Oscillatory actuator and optical scanning device

Abstract

To achieve size reduction and to support a movable object such as a mirror stably and rotationally on two axes.SOLUTION: An oscillatory actuator has a fixed part which has a first coil, a first movable part which has a first magnet opposed to the first coil along the coil axis and is supported by the fixed part to reciprocally rotate on a first axis, and a second movable part which is supported by the first movable part to reciprocally rotate on a second axis orthogonal to the first axis, wherein the first movable part has a plurality of second magnets so arranged that mutually different magnetic poles face each other across a gap in the extension direction of the first axis, the second movable part has a second coil having one side part arranged in the gap, and the first coil and the second coil are supplied with electric power to make a movable object oscillate on the mutually orthogonal first axis and second axis cooperatively with the first magnet and second magnet.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a rocking actuator and an optical scanning device.

Background Art

[0002] Conventionally, as an actuator used in a scanner device such as a multifunction machine, a laser beam printer, a laser processing machine, a laser marker, etc., a reciprocating rotation drive type, that is, a rocking type actuator (hereinafter referred to as "rocking actuator") is known. The laser processing machine is, for example, laser drilling of a printed circuit board.

[0003] The rocking actuator includes, for example, a rotation axis to which a mirror is attached and a drive unit having a coil magnet. By energizing the coil and driving the rotation axis to reciprocally rotate, the reflection angle of the laser beam by the mirror is changed to realize optical scanning of an object.

[0004] In the rocking actuator shown in Patent Document 1, a mirror and a coil are attached to a horizontally extending rotation axis, and a magnet pair in which the S poles and N poles face each other with a gap therebetween is provided in a fixed portion. Each of both side portions of the coil parallel to the rotation axis direction is configured to be positioned in the gap between the S pole and the N pole of the magnet pair, and a total of four magnets are provided in the fixed portion. By energizing the coil, the mirror rocks.

[0005] In addition to the structure in which the mirror is rotated about one axis as in Patent Document 1, an optical scanning device in which the mirror is rotated about two axes is known. For example, in the optical scanning device of Patent Document 2, the mirror is provided so as to rock around a first axis and is also provided so as to rock around a second axis orthogonal to the first axis.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] By the way, in recent years, in an apparatus for rotating a mirror about two axes, it has been desired to make the apparatus itself more compact and drive it stably even when miniaturized. Patent Document 2 does not disclose a specific configuration for rotationally driving a mirror about two axes. Further, although a structure in which the base itself rotates about an axis orthogonal to the rotation axis can be considered in Patent Document 1, the structure for stably supporting the mirror for two-axis rotation makes the apparatus itself large.

[0008] The present invention has been made in view of such points, and an object thereof is to provide a swing actuator and a scanning device that can be miniaturized and can stably rotate and support a movable object such as a mirror about two axes. [Means for Solving the Problems

[0009] The swing actuator of the present invention includes: a fixed portion having a first coil; a first movable portion having a first magnet facing the first coil in the coil axis direction and supported by the fixed portion so as to be reciprocally rotatable about a first axis; a second movable portion connected to a movable object and supported by the first movable portion so as to be reciprocally rotatable about a second axis orthogonal to the first axis; and the first movable portion has a plurality of second magnets arranged such that different magnetic poles face each other with a gap in the extending direction of the first axis; the second movable portion has a second coil having a side portion disposed in the gap, and by energizing the first coil and the second coil, cooperates with the first magnet and the second magnet to cause the movable object to swing about the first axis and the second axis orthogonal to each other.

[0010] The optical scanning device of the present invention includes the swing actuator configured as described above, and the movable object adopts a configuration of a mirror that reflects scanning light.

Effect of the Invention

[0011] According to the present invention, miniaturization is possible, and a movable object such as a mirror can be stably rotationally supported on two axes.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] Regarding each part constituting the swing actuator 1 of the present embodiment, the description is based on the normal state in which the swing actuator 1 is not driven and is in a non-operating state. In addition, when describing the structure of the swing actuator 1 of the present embodiment, a rectangular coordinate system (X, Y, Z) is used. The same rectangular coordinate system (X, Y, Z) is also shown in the figures described later.

[0015] FIG. 1 is a perspective view of a swing actuator according to an embodiment of the present invention, and FIG. 2 is a plan view of the swing actuator according to an embodiment of the present invention. Further, FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2, and FIG. 4 is a cross-sectional view taken along line B-B of FIG. 2. FIG. 5 is a view showing a state in which the fixed part, the first movable part, and the second movable part of the swing actuator according to the present embodiment are separated. Also, FIG. 6 is an exploded perspective view of the swing actuator according to an embodiment of the present invention.

[0016] The swing actuator 1 is used, for example, in an optical scanning device such as a laser processing machine, a multifunction machine, a laser beam printer, or a lidar (Laser Imaging Detection and Ranging) device.

[0017] The swing actuator 1 shown in FIGS. 1 to 6 has a fixed part 2, a first movable part 4, a second movable part 6, and a movable object (mirror 8). The swing actuator 1 supports the mirror 8, which is a movable object, so as to be swingable about two axes orthogonal to the X-axis and the Y-axis with respect to the fixed part 2 via the first movable part 4 and the second movable part 6. The X-axis direction is also referred to as the first axis direction, the Y-axis direction is also referred to as the second axis direction, and the Z-axis direction is also referred to as the third axis direction.

[0018] <Fixed part 2> FIG. 7 is an enlarged exploded perspective view of the fixed part shown in FIG. 6. The fixing part 2 shown in FIGS. 1 to 7 is fixed to a device for attaching the swing actuator 1. The fixing part 2 includes a base part 21, coils 32 and 34, a flexible substrate 25, and a damping member 27. A first movable part 4 is swingably attached to the fixing part 2 via a bearing 28.

[0019] The base part 21 has a plate-shaped bottom surface part 211, a pair of rising parts 214 and 215 spaced apart in the Y direction on the bottom surface part 211, and a pair of support column parts 217 and 218 standing upright and spaced apart in the X direction on the bottom surface part 211.

[0020] The bottom surface part 211 is fixedly attached to the device on which the swing actuator 1 is mounted in surface contact. Thereby, the mirror 8 of the swing actuator 1 is swingably attached to the device. The bottom surface part 211 has a rectangular shape in plan view and is formed, for example, in a square shape. The shape of the bottom surface part 211 defines the outer shape of the swing actuator 1 in plan view.

[0021] The first movable part 4 is disposed above the central part of the bottom surface part 211. A pair of rising parts 214 and 215 and a pair of support column parts 217 and 218 are erected on the bottom surface part 211 so as to surround the first movable part 4 in all four directions of the X-axis direction and the Y-axis direction.

[0022] The rising parts 214 and 215 hold the coils 32 and 34 in a state of facing each other with the first movable part 4 interposed therebetween in the coil axis direction and spaced apart from the first magnets 36 and 38 (also referred to as "outer magnets") of the first movable part 4. The rising parts 214 and 215 support the coils (also referred to as "outer coils") 32 and 34. Openings 214a and 215a are formed in the rising parts 214 and 215. A pair of coils 32 and 34 are disposed in the openings 214a and 215a.

[0023] Coils 32 and 34 are mounted on the flexible substrate 25, and the flexible substrate 25 is attached to the rising portions 214 and 215 so as to cover the openings 214a and 215a. Thereby, the pair of coils 32 and 34 are respectively arranged in the openings 214a and 215a so as to sandwich the first movable portion 4 from both sides in the Y direction.

[0024] The pair of coils 32 and 34 are located at positions symmetric with respect to the center of the bottom surface portion 211, and are arranged at positions where the coil axes are on the same straight line and face each other.

[0025] The support pillar portions 217 and 218 are formed in the same shape and arranged opposite to each other, and notches 217a and 218a into which the bearings 28 are fitted are provided at the upper end portions of the support pillar portions 217 and 218 respectively. The notches 217a and 218a are arranged outside the X direction with the first movable portion 4 interposed therebetween, and are formed to open in the directions facing each other and the Z direction (upward).

[0026] The damping member 27 damps the operation of the first movable portion 4 (specifically, the first holder 41) with respect to the base portion 21. The damping member 27 is arranged between the base portion 21 and the first movable portion 4, and damps the torque in the moving direction when the first movable portion 4 moves (swings).

[0027] The damping member 27 is, for example, a compression coil spring, and is provided so as to protrude upward from the bottom surface portion 211. The damping member 27 is arranged at a position where it contacts the protrusion 44 of the first movable portion 4 when the first movable portion 4 rotates about the shaft portion (X-axis portion) 42.

[0028] The damping member 27 is a member that expands and contracts in the longitudinal direction. For example, as shown in FIGS. 1, 5 to 7, the damping member 27 is disposed in the recesses 2122 formed at the four corners of the bottom surface portion 211, and is a compression coil spring that protrudes in the Z direction (upward). The recesses 2122 are formed corresponding to the protrusions 44 of the first movable portion 4, are arranged symmetrically in the Y direction with the shaft portion 42 interposed therebetween and with the axis of the shaft portion 42 as the center (see FIG. 10).

[0029] The coil spring as the damping member 27 is connected to one of the bottom surface portion 211 of the base portion 21 and the protrusion 44 of the first holder 41 of the first movable portion 4 (the bottom surface portion 211), and is arranged separately from the other (the protrusion 44). Thereby, the biasing force is not always applied to the first movable portion 4 or the bottom surface portion 211 of the base portion 21 during the movement of the protrusion 44, that is, the first movable portion 4, and it does not act as a resistance. The damping member 27 can abut against the contact surface 442 of the protrusion 44 and suppress the movement of the first movable portion 4 before the first movable portion 4 rotates and collides with a mechanical stopper (for example, the bottom surface portion 211) that restricts the movement of the first movable portion 4.

[0030] By damping the operation of the first movable portion 4 by the damping member 27 against the protrusion 44 (contact surface 442), it is possible to suppress the collision of the first movable portion 4 (the first holder 41) against the bottom surface portion 211, and it is possible to reduce the operation noise of the first movable portion 4 (the first holder 41).

[0031] Further, since the damping member 27 has a restoring force, after being pressed by the protrusion 44 of the first movable portion 4 and the pressing state is released, the restoring force can bias the protrusion 44 to move toward the reference position (the original position) side.

[0032] The damping member 27 is attached to the base portion 21 and is arranged at a position separated from the first holder 41 (the protrusion 44) in the reference position (non-driven position), but is not limited to this, and they may be provided so as to be connected. Further, the damping member 27 may be provided so as to be led out from the contact surface 442 of the protrusion 44 toward the bottom surface portion 211 side, and may be configured to abut against and press the bottom surface portion 211 during movement and attenuate the moving force of the first movable portion 4 by the reaction force.

[0033] <The first movable portion 4> FIG. 8 is an enlarged exploded perspective view of the first movable portion and the second movable portion shown in FIG. 6. The first movable portion 4 shown in FIGS. 1 to 8 is rotatable about the first axis, that is, the shaft portion (X-axis portion) 42 with respect to the fixed portion 2, and supports the second movable portion 6 and the movable object (mirror 8) so as to be rotatable about the second axis, that is, the Y-axis.

[0034] The first movable part 4 includes a first holder (outer holder) 41, first magnets (outer magnets) 36 and 38, and second magnets (inner magnets 64, 66, and central magnet 68).

[0035] The outer magnets 36 and 38, together with the coils 32 and 34 of the fixed part 2, form a first magnetic circuit. The first magnetic circuit generates magnetic flux by energizing the coils 32 and 34, and due to this magnetic flux, the first movable part 4 and the second movable part 6 swing around the shaft part (X-axis part) 42.

[0036] The outer magnets 36 and 38 are a pair of permanent magnets with the same shape, each having magnetic pole faces 36n, 36s, 38n, and 38s. The outer magnets 36 and 38 are fixed to both side surfaces of the first holder 41 that are spaced apart in the Y direction.

[0037] The outer magnets 36 and 38 are respectively arranged to extend in the lateral direction (X direction) facing the coils. The outer magnets 36 and 38 have magnetic pole faces 36n, 36s, 38n, and 38s with different poles at the top and bottom. The magnetic pole faces 36n, 36s with different poles and the magnetic pole faces 38n, 38s with different poles respectively face the upper and lower side parts 32a, 32b of the coil 32 and the upper and lower side parts 34a, 34b of the coil 34 in the Y direction.

[0038] The outer magnets 36 and 38 are symmetrically arranged in the Y direction with the shaft part (X-axis part) 42 of the first movable part 4 as the center. The outer magnets 36 and 38 are arranged on the coil axes of the coils 32 and 34. It is preferable that the centers of the outer magnets 36 and 38 are located on the coil axes of the coils 32 and 34.

[0039] The inner magnets 64 and 66 are a pair of permanent magnets with the same shape, and together with the central magnet 68 and the coil (hereinafter referred to as the "inner coil") 63 of the second movable part 6, form a second magnetic circuit. The second magnetic circuit generates magnetic flux by energizing the inner coil 63, and due to this magnetic flux, the second movable part 6 swings around the Y axis, and accordingly, the mirror 8, which is the object to be moved, swings around the Y axis.

[0040] The inner magnets 64 and 66 are arranged so as to sandwich the central magnet 68 and be spaced apart from the central magnet 68. The inner magnets 64 and 66 are disposed outside the inner coil 63 of the second movable part 6 arranged to surround the central magnet 68, and are spaced apart from the inner coil 63 and arranged to sandwich the inner coil 63 in one direction (X direction).

[0041] The inner magnets 64 and 66 have magnetic pole faces 64s and 66n facing each other. The opposing magnetic pole faces 64s and 66n are different magnetic poles from each other and are arranged to face each other with a space therebetween. That is, the inner magnets 64 and 66, together with the central magnet 68, are arranged such that magnetic flux flows in a direction in which the respective magnetic pole faces are attracted in one direction (X direction) in the order of N, S, N, S, or S, N, S, N.

[0042] The inner magnets 64 and 66 are arranged so as to sandwich each of the pair of parallel side portions of the inner coil 63 between the inner magnets 64 and 66 and the central magnet 68. The magnetic pole face 64s faces the magnetic pole face 68n of the central magnet 68, and the magnetic pole face 66n faces the magnetic pole face 68s of the central magnet 68, and the magnetic poles attract each other on the opposing faces.

[0043] The central magnet 68 has magnetic pole faces 68n and 68s that face the inner magnets 64 and 66 in the X-axis direction (axial direction of the shaft portion 42). The central magnet 68 is a block-shaped body magnetized in the same direction as the magnetization directions of the inner magnets 64 and 66. For example, the central magnet 68 is a rectangular parallelepiped having different magnetic pole faces 68n and 68s facing in opposite directions, and may be a cube. The magnetic pole faces 68n and 68s of the central magnet 68 are a pair of parallel and different magnetic pole faces spaced apart in the X-axis direction, which is the first direction. For example, the magnetic pole face 68n is an N pole and the magnetic pole face 68s is an S pole.

[0044] The central magnet 68 is arranged together with the inner magnets 64 and 66 such that N and S are arranged in one direction (X direction), and a flow of magnetic flux is formed in one direction (X direction).

[0045] In the middle of the magnetic flux flow formed by the central magnet 68 and the pair of inner magnets 64, 66, the inner coil 63 of the second movable part 6 is arranged to flow in a direction orthogonal to the magnetic flux flow.

[0046] The outer magnets (first magnets) 36, 38 are respectively provided on both side surfaces of the first movable part 4, and the inner magnets 64, 66 and the central magnet 68 (a plurality of second magnets) are three magnets arranged in the first direction. The central magnet 68 among the three second magnets is positioned at a position sandwiched by the pair of outer magnets (first magnets) 36, 38, and the inner magnets 64, 66 and the central magnet 68 are arranged side by side in the first axial direction.

[0047] The first holder 41 is configured with a compact square-shaped first holder 41 by arranging the outer magnets 36, 38 and the inner magnets 64, 66 to surround the central magnet 68 in a rectangular frame.

[0048] The first holder 41 rotatably holds the mirror 8, which is an object to be moved, the outer magnets 36, 38 of the first magnetic circuit that oscillate on two orthogonal axes, and the inner magnets 64, 66 and the central magnet 68 of the second magnetic circuit, around the shaft part (X-axis part) 42 with respect to the base part 21. Further, the first holder 41 has a shaft part 42 and a protrusion part 44.

[0049] The first holder 41 is formed in a box shape having a bottom surface part 411 that is square in plan view with the central magnet 68 arranged at the center. The first holder 41 is a non-magnetic body and is composed of resin or the like.

[0050] The first holder 41 holds the outer magnets 36, 38 with a gap in the Y direction, with the magnetization direction of the outer magnets 36, 38 being the Y direction. The first holder 41 arranges and holds the inner magnets 64, 66 and the central magnet 68 with a predetermined gap in the X-axis direction, with the magnetization direction of the inner magnets 64, 66 and the central magnet 68 being the X-axis direction, between the outer magnets 36, 38.

[0051] On the bottom surface part 411, ribs 41e for positioning the central magnet 68 and ribs 41c, 41f for positioning the inner magnets 64, 66 protrude and are provided.

[0052] The rib 41e protrudes in a frame shape at the center of the bottom surface portion 411, enabling the accurate attachment of the central magnet 68. Further, the ribs 41c and 41f are ribs for positioning the inner magnets 64 and 66, and maintain the distance between the inner magnets 64 and 66 and the central magnet 68, or the distance from the rectangular frame-shaped inner coil 63 disposed within that distance.

[0053] The first holder 41 has peripheral wall portions (wall portions 412, 413, side wall portions 414, 415) that rise from the bottom surface portion 411. Among the peripheral wall portions, a pair of parallel wall portions 412 and 413 spaced apart in the first direction (X direction) have notch portions 412a and 413a partitioned by ribs 41c and 41f on the inside. Inside these notch portions, the inner magnets 64 and 66 are disposed so as to face each other.

[0054] The elastic support portion 9 is suspended across the upper portions of the other pair of wall portions (also referred to as "side wall portions") 414 and 415 adjacent to the pair of wall portions 412 and 413 of the first holder 41. Concave portions 46 for securing a deformation region of the elastic support portion 9 are respectively formed in the upper portions of the pair of side wall portions 414 and 415.

[0055] Within the first holder 41, a second movable portion 6 supported via the elastic support portion 9 is disposed so as to be rotatable about the Y axis (axis along the second direction).

[0056] The shaft portion (X-axis portion) 42 serves as the rotation center of the first holder 41 and is provided on each of the outer surfaces of the pair of wall portions 412 and 413. The shaft portion (X-axis portion) 42 is arranged so as to be located on the same straight line (X axis) in each of the pair of wall portions 412 and 413, and bearings 28 are externally inserted into each of the shaft portions (X-axis portions) 42. The shaft portion 42, together with the bearing 28, is respectively fitted into the notch portions 217a and 218a of the support column portions 217 and 218 of the fixed portion 2, thereby rotatably supporting the first holder 41, and thus the first movable portion 4, about the X axis with respect to the fixed portion 2.

[0057] FIG. 9 is a partial side cross-sectional view showing the positional relationship of the centers of gravity of the first movable part and the second movable part in the swing actuator according to the embodiment of the present invention. In the first holder 41, the shaft part (X-axis part) 42 is provided in the first holder 41 such that the rotation center position P of the first movable part 4 passes through the center of gravity of the second movable part 6 (specifically, the second holder 61), as shown in FIG. 9.

[0058] Further, the rotation center position (central axis) P of the first movable part 4 around the shaft part 42 is preferably located at a position overlapping with the center of gravity position of the second movable part 6 supported by the first movable part 4 or in the vicinity of the center of gravity position of the second movable part 6. For example, it is configured such that the center of gravity of the second movable part 6 is located on the central axis passing through the rotation center position P of the shaft part 42 or on the shaft part 42 (inside the outer diameter of the shaft part 42). With this configuration, when the first movable part 4 supporting the second movable part 6 reciprocally rotates around the shaft part 42, an increase in the moment of inertia during the rotation operation of the first movable part 4 due to the difference between the rotation center position P of the first movable part 4 and the center of gravity of the second movable part 6 can be prevented. That is, the swing actuator 1 can reduce the moment of inertia during the rotation operation of the first movable part 4 and can preferably reciprocally rotate, that is, swing, the first movable part 4.

[0059] The protruding parts 44 are symmetrically arranged at intervals in the second direction (Y direction) around the shaft part (X-axis part) 42 in each of the pair of wall parts 412 and 413 and protrude in the X-axis direction.

[0060] FIG. 10 is a diagram for explaining the positional relationship between the damping member and the protruding part. The protruding parts 44 shown in FIGS. 9 and 10 come into contact with the damping member 27 and damp its movement when the first movable part, specifically, the first holder rotates around the shaft part (X-axis part) 42. The damping member 27 may be provided at any location of the first movable part 4 as long as it dampens the movement of the first holder 41 around the X-axis.

[0061] Further, the protruding parts 44 are arranged above the coil spring which is the damping member 27. The protruding portion 44 abuts against the damping member 27 when moving and displacing around the shaft portion (X-axis portion) 42, but the damping member 27 may be fixed to the protruding portion 44 and configured to move and abut against the bottom surface portion 211.

[0062] <Second movable part 6> The second movable part 6 is fixed to the mirror 8 which is the object to be moved, is rotatably supported with respect to the first movable part 4 around the Y-axis, and is driven by the second magnetic circuit.

[0063] The second movable part 6, together with the first movable part 4, drives and supports the mirror 8 to be rotatable about two orthogonal axes (X, Y axes).

[0064] The second movable part 6 is connected to the first movable part 4 via the elastic support part 9, and has a second holder 61 supported by the elastic support part 9, a second coil (also referred to as an "inner coil") 63, and a mirror 8.

[0065] The second holder 61 holds the inner coil 63 and the mirror 8, and is rotatably supported around the Y-axis via the elastic support part 9.

[0066] Specifically, the second holder 61 is formed in a lid-shaped cylindrical shape with a square lid and an opening downward. The second holder 61 is arranged so as to cover the central magnet 68 from four directions (XY directions) and above (Z direction).

[0067] The second holder 61 has a square frame-shaped opening, and a step 614 is formed on the outer peripheral surface of the opening so as to have a smaller diameter than the outer peripheral surface 612 of the main body portion of the second holder 61. The inner coil 63 is externally fitted by the step 614, and thereby, the outer peripheral surface of the second holder 61 is flush with the outer peripheral surface of the inner coil 63.

[0068] The inner coil 63 is formed in a square tube shape, for example, formed as a frame body with a square cross section. The inner coil 63 is arranged so as to surround the central magnet 68 in a direction orthogonal to the Z direction, and is disposed between the central magnet 68 and the inner magnets 64, 66. The inner coil 63 is disposed at a predetermined interval from each of the central magnet 68 and the inner magnets 64 and 66, and swings around the X-axis via the second holder 61.

[0069] The elastic support portion 9 rotatably supports the second movable portion 6, specifically the second holder 61 (including the inner coil 63), around the Y-axis with respect to the first movable portion 4. The elastic support portion 9 includes a pair of fixed side portions 92, a fixed surface portion 94 disposed between the fixed side portions 92, and arm portions 96 that connect and elastically deform the fixed side portions 92 and the fixed surface portion 94.

[0070] The elastic support portion 9 is composed of a leaf spring having a pair of fixed side portions 92, arm portions 96, and a fixed surface portion 94, respectively, and is elastically deformable. The pair of fixed piece portions 92 are arranged parallel to each other and spaced apart, and are respectively fixed to the first movable portion 4 (the first holder 41). The fixed surface portion 94 is fixed to the second holder 61 and the mirror 8 is attached thereto. The arm portions 96 extend in the Y-axis direction from the fixed side portions 92 and are fixed to the fixed surface portion 94. The second movable portion 6 fixed to the fixed surface portion 94 is supported by the first movable portion 4 via the elastic support portion 9 such that the center of gravity of the second movable portion 6 is located at the center of the first movable portion 4.

[0071] The arm portion 96 is elastically deformable in a torsional direction around the Y-axis. As a result, the fixed surface portion 94 is displaceable in a torsional direction with respect to the pair of fixed side portions 92 via the arm portions 96. The upper portion of the second holder 61, that is, the lid portion, is fixed to the fixed surface portion 94, and the elastic support portion 9 enables the second holder 61 to rotate around the Y-axis.

[0072] <Operation> FIG. 11 is a diagram showing the operation of the first movable portion of the swing actuator according to the embodiment of the present invention. The state of the first movable portion 4 when there is no movement in FIG. 11 is shown in FIG. 4.

[0073] When the swing actuator 1 energizes the coil of the flexible substrate 25, a magnetic flux is generated in the coil axis direction (Y-axis direction) of the coils 32 and 34.

[0074] As a result, among the outer magnets 36 and 38 of the first movable part 4 (first holder 41) facing the coils 32 and 34, the magnetic pole surfaces 36n, 36s, 38n, and 36s that are different in the vertical direction repel each other on the magnetic pole surfaces having the same poles as the magnetic poles of the coils 32 and 34, and attract each other with the magnetic pole surfaces having different poles.

[0075] The first holder 41 to which the outer magnets 36 and 38 are fixed rotates around the shaft portion 42, and one of the both side wall portions 414 and 415 rotates in the Z direction (upper side) and the other rotates in the -Z direction (bottom surface portion 211 side) around the shaft portion 42 (around the X axis). At this time, the side wall portions 414 and 415 moving in the -Z direction (bottom surface portion side) have the protrusions 44 provided on the side wall portion sides 414 and 415 pressing the corresponding damping members 27, and move in the -Z direction while resisting the biasing force.

[0076] Next, the energization direction to the coils 32 and 34 is reversed. The direction of the magnetic flux generated in the coils 32 and 34 becomes the reverse direction, and due to the magnetic attraction force generated between the coils 32 and 34 and the outer magnets 36 and 38, the first holder 41 swings in the direction opposite to the previous rotation direction.

[0077] The swing actuator 1 has a damping member 27. When the energization direction is switched, the pressing state of the damping member 27 by the protrusions 44 of the side wall portions 414 and 415 displaced in the -Z direction is released. As a result, the side wall portions 414 and 415 displaced in the -Z direction move so as to return to the reference position (default position) side by the restoring force (biasing force) of the damping member 27.

[0078] The magnetic attraction force generated by the switching of the energization direction is added to this restoring force, and the side wall portions 414 and 415 displaced in the -Z direction move to the reference position, further move, and are displaced in the Z direction from the reference position. By repeating this, the first movable part 4 swings.

[0079] Specifically, the outer magnets 36 and 38 are arranged on the first holder 41 so that the magnetic pole surfaces 36n and 38n are N poles and 36s and 38s are S poles. The coils 32 and 34 are energized to drive the first magnetic circuit.

[0080] When the coil 32 is energized, a magnetic field is generated such that the outer magnet 36 side of the coil 32 becomes the N pole and the outer magnet 36 side of the coil 32 becomes the S pole. As a result, the outer magnet 36 repels the coil 32 with the upper magnetic pole surface 36n and attracts it with the lower magnetic pole surface 36s. Therefore, the wall portion 412 to which the outer magnet 36 is fixed moves downward (toward the bottom surface portion 211 side), that is, in the -Z direction.

[0081] At the same time, when the coil 34 is energized, the outer magnet 38 attracts the coil 34 with the upper magnetic pole surface 38n and attracts it with the lower magnetic pole surface 36s. As a result, the side wall portion 413 to which the outer magnet 38 is fixed moves downward, that is, in the -Z direction. In this way, the first magnetic circuit including the coils 32 and 34 and the outer magnets 36 and 38 moves the first movable portion 4 around the Y axis.

[0082] FIG. 12 is a diagram showing the operation of the second movable portion of the swing actuator according to the embodiment of the present invention. The state of the second movable portion 6 shown in FIG. 12 when it is not movable corresponds to FIG. 3. The inner coil 63 has a coil axis extending in a third direction (Z direction) orthogonal to the first direction (X direction) and the second direction (Y direction), and is arranged so as to cross the flow of magnetic flux between the central magnet 68 and the inner magnets 64 and 66.

[0083] As a result, when the inner coil 63 is energized, a flow of magnetic flux is generated in the coil axis direction (Z direction), and magnetic poles are formed at the open end portions of the inner coil 63 located between the inner magnets 64 and 66 and the central magnet 68.

[0084] The magnetic pole surfaces 64s, 68n, 68s, and 66n of the inner magnets 64 and 66 and the central magnet 68 that face each other are different magnetic poles from each other. Therefore, the inner coil 63, the inner magnets 64 and 66, and the central magnet 68, and the magnetic poles at the open end portions of the inner coil 63 therebetween attract each other with like poles and repel with unlike poles.

[0085] The second movable portion 6 having the inner coil 63 is suspended by the elastic support portion 9 so as to rotate about the center of gravity, and swings around the Y axis (in the direction of the arrow) passing through the center of gravity while being supported by the arm portion.

[0086] Specifically, the rocking actuator 1 is configured such that the magnetic pole surface 64s of the inner magnet 64 and the magnetic pole surface 68s of the central magnet 68 are S poles, and the magnetic pole surface 66n of the inner magnet 66 and the magnetic pole surface 68n of the central magnet 68 are N poles. In this configuration, the inner coil 63 is energized so that the open end of the inner coil 63 becomes an N pole. When the open end of the inner coil 63 is an N pole, the coil end (side portion) of the inner coil 63 located between the magnetic pole surface 64s of the inner magnet 64 and the magnetic pole surface 68n of the central magnet 68 repels the magnetic pole surface 68n and attracts the magnetic pole surface 64s.

[0087] At this time, the open end portion (side portion) of the inner coil 63 located between the magnetic pole surface 66n of the inner magnet 66 and the magnetic pole surface 68s of the central magnet 68 repels the magnetic pole surface 66n of the inner magnet 66 and attracts the magnetic pole surface 68s of the central magnet 68.

[0088] As a result, the second movable part 6 moves in the arrow direction (black arrow direction). Next, the energization direction to the inner coil 63 is reversed, and the open end of the inner coil 63 facing the magnetic pole surfaces 64s of the inner magnet 64, 68n and 68s of the central magnet, and 66n of the inner magnet 66 is made an S pole.

[0089] Note that when the energization direction is switched, the arm portion 96 of the elastic support portion 9 is restored, so that the inner coil 63 moves to the reference position (default position).

[0090] By changing the energization direction to the inner coil 63, the second movable part 6 moves in the direction of the dashed arrow, and by repeating this, the second movable part 6 performs a reciprocating rotational motion (rocking).

[0091] The rocking actuator 1 is rotatable with respect to the fixed part 2 by a shaft part 42 extending in the X direction for the first movable part 4, and the second movable part 6 is swingably supported with respect to the first movable part 4 by elastic deformation (twisting) by a leaf spring in the Y direction orthogonal to the X direction. In the rocking actuator 1, the rocking speed of the first movable part 4, that is, the rocking speed around the X axis, and the rocking speed of the second movable part 6, that is, the rocking speed around the Y axis, can be driven at different speeds (the rocking speed around the Y axis is faster than the speed around the X axis).

[0092] As a result, the mirror 8, which is the object to be moved, is parallel to the surface of the mirror 8 and is rotatable about two orthogonal axes. Therefore, the object to be moved can be suitably supported so as to be rotatable about two orthogonal axes with different rotational speeds including rocking.

[0093] FIG. 13 is a block diagram showing the main configuration of a scanner system (laser system) 100 using the rocking actuator 1.

[0094] In addition to the rocking actuator 1, the scanner system 100 includes a laser light emitting unit (light irradiation unit) 101, a laser control unit 102, a drive signal supply unit 103, and a position control signal calculation unit 104.

[0095] The laser light emitting unit 101 includes, for example, an LD (laser diode) serving as a light source, a lens system for converging the laser light output from this light source, and the like. The laser control unit 102 controls the laser light emitting unit 101. The laser light irradiated from the laser light emitting unit 101 is incident on the mirror 8 of the rocking actuator 1.

[0096] The position control signal calculation unit 104 generates and outputs a drive signal for controlling the mirror 8 to the target angular position with reference to the angular position of the surface of the mirror 8 acquired by the angle detection unit 70 and the target angular position. For example, the position control signal calculation unit 104 generates a position control signal based on the acquired angular position of the mirror 8 and a signal indicating the target angular position converted using, for example, the sawtooth wave data stored in a waveform memory (not shown). The position control signal calculation unit 104 outputs the generated position control signal to the drive signal supply unit 103.

[0097] Based on the position control signal, the drive signal supply unit 103 supplies drive signals to the coils 32, 34, and the inner coil 63 of the swing actuator 1 so that the angular position of the mirror 8 becomes a desired angular position. Thereby, the scanner system 100 can emit scanning light from the swing actuator 1 to a predetermined scanning region.

[0098] The embodiments of the present invention have been described above. Note that the above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto. That is, the description of the above configuration and the shape of each part is an example, and it is obvious that various changes and additions to these examples are possible within the scope of the present invention.

Industrial Applicability

[0099] The swing actuator according to the present invention can be miniaturized and has the effect of stably rotatably supporting a movable object such as a mirror on two axes, and is useful as an actuator used in, for example, a scanner device or the like.

Explanation of Reference Numerals

[0100] 1 Swing actuator 2 Fixed part 4 First movable part 6 Second movable part 8 Mirror (movable object) 9 Elastic support part 21 Base part 25 Flexible substrate 27 Damping member 28 Bearing 32, 34 Coils 32a, 34a Upper side parts 32b, 34b Lower side parts 36, 38 Outer magnets 36n, 36s, 38n, 38s, 64s, 66n, 68n, 68s Magnetic pole faces 41 First holder (outer holder) 41c, 41e, 41f Ribs 42 Shaft part 44 Protrusion 46 Concave portion 61 Second holder 63 Inner coil 64, 66 Inner magnet (second magnet) 68 Central magnet (second magnet) 70 Angle detection part 92 Fixed side part 94 Fixed face part 96 Arm part 100 Scanner system 211, 411 Bottom face part 214, 215 Upright part 214a, 215a Opening 217, 218 Support pillar part 217a, 218a, 412a, 413a Notch 412, 413 Wall part 414, 415 Side wall part 612 Outer peripheral surface 614 Step 2122 Concave part

Claims

1. A fixed part having a first coil, A first movable part having a first magnet facing the first coil in the coil axis direction and supported by the fixed part so as to be reciprocally rotatable around a first axis, A second movable part connected to the object to be moved and supported by the first movable part so as to be reciprocally rotatable around a second axis orthogonal to the first axis, And having, The first movable part has a plurality of second magnets arranged such that different magnetic poles face each other with a gap in the extending direction of the first axis, The second movable part has a second coil with one side portion disposed in the gap, and by energizing the first coil and the second coil, cooperates with the first magnet and the second magnet to cause the object to be moved to oscillate around the first axis and the second axis orthogonal to each other, An oscillating actuator.

2. The fixed part has a damping member that abuts against the moving first movable part to damp the movement of the first movable part, The oscillating actuator according to Claim 1.

3. The first coil is a pair of coils disposed to face each of both side surfaces of the first movable part, The first magnet is provided on each of the both side surfaces of the first movable part, The plurality of second magnets are three magnets arranged in the first axis direction, and the central magnet of the three second magnets is located at a position sandwiched by the pair of first magnets, The oscillating actuator according to Claim 1.

4. The second movable part is supported by the first movable part by a leaf spring so as to be reciprocally rotatable around the second axis, The oscillating actuator according to Claim 1.

5. The first movable part is supported by the fixed part by shaft mounting so as to be reciprocally rotatable around the first axis, The oscillating actuator according to Claim 4.

6. Comprising the oscillating actuator according to Claim 1, The object to be moved is a mirror that reflects scanning light, An optical scanning device.

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