ;
3. An optical device according to claim 1 or 2. The arc surface is a surface of revolution having an axis corresponding to a virtual straight line passing through a rotation center of the holder member.
4. The optical device according to claim 3. The virtual straight line is perpendicular to the optical axis of the optical module.
5. The optical device according to claim 4. The permanent magnet comprises a magnetic member.
The optical device according to any one of claims 1 to 5 . An actuator for rotating a rotation object by a predetermined angle,
A holder member for holding the rotating object;
a case member in which the holder member is housed;
a support mechanism attached to the holder member and the case member and configured to rotatably support the holder member relative to the case member;
a drive mechanism including a coil provided in the case member and a permanent magnet provided in the holder member opposite to the coil;
having
a first arc is included in a cross-sectional contour of the permanent magnet along a short side direction on a side facing the coil,
A second arc is included in a cross-sectional contour of the permanent magnet along a longitudinal direction on a side facing the coil.
Actuator. A portable information terminal comprising the optical device according to any one of claims 1 to 6 . A portable information terminal comprising the actuator according to claim 7 .

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