Oscillating actuator and optical scanning device

Abstract

The invention provides a swing actuator and an optical scanning device, which can realize miniaturization and stably rotate and support a movable object such as a mirror by using two axes. The present invention is provided with: a fixed part having a first coil; a first movable part which has a first magnet facing the first coil in the axial direction of the coil, and which is supported by the fixed part so as to be capable of reciprocating rotation about a first axis; and a second movable part supported by the first movable part so as to be capable of reciprocating rotation about a second axis orthogonal to the first axis, the first movable part having a plurality of second magnets disposed so that mutually different magnetic poles face each other with a gap therebetween in the extension direction of the first axis, and the second movable part having a second coil of which one side is disposed in the gap. Through energization of the first coil and the second coil, the movable object swings around a first axis and a second axis which are orthogonal to each other in cooperation with the first magnet and the second magnet.

Description

Technical Field

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

[0002] Conventionally, as an actuator for scanning devices such as multi-function printers, laser beam printers, laser processing machines, and laser marking machines, a reciprocating rotary drive type, that is, a swing type actuator (hereinafter referred to as a "swing actuator") is known. In addition, a laser processing machine is for laser drilling of printed circuit boards and the like.

[0003] The swing actuator includes, for example, a rotary shaft on which a mirror is mounted and a drive unit having a coil magnet. By energizing the coil, the rotary shaft is reciprocally rotationally driven, thereby changing the reflection angle of the mirror with respect to the laser and achieving optical scanning of an object.

[0004] In the swing actuator shown in Patent Document 1, a mirror and a coil are mounted on a horizontally extending rotary shaft, and a magnet pair in which the S pole and the N pole are opposed to each other with a gap therebetween is provided in a fixed portion. Both side portions parallel to the rotary shaft direction in the coil are configured to be located in the gap between the S pole and the N pole of the magnet pair. A total of four magnets are provided in the fixed portion and the coil is energized, whereby the mirror swings.

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

[0006] Prior Art Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-43405

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-227754

[0009] However, in recent years, in a device in which a mirror rotates about two axes, it is desired to stably drive even when the device itself is made more compact and smaller.

[0010] In Patent Document 2, the specific structure for driving the mirror to rotate about two axes is not disclosed.

[0011] In addition, in Patent Document 1, although a configuration in which the base itself rotates about an axis orthogonal to the rotary shaft is considered, the device itself having a configuration for stably supporting the mirror to rotate about two axes becomes large. Summary of the Invention

[0012] The present invention has been completed in view of the above problems, 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 by two axes.

[0013] The swing actuator of the present invention has the following structure:

[0014] A fixed part having a first coil;

[0015] A first movable part having a first magnet opposed to the first coil in the axial direction of the coil and supported by the fixed part so as to be reciprocally rotatable about a first axis; and

[0016] A second movable part connected to a movable object and supported by the first movable part so as to be reciprocally rotatable about a second axis orthogonal to the first axis,

[0017] The first movable part has a plurality of second magnets arranged so as to face each other with different magnetic poles in the extending direction of the first axis with a gap therebetween,

[0018] 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, the movable object is swung about the first axis and the second axis orthogonal to each other in cooperation with the first magnet and the second magnet.

[0019] The optical scanning device of the present invention includes a swing actuator having the above structure,

[0020] and has a structure in which the movable object is a mirror that reflects scanned light.

[0021] The effects of the present invention are as follows.

[0022] According to the present invention, miniaturization can be achieved, and a movable object such as a mirror can be stably rotated and supported by two axes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of a swing actuator according to an embodiment of the present invention.

[0024] Figure 2 is a top view of a swing actuator according to an embodiment of the present invention.

[0025] Figure 3 is Figure 2 a cross-sectional view taken along line A-A of

[0026] Figure 4 is Figure 2 a cross-sectional view taken along line B-B of

[0027] Figure 5This is a diagram showing the separated state of the fixed part, the first movable part, and the second movable part of the swing actuator of the present embodiment.

[0028] Figure 6 This is an exploded perspective view of the swing actuator of the embodiment of the present invention.

[0029] Figure 7 This is Figure 6 an enlarged exploded perspective view of the fixed part shown.

[0030] Figure 8 This is Figure 6 an enlarged exploded perspective view of the first movable part and the second movable part shown.

[0031] Figure 9 This is a partial side 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 of the embodiment of the present invention.

[0032] Figure 10 This is a diagram for explaining the positional relationship between the damping member and the protrusion.

[0033] Figure 11 This is a diagram showing the operation of the first movable part of the swing actuator.

[0034] Figure 12 This is a diagram showing the operation of the second movable part of the swing actuator.

[0035] Figure 13 This is a diagram showing the main part structure of a scanning system using the swing actuator.

[0036] In the figure: 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 - Attenuation component, 28 - Bearing, 32, 34 - Coils, 32a, 34a - Upper edge parts, 32b, 34b - Lower edge parts, 36, 38 - Outer magnets, 36n, 36s, 38n, 38s, 64s, 66n, 68n, 68s - Pole faces, 41 - First bracket (outer bracket), 41c, 41e, 41f - Ribs, 42 - Shaft part, 44 - Protrusion part, 46 - Concave part, 61 - Second bracket, 63 - Inner coil, 64, 66 - Inner magnets (second magnets), 68 - Central magnet (second magnet), 70 - Angle detection part, 92 - Fixed edge part, 94 - Fixed face part, 96 - Arm part, 100 - Scanning system, 211, 411 - Bottom face parts, 214, 215 - Upright parts, 214a, 215a - Openings, 217, 218 - Support pillar parts, 217a, 218a, 412a, 413a - Notches, 412, 413 - Wall parts, 414, 415 - Side wall parts, 612 - Outer peripheral surface, 614 - Step, 2122 - Concave part. Detailed implementation mode

[0037] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0038] Regarding each part of the swing actuator 1 constituting this embodiment, the description is based on the normal state where 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 this embodiment, an orthogonal coordinate system (X, Y, Z) is used. The same orthogonal coordinate system (X, Y, Z) is also used in the figures described later.

[0039] Figure 1 is a perspective view of the swing actuator according to an embodiment of the present invention, Figure 2 is a top view of the swing actuator according to an embodiment of the present invention. In addition, Figure 3 is Figure 2 a cross-sectional view taken along line A - A of Figure 4 is Figure 2 a cross-sectional view taken along line B - B of Figure 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 of this embodiment are separated. In addition, Figure 6 is an exploded perspective view of the swing actuator according to an embodiment of the present invention.

[0040] The swing actuator 1 is used, for example, in optical scanning devices such as laser processing machines, compound machines, and laser beam printers, or radar (LiDAR: Laser Imaging Detection and Ranging) devices.

[0041] Figures 1 to 6 The swing actuator 1 shown has a fixed portion 2, a first movable portion 4, a second movable portion 6, and a movable object (mirror 8). The swing actuator 1 supports the mirror 8 as a movable object via the first movable portion 4 and the second movable portion 6 so as to be swingable about two axes orthogonal to the X-axis and the Y-axis on the fixed portion 2. In addition, the X-axis direction is also referred to as the first axis direction, the Y-axis direction is referred to as the second axis direction, and the Z-axis direction is referred to as the third axis direction.

[0042] <Fixed portion 2>

[0043] Figure 7 is Figure 6 An enlarged exploded perspective view of the fixed portion shown.

[0044] Figures 1 to 7 The fixed portion 2 shown is fixed to the device on which the swing actuator 1 is mounted. The fixed portion 2 has a base portion 21, coils 32, 34, a flexible substrate 25, and a damping member 27. The first movable portion 4 is swingably mounted on the fixed portion 2 via a bearing 28.

[0045] The base portion 21 has a plate-shaped bottom surface portion 211, a pair of upright portions 214, 215 disposed separately in the Y direction on the bottom surface portion 211, and a pair of support pillar portions 217, 218 erected separately in the X direction on the bottom surface portion 211.

[0046] The bottom surface portion 211 is in surface contact with and fixed to the device on which the swing actuator 1 is mounted. Thus, the mirror 8 of the swing actuator 1 is swingably mounted on the device.

[0047] The bottom surface portion 211 has a rectangular shape in plan view, and is formed, for example, in a square shape. The shape of the bottom surface portion 211 defines the outer shape of the swing actuator 1 in plan view.

[0048] The first movable portion 4 is disposed above the central portion of the bottom surface portion 211, and a pair of upright portions 214, 215 and a pair of support pillar portions 217, 218 are erected on the bottom surface portion 211 so as to surround the first movable portion 4 in all four directions in the X-axis direction and the Y-axis direction.

[0049] The upright portions 214, 215 hold the pair of coils 32, 34 respectively at positions sandwiching the first movable portion 4 in the coil axial direction, and in a state of being separated from and opposed to the first magnets (also referred to as "outer magnets") 36, 38 of the first movable portion 4.

[0050] The upright portions 214 and 215 support the coils (also referred to as "outer coils") 32 and 34. Openings 214a and 215a are formed in the upright portions 214 and 215. A pair of coils 32 and 34 are disposed within the openings 214a and 215a.

[0051] The coils 32 and 34 are mounted on the flexible substrate 25, and the flexible substrate 25 is mounted on the upright portions 214 and 215 so as to cover the openings 214a and 215a. Thus, the pair of coils 32 and 34 are respectively disposed within the openings 214a and 215a in such a manner as to sandwich the first movable portion 4 from both sides in the Y direction.

[0052] The pair of coils 32 and 34 are disposed at positions that are centrosymmetric with respect to the center of the bottom surface portion 211 and are opposed to each other with their coil axes arranged on the same straight line.

[0053] The support pillar portions 217 and 218 are formed in the same shape and are opposed to each other. Notch portions 217a and 218a for fitting the bearings 28 are provided at their respective upper end portions. The notch portions 217a and 218a are disposed outside the first movable portion 4 in the X direction, and are respectively opened in the directions of facing each other and in the Z direction (upward).

[0054] The damping member 27 damps the movement of the first movable portion 4 (specifically, the first bracket 41) with respect to the base portion 21. The damping member 27 is disposed 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).

[0055] The damping member 27 is, for example, a compression coil spring and is provided so as to project upward from the bottom surface portion 211. The damping member 27 is disposed at a position where it abuts against the protrusion portion 44 of the first movable portion 4 when the first movable portion 4 rotates about the shaft portion (X-axis portion) 42.

[0056] The damping member 27 is a member that expands and contracts in the length direction. For example, as Figure 1 , Figures 5 to 7 shown, the damping member 27 is a compression coil spring disposed within the concave portions 2122 formed at the four corners of the bottom surface portion 211 and projecting in the Z direction (upward). The concave portions 2122 are formed corresponding to the protrusion portions 44 of the first movable portion 4, and are symmetrically disposed in the Y direction with the axis of the shaft portion 42 as the center across the shaft portion 42 (refer to Figure 10 ).

[0057] The coil spring serving as the damping member 27 is connected to one of the bottom surface portion 211 of the base portion 21 and the protrusion portion 44 of the first bracket 41 of the first movable portion 4 (the bottom surface portion 211), and is disposed separately from the other (the protrusion portion 44). Thus, during the movement of the protrusion portion 44, i.e., the first movable portion 4, a force is never applied to the first movable portion 4 or the bottom surface portion 211 of the base portion 21, and it does not become a resistance. Before the first movable portion 4 rotates and collides with a mechanical stopper (e.g., the bottom surface portion 211) that restricts the movement of the first movable portion 4, the damping member 27 abuts against the abutting surface 442 of the protrusion portion 44 and can suppress the movement of the first movable portion 4.

[0058] By damping the movement of the first movable portion 4 at the protrusion portion 44 (the abutting surface 442), the damping member 27 can suppress the collision of the first movable portion 4 (the first bracket 41) against the bottom surface portion 211, and can reduce the movement sound of the first movable portion 4 (the first bracket 41).

[0059] In addition, since the damping member 27 has a restoring force, after being pressed by the protrusion portion 44 of the first movable portion 4 and the pressing state is released, the restoring force can be used to apply a force to the protrusion portion 44 to move it toward the reference position (the original position) side.

[0060] The damping member 27 is mounted on the base portion 21 and is disposed at a position separated from the first bracket 41 (the protrusion portion 44) in the reference position (non-driven position), but is not limited thereto, and they may be connected. In addition, the damping member 27 may be configured to be provided so as to lead from the abutting surface 442 of the protrusion portion 44 toward the bottom surface portion 211 side, abut against and press the bottom surface portion 211 during movement, and use the reaction force thereof to damp the moving force of the first movable portion 4.

[0061] <The first movable portion 4>

[0062] Figure 8 is Figure 6 an enlarged exploded perspective view of the first movable portion and the second movable portion shown.

[0063] Figures 1 to 8 In the first movable portion 4 shown, the first movable portion itself is rotatable about a first axis, i.e., the shaft portion (X-axis portion) 42, relative to the fixed portion 2, and the second movable portion 6 and the movable object (the mirror 8) are rotatably supported about a second axis, i.e., the Y-axis.

[0064] The first movable portion 4 includes a first bracket (outer bracket) 41, first magnets (outer magnets) 36, 38, and second magnets (inner magnets 64, 66, central magnet 68).

[0065] The outer magnets 36 and 38 and the coils 32 and 34 of the fixed portion 2 together form a first magnetic circuit. The first magnetic circuit energizes the coils 32 and 34 to generate magnetic flux, and through this magnetic flux, the first movable portion 4 and the second movable portion 6 swing around the shaft portion (X-axis portion) 42.

[0066] The outer magnets 36 and 38 are a pair of permanent magnets with the same shape, and each has magnetic pole faces 36n, 36s, 38n, and 38s. The outer magnets 36 and 38 are fixed to both sides of the first bracket 41 that are separated in the Y direction.

[0067] The outer magnets 36 and 38 are respectively arranged to extend in the lateral direction (X direction) opposite to the coils. The outer magnets 36 and 38 have magnetic pole faces 36n, 36s, 38n, and 38s with different poles up and down. The magnetic pole faces 36n, 36s with different poles and the magnetic pole faces 38n, 38s with different poles are respectively opposed to the upper and lower edge portions 32a, 32b of the coil 32 and the upper and lower edge portions 34a, 34b of the coil 34 in the Y direction.

[0068] The outer magnets 36 and 38 are symmetrically arranged in the Y direction with the shaft portion (X-axis portion) 42 of the first movable portion 4 as the center. The outer magnets 36 and 38 are arranged on the coil axes of the coils 32 and 34. Preferably, it is configured such that the centers of the outer magnets 36 and 38 are located on the coil axes of the coils 32 and 34.

[0069] 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 portion 6, they form a second magnetic circuit.

[0070] The second magnetic circuit energizes the inner coil 63 to generate magnetic flux, and through this magnetic flux, the second movable portion 6 swings around the Y axis. Thus, the mirror 8 as the movable object swings around the Y axis.

[0071] The inner magnets 64 and 66 are arranged in a manner that they are separated from and on both sides of the central magnet 68 with the central magnet 68 interposed therebetween. The inner magnets 64 and 66 are arranged outside the inner coil 63 of the second movable portion 6 that is arranged to surround the central magnet 68, and are arranged in a manner that they are separated from the inner coil 63 and sandwich the inner coil 63 in one direction (X direction).

[0072] The inner magnets 64 and 66 have magnetic pole faces 64s and 66n that face each other. The opposing magnetic pole faces 64s and 66n are respectively different magnetic poles and are arranged to face each other separately.

[0073] That is, the inner magnets 64 and 66 and the central magnet 68 are arranged in such a way that magnetic flux flows in the direction of attraction along one direction (X direction) in the order of their respective magnetic pole faces such as N, S, N, S or S, N, S, N.

[0074] The inner magnets 64 and 66 are arranged to sandwich a pair of parallel side portions of the inner coil 63 between them and the central magnet 68 respectively. The magnetic pole faces 64s and 68n of the central magnet 68 are opposed to each other, and the magnetic pole faces 66n and 68s of the central magnet 68 are opposed to each other. They are magnetic poles that attract each other on the opposed surfaces respectively.

[0075] The central magnet 68 has magnetic pole faces 68n and 68s that are opposed to the inner magnets 64 and 66 in the X-axis direction (the axial direction of the shaft portion 42). The central magnet 68 is a massive body magnetized in the same direction as the magnetization directions of the inner magnets 64 and 66. It is, for example, a rectangular parallelepiped having mutually opposite and different magnetic pole faces 68n and 68s, or it may be a cube.

[0076] The magnetic pole faces 68n and 68s of the central magnet 68 are a pair of parallel and different magnetic pole faces separated in the X-axis direction as the first direction. For example, the magnetic pole face 68n is an N pole and the magnetic pole face 68s is an S pole.

[0077] The central magnet 68 and the inner magnets 64 and 66 are arranged such that N and S are arranged in one direction (the X direction), and a magnetic flux flow is formed in one direction (the X direction).

[0078] In the middle of the magnetic flux flow formed by the central magnet 68 and the pair of inner magnets 64 and 66, the inner coil 63 of the second movable portion 6 is arranged to flow in a direction orthogonal to the magnetic flux flow.

[0079] Outer magnets (first magnets) 36 and 38 are respectively provided on both side surfaces of the first movable portion 4. The inner magnets 64 and 66 and the central magnet 68 (a plurality of second magnets) are three magnets arranged along the first direction. The central magnet 68 among the three second magnets is located at a position sandwiched by the pair of outer magnets (first magnets) 36 and 38, and the inner magnets 64 and 66 and the central magnet 68 are arranged and configured in the first axis direction.

[0080] In the first bracket 41, the outer magnets 36 and 38 and the inner magnets 64 and 66 are arranged in a rectangular frame so as to surround the central magnet 68, thereby forming a compact square-shaped first bracket 41.

[0081] The first bracket 41 rotatably holds the outer magnets 36 and 38 of the first magnetic circuit, the inner magnets 64 and 66 of the second magnetic circuit, and the central magnet 68, which cause the mirror 8 as a movable object to swing in two orthogonal axes, around the shaft portion (X-axis portion) 42 on the base portion 21. In addition, the first bracket 41 has a shaft portion 42 and a protrusion portion 44.

[0082] The first bracket 41 is formed in a box shape having a bottom surface portion 411 with a square shape in plan view that positions the central magnet 68 at the center. The first bracket 41 is a non-magnetic body and is made of resin or the like.

[0083] The first bracket 41 sets the magnetization directions of the outer magnets 36 and 38 to the Y direction and holds the outer magnets 36 and 38 separately in the Y direction. Between the outer magnets 36 and 38, the first bracket 41 sets the magnetization directions of the inner magnets 64 and 66 and the central magnet 68 to the X-axis direction, and arranges and holds the inner magnets 64 and 66 and the central magnet 68 at a predetermined interval in the X-axis direction.

[0084] On the bottom surface portion 411, ribs 41e for positioning the central magnet 68 and ribs 41c and 41f for positioning the inner magnets 64 and 66 are protrudingly provided.

[0085] The rib 41e protrudingly provided in a frame shape at the center of the bottom surface portion 411 can accurately mount the central magnet 68. In addition, the ribs 41c and 41f are ribs for positioning the inner magnets 64 and 66, and maintain the intervals between the inner magnets 64 and 66 and the central magnet 68, or the intervals from the rectangular frame-shaped inner coil 63 disposed within this interval.

[0086] The first bracket 41 has a peripheral wall portion (wall portions 412 and 413, side wall portions 414 and 415) that stands up from the bottom surface portion 411. A pair of parallel wall portions 412 and 413 that are separated in the first direction (X direction) in the peripheral wall portion have notch portions 412a and 413a separated by ribs 41c and 41f on the inner side. Inside these notch portions, the inner magnets 64 and 66 are disposed so as to face each other.

[0087] The first bracket 41 suspends an elastic support portion 9 over 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. Concave portions 46 for ensuring 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.

[0088] A second movable portion 6 supported via the elastic support portion 9 is rotatably disposed within the first bracket 41 about the Y axis (an axis along the second direction).

[0089] The shaft portion (X-axis portion) 42 serves as the rotation center of the first bracket 41 and is respectively provided on the outer surfaces of a pair of wall portions 412 and 413. The shaft portion (X-axis portion) 42 is arranged on the pair of wall portions 412 and 413 so as to be located on the same straight line (X-axis) respectively, and bearings 28 are respectively externally inserted on the shaft portion (X-axis portion) 42. The shaft portion 42 and the bearings 28 are respectively fitted into the notch portions 217a and 218a of the support column portions 217 and 218 of the fixed portion 2, whereby the first bracket 41, and further the first movable portion 4, are rotatably supported on the fixed portion 2 about the X-axis.

[0090] Figure 9 is a partial side sectional view showing the positional relationship between the centers of gravity of the first movable portion and the second movable portion in the swing actuator according to the embodiment of the present invention. As Figure 9 shown, in the first bracket 41, the shaft portion (X-axis portion) 42 is provided on the first bracket 41 such that the rotation center position P of the first movable portion 4 passes through the center of gravity of the second movable portion 6 (specifically, the second bracket 61).

[0091] In addition, the rotation center position (central axis) P of the first movable portion 4 about the shaft portion 42 is preferably located at a position overlapping the center of gravity position of the second movable portion 6 supported by the first movable portion 4 or near the center of gravity position of the second movable portion 6. For example, it is configured such that the center of gravity of the second movable portion 6 is located on the central axis passing through the rotation center position P of the shaft portion 42 or on the shaft portion 42 (inside the outer diameter of the shaft portion 42). According to this structure, when the first movable portion 4 supporting the second movable portion 6 reciprocally rotates about the shaft portion 42, an increase in the inertial moment during the rotation operation of the first movable portion 4 caused by the difference between the rotation center position P of the first movable portion 4 and the center of gravity of the second movable portion 6 can be prevented. That is, the swing actuator 1 can reduce the inertial moment during the rotation operation of the first movable portion 4 and can cause the first movable portion 4 to reciprocally rotate appropriately, i.e., swing.

[0092] The protruding portions 44 are symmetrically arranged on the pair of wall portions 412 and 413 so as to be separated from each other in the second direction (Y direction) with the shaft portion (X-axis portion) 42 as the center, and protrude in the X-axis direction.

[0093] Figure 10 is a diagram for explaining the positional relationship between the damping member and the protruding portion.

[0094] Figure 9 and Figure 10 As shown, when the protruding portion 44 rotates about the shaft portion (X-axis portion) 42 in the first movable portion, specifically the first bracket, it abuts against the damping member 27 and causes its movement to be damped. The damping member 27 only needs to damp the movement of the first bracket 41 about the X-axis and can be provided at any part of the first movable portion 4.

[0095] In addition, the protrusion 44 is disposed above the coil spring that is the damping member 27.

[0096] When the protrusion 44 moves and displaces around the shaft portion (X-axis portion) 42, it abuts against the damping member 27. However, it may also be configured such that the damping member 27 is fixed to the protrusion 44 and moves to abut against the bottom surface portion 211.

[0097] <Second movable portion 6>

[0098] The second movable portion 6 is fixed to the mirror 8 that is the object to be moved, is rotatably supported about the Y-axis by the first movable portion 4, and is driven by the second magnetic circuit.

[0099] The second movable portion 6 and the first movable portion 4 together drive and support the mirror 8 rotatably about two orthogonal axes (X and Y axes).

[0100] The second movable portion 6 has a second bracket 61 connected to the first movable portion 4 via an elastic support portion 9 and supported by the elastic support portion 9, a second coil (also referred to as an "inner coil") 63, and a mirror 8.

[0101] The second bracket 61 holds the inner coil 63 and the mirror 8 and is rotatably supported about the Y-axis via the elastic support portion 9.

[0102] Specifically, the second bracket 61 is formed in a lid-shaped cylindrical shape with a square lid and an opening downward. The second bracket 61 is disposed so as to cover the central magnet 68 from four directions (XY directions) and above (Z direction).

[0103] The second bracket 61 has a square frame-shaped opening portion, and a step 614 is formed on the outer peripheral surface of the opening portion so as to have a diameter smaller than the outer peripheral surface 612 of the main body portion of the second bracket 61. The inner coil 63 is externally fitted by the step 614, whereby the outer peripheral surface of the second bracket 61 and the outer peripheral surface of the inner coil 63 are coplanar.

[0104] The inner coil 63 is formed in a square tube shape, for example, in a frame shape with a square cross section.

[0105] The inner coil 63 is disposed 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.

[0106] The inner coil 63 is disposed at a predetermined interval from the central magnet 68 and the inner magnets 64, 66 respectively, and swings about the X-axis via the second bracket 61.

[0107] The elastic support portion 9 rotatably supports the second movable portion 6, specifically the second bracket 61 (including the inner coil 63) about the Y-axis with respect to the first movable portion 4.

[0108] The elastic support portion 9 has: a pair of fixed edge portions 92; a fixed face portion 94 disposed between the fixed edge portions 92; and an arm portion 96 that connects the fixed edge portions 92 and the fixed face portion 94 and elastically deforms.

[0109] The elastic support portion 9 respectively has a pair of fixed edge portions 92, an arm portion 96, and a fixed face portion 94, and is composed of a leaf spring capable of elastic deformation. The pair of fixed piece portions 92 are disposed separately in parallel and are respectively fixed to the first movable portion 4 (the first bracket 41). The fixed face portion 94 is fixed to the second bracket 61 and has a mirror 8 mounted thereon. The arm portion 96 extends from the fixed edge portion 92 in the Y-axis direction and is fixed to the fixed face portion 94. The second movable portion 6 fixed to the fixed face 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.

[0110] The arm portion 96 is elastically deformable freely in the torsional direction about the Y-axis. Thus, the fixed face portion 94 is displaceable freely in the torsional direction with respect to the pair of fixed edge portions 92 via the arm portion 96. The upper portion, i.e., the cover portion, of the second bracket 61 is fixed to the fixed face portion 94, and the elastic support portion 9 enables the second bracket 61 to rotate freely about the Y-axis.

[0111] <Operation>

[0112] Figure 11 This is a diagram showing the operation of the first movable portion of the swing actuator according to the embodiment of the present invention. In addition, Figure 11 the state of the first movable portion 4 when it is immovable is as shown in Figure 4 shown.

[0113] The swing actuator 1 energizes the coil of the flexible substrate 25 to generate a magnetic flux in the coil axial direction (Y-axis direction) of the coils 32, 34.

[0114] Thereby, in the outer magnets 36, 38 on the outer side of the first movable portion 4 (the first bracket 41) opposed to the coils 32, 34, the magnetic pole faces 36n, 36s, 38n, 36s that are different in the up and down directions and are of the same pole as the magnetic poles of the coils 32, 34 repel each other, and the magnetic pole faces of the opposite poles attract each other.

[0115] The first bracket 41 fixed with the outer magnets 36, 38 rotates about the shaft portion 42, and one of the two side wall portions 414, 415 rotates about the shaft portion 42 (about the X-axis) in the Z direction (upper side), and the other rotates in the -Z direction (toward the bottom face portion 211 side). At this time, among the side wall portions 414, 415 moving in the -Z direction (toward the bottom face side), the protrusion portions 44 provided on the side of the side wall portions 414, 415 press the corresponding damping members 27 and move in the -Z direction against their acting forces.

[0116] Next, the energization directions of the coils 32 and 34 are set to opposite directions. The flows of the magnetic fluxes generated by the coils 32 and 34 become opposite directions, and due to the magnetic attraction forces generated between the coils 32 and 34 and the outer magnets 36 and 38, the first bracket 41 swings in the direction opposite to the previous rotation direction.

[0117] The swing actuator 1 has a damping member 27. When switching the energization direction, 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. Thereby, the side wall portions 414 and 415 displaced in the -Z direction move in a manner to return to the reference position (default position) side by the restoring force (acting force) of the damping member 27.

[0118] The magnetic attraction force generated by switching the energization direction acts on this restoring force, and the side wall portions 414 and 415 displaced in the -Z direction move toward the reference position, and further move and are displaced more in the Z direction than the reference position. By repeating this operation, the first movable portion 4 swings.

[0119] Specifically, the outer magnets 36 and 38 are arranged on the first bracket 41 such that the magnetic pole faces 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.

[0120] By energizing the coil 32, a magnetic field is generated such that the outer magnet 36 side of the coil 32 becomes an N pole and the outer magnet 36 side of the coil 32 becomes an S pole. Thereby, the outer magnet 36 is repelled by the upper magnetic pole face 36n with respect to the coil 32 and attracted by the lower magnetic pole face 36s, so the wall portion 412 to which the outer magnet 36 is fixed moves downward (toward the bottom face portion 211 side), that is, in the -Z direction.

[0121] At the same time, by energizing the coil 34, the outer magnet 38 attracts the coil 34 using the upper magnetic pole face 38n and using the lower magnetic pole face 36s. Thereby, 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 causes the first movable portion 4 to move around the Y axis.

[0122] Figure 12 It is a diagram showing the operation of the second movable portion of the swing actuator according to the embodiment of the present invention. In addition, Figure 12 The state when the second movable portion 6 shown is not movable corresponds to Figure 3 The inner coil 63 is arranged such that the coil axis extends in a third direction (Z direction) orthogonal to the first direction (X direction) and the second direction (Y direction), and crosses the flow of the magnetic flux between the central magnet 68 and the inner magnets 64 and 66.

[0123] Accordingly, when the inner coil 63 is energized, a magnetic flux flows in the axial direction (Z direction) of the coil, and magnetic poles are formed at the open ends of the inner coil 63 located between the inner magnets 64, 66 and the central magnet 68.

[0124] The magnetic pole faces 64s, 68n, 68s, 66n that face each other in the inner magnets 64, 66 and the central magnet 68 are magnetic poles different from each other. Therefore, the inner coil 63, the inner magnets 64, 66, and the central magnet 68 and the magnetic poles at the open ends of the inner coil 63 between them attract each other at like poles and repel each other at unlike poles.

[0125] The second movable part 6 having the inner coil 63 is suspended from the elastic support part 9 in a manner of rotating about the center of gravity, and is thus supported by the arm part and swings about the Y axis (arrow direction) passing through the center of gravity.

[0126] Specifically, the swing actuator 1 has a structure in which the magnetic pole face 64s of the inner magnet 64 and the magnetic pole face 68s of the central magnet 68 are set as S poles, and the magnetic pole face 66n of the inner magnet 66 and the magnetic pole face 68n of the central magnet 68 are set as N poles. In this structure, when the inner coil 63 is energized, the open end of the inner coil 63 is set as an N pole. If the open end of the inner coil 63 is an N pole, the coil end (side part) of the inner coil 63 located between the magnetic pole face 64s of the inner magnet 64 and the magnetic pole face 68n of the central magnet 68 repels the magnetic pole face 68n and is attracted by the magnetic pole face 64s.

[0127] At this time, the open end part (side part) of the inner coil 63 located between the magnetic pole face 66n of the inner magnet 66 and the magnetic pole face 68s of the central magnet 68 repels the magnetic pole face 66n of the inner magnet 66 and is attracted by the magnetic pole face 68s of the central magnet 68.

[0128] Accordingly, the second movable part 6 moves in the arrow direction (black arrow direction).

[0129] Next, the energizing direction to the inner coil 63 is reversed, and the open end of the inner coil 63 facing the magnetic pole face 64s of the inner magnet 64, the magnetic pole faces 68n, 68s of the central magnet 68, and the magnetic pole face 66n of the inner magnet 66 is set as an S pole.

[0130] In addition, when the energizing direction is switched, the arm part 96 of the elastic support part 9 is restored, so that the inner coil 63 moves to the reference position (default position).

[0131] By changing the energizing direction to the inner coil 63, the second movable part 6 moves in the direction of the dotted arrow, and by repeating this operation, the second movable part 6 performs a reciprocating rotational motion (swing).

[0132] In the swing actuator 1, the first movable part 4 is rotatable relative to the fixed part 2 via a shaft part 42 extending in the X direction, and the second movable part 6 is swingably supported on the first movable part 4 by elastic deformation (torsion) of a leaf spring in the Y direction orthogonal to the X direction.

[0133] In the swing actuator 1, it is possible to drive at speeds where the swing speed of the first movable part 4, i.e., the swing speed around the X axis, is different from the swing speed of the second movable part 6, i.e., the swing speed around the Y axis (the swing speed around the Y axis is faster than the speed around the X axis).

[0134] As a result, the mirror 8 as the movable object is rotatable about two axes parallel and orthogonal to the face of the mirror 8. Therefore, it is possible to appropriately and rotatably support the movable object using two orthogonal axes with different rotational speeds including swinging.

[0135] Figure 13 It is a block diagram showing the main structure of a scanning system (laser system) 100 using the swing actuator 1.

[0136] In addition to the swing actuator 1, the scanning system 100 also includes a laser light emitting part (light irradiation part) 101, a laser control part 102, a drive signal supply part 103, and a position control signal calculation part 104.

[0137] The laser light emitting part 101 has, for example, an LD (laser diode) as a light source and a lens system for converging the laser output from this light source. The laser control part 102 controls the laser light emitting part 101. The laser irradiated from the laser light emitting part 101 is incident on the mirror 8 of the swing actuator 1.

[0138] The position control signal calculation part 104 refers to the angular position of the surface of the mirror 8 obtained by the angle detection part 70 and the target angular position, and generates and outputs a drive signal for controlling the mirror 8 to be in the target angular position. For example, the position control signal calculation part 104 generates a position control signal based on the obtained angular position of the mirror 8 and a signal representing the target angular position after transformation such as sawtooth waveform data stored in an unillustrated waveform memory. The position control signal calculation part 104 outputs the generated position control signal to the drive signal supply part 103.

[0139] Based on the position control signal, the drive signal supply part 103 supplies a drive signal to the coils 32, 34, and inner coil 63 of the swing actuator 1 to make the angular position of the mirror 8 the desired angular position. As a result, the scanning system 100 can emit scanning light from the swing actuator 1 to a predetermined scanning area.

[0140] The embodiments of the present invention have been described above. In addition, the above description is an illustration of the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto. That is, the description of the above structure and the shape of each part is an example, and it is obvious that various changes and additions can be made to these examples within the scope of the present invention.

[0141] Industrial Applicability

[0142] The swing actuator of the present invention can be miniaturized and has the effect of stably rotating and supporting a movable object such as a mirror by two axes, and is useful as an actuator for a scanning device or the like, for example.

Claims

1. A swing actuator, characterized in that: have: a fixed portion having a first coil; A first movable portion having a first magnet opposed to the first coil in the coil axial direction and supported by the fixed portion so as to be reciprocatingly rotatable about a first axis; as well as a second movable portion connected to the movable object and supported by the first movable portion so as to be reciprocatingly rotatable about a second axis orthogonal to the first axis, The first movable portion includes a plurality of second magnets arranged so that different magnetic poles are opposed to each other with a gap therebetween in the extending direction of the first axis. The second movable part includes a second coil having one side disposed in the gap, and the movable object is swung about the first axis and the second axis orthogonal to each other in cooperation with the first magnet and the second magnet by energizing the first coil and the second coil.

2. The oscillating actuator according to claim 1, characterized in that: The fixed portion includes a damping member that comes into contact with the moving first movable portion to dampen movement of the first movable portion.

3. The oscillating actuator according to claim 1, characterized in that: The first coil is a pair of coils disposed opposite to both side surfaces of the first movable portion. The first magnets are respectively arranged on the two side surfaces of the first movable part. The plurality of second magnets are three magnets arranged along the first axis direction, and a center magnet among the three second magnets is located at a position sandwiched by a pair of the first magnets.

4. The oscillating actuator according to claim 1, characterized in that: The second movable portion is supported by the first movable portion via a leaf spring so as to be reciprocatable and rotatable about the second axis.

5. The oscillating actuator according to claim 4, characterized in that: The first movable portion is supported by the fixed portion via a shaft mount so as to be reciprocatable and rotatable about the first axis.

6. An optical scanning device, characterized in that: A swing actuator according to claim 1, The movable object is a mirror that reflects the scanning light.

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