Actuator

Abstract

One example is to reduce the size of an actuator that drives a mirror along two axes.SOLUTION: The actuator (10) comprises a mirror (20), a first electromagnet (30) and a second electromagnet (40). The mirror (20) is provided with a permanent magnet (21). The mirror (20) can oscillate with respect to a reference surface (101) with a first axis (201) and a second axis (202) non-parallel to the first axis (201) as oscillation axes. The first electromagnet (30) oscillates the mirror (20) with respect to the first axis (201). The second electromagnet (40) oscillates the mirror (20) with respect to the second axis (202). In the actuator (10), at least one of the following (A) and (B) is satisfied. (A) The first electromagnet (30) is not line-symmetric with respect to the first axis (201) when viewed from the direction perpendicular to the reference plane (101). (B) The second electromagnet (40) is not line-symmetric with respect to the second axis (202) when viewed from the direction perpendicular to the reference plane (101).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an actuator. [Background technology]

[0002] 2. Description of the Related Art In a measuring device that scans a predetermined area with light to perform measurement, a movable mirror is used to change the direction in which light is emitted.

[0003] Patent Document 1 describes an optical scanning device in which a permanent magnet fixed to a mirror interacts with an electromagnet to generate a driving torque on the mirror. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-69676 Summary of the Invention [Problem to be solved by the invention]

[0005] Reducing the size of the actuator that drives the mirror is important for reducing the overall size of the measurement device that includes it. However, driving the mirror along two axes requires two sets of electromagnets, which creates the problem of increasing the size of the actuator.

[0006] One example of a problem to be solved by the present invention is to reduce the size of an actuator that drives a mirror along two axes. [Means for solving the problem]

[0007] The first invention is a mirror provided with a permanent magnet and capable of swinging with respect to a reference plane about a first axis and a second axis non-parallel to the first axis; a first electromagnet that oscillates the mirror about the first axis; a second electromagnet that oscillates the mirror about the second axis; At least one of the following is true: (A) when viewed from a direction perpendicular to the reference plane, the first electromagnet is not line-symmetric with respect to the first axis; and (B) when viewed from a direction perpendicular to the reference plane, the second electromagnet is not line-symmetric with respect to the second axis. It is an actuator. [Brief explanation of the drawings]

[0008] [Figure 1] 2A and 2B are diagrams illustrating the configuration of an actuator according to the first embodiment. [Figure 2] 2A and 2B are diagrams illustrating the configuration of an actuator according to the first embodiment. [Figure 3] FIG. 2 is a plan view illustrating a structure including a mirror, an outer frame, and an inner frame. [Figure 4] FIG. 2 is a perspective view illustrating the structure of a first electromagnet and a second electromagnet. [Figure 5] FIG. 10 is a diagram showing a comparative example of the arrangement of electromagnets. [Figure 6] FIG. 10 is a diagram showing a comparative example of the arrangement of electromagnets. [Figure 7] 10A and 10B are diagrams showing modified examples of the cross-sectional shape of the yoke of the second electromagnet. [Figure 8] 10A and 10B are diagrams showing modified examples of the coil winding method. [Figure 9] 10A and 10B are diagrams illustrating examples of the shape of a second electromagnet according to a second embodiment. [Figure 10] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 11] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 12] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 13] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 14]10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 15] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 16] 10A and 10B are diagrams showing modified shapes of the second electromagnet according to the second embodiment. [Figure 17] 10A and 10B are diagrams illustrating the configuration of an actuator according to a third embodiment. [Figure 18] 10A and 10B are diagrams illustrating the structure of a first electromagnet according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and the description thereof will be omitted as appropriate.

[0010] (First embodiment) 1 and 2 are diagrams illustrating the configuration of an actuator 10 according to a first embodiment. FIG. 1 is a plan view of the actuator 10, and FIG. 2 is a side view of the actuator 10. Each diagram also illustrates an x-axis, a y-axis, and a z-axis as three mutually orthogonal axes. In this embodiment, the x-axis is parallel to a first axis 201, and the y-axis is parallel to a second axis 202. FIG. 3 is a plan view illustrating a structure 12 including a mirror 20, an outer frame 50, and an inner frame 60. FIG. 4 is a perspective view illustrating the structures of a first electromagnet 30 and a second electromagnet 40.

[0011] The actuator 10 according to this embodiment includes a mirror 20, a first electromagnet 30, and a second electromagnet 40. The mirror 20 is provided with a permanent magnet 21. The mirror 20 is capable of swinging with respect to a reference plane 101 around a first axis 201 and a second axis 202 as swing axes. The first axis 201 and the second axis 202 are non-parallel. The first electromagnet 30 swings the mirror 20 around the first axis 201. The second electromagnet 40 swings the mirror 20 around the second axis 202. At least one of the following (A) and (B) is satisfied in the actuator 10. (A) When viewed from a direction perpendicular to the reference plane 101 (z-axis direction), the first electromagnet 30 is not line-symmetric with respect to the first axis 201. (B) When viewed from a direction perpendicular to the reference plane 101, the second electromagnet 40 is not symmetrical with respect to the second axis 202. This is explained in detail below.

[0012] The mirror 20 has a reflective surface 22, and a permanent magnet 21 is fixed to the center of the surface opposite the reflective surface 22. One pole of the permanent magnet 21, a first pole 211, faces the mirror 20, and the other pole, a second pole 212, faces the opposite side of the mirror 20, i.e., the side where the first electromagnet 30 and the second electromagnet 40 are provided. The reference plane 101 is a plane including the reflective surface 22 of the mirror 20 in a reference state where no current flows through the coils of all the electromagnets provided in the actuator 10, i.e., where the permanent magnet 21 is not subjected to any force. Note that both Figures 1 and 2 show the reference state. The reference plane 101 is parallel to the xy plane.

[0013] The actuator 10 is a two-axis actuator, and can oscillate the mirror 20 about a first axis 201 and a second axis 202. This allows the direction of light reflected by the reflecting surface 22 of the mirror 20 to be changed two-dimensionally. In this embodiment, the first axis 201 and the second axis 202 are substantially perpendicular or perpendicular to each other.

[0014] In the first electromagnet 30, a coil 32 is wound around at least a portion of a yoke 34. When a current flows through the coil 32, a magnetic flux is generated between an end 341 and an end 342. This magnetic flux acts on the permanent magnet 21, causing the mirror 20 to oscillate about the first axis 201. In the second electromagnet 40, a coil 42 is wound around at least a portion of a yoke 44. When a current flows through the coil 42, a magnetic flux is generated that extends from the first end 441 and the second end 442. This magnetic flux acts on the permanent magnet 21, causing the mirror 20 to oscillate about the second axis 202.

[0015] As described above, at least one of the above (A) and (B) is true for the actuator 10 of this embodiment. By arranging a plurality of electromagnets asymmetrically in this manner, it is possible to reduce the size of the actuator 10.

[0016] 5 and 6 are diagrams showing comparative examples of electromagnet arrangements. Each of FIGS. 5 and 6 shows two electromagnets for oscillating a mirror (not shown) about two axes. In FIG. 5, electromagnet 91 drives the mirror about axis 910 as the oscillation axis, and electromagnet 92 drives the mirror about axis 920 as the oscillation axis. When the two electromagnets are viewed from the z-axis direction, electromagnet 91 is line-symmetrical with respect to axis 910, and electromagnet 92 is line-symmetrical with respect to axis 920. Also, in FIG. 6, electromagnet 93 drives the mirror about axis 930 as the oscillation axis, and electromagnet 94 drives the mirror about axis 940 as the oscillation axis. When the two electromagnets are viewed from the z-axis direction, electromagnet 93 is line-symmetrical with respect to axis 930, and electromagnet 94 is line-symmetrical with respect to axis 940. In these examples, two magnetic flux generating end portions are provided and arranged symmetrically with respect to the oscillation axis. As a result, one electromagnet must straddle the other in order to avoid structural interference with the other, and such a structure inevitably results in an increase in size as a whole.

[0017] In contrast, in the actuator 10 according to this embodiment, the actuator 10 can be prevented from becoming large by arranging a plurality of electromagnets asymmetrically.

[0018] The first electromagnet 30 and the second electromagnet 40 will be further described with reference to FIGS. 1, 2, and 4. In the actuator 10 according to this embodiment, the first electromagnet 30 and the second electromagnet 40 each have a coil and a yoke. Specifically, the first electromagnet 30 includes a coil 32 and a yoke 34. The second electromagnet 40 includes a coil 42 and a yoke 44. The first electromagnet 30 is U-shaped or C-shaped, and the second electromagnet 40 is I-shaped. Specifically, when viewed from a direction perpendicular to the reference plane 101, both ends (end 341 and end 342) of the yoke 34 of the first electromagnet 30 face each other with at least a portion of the permanent magnet 21 sandwiched between them. When viewed in a direction parallel to the reference plane 101, the yoke 44 of the second electromagnet 40 has a first end 441 located on the reference plane 101 side with respect to the coil 42 of the second electromagnet 40, and a second end 442 located on the opposite side from the reference plane 101 side. When viewed in a direction perpendicular to the reference plane 101, the first end 441 at least partially overlaps the second end 442. The end 341, the end 342, the first end 441, and the second end 442 are all magnetic flux generating ends.

[0019] In the example of Fig. 1, the above (A) does not hold, but (B) does hold. However, a configuration in which (A) holds and (B) does not hold, or a configuration in which both (A) and (B) hold, may also be possible.

[0020] In this embodiment, the first electromagnet 30 does not surround the second electromagnet 40. Specifically, when viewed from at least one direction parallel to the reference plane 101 (for example, the y-axis direction), the first electromagnet 30 and the second electromagnet 40 do not overlap each other. In this embodiment, the portion of the yoke 34 of the first electromagnet 30 around which the coil 32 is wound extends parallel to the reference plane 101. When viewed from a direction perpendicular to the reference plane 101, the coil 32 is located on the opposite side of the second electromagnet 40 with respect to the second axis 202. In addition, the ends 341 and 342 are closer to the mirror 20 than the coil 32. The yoke 44 of the second electromagnet 40 extends in a direction perpendicular to the reference plane 101, and only one of the ends of the yoke 44 faces the mirror 20. In the example shown in this figure, the cross section of the yoke 44 around which the coil 42 is wound is square. The number of magnetic flux generating ends facing the structure 12 differs between the first electromagnet 30 and the second electromagnet 40 .

[0021] Next, with reference to FIGS. 1 and 3 , a structure 12 including a mirror 20, an outer frame 50, and an inner frame 60 will be described. The actuator 10 further includes an outer frame 50, a torsion bar 52, an inner frame 60, and a torsion bar 62. The outer frame 50 and the inner frame 60 are connected via two torsion bars 52. The inner frame 60 and the mirror 20 are connected via two torsion bars 62. The outer frame 50, the torsion bar 52, the inner frame 60, the torsion bar 62, and the mirror 20 are integrally formed by, for example, micromachining a semiconductor wafer, and the actuator 10 is a MEMS actuator. In this embodiment, the first electromagnet 30 and the second electromagnet 40 are entirely located on one side of the structure 12 including the outer frame 50, the torsion bar 52, the inner frame 60, the torsion bar 62, and the mirror 20.

[0022] For example, the outer frame 50 is fixed to a housing (not shown) of the actuator 10. The inner frame 60 is capable of swinging relative to the outer frame 50 around a first axis 201 as a swing axis. The two torsion bars 52 coincide with the first axis 201. That is, the two torsion bars 52 overlap along the first axis 201, and the inner frame 60 swings relative to the outer frame 50 as the torsion bars 52 twist. Furthermore, the mirror 20 is capable of swinging relative to the inner frame 60 around a second axis 202 as a swing axis. The two torsion bars 62 coincide with the second axis 202. That is, the two torsion bars 62 overlap along the second axis 202, and the mirror 20 swings relative to the inner frame 60 as the torsion bars 62 twist. In the above-described reference state, no twist occurs in the torsion bars 52 and 62, and one surface of each of the outer frame 50, the inner frame 60 and the mirror 20 is located on the same plane as the reference surface 101.

[0023] 1 and 2, the driving of the actuator 10 by the first electromagnet 30 will be described below. When current flows through the coil 32 of the first electromagnet 30, a magnetic flux is generated between the end 341 and the end 342. At this time, the end 341 and the end 342 have opposite polarities. The orientation of the mirror 20 changes so that the permanent magnet 21 faces the end 341 or 342 that has the opposite polarity from the second pole 212. The orientation of the reflective surface 22 of the mirror 20 can be controlled by changing the direction and magnitude of the current flowing through the coil 32. Note that the magnetic flux can extend not only from the surfaces of the end 341 and the end 342 facing each other (planes perpendicular to the y-axis in this example), but also from the side surfaces (planes perpendicular to the x-axis in this example) and top surfaces (planes perpendicular to the z-axis in this example) of the end 341 and the end 342. These magnetic fluxes act on the permanent magnet 21 to drive the mirror 20.

[0024] The driving of the actuator 10 by the second electromagnet 40 will be described below. When viewed from a direction perpendicular to the reference plane 101, the center of the first end 441 and the center of the mirror 20 do not overlap. In other words, the first end 441 and the mirror 20 are misaligned. In the example shown in this figure, specifically, the center of the first end 441 is misaligned from the center of the mirror 20 in a direction perpendicular to the second axis 202 (x-axis direction). On the other hand, the center of the first end 441 is not misaligned from the center of the mirror 20 in a direction parallel to the second axis 202 (y-axis direction). When a current flows through the coil 42 of the second electromagnet 40, a magnetic flux is generated extending from the first end 441. This magnetic flux from the first end 441 acts on the permanent magnet 21, causing the mirror 20 to oscillate relative to the second axis 202. Specifically, when the polarity of the first end 441 is opposite to that of the second pole 212, the orientation of the mirror 20 changes so that the permanent magnet 21 faces toward the first end 441. On the other hand, when the polarity of the first end 441 is the same as that of the second pole 212, the orientation of the mirror 20 changes so that the permanent magnet 21 faces away from the first end 441. The orientation of the reflective surface 22 of the mirror 20 can be controlled by changing the direction and magnitude of the current flowing through the coil 42. Note that magnetic flux can extend from the upper surface of the first end 441 (a surface perpendicular to the z-axis in the example shown in this figure), the lower surface of the second end 442 (a surface perpendicular to the z-axis in the example shown in this figure), and the side surfaces of the first end 441 and the second end 442 (a surface perpendicular to the y-axis or x-axis in the example shown in this figure). These magnetic fluxes act on the permanent magnet 21 to drive the mirror 20.

[0025] By simultaneously driving the first electromagnet 30 and the second electromagnet 40, the reflecting surface 22 can be directed in a desired direction.

[0026] In this embodiment, the second electromagnet 40 drives the mirror 20 to oscillate at a resonant frequency. When only one magnetic flux generating end is driven toward the permanent magnet 21, as in the case of the second electromagnet 40, the driving force tends to be smaller than when two magnetic flux generating ends are driven toward the permanent magnet 21, as in the case of the first electromagnet 30. In contrast, by driving the mirror 20 to oscillate at a resonant frequency, the mirror 20 can be driven sufficiently with a small force.

[0027] 7 is a diagram showing a modified example of the cross-sectional shape of the yoke of the second electromagnet 40. In the example shown in this figure, the cross section of the yoke 44 of the second electromagnet 40 at the portion around which the coil 42 is wound is rectangular. By doing so, the cross-sectional area of ​​the yoke can be increased, and the magnetic force generated by the second electromagnet 40 can be strengthened. As a result, even when only one magnetic flux generating end is driven toward the permanent magnet 21, the mirror 20 can be driven sufficiently.

[0028] 8 is a diagram showing a modified example of the winding method of the coil 42. In the example shown in this figure, the coil 42 in the second electromagnet 40 is wound in a lap-wound manner around the yoke 44. This makes it possible to strengthen the magnetic force generated by the second electromagnet 40. As a result, even when only one magnetic flux generating end is driven toward the permanent magnet 21, the mirror 20 can be driven sufficiently.

[0029] As described above, according to this embodiment, at least one of the above (A) and (B) is established, which increases the degree of freedom in the design of the arrangement of the two electromagnets, and allows the actuator 10 to be made smaller.

[0030] (Second embodiment) 9 is a diagram illustrating an example of the shape of the second electromagnet 40 according to the second embodiment. The actuator 10 according to this embodiment is the same as the actuator 10 according to the first embodiment except for the shape of the second electromagnet 40, which will be described below. In FIGS. 9 to 16, which will be described below, the upper part of each figure shows a plan view of the second electromagnet 40, and the lower part shows a side view.

[0031] In this embodiment, at least one of the first end 441 and the second end 442 is provided with a protrusion 444 that protrudes toward the permanent magnet 21 when viewed from a direction perpendicular to the reference plane 101. Providing the protrusion 444 makes it possible to bring the magnetic flux generating end of the yoke 44 and the permanent magnet 21 closer together, thereby strengthening the driving force of the mirror 20. Furthermore, when the coil 42 is lap-wound, the portion around which the coil 42 is wound becomes thicker, and it becomes necessary to move the central axis of the yoke 44 away from the permanent magnet 21. Even in this case, providing the protrusion 444 allows the magnetic flux to act sufficiently on the permanent magnet 21.

[0032] 9, a protrusion 444 is provided only on the first end 441. By providing the protrusion 444 on the first end 441, the driving force can be strengthened more effectively. Furthermore, by not providing the protrusion 444 on the second end 442, the actuator 10 can be made smaller and lighter than if the protrusion 444 were provided.

[0033] 10 to 16 are diagrams showing modified examples of the shape of the second electromagnet 40 according to this embodiment. Each will be explained below in order.

[0034] In the example of Fig. 10, the protrusion 444 protrudes not only toward the permanent magnet 21 but also in the y-axis direction. In the example of Fig. 11, the protrusion 444 also protrudes toward the opposite side from the permanent magnet 21. By widening the protrusion 444, the driving force can be made stronger.

[0035] 12, a protrusion 444 is provided only on the second end 442. Even with this configuration, it is possible to strengthen the driving force of the mirror 20 by the second electromagnet 40. The shape of the protrusion 444 on the second end 442 side is not particularly limited, and may be, for example, as shown in FIG. 10 or 11.

[0036] In the example of Figures 13 to 16, protrusions 444 are provided on both the first end 441 and the second end 442. This makes it possible to strengthen the driving force compared to when protrusions 444 are provided on only one of the ends. In the example of Figures 13 to 15, the protrusions 444 on the first end 441 side and the protrusions 444 on the second end 442 side have the same shape. In the example of Figure 16, the protrusions 444 on the first end 441 side and the protrusions 444 on the second end 442 side have different shapes.

[0037] As described above, according to this embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, at least one of the first end 441 and the second end 442 is provided with a protrusion 444 that protrudes toward the permanent magnet 21 when viewed from a direction perpendicular to the reference plane 101. This allows the magnetic flux of the second electromagnet 40 to act more strongly on the permanent magnet 21, thereby increasing the driving force of the mirror 20.

[0038] (Third embodiment) 17 is a diagram illustrating the configuration of an actuator 10 according to a third embodiment. The actuator 10 according to this embodiment is the same as the actuator 10 according to at least one of the first and second embodiments, except that the first electromagnet 30 drives the mirror 20 to oscillate at a resonant frequency.

[0039] In this embodiment, the inner frame 60 can swing relative to the outer frame 50 around a second axis 202 as a swing axis. The two torsion bars 52 coincide with the second axis 202. That is, the two torsion bars 52 overlap along the second axis 202, and the inner frame 60 swings relative to the outer frame 50 as the torsion bars 52 twist. The mirror 20 can swing relative to the inner frame 60 around a first axis 201 as a swing axis. The two torsion bars 62 coincide with the first axis 201. That is, the two torsion bars 62 overlap along the first axis 201, and the mirror 20 swings relative to the inner frame 60 as the torsion bars 62 twist.

[0040] As described above, according to this embodiment, the same actions and effects as those of the first embodiment can be obtained.

[0041] (Fourth embodiment) 18 is a diagram illustrating the structure of the first electromagnet 30 according to this embodiment. The actuator 10 according to this embodiment is the same as the actuator 10 according to at least one of the first to third embodiments, except for the points described below. In this figure, the permanent magnet 21 is indicated by a dashed line.

[0042] In this embodiment, the first electromagnet 30 is made up of two electromagnets, electromagnet 70 and electromagnet 80. In other words, the yoke 34 of the first electromagnet 30 is divided into two parts. The first electromagnet 30 as a whole is line-symmetrical with respect to the first axis 201. The electromagnets 70 and 80 each extend parallel to the first axis 201 when viewed from a direction perpendicular to the reference plane 101. When viewed from a direction perpendicular to the reference plane 101, the first electromagnet 30 does not overlap with the first axis 201.

[0043] Electromagnet 70 includes a coil 72 and a yoke 74, and electromagnet 80 includes a coil 82 and a yoke 84. Coil 72 is wound around at least a portion of yoke 74. Coil 82 is wound around at least a portion of yoke 84. In the configuration according to this embodiment, first electromagnet 30 functions in the same manner as first electromagnet 30 according to the first embodiment. Specifically, end 741 and end 841 face each other and form a pair. End 741 of electromagnet 70 functions as end 341 described in the first embodiment, and end 841 of electromagnet 80 functions as end 342 described in the first embodiment.

[0044] As described above, according to this embodiment, the same actions and effects as those of the first embodiment can be obtained. In addition, the yoke 34 of the first electromagnet 30 is separated into two parts. This further increases the degree of freedom in the design of the arrangement of the two electromagnets, and allows the actuator 10 to be made more compact.

[0045] The above describes the embodiments with reference to the drawings, but these are merely examples of the present invention, and various other configurations may be adopted. For example, the actuator 10 may further include, in addition to the components shown in the drawings, portions that support the respective components, wiring, a control unit, etc. Furthermore, the shapes of the mirror 20, the first electromagnet 30, the second electromagnet 40, the structure 12, etc. are not limited to the examples of this embodiment. Below, examples of reference forms are given. 1. A mirror provided with a permanent magnet and capable of swinging with respect to a reference plane about a first axis and a second axis non-parallel to the first axis; a first electromagnet that oscillates the mirror about the first axis; a second electromagnet that oscillates the mirror about the second axis; At least one of the following is true: (A) when viewed from a direction perpendicular to the reference plane, the first electromagnet is not line-symmetric with respect to the first axis; and (B) when viewed from a direction perpendicular to the reference plane, the second electromagnet is not line-symmetric with respect to the second axis. Actuator. 2. The actuator according to 1., the first electromagnet and the second electromagnet each have a coil and a yoke; both ends of the yoke of the first electromagnet face each other with at least a part of the permanent magnet interposed therebetween when viewed from a direction perpendicular to the reference plane; The yoke of the second electromagnet has a first end portion located on the reference surface side and a second end portion located on the opposite side from the reference surface side, with the coil of the second electromagnet as a reference, when viewed from a direction parallel to the reference surface. Actuator. 3. In the actuator according to 2., The second electromagnet drives the mirror to oscillate at a resonant frequency. Actuator. 4. The actuator according to 2. or 3., When viewed from a direction perpendicular to the reference plane, the center of the first end and the center of the mirror do not overlap. Actuator. 5. The actuator according to any one of 2. to 4., At least one of the first end and the second end is provided with a protruding portion that protrudes toward the permanent magnet when viewed from a direction perpendicular to the reference plane. Actuator. 6. The actuator according to any one of 2. to 5., The cross section of the yoke around which the coil is wound in the second electromagnet is rectangular. Actuator. 7. The actuator according to any one of 2. to 6., In the second electromagnet, the coil is lap wound. Actuator. [Explanation of symbols]

[0046] 10 Actuators 12 Structure 20. Mirror 21 Permanent magnets 22 Reflective surface 30 First electromagnet 32 coils 34 York 40 Second electromagnet 42 Coil 44 York 50 outer frame 52 Torsion bar 60 Inner frame 62 Torsion bar 70 Electromagnet 72 Coil 74 York 80 Electromagnet 82 Coil 84 York 101 Reference plane 201 First Axis 202 Second Axis 211 First Pole 212 Second Pole 341 End 342 End 441 First end 442 Second end 444 Protrusion

Claims

[Claim 1] a mirror provided with a permanent magnet and capable of swinging with respect to a reference plane about a first axis and a second axis non-parallel to the first axis; a first electromagnet that oscillates the mirror about the first axis; a second electromagnet that oscillates the mirror about the second axis; The second electromagnet is smaller than the first electromagnet. Actuator.

Images