Rotary reciprocating drive actuator and optical scanning device

Abstract

The invention provides a rotary reciprocating drive actuator and an optical scanning device, which are easy to assemble and can be driven while achieving thinning, wide angle and high amplitude. The present invention is provided with: a movable body that has a shaft part to which a magnet is fixed on the outer circumference, holds a V-shaped mirror such that the ridge part of the V-shaped mirror follows the shaft part, and is supported so as to be capable of reciprocating rotation about the axis via the shaft part; and a unit main body having: a plurality of magnetic poles facing the magnets in the radial direction of the shaft portion and spaced apart from each other in the circumferential direction of the shaft portion; a coil body that forms, together with the magnet, an electromagnetic drive unit that reciprocates and rotates the movable body; and a magnetic body that faces the magnet in the radial direction of the shaft portion, is disposed between the plurality of magnetic poles in the circumferential direction, attracts the magnet, and urges the movable body toward an initial position at which the movable body reciprocates. The electromagnetic drive unit rotates the movable body in a reciprocating manner, and swings the V-shaped mirror while maintaining the angle formed by the V-shaped mirror.

Description

Technical Field

[0001] The invention relates to a rotary reciprocating drive actuator and an optical scanning device. Background Art

[0002] Conventionally, a rotary reciprocating drive actuator is used as an actuator used in optical scanning devices such as multifunction peripherals and laser printers. Specifically, the rotary reciprocating drive actuator reciprocates a reflection mirror of a scanner to change the reflection angle of laser light to achieve optical scanning of an object.

[0003] As such a rotary reciprocating drive actuator, for example, a rotary reciprocating drive actuator using a current motor disclosed in Patent Document 1 is known. As current motors, various types of current motors are known in addition to the current motor of the structural type disclosed in Patent Document 1 and the coil movable type current motor in which the coil is mounted on a reflector.

[0004] Patent Document 1 discloses a beam scanner in which four permanent magnets are provided on a rotating shaft to which a reflection mirror is attached so as to be magnetized in the radial direction of the rotating shaft, and an iron core having magnetic poles around which a coil is wound is arranged so as to sandwich the rotating shaft.

[0005] The beam scanner of Patent Document 1 is a structure in which a magnet is arranged on the movable body side, i.e., a so-called moving magnet structure, and unlike a coil movable type rotary reciprocating drive actuator, the heating of the coil during driving does not affect the movable body. That is, in the movable body, the heating of the coil does not have an adverse effect on the surface state of the reflector relative to the reflector via the rotating shaft, etc., the connection state of the reflector to the rotating shaft, the shape of the reflector including warping, etc.

[0006] Furthermore, when increasing the scanning angle of view to achieve a higher amplitude of the reflector, unlike the movable coil type, there is no need to consider the heating of the coil when energized, so the reflector can be enlarged and the input current to the coil that makes it movable can be increased to cope with the problem.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent No. 4727509

[0010] However, in the previous structure, although it is possible to achieve a wide angle, that is, a high amplitude, by enlarging the reflector, the product itself becomes larger as the reflector becomes larger, making it difficult to achieve a thinner structure. In addition, in the structure of Patent Document 1, since a 4-pole magnet is used, the assembly is complicated and the assembly performance is poor. Summary of the invention

[0011] In view of this, in the field of scanners, there is a demand for a rotary reciprocating drive device that is easy to assemble and has high precision, further has a wide angle, can be driven with a high amplitude, and is thin.

[0012] The present invention has been made in consideration of the above points, and provides a rotary reciprocating drive actuator and an optical scanning device which are easy to assemble and can be driven while achieving a thinner profile, a wider angle, and a higher amplitude.

[0013] One embodiment of the rotary reciprocating drive actuator of the present invention is configured to include:

[0014] A movable body having a shaft portion having a magnet fixed to the outer periphery thereof, holding a V-shaped reflector with a ridgeline of the V-shaped reflector along the shaft portion, and supported via the shaft portion so as to be reciprocatingly rotatable about an axis; and

[0015] The unit body comprises: a plurality of magnetic poles which are opposite to the magnet in the radial direction of the shaft portion and are separated from each other in the circumferential direction of the shaft portion; a coil body which, together with the magnet, forms an electromagnetic drive unit for reciprocating the movable body; and a magnetic body which is opposite to the magnet in the radial direction of the shaft portion and is arranged between the plurality of magnetic poles in the circumferential direction to attract the magnet and apply force to the movable body toward an initial position of reciprocating rotation.

[0016] The electromagnetic drive unit reciprocates the movable body to swing the V-shaped mirror while maintaining the angle formed by the V-shaped mirror.

[0017] One aspect of the optical scanning device of the present invention is configured to include:

[0018] A rotary reciprocating drive actuator of the above structure; and

[0019] A light irradiation unit irradiates the V-shaped reflecting mirror of the rotary reciprocating drive actuator with scanning light.

[0020] The effects of the present invention are as follows.

[0021] According to the present invention, it is easy to assemble, and it is possible to drive while achieving a thinner body, a wider angle, and a higher amplitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a perspective view of the appearance of a rotary reciprocating drive actuator according to one embodiment of the present invention.

[0023] Figure 2 This is a longitudinal sectional view passing through the axis of the rotary reciprocating drive actuator.

[0024] Figure 3 yes Figure 2Section view along line BB.

[0025] Figure 4 This is an exploded perspective view of the upper surface side of the rotary reciprocating drive actuator according to one embodiment of the present invention.

[0026] Figure 5 This is an exploded perspective view of the bottom surface side of the rotary reciprocating drive actuator.

[0027] Figure 6 It is a horizontal cross-sectional view showing the positional relationship between the mirror holding portion and the rotation axis.

[0028] Figure 7 It is a diagram showing a magnetic circuit of a rotary reciprocating drive actuator according to one embodiment of the present invention.

[0029] Figure 8 It is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocating drive actuator.

[0030] Fig. 9 It is a diagram for explaining the assembly structure of the rotary reciprocating drive actuator to the housing.

[0031] Fig.10 FIG. 1 is a diagram showing a main part configuration of a scanner system using the rotary reciprocating drive actuator.

[0032] In the figure: 1—rotational reciprocating drive actuator, 2—movable body, 4—drive unit, 7—angle detection part, 10—V-shaped reflector, 12—first reflector, 14—second reflector, 16—mirror holding part, 20—rotation axis (axis part), 21—one end part, 23—other end part, 26—preload spring, 27—stop part, 28—spacer, 30—magnet, 32a, 32b—poles, 32c—magnetic pole switching part, 40—unit body, 41—core assembly, 42—first core, 44—second core, 46—third core, 48—position holding part, 50—coil body, 52, 54—coil, 52a, 54a—coil end, 56, 57—bobbin, 58—terminal, 60—frame part, 61—base part, 62—axis bracket, 64, 65—bearing, 66—bearing outer Shell, 67—base plate, 69—fixing hole, 72—sensor base plate, 74—encoder disk, 76—encoder hub, 77, 81, 86a, 87—fastening component, 78—optical sensor, 79, 616—positioning pin, 82—positioning cover, 84—bottom cover, 86b—fastened component, 87—fastening component, 420a, 420b—magnetic pole at the end, 421, 421a, 421b— Rod-shaped body, 422—connecting edge portion, 423, 423a, 423b—side edge portion, 424—auxiliary pole portion, 561, 571—flange, 563, 573—holding portion, 612—opening portion, 614—connecting hole, 624—rising wall portion, 626—wall portion, 626a—storage portion for sensor, 827—through hole, 800—fixed platform portion, 804, 806—fixed wall portion. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0034] Figure 1 is a perspective view of the appearance of a rotary reciprocating drive actuator according to one embodiment of the present invention. Figure 2 This is a longitudinal sectional view through the axis of the rotary reciprocating drive actuator. Figure 3 yes Figure 2 The BB line section view, Figure 4 is an exploded perspective view of the upper surface side of the rotary reciprocating drive actuator, Figure 5 This is an exploded perspective view of the bottom surface side of the rotary reciprocating drive actuator.

[0035] <Overall Structure of Rotary Reciprocating Drive Actuator>

[0036] The rotary reciprocating drive actuator 1 is used in, for example, a laser radar (LiDAR: Laser Imaging Detection and Ranging) device. In addition, the rotary reciprocating drive actuator 1 can also be applied to optical scanning devices such as multifunction peripherals and laser beam printers.

[0037] The rotary reciprocating drive actuator 1 generally includes: a V-shaped reflector 10; a drive unit 4 having a movable body 2 fixed to the V-shaped reflector 10; and a frame portion 60 that supports the V-shaped reflector 10 via the drive unit 4. In the rotary reciprocating drive actuator 1, the drive unit 4 includes a unit main body 40 that includes an iron core assembly 41 and constitutes a fixed body, and the movable body 2, the drive unit 4 is fixed to the frame portion 60, and the movable body 2 has a rotating shaft 20 and a magnet (permanent magnet) 30 fixed to the rotating shaft 20.

[0038] The driving unit 4 includes an electromagnetic driving unit including a coil body and a magnet 30 disposed on a core assembly 41 . The electromagnetic driving unit reciprocates the movable body 2 to swing the V-shaped mirror while maintaining the angle formed by the V-shaped mirror.

[0039] The movable body 2 has a rotating shaft 20 with a magnet 30 fixed to the outer periphery, and the V-shaped reflector 10 is held so that the ridgeline of the V-shaped reflector 10 is along the rotating shaft 20. The movable body 2 is supported by the unit body 40 (the frame 60 that fixes the unit body 40) via the rotating shaft 20 so as to be reciprocatingly rotatable about the axis.

[0040] The V-shaped reflector 10 is supported by the drive unit 4 fixed to the frame portion 60 so as to be reciprocatingly rotatable relative to the frame portion 60 (specifically, the base portion 61). In addition, the frame portion 60 has a plate-shaped base portion 61, a shaft support 62, and bearings 64 and 65, which together with the unit body 40 of the drive unit 4 constitute a fixed body that supports the movable body 2 in a reciprocatingly rotatable manner.

[0041] The components of the rotary reciprocating drive actuator 1 including the drive unit 4 and the frame portion 60 are assembled using fastening members 77, 81, 86a, etc. The fastening member 81 fixes the shaft support 62 to the base portion 61. In addition, the fastening members 77, 81, 86a can be used in any manner as long as they can fix the connected components, but the assembly of the drive unit 4, the assembly of the frame portion 60, or the assembly of the drive unit 4 and the frame portion 60 only needs to fasten the connected objects to each other from the axial direction.

[0042] That is, the components of the rotary reciprocating drive actuator 1 are fixed to each other by connecting or joining in the axial direction. The fastening member may be, for example, an external thread such as a screw or a bolt, or a nut or bolt, or may be composed of a fastening part and a fastened part that join the joining objects to each other by inserting and threading in the axial direction.

[0043] The V-shaped reflector 10 is a movable object in the rotary reciprocating drive actuator 1, and is connected to the rotating shaft 20. The V-shaped reflector 10 has two reflective surfaces 12a and 14a adjacent to each other on a ridgeline parallel to the rotating shaft 20. The V-shaped reflector 10 has a first reflector 12, a second reflector 14, and a mirror holding portion 16, and is formed by holding the first reflector 12 and the second reflector 14 by adhering to the mirror holding portion 16 or the like. In the V-shaped reflector 10, a scanning line is irradiated onto the surfaces (reflective surfaces) 12a and 14a of the first reflector 12 and the second reflector 14, respectively.

[0044] The rotating shaft 20 is inserted through the insertion hole 162 of the mirror holding portion 16 and fixedly mounted so as to be integrally provided on the V-shaped reflecting mirror 10. The specific mounting positions of the V-shaped reflecting mirror 10 and the rotating shaft 20 will be described later.

[0045] The frame portion 60 supports the V-shaped reflector 10 so as to be reciprocatable and rotatable together with the drive unit 4. The frame portion 60 supports the V-shaped reflector 10 at a position sandwiching the V-shaped reflector 10 by a pair of wall-like portions facing each other in the base portion 61 and the shaft bracket 62.

[0046] The base portion 61 is in the shape of a flat plate, and a shaft bracket 62 is provided on one side surface (e.g., the surface) in the axial direction (thickness direction) so as to stand up from the base portion 61. The unit body 40 of the drive unit 4 is mounted on the other surface (the back surface) of the base portion 61. The base portion 61 and the unit body 40 of the drive unit 4 are fixed by, for example, fastening in parallel to the axial direction via a fastening member 86a and a fastened member 86b.

[0047] The shaft support 62 holds the V-shaped reflector 10 of the rotating shaft 20 together with the base portion 61 .

[0048] The bracket 62 includes a rising wall portion 624 arranged to rise from the base portion 61 in the axial direction, and an opposing wall portion 626 connected to the front end of the rising wall portion 624 in a bent manner and arranged to oppose the base portion 61 .

[0049] The base 61 and the opposing wall 626 are disposed opposite to each other with the rising wall 624 interposed therebetween, and are held at a position sandwiching the V-shaped reflector 10 by the rotating shaft 20 inserted through the opening 612 of the base 61 , and have a substantially U-shaped cross section.

[0050] In this way, the frame portion 60 supports the V-shaped reflector 10 disposed between the base portion 61 and the opposing wall portion 626 from both sides via the rotating shaft 20. Thus, compared with a structure in which the V-shaped reflector 10 is supported by the rotating shaft 20 supported by the drive unit 4 in a cantilever manner, the V-shaped reflector 10 can be supported more firmly, and the impact resistance and vibration resistance are improved.

[0051] The base portion 61 is inserted in the axial direction, and a connection hole 614 is formed for inserting a part of the coil body (coil and bobbin). The holding portions 563 and 573 of the coil body are inserted into the connection hole 614, and the coil ends 52a and 54a arranged on the insertion protrusion are connected to the substrate 67. In addition, the substrate 67 is a power supply substrate for driving the power supply of the actuator, and is connected to the coils 52 and 54 to supply power. In addition, these holding portions 563 and 573 hold the terminal 58, and the coil ends 52a and 54a are wound around the terminal 58, and the coil ends 52a and 54a are immersed (welded) in the terminal 58.

[0052] The base portion 61 and the facing wall portion 626 are arranged to be spaced apart from each other in the axial direction and to face each other. The base portion 61 and the facing wall portion 626 rotatably support the rotating shaft 20 inserted therethrough via bearings 64 and 65 , respectively.

[0053] Specifically, the bearing 64 is fitted in the bearing housing 66 , and each bearing housing 66 is fitted in the opening 612 of the base portion 61 (the base portion 61 functions as a shaft support body).

[0054] The bearing 65 has a flange that engages with the surface of the wall portion so as to be fitted into an insertion hole 627 of a facing wall portion 626 disposed facing the opening portion 612 , and restricts movement of the rotating shaft 20 toward the one end portion 21 side.

[0055] Meanwhile, the bearing 64 has a flange that restricts movement toward the other end 23 relative to the bearing housing 66 and is fitted with the bearing housing 66. The bearing housing 66 is fixed to the base 61 by caulking or the like, and restricts movement of the bearing 64 toward the other end 23.

[0056] Thus, when the bearings 64 and 65 are mounted to the frame portion 60 during assembly of the rotary reciprocating drive actuator 1 , the mounting state of the bearings 64 and 65 to the base portion 61 and the facing wall portion 626 can be easily viewed from the axial direction.

[0057] The bearings 64 and 65 may be rolling bearings (eg, ball bearings) or sliding bearings for the base 61. For example, if the bearings 64 and 65 are rolling bearings, the friction coefficient is low and the rotating shaft 20 can rotate smoothly, thereby improving the driving performance of the rotary reciprocating drive actuator 1.

[0058] Thus, the rotating shaft 20 is rotatably mounted on the frame portion 60 via the bearings 64 and 65 , and the V-shaped mirror 10 as a movable object is rotatably disposed between the pair of opposing base portions 61 and the opposing wall portion 626 .

[0059] The rotating shaft 20 is mounted on the base 61 and the shaft support 62 via bearings 64 and 65. The V-shaped reflector 10 is supported between the base 61 and the shaft support 62 via the rotating shaft 20 so as to be reciprocatingly rotatable about the axial direction of the rotating shaft 20.

[0060] In the rotating shaft 20 , the magnet 30 is disposed at the one end portion 21 protruding to the outside of the base portion 61 via the bearing 64 .

[0061] On the rotating shaft 20 , a cylindrical spacer 28 is externally inserted in a portion between the mirror holding portion 16 of the V-shaped reflecting mirror 10 and the facing wall portion 626 through which the other end portion 23 of the rotating shaft 20 is inserted.

[0062] The movement of the rotating shaft 20 toward the one end 21 of the V-shaped reflector 10 is restricted by the stopper 27 , and the movement toward the other end 23 is restricted by the biasing force of the preload spring 26 that biases the magnet 30 toward the one end 21 via the bearing 64 .

[0063] The stopper 27 , also called a retaining ring, is attached to the other end portion 23 of the rotating shaft 20 inserted through the opposing wall portion 626 so as to be embedded in a portion on the outer surface side of the opposing wall portion 626 and protrude in the radial direction.

[0064] The spacer 28 and the stopper 27 restrict the axial movement of the movable body 2 including the V-shaped reflector 10, the rotating shaft 20 and the magnet 30 to a predetermined range including tolerances, and prevent the movable body 2 from falling off the base 61. In addition, the movement of the magnet 30 itself toward the other end 23 is restricted by the bearing 64.

[0065] The preload spring 26 is inserted on the rotating shaft 20 at a portion protruding outside (on the one end 21 side) of the frame 60 (base 61 ). The preload spring 26 is disposed between the base 61 (specifically, the bearing 64 ) and the magnet 30 .

[0066] The preload spring 26 expands and contracts in the axial direction and applies axial force to the bearing 64 via the magnet 30. The preload spring 26 applies a constant preload to the bearing 64. The preload spring 26 applies a constant preload to the bearing 64, so that the preload spring 26 absorbs the load fluctuation, the expansion and contraction of the rotating shaft 20 caused by the temperature difference between the rotating shaft 20 and the base 61, etc. in rotation. As a result, the preload amount changes less with respect to the bearing 64, and a stable preload amount can be obtained. Therefore, the preload spring 26 can prevent high-speed rotation of the rotating shaft 20 and axial vibration of the rotating shaft 20, and can be driven at a high speed compared to the fixed position preload, and can prevent axial vibration.

[0067] The preload spring 26 may also be a compression spring having a predetermined length corresponding to the space in which it is arranged and having flat surfaces formed at both ends separated in the predetermined length direction, and more preferably, may be a conical spring with a large deflection. By using a conical spring, an effective acting force can be obtained even if it is arranged in a limited area.

[0068] In this way, the preload spring 26 is disposed between the bearing (particularly the ball bearing) 64 and the magnet 30, and by applying preload to the bearing 64, the low slip and high reliability of the rotation drive of the rotating shaft 20 can be maintained, and stable driving can be performed. In other words, the preload spring 26 applies a force to the magnet 30 in advance to move the magnet 30 in a direction away from the bearing 64, and restricts the movement of the magnet 30 toward the base portion 61 or the bearing 64 side.

[0069] The magnet 30 is disposed at a portion protruding outward from the base portion 61 at one end portion 21 of the rotating shaft 20. The magnet 30 is disposed, for example, in a drive unit 4 described later. The magnet 30 is driven to reciprocate by the magnetic flux generated by the drive unit 4. That is, the rotating shaft 20 is driven together with the magnet 30 that is reciprocated by the mutual electromagnetic action between the drive unit 4 and the magnet 30, so that the V-shaped reflector 10 reciprocates.

[0070] Furthermore, since the preload spring 26 is disposed inside the rotary reciprocating drive actuator 1 , a stable preload design can be ensured without being affected by the outside of the rotary reciprocating drive actuator 1 .

[0071] In addition, the preload spring 26 can also replace the cylindrical coil spring formed by winding a round steel wire into a spiral shape, and use a wave spring with a lower spring height in the expansion and contraction direction, that is, a wave spring formed by winding a plate steel wire into a spiral or ring shape and applying waves.

[0072] <Unit body 40>

[0073] Figure 2 to Figure 5 The unit main body 40 shown surrounds the magnet 30 of the movable body 2 in a direction perpendicular to the axial direction, and constitutes a part of the fixed body.

[0074] The unit body 40 is provided on one axial side of the frame portion 60 , namely, on the outer surface (back surface) of the base portion 61 , and is driven by supplying electricity to the coils 52 and 54 , and is driven in cooperation with the magnet 30 to move the movable body 2 .

[0075] The unit body 40 is formed in a rectangular column or plate shape, and one axial surface, that is, the front surface, is covered by the base portion 61, and the other axial surface, that is, the back surface, is covered by the bottom cover 84. The unit body 40 includes: a coil body 50 having coils 52, 54 and bobbins 56, 57 around which the coils 52, 54 are wound; an iron core assembly 41; and a neutral position holding portion 48.

[0076] In the present embodiment, the unit body 40, specifically, the core assembly 41 is formed in a rectangular frame-shaped block (specifically, a rectangular parallelepiped shape) in which the magnetic poles 420a and 420b are arranged inside.

[0077] The unit body 40 is formed in a frame-shaped outer peripheral portion of the core assembly 41 so as to surround the magnetic poles 420a and 420b arranged inside the outer peripheral portion. The unit body 40 has a magnetic path arranged inside the outer peripheral portion along the rectangle, and the magnet 30 is arranged on the magnetic path, for example, in a rectangular area viewed from the axial direction relative to the base portion 61, that is, the back side of the base portion 61.

[0078] <Core Assembly 41>

[0079] The core assembly 41 forms a magnetic circuit having a magnetic circuit arranged in a direction perpendicular to the axial direction, that is, in a manner surrounding the magnet 30 and the coils 52 and 54 on all sides. The adjacent sides of the core assembly 41 are formed with substantially the same length to form a square magnetic circuit. The magnetic circuit of the core assembly 41 has a shape that surrounds the portion where the coils 52 and 54 are inserted, the magnet 30, and the magnetic poles 420a and 420b on all sides in the radial direction of the magnet 30.

[0080] The core assembly 41 includes: a first core 42 integrally provided with a plurality of magnetic poles 420a and 420b; a second core 44 disposed adjacent to the first core and surrounding the plurality of magnetic poles 420a and 420b together with the first core 42; and a frame-shaped third core 46 connecting the first core 42 and the second core 44. The core assembly 41 integrates the first to third cores by magnetically coupling them.

[0081] The first to third cores 42 to 46 form a magnetic path through the magnetic poles 420a and 420b sandwiching the magnet 30, and allow magnetic flux generated when current is supplied to the coils 52 and 54 to pass through the plurality of magnetic poles 420a and 420b.

[0082] Each of the first to third cores 42 to 46 is a laminated core formed by laminating electromagnetic steel sheets (laminated members) such as silicon steel sheets. By making the core assembly 41 a laminated structure, the first to third cores 42 to 46 having a complex shape can be constructed at low cost.

[0083] <First Core 42>

[0084] The first core 42 includes: a plurality of rod-shaped bodies 421 ( 421 a , 421 b ) each having opposing magnetic poles 420 a , 420 b and arranged in parallel; a connecting side 422 and side sides 423 a , 423 b arranged to surround the rod-shaped body 421 from three directions; and an auxiliary pole portion 424 .

[0085] In the first core 42, magnetic poles 420a and 420b are arranged at the front ends of a plurality of rod-shaped bodies 421a and 421b. A connecting side portion 422 extending perpendicularly to the extending direction of the rod-shaped bodies 421a and 421b is connected to the base ends of the rod-shaped bodies 421a and 421b, and two side sides 423a and 423b are protrudingly arranged at the two ends of the connecting side portion 422 in parallel with the rod-shaped bodies 421a and 421b. The connecting side portion 422 and the side sides 423a and 423b on both sides of the connecting side portion 422 are arranged in a C shape that surrounds the plurality of rod-shaped bodies 421a and 421b from three directions.

[0086] The first core 42 will be described in more detail. The rod-shaped body 421 (421a, 421b), the connecting side portion 422, the side portion 423 (423a, 423b) and the auxiliary pole portion 424 are integrally structured, and the first core 42 is formed into a so-called comb-teeth shape.

[0087] The magnetic poles 420a and 420b are formed at the front ends of the rod-shaped bodies 421a and 421b so as to face each other with the magnet 30 interposed therebetween in a direction perpendicular to the extending direction of the rod-shaped bodies 421a and 421b.

[0088] The magnetic poles 420 a and 420 b face the magnet 30 in the radial direction of the rotating shaft 20 , and are arranged to be separated from each other in the circumferential direction of the rotating shaft 20 .

[0089] The coil bobbins 56 and 57 are inserted outside the center of the rod-shaped bodies 421a and 421b, which are adjacent to the magnetic poles 420a and 420b. When the coils 52 and 54 are excited by energizing, the magnetic poles 420a and 420b at the front end of the rod-shaped bodies 421a and 421b generate polarities corresponding to the energizing direction of the coils 52 and 54.

[0090] The magnetic poles 420a and 420b have shapes corresponding to the outer circumference of the magnet 30, for example, curved along the outer circumference of the magnet. These curved shapes are arranged to face each other with the magnet 30 interposed therebetween in a direction perpendicular to the extending direction of the rod-shaped bodies 421a and 421b.

[0091] The rod-shaped bodies 421a and 421b have outer dimensions that allow the bobbins 56 and 57 to be inserted from the front end. The bobbins 56 and 57 can be inserted from the front end of the rod-shaped bodies 421a and 421b in the extending direction, that is, the front end of the magnetic poles 420a and 420b to be located at a predetermined position.

[0092] The connecting side 422 constitutes one side of the rectangular core assembly 41. The connecting side 422 is connected to the base ends of the rod-shaped bodies 421a and 421b and is arranged to extend in a direction perpendicular to the parallel direction of the rod-shaped bodies 421a and 421b.

[0093] The connecting side 422 mainly connects the base ends of the rod-shaped bodies 421a and 421b to the side sides 423a and 423b. Preferably, the side sides 423a and 423b are in close contact with the two ends of the second core 44, but here, a gap is provided between the side sides 423a and 423b and the two ends of the second core 44.

[0094] The connecting side portion 422 and the both side portions 423 a and 423 b are provided so as to be stacked together with the second core 44 in a state of being in close contact with the third core 46 in the axial direction.

[0095] By connecting the side portions 422 , the opposing positions of the plurality of magnetic poles 420 a and 420 b can be arranged with high accuracy without positional displacement when assembling the core assembly 41 and further assembling the drive unit 4 .

[0096] On the other hand, the auxiliary pole 424a at the front end of the auxiliary pole portion 424 generates a magnetic attraction with the magnet 30 arranged opposite to it, so that the magnet 30 is located at a neutral position equidistant from both of the plurality of magnetic poles 420a and 420b and serves as a rotation reference position during reciprocating rotation.

[0097] The auxiliary pole portion 424 is provided between the rod-shaped bodies 421 a and 421 b at the connecting side portion 422 and extends in parallel with the rod-shaped bodies 421 a and 421 b , and faces the outer periphery of the magnet 30 in the radial direction at the front end.

[0098] The auxiliary pole portion 424 is disposed opposite to the neutral position holding portion 48, and when the neutral position holding portion 48 attracts the first pole of the magnet 30, the auxiliary pole portion 424 attracts the second pole of the other pole of the magnet 30, thereby reinforcing the attracting state of the neutral position holding portion 48. In addition, the neutral position holding portion 48 attracts the magnet 30 by using the magnetic pole generated between the neutral position holding portion 48 and the magnet 30, and holds the magnet 30 in the neutral position where the distance between the magnetic poles 420a and 420b is equal when the magnet 30 reciprocates. The details of the neutral position holding portion 48 will be described later.

[0099] The auxiliary pole portion 424 is made of a magnetic body, and generates a magnetic attraction force between the neutral position holding portion magnet 30 (more specifically, the pole 32b), and moves the pole 32b different from the pole 32a attracted to the neutral position holding portion 48 in the magnet 30 to an opposite position (just in front). The auxiliary pole portion 424 cancels the axial radial load acting on the movable body 2 due to the magnetic attraction force of the neutral position holding portion 48 through this action. In addition, "cancelling the axial radial load" also includes "cancelling the axial radial load".

[0100] In addition, the auxiliary pole (auxiliary pole surface) at the front end of the auxiliary pole portion 424 facing the outer peripheral surface of the magnet 30 is a curved surface corresponding to the shape of the outer peripheral surface of the magnet 30, and there is a uniform gap between the auxiliary pole portion 424 and the outer peripheral surface of the magnet 30 over the entire surface. In addition, the auxiliary pole portion 424 is arranged in a manner surrounding the magnet 30 together with the neutral position holding portion 48 in the core assembly 41, so that a more compact rotary reciprocating drive actuator 1 can be realized with a minimum space layout.

[0101] <Coil body (coil and bobbin)>

[0102] like Figure 2 to Figure 5 As shown, coils 52 and 54 are wound around cylindrical bobbins 56 and 57 to form a coil body. The coil body and magnet 30 together form an electromagnetic drive unit that reciprocates the movable body 2.

[0103] The bobbins 56 and 57 are provided with flanges 561 and 571 at both ends of the cylindrical bodies on the outer periphery of which the coils 52 and 54 are arranged. A retaining portion 563 and 573 partially protruding in a direction orthogonal to the axis of the coils 52 and 54 is provided on one side of the flange of each bobbin 56 and 57. The retaining portions 563 and 573 retain the terminals (pin terminals) 58 to which the windings of the coils 52 and 54 are connected.

[0104] The holding parts 563 and 573 hold the other end of the L-shaped terminal 58 connected to the end of the winding of the coil 52 and 54 in a manner exposed to the outside. The coil body is respectively inserted into the rod-shaped bodies 421a and 421b of the first core 42 and arranged adjacent to the magnetic poles 420a and 420b of the first core 42.

[0105] The winding directions of the coils 52 and 54 are set so that magnetic flux is appropriately generated from one of the plurality of magnetic poles of the first core 42 toward the other when current is supplied.

[0106] The coil body is arranged in the core assembly 41 with the holding parts 563 and 573 protruding upward. When the core assembly 41 is fixed to the base 61 , the holding parts 563 and 573 are inserted into the connection holes 614 of the base 61 to connect the terminals 58 to the substrate 67 .

[0107] That is, the coils 52 and 54 are connected to the substrate 67 so that magnetic flux is appropriately generated from one of the plurality of magnetic poles 420 a and 420 b of the first core 42 toward the other when current is supplied to the coils 52 and 54 .

[0108] <Second Core 44>

[0109] The second core 44 is formed in a columnar shape with a C-shaped cross section, and forms a magnetic path in which magnetic flux passes through the magnetic poles 420 a and 420 b when electricity is supplied to the coils 52 and 54 .

[0110] The second core 44 has the same thickness (length in the axial direction) as that of the two side sides 423a and 423b, and is disposed so as to be connected to or close to the front end surfaces of the two side sides 423a and 423b.

[0111] The second core 44 is fixed to the base 61 and the bottom cover 84 in a state of being closely attached to the third core 46 via the fastening members 86a inserted into the mounting holes (fastening holes) 402 which are the same as the mounting holes (fastening holes) 402 provided at both ends of the connecting side portions 422 of the first core 42. The mounting holes 402 have the same diameter as the through holes of the bottom cover 84 and are formed so as to extend parallel to the rotating shaft 20.

[0112] A neutral position holding portion 48 is attached to the second core 44 at a location in the center of the second core 44 in the extending direction and facing the magnet 30 .

[0113] <Third Core 46>

[0114] The third core 46 is attached to a rectangular frame-shaped portion formed in a rectangular frame plate shape and composed of both the first core 42 and the second core 44 , that is, the connecting side 422 and both side sides 423 of the first core 42 , and the second core 44 in surface contact.

[0115] The third core 46 forms a square frame-shaped magnetic circuit having a predetermined thickness surrounding the plurality of magnetic poles 420a and 420b and connecting the plurality of magnetic poles 420a and 420b by connecting the first core 42 and the second core 44. The core assembly is fixed to the base 61 via the third core 46.

[0116] Specifically, the third core 46 faces the connecting side portion 422 and both side portions 423 a and 423 b of the first core 42 in the extending direction of the rotating shaft 20 , and is in surface contact with each other.

[0117] Thus, the third core 46 is arranged around the rotating shaft 20 so as to surround the magnetic poles of the rod-shaped bodies 421 a and 421 b and the coils 52 and 54 , thereby forming a seamless magnetic path around the rotating shaft 20 .

[0118] The first to third cores 42 to 43 include an enclosure that surrounds the coils 52 and 54, and can form a flow of magnetic flux that passes through the first core 42, the third core 46, the second core 44, the third core 46, and the other magnetic pole of the first core 42 in sequence from one of the magnetic poles 420a and 420b. In addition, the enclosure includes, for example, both side sides 423a and 423b, the connecting side 422, and the entire third core 46. In addition, the frame-shaped enclosure in the first to third cores 42 to 43 surrounds the magnetic poles 420a and 420b and the magnet 30 between the magnetic poles 420a and 420b, so that external components can be prevented from contacting the coils 52 and 54 from the outside.

[0119] When the drive unit 4 is assembled, the rotating shaft 20 is inserted into the space surrounded by the magnetic poles. The magnet 30 attached to the rotating shaft 20 is located in the space, and the magnetic poles face the magnet 30 with the air gap G therebetween at the correct position.

[0120] <Magnet 30>

[0121] The magnet 30 is a ring-shaped magnet in which the S pole 32a and the N pole 32b are alternately arranged in the circumferential direction. The magnet 30 is mounted on the circumferential surface of the rotating shaft 20 in a state where the rotating reciprocating drive actuator 1 is assembled and is located in a space surrounded by the magnetic poles 420a, 420b of the core assembly 41, the neutral position holding portion 48, and the auxiliary pole. The magnet 30 is fixed in a manner surrounding the outer circumference of the rotating shaft 20. When the coils 52 and 54 are energized, the first core 42, the second core 44, and the third core 46 including the rod-shaped bodies 421a and 421b are excited so that the magnetic poles 420a and 420b have polarities corresponding to the energization direction. As a result, magnetic forces (attractive forces and repulsive forces) are generated between the magnetic poles 420a and 420b and the magnet 30.

[0122] In the present embodiment, the magnet 30 is a two-pole magnet that is equally divided into an S pole 32a and an N pole 32b. The number of magnetic poles of the magnet 30 (two in the present embodiment) can be equal to the number of magnetic poles 420a and 420b of the core assembly 41, and may have more than two poles depending on the amplitude when the movable body moves.

[0123] The magnet 30 switches polarity at the boundary portion (magnetic pole switching portion) 32c of different magnetic poles (S pole 32a and N pole 32b) in the circumferential direction. When the magnet 30 is held at an initial angle corresponding to the initial position (neutral position, also referred to as the initial position of the movable body 20), the magnetic pole switching portion 32c faces the magnetic poles 420a and 420b respectively, thereby generating maximum torque during driving of the drive unit 4 and being able to stably drive the movable body 2.

[0124] Furthermore, by forming the magnet 30 with a two-pole magnet, it is easy to drive the movable object with a high amplitude through cooperation with the core assembly 41, and the driving performance can be improved. That is, compared with a structure using a single-sided reflector with the same width as the V-shaped reflector 10, a wide-angle amplitude can be achieved. In addition, in the embodiment, the case where the magnet 30 has a pair of magnetic pole switching parts 32c is described, but it may also have more than two pairs of magnetic pole switching parts.

[0125] <Neutral Position Holding Unit (Magnet Initial Angle Position Holding Unit) 48>

[0126] Figure 2 to Figure 5 The neutral position holding portion 48 shown is assembled to the core assembly 41 so as to face the magnet 30 via the air gap G. The neutral position holding portion 48 is attached to the second core 44 in a posture in which the magnetic pole faces the magnet 30, for example.

[0127] Neutral position holding member 48 is a magnetic body, facing magnet 30 in the radial direction of rotating shaft 20 and disposed between a plurality of magnetic poles 420a and 420b in the circumferential direction. Neutral position holding member 48 attracts magnet 30 and urges magnet 30 (movable body 2) toward the initial position (initial angular position) of reciprocating rotation.

[0128] The neutral position holding portion 48 is a magnetic body, for example, a permanent magnet, is arranged with its magnetic pole facing the magnet 30 , and attracts the magnet 30 by a magnetic attraction force generated between the neutral position holding portion 48 and the magnet 30 .

[0129] The neutral position holding portion 48, together with the rod-shaped bodies 421a and 421b, functions as a magnetic spring forming portion that forms a magnetic spring between the magnet 30. By means of the magnetic spring, in a normal state (non-energized state) when no power is supplied to the coils 52 and 54, the rotation angle position of the magnet 30, that is, the rotation angle position of the rotating shaft 20 is maintained at a neutral position.

[0130] At this time, the pole 32a ( Figure 3 The pole 32b ( Figure 3 The N pole shown in FIG. 4 attracts the auxiliary pole portion 424. As described above, the neutral position holding portion 48 and the auxiliary pole portion 424 effectively hold the magnet 30, that is, the movable object, that is, the V-shaped reflector 10, at the neutral position.

[0131] In addition, as described above, the neutral position refers to the position at which the magnet 30 is located at the initial angle that serves as a reference during the reciprocating motion when the magnet 30 reciprocates around the axis. In addition, the neutral position is a neutral position in which the magnet 30 rotates left and right at the same distance during the reciprocating rotation (swinging), and is a position in which the angles when the magnet 30 rotates left and right around the axis are the same rotation angle during the reciprocating rotation. When the magnet 30 is maintained at the neutral position, the magnetic pole switching portion (boundary portion) 32c of the magnet 30 is directly opposite to the magnetic poles of the rod-shaped bodies 421a and 421b.

[0132] The installation posture of the V-shaped reflector 10 is adjusted based on the state where the magnet 30 is located at the neutral position. In addition, the neutral position holding portion 48 can also be composed of a magnetic body (unmagnetized magnetic body) that generates magnetic attraction between the magnet 30 instead of a permanent magnet (magnetized magnetic body).

[0133] <Positioning cover 82 and bottom cover 84>

[0134] like Figure 2 , Figure 4-5 As shown, one axial surface (upper surface) of the core assembly 41 is covered by the base portion 61 , and the other axial surface (lower surface) is covered by the positioning cover 82 and the bottom cover 84 .

[0135] The positioning cover 82 is formed in a frame shape and is installed in a manner to position the magnet 30 and the core assembly 41. The gap between the core assembly 41 and the bottom cover 84 can be maintained to maintain a gap such as a movable area in a manner that forms an appropriate drive circuit. The positioning cover 82 is installed in a manner that overlaps with the outer surface of the core assembly 41.

[0136] In addition, the positioning cover 82 is provided with a cutout portion 822 that serves as an escape portion for the magnet 30, a through hole for fixing to the base portion 61, a positioning hole, a position adjustment hole, and other hole portions. These hole portions are formed parallel to the axial direction of the rotating shaft 20. The fastening member can be inserted through the through hole, and the assembly to the base portion 61 or the drive unit 4 can be performed in one axial direction, and the rotary reciprocating drive actuator 1 can be assembled.

[0137] The bottom cover 84 prevents contaminants from entering the core assembly from one end (one end face) of the rotary reciprocating drive actuator 1. In addition, the bottom cover 84 is preferably made of a non-magnetic and highly conductive conductive material to function as an electromagnetic shield. That is, the bottom cover 84 can suppress the incidence of noise on the core assembly 41 and the emission of noise from the core assembly 41 to the outside.

[0138] The bottom cover 84 may be formed of a non-magnetic material such as aluminum alloy, which has electrical conductivity and high thermal conductivity. Aluminum alloy has a high degree of freedom in design and can be easily given a desired rigidity.

[0139] The outer surface (upper surface) of the facing wall 626 is formed in a concave shape, and functions as a sensor housing portion 626a. The other end portion 23 of the rotating shaft 20 protrudes into the facing wall 626 and is disposed in the concave sensor housing portion 626a.

[0140] <Angle Detection Unit 7>

[0141] An angle detection unit 7 is disposed on the surface (top surface) side of the opposing wall portion 626. The angle detection unit 7 detects the rotation angle of the movable body 2 including the magnet 30 and the rotating shaft 20. The rotary reciprocating drive actuator 1 can control the rotation angle position and the rotation speed of the movable body, specifically the movable object, i.e., the V-shaped reflector 10, during driving via a control unit (not shown) based on the detection result of the angle detection unit 7. In addition, the control unit can also be mounted on the substrate 67.

[0142] The angle detection unit 7 may use a magnetic or optical sensor. In this embodiment, the angle detection unit 7 includes a sensor substrate 72, an encoder disk 74 housed in a sensor housing 626a, an encoder hub 76, and a light sensor (sensor) 78 having a light source and a light receiving element.

[0143] The angle detection unit 7 detects the rotation angle of the rotating shaft 20 and the V-shaped reflector 10 by detecting the rotation of the encoder disk 74. The encoder disk 74 is fixed to the other end 23 of the rotating shaft 20 in the sensor storage portion 626a via the encoder hub 76, and rotates integrally with the magnet 30 and the V-shaped reflector 10 around the rotating shaft 20. The rotation position of the encoder disk 74 is the same as the rotation position of the rotating shaft 20.

[0144] The optical sensor 78 is mounted on the sensor substrate 72, and emits light parallel to the axial direction to the code disk 74, and detects the rotation position (angle) of the code disk 74 based on the reflected light. In this way, the rotation position of the magnet 30 and the V-shaped reflector 10 can be detected. The optical sensor 78 is mounted on the back side of the sensor substrate, and is therefore stored in the sensor storage portion 626a through the sensor substrate 72.

[0145] The optical sensor 78 is mounted on the sensor substrate 72 disposed perpendicularly to the other end portion 23 of the rotating shaft 20 , and can therefore be easily located at a position facing the encoder disk 74 in the rotating shaft direction.

[0146] The sensor substrate 72 is mounted on the upper surface of the opposing wall portion 626 so as to close the sensor housing portion 626 a , thereby closing the sensor housing portion 626 a .

[0147] The sensor substrate 72 is a substrate on which a light sensor 78 for detecting the rotation angle of the rotating shaft 20 is mounted. The sensor substrate 72 is arranged such that the light sensor 78 faces the magnet 30 side in the axial direction and covers the core assembly 41.

[0148] The sensor substrate 72 is fastened to the opposing wall portion 626 via a fastening member 77, which can prevent unwanted substances such as foreign matter from intruding into the sensing portion of the angle detection unit 7 from the outside, that is, it can prevent contamination of the sensor housing portion 626a.

[0149] In this way, the sensor substrate 72 and the opposing wall portion 626 are positioned by a positioning pin 79 through holes formed in the same shape in the axial direction, and are detachably fixed by a fastening member 77.

[0150] In addition to the circuit for detecting the rotational position (angle) of the code disk, the sensor substrate 72 can also be equipped with a circuit for supplying power to the coils 52 and 54. In the case of this structure, the power supply circuit is not mounted on the substrate 67.

[0151] <The positional relationship between the V-shaped mirror and the rotating shaft>

[0152] Figure 6 It is a horizontal cross-sectional view showing the positional relationship between the mirror holding portion and the rotating shaft.

[0153] As Figure 2 , Figure 4 and Figure 6 shown, the V-shaped mirror 10 is configured to hold the first mirror 12 and the second mirror 14 by the mirror holding portion 16, and is fixed to the rotating shaft 20 such that its center of gravity position CG is aligned (close) with the center (axis) J of the rotating shaft 20.

[0154] The first mirror 12 and the second mirror 14 are each formed in a rectangular plate shape, for example, and their back surfaces are held by the mirror holding portion 16 with the surfaces being the reflection surfaces 12a and 14a respectively. The first mirror 12 and the second mirror 14 are configured such that the distances from the rotating shaft 20 to the reflection surfaces 12a and 14a are the same.

[0155] The first mirror 12 and the second mirror 14 are arranged symmetrically about the ridge line parallel to the axis of the rotating shaft 20.

[0156] When the V-shaped reflector 10 is observed from the axial direction, the rotation axis 20 is arranged inside a triangular region formed by the first reflector 12 and the second reflector 14, and an imaginary line T connecting the respective ends of the first reflector 12 and the second reflector 14. That is, the axis J of the rotation axis 20 is located in a triangular region sandwiched by the imaginary line T connecting the two separated ends of the reflector portion (the first reflector 12 and the second reflector 14) arranged in a V shape.

[0157] The angle formed by the first reflector 12 and the second reflector 14 at a predetermined angle, i.e., the angle of the V-shape formed by the first reflector 12 and the second reflector 14 with the ridgeline as the center, is preferably a right angle, but may also be an angle less than 90 degrees, i.e., an acute angle.

[0158] The mirror holding portion 16 includes: a rotating shaft holding portion 162 to which the rotating shaft 20 is mounted and which has an outer surface capable of holding the first reflecting mirror 12 and the second reflecting mirror 14 in a V shape; and holding frames 164 and 166 extending in a V shape from the outer surface of the rotating shaft holding portion.

[0159] The holding frames 164 and 166 are, for example, planar, have a length extending along the width direction (the direction extending in a V-shape) of the first reflector 12 and the second reflector 14, and are joined and held at the back sides of the first reflector 12 and the second reflector 14. The holding frames 164 and 166 are respectively on the back sides of the first reflector 12 and the second reflector 14, and are longer than half of the width direction of the first reflector 12 and the second reflector 14, preferably more than 2 / 3 of the length.

[0160] For example, the holding frames 164 and 166 are strip-shaped bodies formed into a V-shape, and a prism-shaped rotating shaft holding portion 162 into which the rotating shaft 20 is inserted and engaged is integrally provided on the back side of the ridgeline portion, thereby forming the mirror holding portion 16. The mirror holding portion 16 can be made of metal, preferably aluminum. In addition, the first reflector 12 and the second reflector 14 can also be made of glass or the like.

[0161] For example, the rotation axis 20 may be arranged within a circle r with a predetermined radius (for example, a radius of 3 mm) centered at the midpoint of a line connecting the midpoints of the widths w of the first reflector 12 and the second reflector 14, i.e., the two reflectors. In addition, the rotation axis 20 may be arranged so that the eccentricity e between the center of gravity and the axis of the rotation axis satisfies (where x is the distance between the reflector surface and the center of gravity, and w is the width of the reflector).

[0162] In this way, the mirror holding portion 16 can be joined to the rotating shaft 20 in such a way that the center of gravity position CG of the V-shaped reflector (including the mirror holding portion 16, the first reflector 12 and the second reflector 14) is adjacent to the axis J of the rotating shaft 20, and the rotating shaft 20 can also be configured at a position including the center of gravity of the mirror holding portion 16.

[0163] The mirror holding portion 16 is provided so as to be located in a region where the rotation shaft 20 or the rotation center of the rotation shaft 20 is sandwiched between two reflecting mirrors in a direction perpendicular to the axial direction.

[0164] In addition, the mirror holding portion 16 includes a first reflector 12 and a second reflector 14 arranged in a V shape, V-shaped holding frames 164 and 166 for fixing and holding each reflector, and a rotation axis holding portion 162. The first reflector 12 and the second reflector 14 have a ridge portion formed by abutting one adjacent side to form a V shape. The holding frames 164 and 166 are arranged on the back side of each reflector 12 and 14.

[0165] The rotation axis holding portion 162 is a thick wall portion on the back side of the V-shaped butt joint of the holding frames 164 and 166, to which the holding frames 164 and 166 are fixed, and has an axis extending parallel to the one side. The rotation axis holding portion 162 is a thick wall portion provided at the back side of the corner of the V-shaped holding frame that holds the reflector arranged in the V-shape on the back side.

[0166] The mirror holding portion 16 has a V-shaped surface 16a that holds a V-shaped reflector (which may be formed by a single reflector) having the first reflector 12 and the second reflector 14, and a W-shaped back surface 16b on the opposite side, so that a thick wall portion is provided between the middle curved portions (which may also be referred to as the middle curved portion of the V-shaped reflector 10) on the front and back sides of the mirror holding portion 16. The rotating shaft 20 is held by the thick wall portion.

[0167] The mirror holding portion 16 can realize low-inertia driving while ensuring the rigidity of the reflecting mirror by adopting any structure.

[0168] This prevents eccentricity during rotational reciprocation driving, thereby preventing an increase in radial load on the bearing 64 , unnecessary vibration, or increase in driving noise.

[0169] Alternatively, the first reflecting mirror 12 and the second reflecting mirror 14 may be integrally formed in a V-shape.

[0170] Among them, use Figure 7 as well as Figure 8 The operation of the rotary reciprocating drive actuator 1 will be described. Figure 7 is a diagram showing a magnetic circuit of a rotary reciprocating drive actuator according to an embodiment of the present invention, Figure 8It is a diagram for explaining the operation of the magnetic circuit of the rotary reciprocating drive actuator according to one embodiment of the present invention.

[0171] like Figure 7 As shown in FIG. 1 , the magnetic poles 420a and 420b of the two rod-shaped bodies 421a and 421b of the core assembly 41 are arranged so as to sandwich the magnet 30 with an air gap G therebetween. Figure 7 As shown, when no current is supplied to the coils 52 and 54 , the magnet 30 is held in the neutral position by the magnetic attraction force between the magnet 30 and the neutral position holding portion 48 .

[0172] In this neutral position, one of the S pole 32a and the N pole 32b of the magnet 30 (at Figure 7 The S pole 32a in the middle is attracted by the neutral position holding portion 48 (refer to Figure 8 At this time, the magnetic pole switching portion of the magnet 30 is located at a position opposite to the center position of the magnetic poles 420a and 420b of the core assembly 41. In addition, the auxiliary pole portion 424 is located at the other of the S pole 32a and the N pole 32b of the magnet 30 (at Figure 7 The N pole 32b in the middle attracts each other. As a result, the magnet 30 moves to the neutral position more effectively.

[0173] When the coils 52 and 54 are energized, the core assembly 41 is excited, and polarities corresponding to the energization direction are generated at the magnetic poles 420a and 420b. Figure 8 As shown, when the coils 52 and 54 are energized, a magnetic flux is generated inside the core assembly 41, and the magnetic pole 420a becomes an N pole and the magnetic pole 420b becomes an S pole.

[0174] As a result, the magnetic pole 420a magnetized to the N pole attracts the S pole 32a of the magnet 30, and the magnetic pole 420b magnetized to the S pole attracts the N pole 32b of the magnet 30. Furthermore, a torque in the F direction is generated around the rotating shaft 20 in the magnet 30, and the magnet 30 rotates in the F direction. In conjunction with this, the rotating shaft 20 also rotates in the F direction, and the V-shaped reflector 10 fixed to the rotating shaft 20 also rotates in the F direction.

[0175] Next, when the coils 52 and 54 are energized in the reverse direction, the flow of the magnetic flux generated inside the core assembly 41 is as follows: Figure 8As shown, the magnetic pole 420a becomes the S pole and the magnetic pole 420b becomes the N pole. The magnetic pole 420a magnetized to the S pole attracts the N pole 32b of the magnet 30, and the magnetic pole 420b magnetized to the N pole attracts the S pole 32a of the magnet 30. Moreover, a torque in the opposite direction to the torque F in the direction opposite to the F direction is generated around the axis of the rotating shaft 20 of the magnet 30, and the magnet 30 rotates in the opposite direction to the F direction. In conjunction with this, the rotating shaft 20 also rotates, and the V-shaped reflector 10 fixed to the rotating shaft 20 also rotates in the same direction as shown. Figure 8 Rotate in the opposite direction as shown.

[0176] The rotary reciprocating drive actuator 1 rotary reciprocatingly drives the V-shaped mirror 10 by repeating the above-mentioned operation.

[0177] In fact, the rotary reciprocating drive actuator 1 is driven by an AC wave input from a power supply unit (e.g., the drive signal supply unit 103 in FIG. 32) to the coils 52 and 54. That is, the energizing direction of the coils 52 and 54 is periodically switched. When the energizing direction is switched, the magnetic attraction between the neutral position holding unit 48 and the magnet 30, that is, the restoring force of the magnetic spring ( Figure 8 The magnet 30 is urged to return to the neutral position by the magnetic spring torque FM shown in the figure and the torque in the opposite direction thereof. Thus, the torque in the F direction and the torque in the opposite direction to the F direction act alternately on the movable body 2 around the axis. Thus, the movable body 2 is driven to rotate and reciprocate.

[0178] The following briefly describes the driving principle of the rotary reciprocating drive actuator 1. In the rotary reciprocating drive actuator 1 of the present embodiment, the inertia moment of the movable body (movable body 2) is set to J [kg·m2], and the spring constant of the magnetic spring (magnetic poles 420a, 420b, neutral position holding portion 48 and magnet 30) in the torsion direction is set to K sp [N·m / rad], the movable body moves relative to the fixed body at the resonance frequency F calculated by equation (1) r [Hz] Vibration (reciprocating rotation).

[0179] [Formula 1]

[0180]

[0181] Fr: Resonance frequency [Hz]

[0182] J: Inertia moment [kg·m 2 ]

[0183] K sp : Spring constant [N·m / rad]

[0184] The movable body constitutes the mass part in the vibration model of the spring mass system. Therefore, when the resonance frequency F of the movable body is input to the coils 52 and 54, r When an AC wave with the same frequency as the resonant frequency F of the movable body is input to the coils 52 and 54 from the power supply unit, the movable body enters a resonant state. r The AC waves of substantially equal frequency cause the movable body to vibrate efficiently.

[0185] The following are motion equations and circuit equations that represent the driving principle of the rotary reciprocating drive actuator 1. The rotary reciprocating drive actuator 1 is driven based on the motion equation shown in equation (2) and the circuit equation shown in equation (3).

[0186] [Formula 2]

[0187]

[0188] J: Inertia moment [kg·m 2 ]

[0189] θ(t): angle [rad]

[0190] K t : Torque constant [N·m / A]

[0191] i(t): current [A]

[0192] K sp : Spring constant [N·m / rad]

[0193] D: Attenuation coefficient [N·m / (rad / s)]

[0194] T Loss : Load torque [N·m]

[0195] [Formula 3]

[0196]

[0197] e(t): voltage [V]

[0198] R: Resistance [Q]

[0199] L: Inductance [H]

[0200] K e : Back electromotive force constant [V / (rad / s)]

[0201] That is, the inertia moment J [kg·m 2 ], rotation angle θ(t)[rad], torque constant K t [N·m / A], current i(t)[A], spring constant Ksp [N·m / rad], attenuation coefficient D [N·m / (rad / s)], load torque T Loss [N·m] etc. can be changed appropriately within the range satisfying equation (2). In addition, voltage e(t) [V], resistance R [Ω], inductance L [H], back electromotive force constant K e [V / (rad / s)] can be changed appropriately within the range satisfying the formula (3).

[0202] In this way, the rotary reciprocating drive actuator 1 is driven by the inertia moment J of the movable body and the spring constant K of the magnetic spring. sp Determine the resonant frequency F r When the coil is energized by a corresponding AC wave, a high-efficiency vibration output can be obtained.

[0203] <Assembly structure>

[0204] Fig. 9 It is a diagram for explaining the assembly structure of the rotary reciprocating drive actuator to the housing.

[0205] When the rotary reciprocating drive actuator 1 is mounted on a body of a product, the rotary reciprocating drive actuator 1 is fixed to a fixing table 800 provided on the body side (for example, as a part of the body).

[0206] When fixing the rotary reciprocating drive actuator 1 to the product housing, it is preferable to fix it at a position where the size can be specified based on the reference, that is, after the positioning of the movable part is determined, the position of the movable part is set as the reference, so that it can be fixed with high accuracy. In addition, it is necessary to consider the influence of interference, etc., for example, it is preferable to fix it at a position close to the center of gravity.

[0207] The fixed platform 800 is configured as a U-shaped portion having fixed wall portions 804 and 806 that are separated and erected opposite to each other. The rotary reciprocating drive actuator 1 is fixed to the fixed platform 800 in such a manner that the core assembly 41 of the drive unit 4 is located inside the U-shaped portion. The rotary reciprocating drive actuator 1 makes the erection direction of the fixed platform 800 parallel to the axial direction, makes the side edges of the base portion 61 abut against the upper end surfaces of the fixed wall portions 804 and 806, and is fastened to the fixed platform 800 by the fastening member 87 inserted through the fixing hole 69. In addition, on the upper end surfaces of the fixed wall portions 804 and 806, in addition to the fastening hole 807 for inserting the fastening member 87, a positioning hole (one is a long hole) 809 for inserting the positioning pin 616 is also provided.

[0208] When the rotary reciprocating drive actuator 1 is mounted on the fixed platform 800, the positioning pin 616 parallel to the axis is inserted into the positioning hole 809 in the direction parallel to the axis, and the positioning pin 616 is rotated around the positioning hole 809. In this way, the positions of the rotary reciprocating drive actuator 1 and the fixed platform 800 are adjusted. A rod or the like can be inserted into the positioning notch to further adjust the position so that the fixing hole 69 and the fastening hole 807 are aligned and the fastening member 87 is inserted through and fixed to both.

[0209] The axial direction of the rotating shaft 20 is the same direction as the axial direction of the bearings 64 and 65 due to the position of the V-shaped reflector 10 , so the rotary reciprocating drive actuator 1 can be positioned and fixed to the fixed stage 800 with high accuracy.

[0210] The rotary reciprocating drive actuator 1 can be manufactured by fixing each part in a direction parallel to the axis, or fixed to the housing. In addition, the base portion 61 between the driving part (core assembly 41) of the drive unit 4 and the V-shaped reflector 10 has a fixing hole 69. In addition, the base portion 61 is provided with holes for fixing each part including the bearing 64, and the wall portion 211B is fixed to the fixed platform portion 800 using these holes. They can be positioned and fixed to the fixed platform portion 800 on the same processing surface, and can be fixed with high precision.

[0211] In this way, the rotary reciprocating drive actuator 1 can be positioned and fixed relative to the fixed platform (housing) 800 in a direction parallel to the rotating shaft 20, so compared with fixing using other components, it is possible to perform positioning and fixing with less additional size and high precision. In addition, since there is a center of gravity between the V-shaped reflector 10 and the core assembly 41, it can be stably maintained.

[0212] Fig.10 1 is a block diagram showing a main part configuration of a scanner system 100 using the rotary reciprocating drive actuator 1 .

[0213] The scanner system 100 includes a laser light emitting unit (light irradiating unit) 101 , a laser control unit 102 , a drive signal supply unit 103 , and a position control signal calculation unit 104 in addition to the rotary reciprocating drive actuator 1 .

[0214] The laser light emitting unit 101 includes, for example, an LD (laser diode) as a light source and a lens system for converging laser light output from the light source, etc. The laser control unit 102 controls the laser light emitting unit 101. The laser light irradiated from the laser light emitting unit 101 enters the reflection mirror 121 of the rotary reciprocating drive actuator 1.

[0215] The position control signal calculation unit 104 generates and outputs a drive signal to control the rotation shaft 20 (reflector 121) to the target angular position by referring to the angular position of the rotation shaft 20 (reflector 121) obtained by the angle detection unit 7 and the target angular position. For example, the position control signal calculation unit 104 generates a position control signal based on the obtained angular position of the rotation shaft 20 (reflector 121) and a signal indicating the target angular position after transformation using sawtooth waveform 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.

[0216] The drive signal supply unit 103 supplies a drive signal to the coils 52 and 54 of the reciprocating actuator 1 to adjust the angular position of the rotating shaft 20 (mirror 121) to a desired angular position based on the position control signal. Thus, the scanner system 100 can emit scanning light from the reciprocating actuator 1 to a predetermined scanning area.

[0217] <Conclusion>

[0218] As described above, the rotary reciprocating drive actuator 1 of this embodiment includes: a movable body 2 having a rotating shaft (shaft portion) 20 to which a reflector portion (movable object) is connected and a magnet 30 fixed to the rotating shaft 20. As a movable object, the V-shaped reflector 10 is reciprocatingly driven. In addition, the magnet 30 is a ring-shaped magnet with S poles 32a and N poles 32b alternately arranged on the outer peripheral surface in the circumferential direction.

[0219] Thus, the magnet 30 rotates on the movable body 2 side, so the heating of the coil during movement has no effect on the reflector (movable part) on the movable body side, and the input current can be increased to achieve high output. In addition, the initial position holding structure based on the magnetic spring can realize a high-amplitude actuator.

[0220] In the rotary reciprocating drive actuator 1, the axis of the rotating shaft 20 is arranged close to the center of gravity in such a manner that the V-shaped reflector 10 is aligned with the center of gravity of the V-shaped reflector on the rotating shaft 20. As a result, the inertia is reduced, the input current is increased, the resonance of the V-shaped reflector 10 can be appropriately increased and driven, and a thin and high-output rotary reciprocating drive actuator can be realized.

[0221] In addition, since the reflector is a V-shaped structure, in the optical scanning scanner structure, the reflective surface for optical scanning can be widened and the scanner structure can be thinned according to the need for a wide field angle and a thin structure. In addition, the left and right configuration structures of the light emitting and light receiving parts via the V-shaped reflector 10 can be any structure.

[0222] In addition, the sensor substrate 72 covers the elements of the rotation detection part such as the detection part (encoder disc) of the sensor part at a position axially outward from the unit body 40 (core assembly 41, positioning cover 82, bottom cover 84). As a result, the sensor storage part 626a and the air gap G between the magnet 30 and the core assembly 41 can be prevented from being contaminated by the sensor substrate 72. In this way, foreign matter can be prevented from mixing into the air gap G, malfunction can be prevented, and proper driving can be performed.

[0223] In addition, since the magnet 30 is arranged inside the driving unit 4 of the rotary reciprocating drive actuator, the magnet is not arranged on the outside, and the magnetic flux is not distributed on the outside (front side), which can reduce the magnetic flux leakage to the front side and can be arranged even if there are products with weak magnetism in the surrounding area.

[0224] Since the core assembly 41 of the driving unit 4 is a rectangular frame-shaped block, the installation space of the core assembly 41 is confined to a limited space, such as the rectangular area on the back side of the base 61 (the area observed in the axial direction) to ensure sufficient magnetic path length, so that the movable body 2 can be driven at high amplitude.

[0225] Furthermore, when maintaining the angle detection unit 7, the sensor substrate 72 can be removed and the sensor parts can be exposed to the outside by simply removing the fastening member 77. The sensor parts are, for example, rotation angle detection parts such as the light sensor 78, the encoder disk 74, and the encoder hub 76 on the mounting surface of the sensor substrate 72, and the light emitting and receiving parts. That is, in the event of a malfunction, the expensive sensor parts can be immediately exposed to the outside, so that modification or replacement can be easily performed without discarding each sensor part.

[0226] In addition, when the sensor portion is an optical sensor, it is possible to prevent light from interfering with the sensor housing portion 626a without using a separate light shielding member.

[0227] In addition, the movable object is the V-shaped mirror 10 (particularly the mirror 121) that reflects the scanning light. Thus, the rotary reciprocating drive actuator 1 can be used for a scanner that performs optical scanning.

[0228] In addition, in the unit body 40, since the coils 52 and 54 are surrounded by the first to third cores, electromagnetic noise generated from the coils 52 and 54 can be suppressed. In addition, magnetic flux leakage from the magnet 30 and the coils 52 and 54 can be suppressed.

[0229] Furthermore, for example, in the embodiment, the case where the rotary-reciprocating drive actuator 1 is resonantly driven is described, but the present invention can also be applied to the case of non-resonant driving.

[0230] In addition, the structure of the drive unit 4 is not limited to the structure described in the embodiment. For example, the core has a magnetic pole portion that is excited and generates polarity by energizing the coil, and when the rotating shaft is mounted on the fixed body, the magnetic pole portion and the outer peripheral surface of the magnet are opposed to each other with an air gap therebetween. In addition, the coil only needs to have a structure that appropriately generates magnetic flux from one side of the magnetic pole portion of the core to the other side when energized.

[0231] Furthermore, the neutral position holding portion 48 provided on the fixed body is mounted on the second core 44, but the present invention is not limited thereto and may be provided on other components of the fixed body. In these cases, the neutral position holding portion 48 may be accommodated in the second core 44.

[0232] In addition, in the V-shaped reflector 10, the first reflector 12 and the second reflector 14 may be integrated reflectors, and at least one of the first reflector 12 and the second reflector 14 may be formed integrally with the mirror holding portion 16. Furthermore, the mirror holding portion 16 and the rotation axis 20 may be formed integrally, or the reflector portion, the mirror holding portion, and the rotation axis of the first reflector 12 and the second reflector 14 may all be formed integrally.

[0233] The embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

[0234] The industrial applicability is as follows.

[0235] The present invention is applicable to, for example, LiDAR devices, scanner systems, etc.

Claims

1. A rotary reciprocating drive actuator, characterized in that: have: A movable body having a shaft portion with a magnet fixed to the outer periphery, holding a V-shaped reflector in a manner such that a ridgeline of the V-shaped reflector is along the shaft portion, and supported via the shaft portion so as to be reciprocatingly rotatable about an axis; as well as The unit body comprises: a plurality of magnetic poles which are opposed to the magnet in the radial direction of the shaft and separated from each other in the circumferential direction of the shaft; a coil body which, together with the magnet, forms an electromagnetic drive part for reciprocating the movable body; and a magnetic body which is opposed to the magnet in the radial direction of the shaft portion and is disposed between the plurality of magnetic poles in the circumferential direction, and which attracts the magnet to apply force to the movable body toward an initial position of reciprocating rotation, The electromagnetic drive unit reciprocates the movable body to swing the V-shaped mirror while maintaining the angle formed by the V-shaped mirror.

2. The rotary reciprocating drive actuator according to claim 1, characterized in that: The axis of the shaft portion is arranged at a position near the center of gravity of the V-shaped reflector or a position adjacent to the center of gravity to fix the V-shaped reflector.

3. The rotary reciprocating drive actuator according to claim 1, characterized in that: The axis center of the shaft portion is located within a triangular region sandwiched by an imaginary line connecting both separated ends of the reflector portion arranged in a V-shape.

4. The rotary reciprocating drive actuator according to claim 1, characterized in that: One of the two axial surfaces of the unit body is covered by an axial support body. The shaft support body rotatably supports the shaft portion.

5. The rotary reciprocating drive actuator according to claim 1, characterized in that: The number of the plurality of magnetic poles is two poles arranged opposite to each other with the magnet interposed therebetween. On the outer peripheral surface of the magnet, different magnetic poles are alternately arranged in the circumferential direction. The magnetic pole switching portion of the magnetic pole provided on the outer periphery of the magnet is configured to be located at an angle opposing a circumferential center portion of each of the plurality of magnetic poles when the magnet is located at an initial angle corresponding to the initial position.

6. The rotary reciprocating drive actuator according to claim 1, characterized in that: The unit body includes a core assembly having the plurality of magnetic poles, the coil body being disposed thereon and being disposed so as to surround the magnet in the radial direction. The core assembly is composed of a laminated core formed by laminating steel plates, which are magnetic bodies.

7. The rotary reciprocating drive actuator according to claim 6, characterized in that: The coil body is configured such that the core assembly surrounds the axis.

8. The rotary reciprocating drive actuator according to claim 1, characterized in that: The unit body is fixed on the back side of the plate-shaped base, and the V-shaped reflector is arranged on the front side via a rotation axis protruding to the front side through a through hole in parallel with the axial direction. The base portion and the unit main body are positioned or fixed by a fastening member fastened from a direction parallel to the shaft portion.

9. The rotary reciprocating drive actuator according to claim 1, characterized in that: A rotation detection unit is provided, which is arranged on the opposite side of the unit body with respect to the unit body, sandwiching the V-shaped reflective mirror in the axial direction, and detects rotation of one end of the shaft.

10. The rotary reciprocating drive actuator according to claim 9, characterized in that: The rotation detection unit includes a sensor substrate on which a sensor for detecting the rotation of the one end portion is mounted. A wall portion rotatably supports one end of the shaft portion. The sensor substrate is detachably mounted on the wall portion so as to cover the one end portion.

11. An optical scanning device, characterized in that: have: The rotary reciprocating drive actuator of claim 1; and A light irradiation unit irradiates the V-shaped reflecting mirror of the rotary reciprocating drive actuator with scanning light.

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