Oscillating device

Abstract

Increase the torque required to drive the object being oscillated. [Solution] The device comprises a movable part 20 that can swing about an oscillating axis, a coil 40, and a magnet 30 provided between the movable part and the coil in a direction intersecting the oscillating axis AX, connected to the movable part at one end, and capable of swinging together with the movable part. The magnet has different polarities in the direction along the oscillating trajectory, and the coil has a plurality of coil parts at different distances from the oscillating axis. The plurality of coil parts include a first coil part 401 and a second coil part 402 provided closer to the midpoint of the oscillating trajectory than the first coil part, and the distance between the oscillating axis and the first coil part is shorter than the distance between the oscillating axis and the second coil part.

Description

Technical Field

[0001] The present invention relates to a rocking device.

Background Art

[0002] Conventionally, a rocking device that rocks a sensor or the like by a magnetic field generated in a magnetic circuit is known. Patent Document 1 discloses a rocking device in which a yoke around which a coil is wound is disposed within the magnetic field of a permanent magnet fixed to a mirror body that is the rocking target. The yoke of Patent Document 1 has a pair of end portions that protrude toward the permanent magnet, and the yoke is disposed such that the pair of end portions sandwich the permanent magnet in a non-contact manner. When an electric current flows through the coil, magnetic fields in different directions are generated at one end portion and the other end portion of the yoke, and the rocking target rocks.

Prior Art Documents

Patent Documents

[0003] <0000上記の特許文献1に記載の揺動装置において、ヨークの一対の端部が永久磁石を挟み込むことで、永久磁石の磁界を利用して揺動対象を駆動させることができる。

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desired to increase the torque for driving the rocking target.

Means for Solving the Problems

[0005] One embodiment of the rocking device comprises a movable part that can rock about a rocking axis, a coil, and a magnet provided between the movable part and the coil in a direction intersecting the rocking axis, connected to the movable part at one end, and capable of rocking together with the movable part. The magnet has different polarity in the direction along the rocking trajectory. The coil has a plurality of coil sections at different distances from the rocking axis, and the plurality of coil sections include a first coil section and a second coil section provided closer to the midpoint of the rocking trajectory than the first coil section. The distance between the rocking axis and the first coil section is shorter than the distance between the rocking axis and the second coil section. [Effects of the Invention]

[0006] According to this disclosure, it is possible to increase the torque used to drive the movable part. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is an external perspective view of the rocking device according to the embodiment. [Figure 2] Figure 2 is a cross-sectional view of the oscillating device along line AA in Figure 1. [Figure 3] Figure 3 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 4] Figure 4 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 5] Figure 5 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 6] Figure 6 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 7] Figure 7 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 8] Figure 8 illustrates the movement of the oscillating device and the vibration of the magnet. [Figure 9] Figure 9 is a graph showing the relationship between the oscillation angle of the magnet and the torque in the oscillating device of the embodiment and the oscillating device of the comparative example. [Modes for carrying out the invention]

[0008] The following describes in detail an oscillating device according to one embodiment, with reference to the drawings. The oscillating device is a device to which an object to be oscillated, such as a sensor, is attached, and which changes the orientation of the object to be oscillated, or it may be attached to a mirror device to which a mirror is provided as the object to be oscillated.

[0009] <Overall Structure> Figure 1 is an external perspective view of the oscillating device 10 according to the embodiment. Figure 2 is a cross-sectional view of the oscillating device 10 along line AA in Figure 1. The oscillating device 10 comprises a movable part 20, a magnet 30, and a coil 40. The oscillating device 10 is housed in, for example, a housing (not shown).

[0010] <Movable part 20> The movable part 20 has a rod 21 and a main body 22. The rod 21 is, for example, cylindrical and is pivotably fixed to the housing at one end and the other end via bearings or the like. In the following description, the direction in which the rod 21 extends may be referred to as the vertical direction.

[0011] The main body 22 is supported by the rod 21. Since the rod 21 is fixed in a pivotable manner, the main body 22 can pivot about the axis (pivot axis) AX, which is aligned with the vertical direction in which the rod 21 extends. In other words, the movable part 20 can pivot about the pivot axis AX.

[0012] The main body 22 is, for example, rectangular in shape. A magnet 30, described later, is attached to the first mounting surface 220 of the main body 22. An object to be oscillated by the oscillating device 10 is attached to the second mounting surface 221, which is the surface opposite to the first mounting surface 220. Note that the main body 22 is not limited to a rectangular in shape, and can be any shape to which the magnet 30 and the object to be oscillated can be attached.

[0013] In the following explanation, the side on which the first mounting surface 220 is formed may be referred to as the rear, and the side on which the second mounting surface 221 is formed may be referred to as the front.

[0014] <Magnet 30> The magnet 30 is, for example, rectangular columnar. As described above, the magnet 30 is attached to the first attachment surface 220 of the main body portion 22. The magnet 30 extends rearward along a direction intersecting the swing axis AX from the first attachment surface 220. That is, the magnet 30 is connected to the movable portion 20 at one end (front end) in the extending direction. Incidentally, a virtual line along the direction in which the magnet 30 extends passing through the center or substantially the center of the magnet 30 is called a center line CL.

[0015] Since the magnet 30 is attached to the main body portion 22, it can swing about the swing axis AX together with the movable portion 20. The rear end of the magnet 30 moves along an arc-shaped orbit R (see FIG. 2) centered on the swing axis AX. Specifically, the magnet 30 moves between one end (orbit end) R1 and the other end (orbit end) R2 of the orbit R. Incidentally, the midpoint of the orbit ends R1 and R2 along the orbit R is taken as an orbit midpoint R3. Also, in the following description, the orbit end R1 side may be referred to as the right side, and the orbit end R2 side may be referred to as the left side.

[0016] When the movable portion 20 and the magnet 30 are not swinging, the rear end of the magnet 30 is located at the orbit midpoint R3 on the orbit R. More specifically, the orbit midpoint R3 is located on the center line CL of the magnet 30. For this reason, FIG. 2 shows a state in which the movable portion 20 and the magnet 30 are not swinging.

[0017] When the movable part 20 and the magnet 30 swing, the rear end of the magnet 30 is located at the track ends R1, R2. More specifically, the track ends R1, R2 are located on the center line CL of the magnet 30. The angle formed by the straight line (reference line DX2) connecting the track end R1 and the swing axis AX with respect to the straight line (reference line DX1) connecting the track midpoint R3 and the swing axis AX is, for example, 15°. The angle formed by the straight line (reference line DX3) connecting the track end R2 and the swing axis AX with respect to the reference line DX1 is, for example, 15°. When the movable part 20 and the magnet 30 are not swinging, the center line CL of the magnet 30 coincides or substantially coincides with the reference line DX1. Note that the angle formed by the reference line DX2 with respect to the reference line DX1 and the angle formed by the reference line DX3 with respect to the reference line DX1 are not limited to 15°, and appropriate values are set according to the application of the swinging object, the installation location of the swinging device 10, etc.

[0018] The magnet 30 is composed by combining a plurality of magnets 301, 302, 303. The magnets 301, 302, 303 are combined in this order from the left, for example, to form a Halbach array. Specifically, the magnet 301 is arranged such that the front part 301a on the main body part 22 side is the S pole and the rear part 301b facing the coil 40 described later is the N pole. The magnet 302 is arranged such that the left part 302a on the left side with respect to the center line CL is the N pole and the right part 302b on the right side is the S pole. The magnet 303 is arranged such that the front part 303a on the main body part 22 side is the N pole and the rear part 303b facing the coil 40 is the S pole. In the drawings, for the purpose of easily grasping the polarity of each magnet 301, 302, 303, "N" is given to the N pole and "S" is given to the S pole.

[0019] Therefore, as a whole for the magnet 30, on the rear side of the magnet 30, the left side with respect to the center line CL is the N pole and the right side is the S pole. That is, the magnet 30 has different polarities on one side (left side) and the other side (right side) in the direction along the track R when swinging. Note that a plurality of magnets 301, 302, 303 may be combined such that the left side of the magnet 30 with respect to the center line CL is the S pole and the right side is the N pole.

[0020] Furthermore, the arrangement of the three magnets 301, 302, and 303 constituting the magnet 30 is not limited to a Halbach arrangement. The number of magnets is not limited to the above example; it may be four or more, two, or even just one. In any case, the magnets 30 are arranged such that their polarity differs on one side (left) and the other side (right) in the direction along the orbit R.

[0021] <Coil 40> The coil 40 is fixed to the housing. Specifically, the rear end face of the coil 40 is attached to the housing by adhesive or the like. The coil 40 is positioned behind the magnet 30, separated from it. In other words, the magnet 30 is provided between the movable part 20 and the coil 40 in the direction intersecting the oscillating axis AX (front-rear direction).

[0022] The coil 40 has a first coil section 401 and a second coil section 402, which are separate components. The first coil section 401 and the second coil section 402 are air-core coils centered on the reference line DX1, and are flattened coils with the vertical direction as the longitudinal direction.

[0023] The second coil section 402 is located inside the first coil section 401. That is, the second coil section 402 is located closer to the trajectory midpoint R3 than the first coil section 401. In the front-rear direction, i.e., along the reference line DX1 connecting the oscillation axis AX and the trajectory midpoint R3, the length of the first coil section 401 is longer than the length of the second coil section 402. Therefore, the front surface 403 of the first coil section 401 is located in front of the front surface 404 of the second coil section 402. In other words, the distance between the first surface 403 and the oscillation axis AX is shorter than the distance between the second surface 404 and the oscillation axis AX. That is, the coil 40 has multiple coil sections (first coil section 401 and second coil section 402) at different distances from the oscillation axis AX.

[0024] Furthermore, it can be said that the second coil section 402 is spaced further away from the rear end of the magnet 30 compared to the first coil section 401. Therefore, the second coil section 402 is less affected by the magnetic field from the magnet 30 than the first coil section 401. Consequently, when current flows through the coil 40, as will be described later, the force acting on the magnet 30 by the second coil section 402 is smaller than the force acting on the magnet 30 by the first coil section 401.

[0025] Furthermore, the coil 40 may have three or more coil sections. In this case as well, the length of each coil section in the front-to-back direction increases as it moves away from the reference line DX1. As a result, even when the coil 40 is composed of three or more coil sections, the coil 40 has multiple front surfaces at different distances from the pivot axis AX. In this case, the multiple coil sections of the coil 40 may be composed of separate members or of a single member. Alternatively, the coil 40 may have a first coil section 401 and a second coil section 402, where the first coil section 401 and the second coil section 402 are at different distances from the pivot axis AX, and one of the first coil section 401 and the second coil section 402 may have multiple front surfaces at different distances from the pivot axis AX.

[0026] The direction of the current flowing through the first coil section 401 and the direction of the current flowing through the second coil section 402 are the same. When the direction of the current flowing through the first coil section 401 and the second coil section 402 is switched, the direction of oscillation of the magnet 30 and the movable part 20 is switched, causing the magnet 30 and the movable part 20 to vibrate (oscillate). The oscillation motion of the magnet 30 and the movable part 20 will be described below.

[0027] <Oscillation of magnet 30 and movable part 20> Figure 3 is a cross-sectional view similar to the cross-sectional view of the oscillating device 10 shown in Figure 2, and shows the state in which the movable part 20 and the magnet 30 are not oscillating. As shown in Figure 3, the movable part 20 and the magnet 30, which are not oscillating, are located on the reference line DX1. That is, the center line CL of the magnet 30 is located at the midpoint R3 of the trajectory R. In this case, the rear end of the magnet 30 faces the second surface 404 on the front side of the second coil part 402. Specifically, the north pole of magnet 301 and the north pole of magnet 302 face the region 404a on the second surface 404 to the left of the reference line DX1, and the south pole of magnet 302 and the south pole of magnet 303 face the region 404b on the second surface 404 to the right of the reference line DX1.

[0028] In this state, current flows through coil 40 as shown in Figure 3. Specifically, to the left of the reference line DX1 of the first coil section 401 and the second coil section 402, current flows upward towards DR1, and to the right of the reference line DX1, current flows downward towards DR2. Since region 404a is opposite the north pole of the magnet 30, a force F1 is generated to the right to the left of the center line CL of the second coil section 402. Since region 404b is opposite the south pole of the magnet 30, a force F2 is generated to the right to the right of the center line CL of the second coil section 402. Because coil 40 is fixed to the housing, the above-mentioned rightward forces F1 and F2 cause the movable part 20 and the magnet 30 to begin oscillating along the trajectory R in the rightward oscillation direction D1.

[0029] Figure 4 is a cross-sectional view of the oscillating device 10 when the movable part 20 and the magnet 30 reach the track end R1 by oscillating. In this case, the reference line DX2 and the center line CL of the magnet 30 coincide or approximately coincide. When the magnet 30 reaches the track end R1, the north pole of the magnet 30 (the north pole of magnet 301 and the north pole of magnet 302) faces the region 404b of the second coil section 402, and the south pole of the magnet 30 (the south pole of magnet 302 and the south pole of magnet 303) faces the region 403a of the first surface 403 of the first coil section 401 to the right of the reference line DX1. That is, when the magnet 30 is located at the track end R1, one pole, the north pole, faces the second coil section 402, and the other pole, the south pole, faces the first coil section 401.

[0030] Therefore, a force F3 is generated to the right in region 403a of the first coil section 401. Also, a force F4 is generated to the left in region 404b of the second coil section 402. In other words, forces F3 and F4 are generated in different directions.

[0031] As described above, the second surface 404 of the second coil portion 402 is at a greater distance from the oscillation axis AX than the first surface 403 of the first coil portion 401. That is, the second surface 404 is further away from the magnet 30 than the first surface 403. For this reason, the leftward force F4 generated in region 404b is smaller than the rightward force F3 generated in region 403a. Also, the force F3 generated in region 403a is greater than the rightward force F1 or F2 in Figure 3.

[0032] Therefore, when the magnet 30 reaches the track end R1, a force F3 to the right, which is greater than force F1 or force F2, and a force F4 to the left, which is less than force F3, act on it. That is, force F4 reduces the force F3 to the right, but because force F3 is greater than force F1 or force F2, the amount of reduction in force F3 is suppressed. As a result, torque in the oscillation direction D1 is generated for the movable part 20 and the magnet 30 even at the track end R1. Therefore, even when the movable part 20 and the magnet 30 approach the track end R1, the decrease in the driving force in the oscillation direction D1 is suppressed.

[0033] Figure 5 is a cross-sectional view of the oscillating device 10 when the movable part 20 and the magnet 30 reach the track end R1 by oscillating and the direction of the current flowing through the coil 40 is switched. In this case as well, as shown in Figure 4, the north pole of the magnet 30 faces the region 404b of the second coil part 402, and the south pole of the magnet 30 faces the region 403a of the first coil part 401.

[0034] As a result of the reversal of the direction of the current flowing through coil 40, a current flows downward DR2 to the left of the reference line DX1 in the first coil section 401 and the second coil section 402, and a current flows upward DR1 to the right of the reference line DX1. A force F5 is generated to the left in region 403a of the first coil section 401. A force F6 is generated to the right in region 404b of the second coil section 402. In other words, forces F5 and F6 are generated in different directions.

[0035] In this case, the positional relationship between the magnet 30 and the coil 40 is the same as in the case shown in Figure 4. Therefore, the force F5 is equal to or approximately equal to the magnitude of force F3 shown in Figure 4, and the force F6 is equal to or approximately equal to the magnitude of force F4 shown in Figure 4.

[0036] In other words, the force F6 reduces the force F5 to the left, but since force F5 is greater than force F1 or force F2, the amount of reduction in force F5 is suppressed. As a result, torque is generated in the leftward oscillation direction D2 of the track R at the track end R1 for the movable part 20 and the magnet 30. Therefore, even if the direction of the current flowing through the coil 40 switches at the track end R1, the decrease in the driving force in the oscillation direction D2 is suppressed for the movable part 20 and the magnet 30. As a result, the movable part 20 and the magnet 30 begin to oscillate in the oscillation direction D2.

[0037] Figure 6 is a cross-sectional view of the oscillating device 10 when the movable part 20 and the magnet 30 oscillate in the oscillation direction D2 and reach the midpoint R3 of the trajectory. In this case, as in the case shown in Figure 3, the magnet 30 faces the second surface 404 of the second coil part 402. Specifically, the north pole of the magnet 30 faces region 404a of the second surface 404, and the south pole of the magnet 30 faces region 404b of the second surface 404.

[0038] In the first coil section 401 and the second coil section 402, a current flows downward DR2 to the left of the reference line DX1, and a current flows upward DR1 to the right of the reference line DX1. Since region 404a is opposite the north pole of the magnet 30, a leftward force F7 is generated in region 404a. Since region 404b is opposite the south pole of the magnet 30, a leftward force F8 is generated in region 404b. As a result of forces F7 and F8, the movable part 20 and the magnet 30 continue to swing in the leftward oscillation direction D2 along the trajectory R.

[0039] Figure 7 is a cross-sectional view of the oscillating device 10 when the movable part 20 and the magnet 30 reach the track end R2 by oscillating. In this case, the reference line DX3 and the center line CL of the magnet 30 coincide or approximately coincide. When the magnet 30 reaches the track end R2, the north pole of the magnet 30 faces the left region 403b of the first surface 403 of the first coil portion 401, and the south pole of the magnet 30 faces the region 404a of the second coil portion 402. That is, when the magnet 30 is located at the track end R2, one pole, the south pole, faces the first coil portion 401, and the other pole, the north pole, faces the second coil portion 402.

[0040] Therefore, a force F9 is generated to the left in region 403b of the first coil section 401. Also, a force F10 is generated to the right in region 404a of the second coil section 402. In other words, forces F9 and F10 are generated in different directions.

[0041] Because the second surface 404 of the second coil portion 402 is at a greater distance from the oscillation axis AX than the first surface 403 of the first coil portion 401, region 404a is further away from the magnet 30 than region 403b. Therefore, the force F10 acting on the right in region 404a is smaller than the force F9 acting on the left in region 403b. Also, the force F9 acting on region 403b is greater than the leftward force F7 or F8 in Figure 6.

[0042] Therefore, when the magnet 30 reaches the track end R2, a force F9 acting on it to the left is greater than force F7 or force F8, and a force F10 acting on it to the right is less than force F9. That is, force F10 reduces the force F9 to the left, but because force F9 is greater than force F7 or force F8, the amount of reduction in force F9 is suppressed. As a result, torque in the oscillation direction D2 is generated for the movable part 20 and the magnet 30 even at the track end R2. Therefore, even when the movable part 20 and the magnet 30 approach the track end R2, the decrease in the driving force in the oscillation direction D2 is suppressed.

[0043] Figure 8 is a cross-sectional view of the oscillating device 10 when the movable part 20 and the magnet 30 reach the track end R2 by oscillating, and the direction of the current flowing through the coil 40 is switched. In this case as well, as shown in Figure 7, the north pole of the magnet 30 faces the region 403b of the first coil part 401, and the south pole of the magnet 30 faces the region 404a of the second coil part 402.

[0044] Then, when the direction of the current flowing through coil 40 is switched, as in the cases shown in Figures 3 and 4, a current flows upward towards DR1 to the left of the reference line DX1 of the first coil section 401 and the second coil section 402, and a current flows downward towards DR2 to the right of the reference line DX1.

[0045] Since region 403b of the first coil section 401 faces the north pole of the magnet 30, a force F11 is generated in region 403b to the right. Since region 404a of the second coil section 402 faces the south pole of the magnet 30, a force F12 is generated in region 404a to the left. In other words, forces F11 and F12 are generated in different directions.

[0046] In this case, the positional relationship between the magnet 30 and the coil 40 is the same as in the case shown in Figure 7. Therefore, the magnitude of force F11 is equal to or approximately equal to the magnitude of force F9 shown in Figure 7, and the magnitude of force F12 is equal to or approximately equal to the magnitude of force F10 shown in Figure 7.

[0047] In other words, although the force F12 reduces the force F11 to the right, the reduction in force F11 is suppressed because force F11 is greater than force F7 or force F8. As a result, torque is generated in the direction of oscillation D1 to the right of the track R at the track end R2 for the movable part 20 and the magnet 30. Therefore, even if the direction of the current flowing through the coil 40 switches at the track end R2, the decrease in the driving force in the oscillation direction D1 is suppressed for the movable part 20 and the magnet 30.

[0048] As a result, the movable part 20 and the magnet 30 begin to oscillate in the oscillation direction D1. Subsequently, as the movable part 20 and the magnet 30 continue to oscillate in the oscillation direction D1, they reach the state shown in Figure 3. Then, as the above oscillation of the movable part 20 and the magnet 30 and the switching of the direction of the current flowing through the coil 40 are repeated, the movable part 20 and the magnet 30 oscillate along the trajectory R between the trajectory end R1 and the trajectory end R2.

[0049] Figure 9 is a graph showing the relationship between the oscillation angle of the magnet 30 in the oscillating device 10 of this embodiment and the torque, and the relationship between the oscillation angle of the magnet in the oscillating device of the comparative example and the torque. In the oscillating device of the comparative example, the length of the first coil section 401 in the front-rear direction and the length of the second coil section 402 in the front-rear direction are the same, and the first coil section 401 and the second coil section 402 are arranged along the oscillation trajectory R of the magnet 30.

[0050] In Figure 9, the relationship between the oscillation angle of the magnet 30 in the oscillating device 10 of this embodiment and the torque is represented by the solid line L1, and the relationship between the oscillation angle of the magnet 30 in the oscillating device of the comparative example is represented by the dashed line L2. In Figure 9, the vertical axis represents torque [Nm] and the horizontal axis represents the oscillation angle [°]. Note that when the oscillation angle is 0 [°], the magnet 30 is located at the end of the track R2; when the oscillation angle is 15 [°], the magnet 30 is located at the midpoint of the track R3; and when the oscillation angle is 30 [°], the magnet 30 is located at the end of the track R1.

[0051] As shown in Figure 9, at the trajectory ends R1 and R2 (i.e., oscillation angles of 0° and 30°), the torque value acting on the magnet 30 in the comparative example's oscillating device is v2. In contrast, in the embodiment's oscillating device 10, the torque value acting on the magnet 30 is v1, which is greater than v2. That is, by arranging the second coil section 402 inside the first coil section 401 and making the length from the oscillation axis AX to the second coil section 402 longer than the length from the oscillation axis AX to the first coil section 401, torque is obtained on the magnet 30 even at the trajectory ends R1 and R2. Furthermore, at the trajectory midpoint R3 (i.e., oscillation angle of 15°), the torque value in the comparative example is v4. In contrast, in the embodiment's oscillating device 10, the torque value is v3, which is greater than v4. That is, because the coil 40 has the above-described configuration, sufficient torque is obtained on the magnet 30 even at the center of oscillation.

[0052] According to the above-described embodiment, at least one of the following effects can be obtained.

[0053] (1) The oscillating device 10 comprises a movable part 20, a coil 40, and a magnet 30 provided between the movable part 20 and the coil 40. The magnet 30 has different polarities in the direction along the trajectory R of the oscillating motion of the movable part 20 and the magnet 30. The coil 40 has a plurality of coil sections at different distances from the oscillating axis AX. The plurality of coil sections include a first coil section 401 and a second coil section 402 provided closer to the midpoint R3 of the trajectory than the first coil section 401, and the distance between the oscillating axis AX and the first coil section 401 is shorter than the distance between the oscillating axis AX and the second coil section 402.

[0054] As a result, the force acting on the magnet 30 in the opposite direction to the oscillation directions D1 and D2 is reduced, especially at the track ends R1 and R2. Therefore, even if the coil 40 is an air-core flat coil having a flat shape in the front-rear direction, the reduction in torque on the magnet 30 at the track ends R1 and R2 is suppressed, and the torque required for the oscillation of the movable part 20 and the magnet 30 can be increased.

[0055] Furthermore, by having the magnet 30 composed of magnets 301, 302, and 303 arranged in the Halbach array shown in the embodiment, the magnetic field generated by the magnet 30 can be strengthened. With the magnetic field strengthened in this way, the reduction in torque is suppressed as described above, making it possible to swing the movable part 20 and the magnet 30 with a large torque.

[0056] (2) The second coil section 402 is spaced further away from the magnet 30 than the first coil section 401. That is, the second coil section 402 is less affected by the magnetic field from the magnet 30 than the first coil section 401. As a result, when the magnet 30 is located at the track ends R1 and R2, the magnitudes of the forces F4, F6, F10, and F12 in the opposite direction to the oscillation directions D1 and D2 become smaller. As a result, the reduction in torque on the magnet 30 at the track ends R1 and R2 is suppressed.

[0057] (3) In the direction along the reference line DX1 connecting the oscillation axis AX and the midpoint R3 of the trajectory, the length of the first coil section 401 is longer than the length of the second coil section 402. This makes it possible to form multiple coil sections in the coil 40 that are at different distances from the oscillation axis AX.

[0058] (4) When the magnet 30 is located at the ends of the oscillating trajectory R1 and R2, one pole faces the first coil section 401 and the other pole faces the second coil section 402. As a result, when the magnet 30 is located at the ends of the trajectory R1 and R2, the magnitude of the forces F4, F6, F10, and F12 in the opposite direction to the oscillating directions D1 and D2 is reduced. As a result, the reduction in torque on the magnet 30 at the ends of the trajectory R1 and R2 is suppressed. Furthermore, when the magnet 30 is located at the midpoint of the oscillating trajectory R3, both poles face the second coil section 402. As a result, when the magnet 30 is located at the midpoint of the trajectory R3, no force is generated in the opposite direction to the oscillating directions D1 and D2. As a result, only the torque necessary for the oscillation of the magnet 30 can be applied at the midpoint of the trajectory R3.

[0059] Furthermore, this technology can be configured as follows:

[0060] (1) A rocking device comprising: a movable part that can rock about an axis of oscillation; a coil; and a magnet provided between the movable part and the coil in a direction intersecting the axis of oscillation, connected to the movable part at one end, and capable of rocking together with the movable part, wherein the magnet has different polarities in the direction along the trajectory of oscillation, and the coil has a plurality of coil parts at different distances from the axis of oscillation, the plurality of coil parts including a first coil part and a second coil part provided closer to the midpoint of the trajectory of oscillation than the first coil part, and the distance between the axis of oscillation and the first coil part is shorter than the distance between the axis of oscillation and the second coil part.

[0061] (2) The rocking device according to (1), wherein the second coil portion is spaced further away from the magnet than the first coil portion.

[0062] (3) The rocking device according to (1) or (2), wherein the length of the first coil portion is longer than the length of the second coil portion in the direction connecting the rocking axis and the midpoint of the trajectory.

[0063] (4) The rocking device according to any one of (1) to (3), wherein when the magnet is located at the end of the rocking trajectory, one pole faces the first coil portion and the other pole faces the second coil portion, and when it is located at the midpoint of the rocking trajectory, both poles face the second coil portion.

[0064] (5) The oscillating device according to any one of (1) to (4), wherein the multiple coil sections are separate components.

[0065] (6) The oscillating device according to any one of (1) to (5), wherein the coil is an air-core flat coil. [Explanation of Symbols]

[0066] 10 Oscillating mechanism, 20 Movable part, 30 Magnet, 40 Coil, 301, 302, 303 Magnet, 401 First coil section, 402 Second coil section, AX Oscillating axis, DX1 Reference line, R Orbit, R1, R2 Orbital ends

Claims

1. A movable part that can swing around a pivot axis, Coil and, The system includes a magnet provided between the movable part and the coil in a direction intersecting the pivot axis, connected to the movable part at one end, and capable of pivoting together with the movable part, The aforementioned magnet has different polarities in the direction along the oscillating trajectory. The coil has a plurality of coil sections at different distances from the pivot axis, and the plurality of coil sections include a first coil section and a second coil section provided closer to the midpoint of the pivot trajectory than the first coil section. A rocking device in which the distance between the rocking shaft and the first coil portion is shorter than the distance between the rocking shaft and the second coil portion.

2. In the rocking device according to claim 1, The oscillating device wherein the second coil portion is spaced further away from the magnet than the first coil portion.

3. In the rocking device according to claim 2, An oscillating device in which, in the direction connecting the oscillating axis and the midpoint of the trajectory, the length of the first coil portion is longer than the length of the second coil portion.

4. In the rocking device according to claim 3, The rocking device wherein, when the magnet is located at the end of the rocking trajectory, one pole faces the first coil portion and the other pole faces the second coil portion, and when the magnet is located at the midpoint of the rocking trajectory, both poles face the second coil portion.

5. In the rocking device according to claim 4, A rocking device in which the multiple coil sections are separate components.

6. In the rocking device according to any one of claims 1 to 5, The aforementioned coil is an air-core flat coil, and the device is an oscillating mechanism.

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