CN117411273A - Rotary reciprocating drive actuator - Google Patents

Abstract

The present invention provides a rotary reciprocating drive actuator capable of driving a movable object with high amplitude more appropriately, comprising: a movable body having a shaft portion to which the movable object is connected and a magnet fixed to the shaft portion, and supported so as to be capable of reciprocating rotation about an axis; a base portion rotatably supporting the shaft portion via a bearing, the base portion having a pair of wall portions; a core assembly having a core body, a coil body, and a magnet position holding portion, the core body being attached to the other of the pair of wall portions, the core body having a plurality of magnetic poles, the coil body being wound around the core body and reciprocally rotating the movable body by generating magnetic flux that interacts with the magnet by energization, the magnet position holding portion generating magnetic attraction force with the magnet, and defining a reference position for reciprocal rotation; and a sensor substrate that is attached to one of the pair of wall portions, is provided with a sensor that detects a rotation angle of the shaft portion, and is disposed on the one wall portion from one end portion side toward the one wall portion side.

Description

Rotary reciprocating drive actuator

Technical field

The present invention relates to a rotary reciprocating drive actuator.

Background technique

Conventionally, rotational reciprocating drive actuators have been used as actuators used in optical scanning devices such as multifunction peripherals and laser beam printers. Specifically, the rotary reciprocating drive actuator reciprocates the mirror of the scanner to change the reflection angle of the laser light, thereby achieving optical scanning of the object.

Patent Document 1 discloses a technology using a galvanometer motor as such a rotational reciprocating drive actuator. As galvanometer motors, various types are known, in addition to the type having the structure disclosed in Patent Document 1 and the coil-movable type in which a coil is attached to a reflecting mirror.

Patent Document 1 discloses a beam scanner in which four permanent magnets are provided on a rotation axis on which a mirror is mounted so as to be magnetized in the radial direction of the rotation axis, and a core with a magnetic pole around which a coil is wound is sandwiched. The way the axis of rotation is configured.

existing technical documents

patent documents

Patent Document 1: Japanese Patent No. 4727509

Contents of the invention

The problem to be solved by the invention

However, as described in Patent Document 1, the rotational reciprocating drive actuator is provided with an angle sensor that detects the rotation angle of the rotation shaft connected to the reflecting mirror. The scanning accuracy of the scanner greatly depends on the detection accuracy of the angle sensor. In order to improve the detection accuracy of the angle sensor, it is necessary to adjust the assembly position of the angle sensor with high precision so that the relative relationship between the angle sensor and other structural components of the rotational reciprocating drive actuator such as the mirror is determined.

When the angle sensor is not arranged near the bearing that supports the rotating shaft, it is difficult to detect the rotation angle of the rotating shaft with high accuracy due to the influence of shaft wobbling. In addition, when the angle sensor and the motor are arranged close to each other, there is a problem that it is difficult to perform appropriate measurement due to the influence of electromagnetic noise, heat generation, etc. from the motor.

The present invention is proposed in consideration of the above points, and provides a rotational reciprocating drive actuator capable of driving a movable object at a high amplitude more appropriately.

Solutions for solving problems

One solution of the rotary reciprocating drive actuator of the present invention adopts the following structure, that is, it has:

The movable body has a shaft connected to the movable object at one end and a magnet fixed to the shaft at the other end, and is supported to be capable of reciprocating around the shaft;

A base portion that rotatably supports the shaft portion via a bearing on the one end side and has a pair of wall portions disposed across the movable object;

A core assembly having a core body, a coil body, and a magnet position retaining portion, and is mounted on the other wall portion of the pair of wall portions, wherein the core body has a core body connected to the magnet body with the magnet body interposed therebetween. There are a plurality of magnetic poles facing each other on the outer periphery. The coil body is wound around the core body and generates magnetic flux that interacts with the magnets when energized to cause the movable body to reciprocate. The magnet position holding portion is generated between the magnets. Magnetic attraction, which defines the reference position of the above-mentioned reciprocating rotation; and

A sensor substrate is mounted on one of the pair of wall portions, has a sensor that detects the rotation angle of the shaft portion, and is disposed on the one side from the one end side toward the one wall portion side. of the wall.

Effect of the invention

According to the present invention, the rotation of the shaft connected to the movable object can be accurately detected, and therefore the movable object can be driven with a high amplitude more appropriately.

Description of the drawings

FIG. 1 is an external perspective view of a rotary reciprocating drive actuator according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the axis center of the rotational reciprocating drive actuator.

FIG. 3 is an end view of a portion along line A-A from the front end surface of the drive unit in FIG. 2 , with the left component removed.

FIG. 4 is an exploded perspective view of the rotary reciprocating drive actuator.

Fig. 5 is an enlarged view of the preload spring.

FIG. 6 is a diagram showing a wave spring as a modified example of the preload spring.

Figure 7 is an exploded perspective view of the drive unit.

Fig. 8 is a perspective view of the coil body.

Figure 9 is an exploded view of the coil body.

FIG. 10 is a perspective view showing the wiring state of the coils in the coil body.

Fig. 11 is a front perspective view of the bottom cover.

FIG. 12 is an external perspective view of the angle sensor unit in the rotational reciprocating drive actuator.

FIG. 13 is an exploded perspective view of the angle sensor unit from the front side.

Fig. 14 is an exploded perspective view of the back side of the angle sensor unit.

FIG. 15 is a diagram for explaining the operation of the magnetic circuit of the rotation reciprocating drive actuator.

FIG. 16 is an external perspective view of Modification 1 of the rotation reciprocating drive actuator.

FIG. 17 is a longitudinal cross-sectional view showing Modification 1 of the rotation reciprocating drive actuator.

FIG. 18 is an exploded perspective view of Modification 1 of the rotation reciprocating drive actuator.

FIG. 19 is a perspective view of the wall portion on the front side of Modification 1 of the rotation reciprocating drive actuator.

Fig. 20 is an exploded perspective view of the sensor unit disposed on the wall portion on the one end side;

FIG. 21 is a diagram showing the main structure of a scanner system using a rotary reciprocating drive actuator.

(A) and (B) in FIG. 22 are a front view and a right side view of Modification 1 of the magnet.

(A) and (B) in Fig. 23 are a front view and a right side view of modification 2 of the magnet.

(A) and (B) in FIG. 24 are a front view and a right side view of Modification 3 of the magnet.

(A) and (B) in FIG. 25 are a front view and a right side view of Modification 4 of the magnet.

FIG. 26 is a diagram showing a core assembly of a rotational reciprocating drive actuator according to Modification 4 including a magnet.

In the picture:

1. 1A - Rotary reciprocating drive actuator, 2 - Main unit, 4 - Drive unit, 10, 10A - Movable body, 12 - Reflector part, 13 - Rotation shaft, 14 - Stopper part, 15, 15A - Limiting part, 20—fixed body, 21, 21A—base part, 21a—outer surface, 22, 23—bearing, 30—driving part, 32, 320, 320A, 320B—magnet, 32a, 32b, 410a, 410b - Magnetic pole, 32c, 32d, 32e, 32f, 32g, 32h - magnetic pole switching part, 35 - preload spring, 37 - annular receiving part, 39 - bushing, 40 - core assembly, 41 - first core, 42—Second core (bridging part), 43—Third core, 44, 45—coil, 46, 47—coil frame, 48—rotation angle position maintaining portion, 49—coil body, 50—bottom cover, 52— Cover main body, 53, 321, 732 - opening, 54, 55, 66 - through hole, 56, 205, 705, 725 - positioning hole, 57, 207, 707, 727 - position adjustment hole, 58 - positioning protrusion, 60 -Top cover, 62-top cover main body, 64-peripheral wall part, 67-coil frame engaging hole, 70, 70A-angle sensor part, 72-sensor substrate, 73-substrate holding part, 74-encoder disk (detected Department), 76—Optical sensor (sensor), 81, 84, 85, 86—Fixed parts, 100—Laser system, 101—Laser light emitting unit, 102—Laser control unit, 103—Drive signal supply unit, 104—Position control Signal calculation part, 121—reflector, 122—mirror holder, 122a, 211a, 212a—insertion hole, 131—one end, 132—other end, 133—fitting groove, 203, 215, 402, 702, 703, 723—fixing hole, 211, 211A, 212, 212A—wall, 211a, 211Aa, 212a—insertion hole, 213, 213A—bottom, 218—recess, 222, 232—bearing body, 224, 234—convex Edge, 230, 701—sensor placement part, 322—end surface, 326—outer peripheral surface, 328—flat surface, 400—core body, 411, 411a, 411b—rod-shaped portion, 412—connecting edge portion, 413, 413a, 413b— Side part, 414 - auxiliary pole part, 492 - coil frame part, 494 - terminal support part, 496 - terminal, 522 - mounting part, 541 - countersink part, 621 - concave part, 742 - mounting shaft part, 4964 - The other side, 4962—one side.

Detailed ways

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

FIG. 1 is an external perspective view of the rotary reciprocating drive actuator 1 according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view through the axis center of the rotary reciprocating drive actuator 1 . In addition, FIG. 3 is an end view of the A-A line portion of FIG. 2 in which the left component is removed from the front end surface in order to see the inside of the drive unit 4. FIG. 4 is a view of the rotational reciprocating drive actuator 1. Exploded perspective view.

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

The rotational reciprocating drive actuator 1 is roughly divided into a base portion 21 including a movable body 10 , a base portion 21 that rotatably supports the movable body 10 and is mounted with an angle sensor portion 70 , and a base portion 21 that moves the movable body 10 relative to the base portion 21 . Driving unit 4 for reciprocating rotation. The base portion 21 and the drive unit 4 constitute a fixed body 20 that supports the movable body 10 in a reciprocating and rotatable manner.

In addition, in the rotational reciprocation drive actuator 1 , the movable body 10 is attached to the base portion 21 to form a main body unit 2 , and the rotational reciprocation drive actuator 1 has the drive unit 4 at one end of the main body unit 2 .

As shown in FIG. 1 , in the rotational reciprocating drive actuator 1 , the main body unit 2 in which the movable body 10 is mounted on the base portion 21 and the drive unit 4 are joined through the fixing member 81 . In addition, the fixing member 81 may be any member as long as it can integrally fix the main body unit 2 and the drive unit 4. For example, screws, external threads such as screws, and bolts and nuts may be used.

As shown in FIG. 4 , the movable body 10 has a rotation shaft 13 , a mirror portion 12 , and a movable magnet (hereinafter simply referred to as “magnet”) 32 . In addition, the details of the magnet 32 will be described in detail together with the drive unit 4 described later.

The mirror unit 12 is a movable object in the rotational reciprocating drive actuator 1 and is connected to the rotation shaft 13 . The mirror portion 12 is formed, for example, by affixing the mirror 121 to one surface of the mirror holder 122 . The rotation shaft 13 is inserted into and fixed to the insertion hole 122a of the mirror holder 122. The mirror portion 12 reflects the scanning light.

The base part 21 has a flat bottom 213 and a pair of wall parts 211 and 212 spaced apart from each other. The bottom 213 is flat and extends in the axial direction, and a pair of wall portions 211 and 212 are erected at both ends of the bottom 213 to face each other. The base portion 21 is formed into a substantially U-shaped cross section by a bottom portion 213 and a pair of wall portions 211 and 212 .

The pair of wall portions 211 and 212 each have a rectangular plate shape, and insertion holes 211a and 212a are formed in the center portions (see FIG. 4 ). Bearings 22 and 23 are embedded in the insertion holes 211a and 212a, and the rotation shaft 13 is inserted into the bearings 22 and 23.

In addition, in the insertion holes 211a and 212a, counterbore portions having a larger diameter than the through portions are respectively provided at the opening edges on the axially outer sides of the wall portions 211 and 212. The flanges 224 and 234 of the bearings 22 and 23 are fitted into this countersunk portion.

In the bearings 22 and 23, flanges 224 and 234 are provided on the opening edge on one side of the annular bearing body 222 and 232. The bearings 22 and 23 are fitted into the insertion holes 211 a and 212 a of the wall portions 211 and 212 of the base portion 21 from the axial outside, so that the flanges 224 and 234 are fitted into the countersunk portions. The bearings 22 and 23 are fixed to the base portion 21 by press-fitting or the like in a state that prevents the bearings 22 and 23 from coming off in the fitting direction.

This makes it possible to reduce the thickness of the wall portions 211 and 212 of the base portion 21 without causing the bearing bodies 222 and 232 of the bearings 22 and 23 to protrude outward from the wall portions 211 and 212 relative to the base portion 21, thereby enabling rotation. The entire length of the reciprocating drive actuator 1 is shortened and miniaturized.

In addition, the flanges 224 and 234 of the bearings 22 and 23 are fitted into the countersunk portions on the axial outer sides of the insertion holes 211a and 212a (the outer surface sides of the wall portions 211 and 212). Thereby, during assembly of the main body unit 2, the fitting state of the flanges 224, 234 and the insertion holes 211a, 212a can be easily visually confirmed and measured from the outside of the wall portions 211, 212.

The bearings 22 and 23 may be composed of rolling bearings (for example, ball bearings) or sliding bearings for the base portion 21 . For example, as long as the bearings 22 and 23 are rolling bearings, the friction coefficient is low and the rotating shaft 13 can be rotated smoothly. Therefore, the driving performance of the rotational reciprocating drive actuator 1 is improved. Thereby, the rotating shaft 13 is rotatably mounted on the base part 21 via the bearings 22 and 23, and the mirror part 12 as a movable object is arrange|positioned between the pair of wall parts 211 and 212.

The rotating shaft 13 is inserted into the bearings 22 and 23, and both ends of the rotating shaft 13 protrude outward from the bearings 22 and 23 in the axial direction. The bearings 22 and 23 support the rotation shaft 13 on the base portion 21 so as to be rotatable about the axis.

On one end side 131 of the rotating shaft 13, the mirror portion 12 as a movable object is fastened at a location inserted between the pair of wall portions 211 and 212 of the base portion 21, and on the other end side of the rotating shaft 13 Magnet 32 is fastened to side 132 . Thereby, the rotation shaft 13 is pivotally supported by the pair of wall portions 211 and 212 of the base portion 21 . The base part 21 supports the mirror part 12 arranged between the pair of wall parts 211 and 212 via the rotation shaft 13 from both sides. Therefore, compared with the structure in which the mirror part 12 is supported by the rotation shaft supported by the cantilever shaft, It can firmly support the rotating shaft and improve impact resistance and vibration resistance.

The magnet 32 is arranged in the drive unit 4 described below, and is driven to reciprocate by the magnetic flux generated by the drive unit 4 . In addition, the rotating shaft 13 reciprocates the mirror portion 12 through the mutual electromagnetic interaction between the drive unit 4 and the magnet 32 .

In the rotating shaft 13, a stopper (stop ring) 14 is fitted in the fitting groove 133 at one end 131 protruding outward of the bearing 23. Through this stopper 14, the rotating shaft 13 moves toward the other end 132 side. movement is restricted. In addition, one end portion 131 of the rotation shaft 13 is inserted into the wall portion 212 on the one end side, and is connected to the angle sensor portion 70 on the outer surface side of the wall portion 212 . The angle sensor unit 70 is used to detect the angle of the rotation shaft 13 and is disposed in the rotation reciprocating drive actuator 1 so as to sandwich the mirror unit 12 with the drive unit 4 . That is, the angle sensor unit 70 is separated from the magnetic circuit of the drive unit 4 and is arranged near the bearing 23 . Details of the angle sensor unit 70 will be described later.

On the rotating shaft 13 , a cylindrical stopper 15 is inserted between the mirror holder 122 of the mirror portion 12 and the wall portion 212 on the one end 131 side of the pair of wall portions.

The limiting part 15 is fixed relative to the rotating shaft 13 . The movement of the rotating shaft 13 toward the one end 131 side is restricted by the bearing 23 , and the movement of the rotating shaft 13 toward the other end 132 side is restricted by the stopper 14 . The movement of the mirror portion 12 fastened to the rotating shaft 13 toward the other end 132 side in the axial direction relative to the base portion 21 is restricted by the stopper 14 .

The stopper 15 prevents the rotation shaft 13 from falling off from the bearing 23 toward one axial end side, that is, to the outside, via the mirror portion 12 .

The limiting part 15 together with the stopper part 14 limits the axial movement of the movable body 10 including the mirror part 12, the rotating shaft 13 and the magnet 32 within a predetermined range including tolerances, etc., and prevents it from falling off the base part 21 .

The rotating shaft 13 is disposed in the base portion 21 so that the other end portion 132 side of the bearing 22 protrudes from the wall portion 211 side toward the outside of the base portion 21 . The portion protruding from the wall portion 211 is inserted into the drive unit 4 .

The magnet 32 fastened to the other end portion 132 side of the rotation shaft 13 is arranged at a portion protruding outward from the wall portion 211 of the base portion 21 .

On the rotating shaft 13, at a portion protruding from the wall portion 211 to the other end portion 132 side, a preload spring 35, an annular receiving portion 37, and a magnet 32 are arranged in order from the wall portion 211 side.

The preload spring 35 expands and contracts in the axial direction to bias the bearing 22 in the axial direction.

For example, as shown in FIG. 5 , the preloading spring 35 is a cylindrical coil spring that has a predetermined length L1 corresponding to the space in which the preloading spring 35 is arranged and is separated in a predetermined length direction. Both ends are formed with flat surfaces.

The preload spring 35 is externally disposed on the rotating shaft 13 and biases the magnet 32 in the separation direction from the bearing 22 fitted to the wall portion 211 .

The preload spring 35 is interposed between the annular receiving portion 37 adjacent to the magnet 32 and the bearing 22 in a state in which the rotating shaft 13 is inserted.

The preload spring 35 applies a constant pressure preload to the bearing 22 . By applying a constant pressure preload to the bearing 22 by the preload spring 35, the spring can absorb the fluctuation of the load, the expansion and contraction of the rotating shaft 13 due to the temperature difference between the rotating shaft 13 and the base portion 21, etc., and can adjust the preload amount. The change is small, and a stable preload amount is obtained. Thereby, the preloading spring 35 can prevent the axial vibration of the rotating shaft 13 caused by the high-speed rotation of the rotating shaft 13. Compared with the fixed-position preloading, the preloading spring 35 can rotate at a high speed and prevent the axial vibration.

The preload spring 35 applies preload to the bearings (especially ball bearings) 22 and 23 to maintain low sliding properties and high reliability of the rotational driving of the rotating shaft 13, thereby enabling stable driving.

In addition, it is preferable that the preload spring 35 is in contact with a firmly fixed member and has a structure in which the preload is received by the member. The annular receiving portion 37 is a press-fitting ring, and is fastened to the rotating shaft 13 by press-fitting the outer peripheral portion of the rotating shaft 13 with respect to the rotating shaft 13 .

The annular receiving portion 37 receives one end portion of the preload spring 35 that is in contact with the bearing 22 on one end side, thereby preventing direct impact on the magnet 32 as an adhesively fixed member. This prevents unnecessary force from being applied to the magnet 32 and improves reliability.

In addition, since the preloading spring 35 is disposed inside the rotational reciprocating drive actuator 1 , it is not affected by the outside of the rotational reciprocating drive actuator 1 , and a stable preloading design can be ensured.

In addition, the preload spring 35 may be used instead of a cylindrical coil spring in which a circular steel wire is wound in a spiral shape, and a plate-shaped steel wire wound in a spring with a low height in the expansion and contraction direction may be used. A wave spring that is formed into a spiral or annular shape and has a waveform applied thereto.

For example, as the preload spring 350 having a shorter axial length than the cylindrical coil spring having the axial length L1 of the preload spring 35 , a preload spring as a wave spring shown in FIG. 6 may be used. Use spring 350.

In the preload spring 350 which is a wave spring, the length L2 in the axial direction as the expansion and contraction direction is shorter than the length L1 of the cylindrical coil spring, and the expansion and contraction length is shorter.

The preloading spring 350 is formed by overlapping a plurality of preloading springs 350 in the direction of the length L2 when the length L0 of the wall portion 211 and the annular receiving portion 37 corresponds to the range of length L2<L0<L1. , its telescopic length can be changed.

In this way, the preloading springs 35 and 350 can adjust the preloading force appropriately according to the installation location or the preloading target, and can appropriately perform high-speed rotation, prevent axial vibration, and drive stably.

<Drive unit 4>

The drive unit 4 shown in FIGS. 2 to 4 and 7 is provided at one of the two ends separated in the axial direction of the base portion 21 and constitutes a part of the fixed body 20 . The drive unit 4 is disposed between the angle sensor part 70 and the base part 21 in the axial direction. The drive unit 4 constitutes the drive part 30 together with the magnet 32, and moves the movable body 10. The drive unit 4 has a bottom cover 50 , a core assembly 40 and a top cover 60 . The drive unit 4 is formed, for example, in a square parallelepiped shape when viewed from the front.

<Core assembly 40>

The core assembly 40 shown in FIGS. 3 , 4 , and 14 includes coils 44 and 45 , bobbins 46 and 47 around which the coils 44 and 45 are wound, a core 400 , and a rotation angle position retaining portion 48 .

In this embodiment, the core assembly 40 is formed into a rectangular frame-shaped block (more specifically, a rectangular parallelepiped shape) in which the magnetic poles 410 a and 410 b are arranged inside. The core assembly 40 is formed such that the frame-shaped outer peripheral portion surrounds the magnetic poles 410a and 410b arranged inside the outer peripheral portion. The core assembly 40 forms, for example, a magnetic strip extending from the magnetic poles 410a and 410b across the magnet 32 in a rectangular area of the wall surface of the wall portion 211 of the base portion 21 when viewed in the axial direction, and surrounding the magnetic poles 410a and 410b. road.

＜Core 400＞

The core 400 constitutes a magnetic circuit including a magnetic circuit arranged to surround the magnet 32 . The core body 400 has a first core 41 with an integrated structure including a plurality of magnetic poles 410 a and 410 b and a C-shaped magnetic circuit portion (connecting edge portion 412 and side portion 413 ); and is mounted on the side of the first core 41 The second core 42 is arranged between one end portions of the portion 413; and the frame-shaped third core 43. The core body 400 is integrated by magnetically coupling the first to third cores.

The first to third cores 41 to 43 allow the magnetic flux generated when the coils 44 and 45 are energized to pass through the plurality of magnetic poles 410a and 410b. The first to third cores 41 to 43 are, for example, laminated cores in which electromagnetic steel plates (laminated components) such as silicon steel plates are laminated. By having the core body 400 have a laminated structure, it is possible to configure the first to third cores 41 to 43 having complex shapes at low cost.

＜First Core 41＞

The first core 41 includes a rod-shaped portion 411 (411a, 411b), a connecting edge portion 412, and a side portion 413. The first core 41 has opposing magnetic poles 410a and 410b at the front end portion, and each has a plurality of rod-shaped portions 411 (411a and 411b) arranged in parallel to each other. The connecting edge portion 412 extending perpendicularly to the extending direction of the rod-shaped portion 411 (411a, 411b) is connected to the base end portion thereof. Two side edge portions 413a and 413b are respectively vertically protruded from both ends of the connecting edge portion 412. The connecting edge portion 412 is provided with an auxiliary pole portion 414 extending parallel to the rod-shaped portions 411a and 411b between the rod-shaped portions 411a and 411b.

The rod-shaped portion 411 (411a, 411b), the connecting edge portion 412, the side portion 413 (413a, 413b) and the auxiliary pole portion 414 are of an integral structure, and the first core 41 has a comb-tooth shape.

The rod-shaped portions 411a and 411b are each provided with a magnetic pole on the side surface of the front end portion, and the coil bobbins 46 and 47 are externally inserted on the proximal end side of the outer periphery of the rod-shaped portions 411a and 411b. Thereby, the coils 44 and 45 are arranged to wind the rod-shaped portions 411a and 411b.

When the coils 44 and 45 are excited by being energized, the magnetic poles at the tip portions of the rod-shaped portions 411a and 411b generate polarities corresponding to the direction of energization. The magnetic poles are arranged to face the magnet 32 and have a shape curved along the outer peripheral surface of the magnet 32 . These curved shapes are arranged to face each other in a direction orthogonal to the extending directions of the rod-shaped portions 411a and 411b, for example.

The rod-shaped portions 411a and 411b have external dimensions such that the coil bobbins 46 and 47 can be inserted from the front end side, for example. Thereby, the coil bobbins 46 and 47 can be externally inserted from the front end side in the extending direction of the rod-shaped portions 411a and 411b, that is, the front ends of the magnetic poles 410a and 410b, and can be positioned at the base end sides of the rod-shaped portions 411a and 411b. They are positioned in such a way that surrounds them. The externally inserted coil formers 46 and 47 are respectively arranged between the side part 413 and the auxiliary pole part 414.

The connecting edge portion 412 constitutes one side of the rectangular core 400, is connected to the base end portions of the rod-shaped portions 411a, 411b, and extends in a direction orthogonal to the parallel direction of the rod-shaped portions 411a, 411b.

The connecting edge portion 412 mainly connects the base end portions of the rod-shaped portions 411a and 411b and both side portions 413a and 413b. The two side edges 413a and 413b are preferably in close contact with both ends of the second core 42, but here they are arranged to be spaced apart from each of the two end portions of the second core 42. There is a gap.

The connecting edge portion 412 and both side edge portions 413a and 413b are provided so as to be laminated on the third core 43 in an axially close state together with the second core 42.

The auxiliary pole part 414 is arranged opposite to the rotation angle position holding part 48. When the magnet 32 attracts the rotation angle position holding part 48, it attracts the other pole of the magnet 32 to strengthen the attraction state with the rotation angle position holding part 48. .

Specifically, the auxiliary pole portion 414 is made of a magnetic body, and is arranged to surround the magnet 32 in four directions, for example, together with the magnetic poles 410 a and 410 b and the rotation angle position holding portion 48 . The auxiliary pole portion 414 generates a magnetic attraction force between the magnet 32 (more specifically, the pole 32b) and moves the pole 32b of the magnet 32 that is different from the pole 32a that attracts the rotation angle position holding portion 48 to an opposite position. Through this action, the auxiliary pole portion 414 uses the magnetic attraction force of the rotation angle position holding portion 48 to offset the axial radial load acting on the movable body 10 . In addition, "offset the radial load of the shaft" also includes "offset the radial load of the shaft".

In addition, the auxiliary pole surface of the auxiliary pole portion 414 that faces the outer peripheral surface of the magnet 32 is a curved surface corresponding to the shape of the outer peripheral surface of the magnet 32 and has a uniform gap across the entire surface thereof. In addition, since the auxiliary pole portion 414 is arranged to surround the magnet 32 in the core assembly 40 together with the rotation angle position holding portion 48, the rotational reciprocating drive actuator 1 can be realized in a minimal space layout.

＜Second Core 42＞

The second core 42 forms a magnetic circuit together with the first core 41, and the magnetic circuit is arranged to surround the magnetic poles of the tip portions of the rod-shaped portions 411a and 411b from all four directions. The second core 42 is formed in a prismatic shape, and forms a magnetic path through which magnetic flux passes through the magnetic poles 410a and 410b when the coils 44 and 45 are energized.

The second core 42 has the same thickness (axial length) as both side portions 413a and 413b. The second core 42 is in close contact with the third core 43 through the fixing member 86 inserted into the same mounting hole (fixing hole) 402 as the mounting hole (fixing hole) 402 provided at both ends of the connecting edge portion of the first core 41 is fixed to the bottom cover 50 and the top cover 60 (see FIG. 13 ). The mounting hole 402 has the same diameter as the through hole 54 of the bottom cover 50 and is formed to extend parallel to the rotation axis 13 .

A rotation angle position holding portion 48 is attached to a central portion of the second core 42 in the extending direction and at a portion facing the magnet 32 . Another core is disposed so as to be joined to both ends of the second core 42 , and the second core 42 is disposed at a position surrounding the magnet 32 and the magnetic poles 410 a and 410 b with the other core.

＜Third core 43＞

The third core 43 forms a magnetic circuit surrounding and connecting multiple magnetic poles together with the connecting edge portion 412 and both side edges 413 of the first core 41 and the second core 42 .

The third core 43 has a rectangular frame plate shape and is attached to the rectangular frame portion composed of both the first core 41 and the second core 42 so as to be in surface contact.

Specifically, the third core 43 is in face-to-face contact with the connecting edge portion 412 and both side edges 413 a and 413 b of the first core 41 in the extending direction of the rotation shaft 13 . In addition, the third core 43 is assembled to the first core 41 in a state where the plurality of magnetic poles of the rod-shaped portions 411 a and 411 b of the first core 41 are positioned around the rotation axis 13 . In addition, the third core 43 is in face-to-face ground contact with the second core 42 in the extending direction of the rotation shaft 13 .

Thereby, the third core 43 is arranged around the rotating shaft 13 so as to surround the magnetic poles of the rod-shaped portions 411 a and 411 b and the coils 44 and 45 , and forms a seamless magnetic path around the rotating shaft 13 . The first to third cores 41 to 43 have a surrounding portion surrounding the coils 44 and 45, and can form a structure that passes through the first core 41 + the third core 43, the third core 43, and the third core 43 + the second core in order from one magnetic pole. 42. The magnetic flux flow of the third core 43 + the other magnetic pole of the first core 41. In addition, since the first to third cores 41 to 43 surround the magnetic poles and the magnet 32 between the magnetic poles in an annular shape, the coils 44 and 45 can be prevented from being contacted from the outside.

With the drive unit 4 assembled, the rotation shaft 13 is inserted into the space surrounded by the magnetic poles. In addition, the magnet 32 attached to the rotating shaft 13 is located in this space, and the magnetic pole faces the magnet 32 across the air gap G at the correct position.

The magnet 32 is a ring-shaped magnet in which S poles 32a and N poles 32b are alternately arranged in the circumferential direction. The magnet 32 is attached to the peripheral surface of the rotation shaft 13 so that it may be located in the space surrounded by the magnetic poles 410a and 410b of the core 400 when the rotational reciprocating drive actuator 1 is assembled. The magnet 32 is fixed so as to surround the outer periphery of the rotation shaft 13 . When the coils 44 and 45 are energized, the first core 41 , the second core 42 and the third core 43 including the rod-shaped portions 411 a and 411 b are excited to generate polarities corresponding to the energization directions in the magnetic poles 410 a and 410 b. Thereby, magnetic force (attractive force and repulsive force) is generated between the magnetic poles 410a, 410b and the magnet 32.

In this embodiment, the magnet 32 is magnetized into different polarities with a plane along the axial direction of the rotation axis 13 as a boundary. That is, the magnet 32 is a two-pole magnet which is magnetized and divided equally into the S pole 32a and the N pole 32b. The number of magnetic poles of the magnet 32 (two in this embodiment) is equal to the number of the magnetic poles 410a and 410b of the core 400. In addition, the magnet 32 may be magnetized to have two or more poles depending on the amplitude during movement. In this case, the magnetic pole portion of the core 400 is provided corresponding to the magnetic pole of the magnet 32 .

＜Magnet 32＞

The magnet 32 switches polarity at the boundary portions 32c and 32d between the S pole 32a and the N pole 32b (hereinafter referred to as "magnetic pole switching part"). The magnetic pole switching portions 32c and 32d are formed in a groove shape extending through the axis center on one end surface of the magnet 32 . The magnetic pole switching portions 32c and 32d face the magnetic poles 410a and 410b respectively when the magnet 32 is held in the neutral position. In addition, the magnetic pole switching parts 32c and 32d function as a positioning reference for the components of each part when assembling the rotational reciprocating drive actuator 1 .

In particular, since the magnet 32 is fixed to the rotating shaft 13, the clamp axially abuts against the grooves of the magnetic pole switching portions 32c and 32d to restrict the rotation of the magnet 32, and the positional relationship between the mirror portion 12 and the sensor member can be adjusted and determined. . In addition, since the rotation axis 13 serving as the center of the rotation reciprocating drive actuator 1 can be defined as a reference, the dimensions of other components can also be easily set and can be manufactured with high accuracy.

If the magnetic pole switching portions 32 c and 32 d are formed in a groove shape, the positional relationship of each member fixed to the rotating shaft 13 can be adjusted based on the groove during assembly or maintenance of the rotational reciprocating drive actuator 1 . In particular, in conjunction with the positions of the magnetic pole switching portions 32c and 32d of the magnet 32, the position of the mirror portion 12, the mounting position of the encoder of the angle sensor portion 70, and the like can be determined appropriately and accurately with respect to the rotation axis 13. For example, the clamp is axially abutted against the groove and the protrusion is fitted into the groove to restrict the rotation of the rotating shaft 13 around the axis so that it does not move and becomes a reference position for other components to be mounted on the rotating shaft 13 . In particular, the adjustment of the angle of the mirror with respect to the pole of the magnet 32 requires precision, and this adjustment can be performed.

In the neutral position, since the magnetic pole switching portions 32c and 32d of the magnet 32 face the magnetic poles 410a and 410b, the drive unit 4 can generate the maximum torque and stably drive the movable body 10.

In addition, since the magnet 32 is composed of a two-pole magnet, it is possible to easily drive the movable object with a high amplitude by cooperating with the core 400 and to improve the driving performance. That is, the mirror portion 12 that is a movable object can be driven at a wide angle. In addition, in the embodiment, the case where the magnet 32 has a pair of magnetic pole switching parts 32c and 32d has been described, but it may have two or more pairs of magnetic pole switching parts.

＜Coil body (coil and coil former)＞

The coils 44 and 45 are wound around cylindrical coil bobbins 46 and 47. The coils composed of the coils 44 and 45 and the coil bobbins 46 and 47 are inserted outside the rod-shaped portions 411a and 411b of the first core 41, so that the coils 44 and 45 are wound around the rod-shaped portions 411a and 411b. In this way, the coils 44 and 45 are arranged adjacent to the magnetic poles of the tip portions of the rod-shaped portions 411a and 411b.

The winding directions of the coils 44 and 45 are set so that magnetic flux is appropriately generated from one to the other of the plurality of magnetic poles of the first core 41 when energized.

FIG. 8 is a perspective view of the coil body, FIG. 9 is an exploded view of the coil body, and FIG. 10 is a perspective view showing the wiring state of the coils in the coil body.

The coil body having the coil bobbin 46 around which the coil 44 is wound and the coil bobbin 47 around which the coil 45 is wound are identical in structure. Therefore, the description of the coil body having the coil bobbin 46 around which the coil 44 is wound is omitted. Description of the coil body of the coil bobbin 47.

The coil body 49 has a bobbin portion 492 around which the coil 44 is wound, and a terminal support portion 494 that supports the terminal 496 and is provided integrally with the bobbin portion 492 .

The bobbin part 492 has a through hole through which the rod-shaped part 411 (411a, 411b) is inserted, and the terminal support part 494 is protrudingly provided on the flange of the opening edge part on one side of the bobbin part 492.

The terminal support part 494 has a cylindrical shape, a terminal 496 is inserted therein, and the terminal 496 is held therein.

The terminal 496 is L-shaped. The end of the connected coil 44 is bundled at one side 4962 , the base end of the other side 4964 is inserted into and supported by the terminal support 494 , and the front end of the other side 4964 extends from the terminal support 494 protrudes outward.

The front end side of the other side portion 4964 is connected to an external device that supplies power to the coil 44 or an end portion of an adjacent coil. In the present embodiment, the terminal 496 has one side portion 4962 extending in a direction parallel to the axial direction of the coil 44 , and the other side portion 4964 extending in a direction orthogonal to the axial direction of the coil 44 .

In the coil body 49 , one side portion 4962 of the terminal 496 is arranged to extend in the opening direction of the opening of the coil bobbin portion 492 , and the other side portion 4964 is arranged to extend in the direction in which the flange of the coil bobbin portion 492 extends.

Coil wires at both ends of the coil 44 are connected to one side portion 4962 via a wiring portion H made of solder or the like.

In this way, the terminal 496 has an L-shape, and the coil winding (connection portion H as the solder fillet) is connected to one side 4962 and is joined to the sensor substrate 72 through the other side 4964 .

Since the terminal 496 is L-shaped, it can be separately connected to the sensor substrate connection side and the coil connection side. In particular, the connection portion (solder leg) connecting the coil windings can be easily formed using solder without interference of solder or windings. Homework during H hour.

That is, even if the wiring work of the sensor substrate 72 and the work of fixing the winding to the same terminal 496 occur, it will not become a factor that hinders the wiring process with the substrate such as solder attachment when conducting the winding. By arranging the sensor substrate 72 in the axial direction relative to the drive unit 4, the wiring between the sensor substrate 72 and the terminal 496 can be positioned while responding to contamination, and the photosensor 76 can be easily arranged perpendicular to the axial direction.

<Rotation angle position holding unit (magnet position holding unit) 48>

The rotation angle position holding part 48 shown in FIGS. 2 to 4 is assembled to the core assembly 40 so as to face the magnet 32 via the air gap G in a state where the rotation reciprocating drive actuator 1 is assembled. The rotation angle position holding part 48 is attached to the second core 42 in an attitude such that the magnetic poles and the magnet 32 face each other, for example.

The rotation angle position holding part 48 uses, for example, a magnet with its magnetic pole facing the magnet 32 , and generates a magnetic attraction force between the magnet 32 and the magnet 32 to attract the magnet 32 . That is, the rotation angle position holding part 48 forms a magnetic spring with the magnet 32 together with the rod-shaped parts 411a and 411b. This magnetic spring maintains the rotational angle position of the magnet 32 , that is, the rotational angle position of the rotation shaft 13 in a neutral position when the coils 44 and 45 are not energized (during non-energization).

At this time, the magnetic pole 32b (the N pole shown in FIG. 3 ) of the magnet 32 on the opposite side to the magnetic pole 32a (the S pole in FIG. 3 ) of the magnet 32 that is attracted to the rotation angle position holding part 48 attracts the approaching magnetic body. The auxiliary pole portion 414 of the first core 41 . Thereby, the magnet 32, that is, the mirror part 12 which is a movable object, is maintained in a neutral position more effectively.

The neutral position is the reference position of the reciprocating rotation operation of the magnet 32, that is, the center position of the reciprocating rotation (oscillation), and is a position at which the same rotation angle is achieved when the magnet 32 rotates left and right about the axis during the reciprocating rotation. When the magnet 32 is held in the neutral position, the magnetic pole switching portions 32c and 32d of the magnet 32 face the magnetic poles of the rod-shaped portions 411a and 411b.

In addition, the mounting posture of the mirror portion 12 is adjusted based on the state in which the magnet 32 is located in the neutral position. In addition, the rotation angle position holding part 48 may be composed of a magnetic body that generates a magnetic attraction force between the magnet 32 and the rotation angle position holding part 48 .

<Bottom cover 50 and top cover 60>

The bottom cover 50 and the top cover 60 shown in FIGS. 1 , 2 , 4 to 6 and 11 to 14 are preferably made of a non-magnetic and highly conductive conductive material and function as an electromagnetic shield.

The bottom cover 50 and the top cover 60 are respectively arranged on both sides of the core assembly 40 in the axial direction (thickness direction).

The bottom cover 50 and the top cover 60 can suppress the noise from being injected into the core assembly 40 and the noise from being emitted to the outside from the core body 400 .

The bottom cover 50 and the top cover 60 are formed of a non-magnetic, electrically conductive and high thermal conductivity material such as aluminum alloy. Aluminum alloys have a high degree of freedom in design and can easily provide desired rigidity. Therefore, if the bottom cover 50 and the top cover 60 are made of aluminum alloy, it is suitable for the case where the top cover 60 functions as a support body that supports the rotation shaft 13 .

Figure 11 shows a front side view of the top cover. The bottom cover 50 is attached to the outer surface of the wall portion 211 so as to overlap. The bottom cover 50 is formed into a rectangular plate shape corresponding to the outer shape of the wall portion 211 . The bottom cover 50 has a rectangular plate-shaped cover main body 52, and an opening 53 through which the rotation shaft 13 is inserted is formed in the center of the cover main body 52. The opening 53 is disposed at a position facing the bearing 22 , and the inner diameter of the opening 53 is larger than the outer diameter of the magnet 32 . The bottom cover 50 allows the rotation shaft 13 equipped with the magnet 32 to be inserted into the opening 53 so that the magnet 32 can be inserted and disposed in the core assembly 40 .

The rotation shaft 13 is inserted into the opening 53 , and a preload spring 35 (see FIG. 2 ) inserted outside the rotation shaft 13 is arranged.

The cover main body 52 of the bottom cover 50 is provided with a through hole 54, a through hole 55 for fixing to the base portion 21, a positioning hole 56, a position adjustment hole 57, and a core holding protrusion 58. The fixing member 86 for integrating the bottom cover 50 with the core assembly 40 and the top cover 60 into the drive unit 4 is inserted into the through hole 54 . The through hole 55 is formed in the attachment portion 522 attached to the wall portion 211 . In addition, the mounting portion 522 forms left and right side portions of the cover body 52 that are separated in a direction orthogonal to the axial direction, and includes four corner portions of the cover body 52 . Through holes 55 are respectively formed in these corners.

The opening 53 , the through holes 54 and 55 , the positioning hole 56 and the position adjustment hole 57 are formed parallel to the axial direction of the rotation shaft 13 . By inserting the fixing members 81 and 86 into the through holes 54 and 55 , the base portion 21 or the drive unit 4 or even the rotational reciprocating drive actuator 1 can be assembled in one axial direction.

As shown in FIGS. 7 and 11 , the through hole 54 has a concave countersunk portion 541 formed on the back surface of the cover body 52 , and the countersunk portion 541 accommodates the head of the fixing member 86 such as a screw.

The core holding protrusion 58 protrudes from the cover body 52 across the opening 53 in the axial direction, and is fitted and positioned with the core assembly 40 when combined with the core assembly 40 (see FIGS. 3 and 4 ).

The core holding protrusion 58 is inserted between the rod-shaped portions 411a and 411b and both side portions 413a and 413b to prevent leakage of magnetic flux flowing between both sides.

In addition, as shown in FIG. 6 , a positioning protrusion 59 is protrudingly provided on the back surface of the bottom cover 50 . When the bottom cover 50 and the base portion 21 are in contact with each other with their centers aligned with each other, the positioning protrusion 59 is engaged with the recessed portion 218 (see FIGS. 2 and 4 ) formed in the wall portion 211 .

The positioning protrusion 59 is, for example, an annular protrusion. On the other hand, as shown in FIGS. 2 and 4 , the recessed portion 218 of the wall portion 211 is an annular groove formed in the base portion 21 to surround the insertion hole 211 a. The positioning protrusion 59 is engaged with the recessed portion 218 of the annular groove, and both the wall portion 212 and the drive unit 4 are positioned.

The top cover 60 and the bottom cover 50 sandwich the core assembly 40 from both sides in the axial direction and are integrally fixed by the fixing member 86 to form the drive unit 4 . As shown in FIGS. 2 and 4 , the top cover 60 of this embodiment functions as a sensor storage portion 65 that accommodates a photosensor 76 that detects the rotation angle of the movable body 10 , that is, the rotation shaft 13 .

The top cover 60 includes a top cover main body 62 that covers the front end side surface of the core assembly 40 and a peripheral wall portion 64 that protrudes from the outer peripheral edge of the top cover main body 62 toward the other end 132 side in the axial direction.

The top cover main body 62 is a plate-shaped body that is square when viewed in the axial direction and has a concave portion 621 that opens toward the core assembly 40 side. The top cover main body 62 is a square plate-shaped body, and the peripheral wall portion 64 is formed in a rectangular frame shape standing up from the outer peripheral portion of the top cover main body 62 .

The top cover main body 62 of the top cover 60 is provided with a through hole 66 . The through hole 66 is disposed in the top cover main body 62 so as to be coaxial with the opening 53 of the bottom cover 50 and the bearings 22 and 23 of the base portion 21 . A bushing 39 through which the rotating shaft 13 is inserted is fitted into the through hole 66 from the back side (the one end portion 131 side). Thereby, the bushing 39 is attached to the top cover main body 62 with the movement direction being restricted. In addition, the bushing 39 and the rotating shaft 13 may be arranged to slide with each other, or may be arranged with a gap therebetween.

The bushing 39 supports the other end 132 side of the rotation shaft 13 . The bushing 39 is supported by the top cover 60 on the other end 132 side so that when the rotating shaft 13 receives an impact, the shaft will not wobble due to the impact. The bushing 39 is installed on the top cover 60 so that the other end is embedded in the through hole 66 and the one end is located in the concave portion 621 .

The top cover main body 62 is provided with a bobbin engaging hole 67 that penetrates in the axial direction in addition to the through hole 66 and is engaged with the coil bobbins 46 and 47 .

The terminal support portion 494 of the coil body 49 having the coil bobbins 46 and 47 is fitted in the bobbin engaging hole 67 . Thereby, the terminal support part 494 is inserted into the top cover main body 62, and the other side part 4964 is arrange|positioned so that it may protrude from the terminal support part 494.

The engagement between the bobbin engaging hole 67 and the terminal support portion 494 also functions as positioning when assembling the core assembly 40 and the top cover 60 .

The top cover 60 , the core assembly 40 (core body 400 ), and the bottom cover 50 are fixed by the fixing member 86 through holes of the same diameter that are continuous in the axial direction such as the fixing hole 402 and the through hole 54 .

<Angle sensor unit 70>

FIG. 12 is an external perspective view of the angle sensor unit in the rotational reciprocating drive actuator 1 , FIG. 13 is an exploded perspective view of the angle sensor unit from the front side, and FIG. 14 is an exploded perspective view of the angle sensor unit from the back side.

The angle sensor portion 70 is provided on the outer surface 21 a of the wall portion 212 on one end side of the base portion 21 .

The angle sensor unit 70 detects the rotation angle of the movable body 10 including the magnet 32 and the rotation shaft 13 (the same applies to the mirror unit 12 ). The rotational reciprocating drive actuator 1 can control the rotational angle position and rotational speed of the movable body during driving, specifically, the mirror unit 12 as the movable object, based on the detection result of the angle sensor unit 70 via the control unit. control.

The angle sensor unit 70 may be a magnetic sensor or an optical sensor. In this embodiment, the angle sensor unit 70 includes a sensor member, a sensor substrate 72 and a substrate holding unit 73 .

Sensor components included in the angle sensor unit 70 are, for example, an encoder disk 74 and a photosensor (sensor) 76 including a light source, a light-receiving element, and the like. The photosensor 76 is mounted on, for example, the sensor substrate 72 .

The substrate holding part 73 holds the mounted sensor substrate 72, and forms an arrangement space (sensor arrangement part 701) in which the sensor member is arranged by the sensor substrate 72 and the wall part 212.

The substrate holding portion 73 is, for example, a plate-shaped body having an opening 732 in the center. It is fixed to the outer surface 21 a of the wall portion 212 and constitutes a concave sensor placement portion 701 in which the rotation shaft 13 is inserted. The sensor substrate 72 is attached to the substrate holding part 73 so as to cover the internal space. Thereby, the substrate holding part 73 can accommodate the sensor member in a contamination-prevented state.

The substrate holding portion 73 is formed in a frame shape, but is not limited thereto. It may be formed in a concave shape as long as it is inserted through the rotation shaft 13 and forms a space in which the sensor member can be arranged. The substrate holding portion 73 is fixed to the wall portion 212 by inserting the fixing member 85 inserted into the fixing hole 702 and fitting (for example, screwing) into the fixing hole 215 of the wall portion 212 .

The encoder disk 74 is fixed to the one end portion 131 side of the rotating shaft 13 via a central mounting portion (encoder hub) 742 and is arranged within the opening 732 of the substrate holding portion 73 (inside the sensor arrangement portion 701 ).

The encoder disk 74 is used to detect the rotational speed of the rotating shaft 13 and rotates integrally with the magnet 32 and the mirror unit 12 . The rotational position of the encoder disk 74 about the axis is the same as the rotational position of the rotary shaft 13 .

The photosensor 76 and the encoder disk 74 are arranged to face each other. The optical sensor 76 emits light toward the encoder disk 74 and detects the rotational position (angle) of the encoder disk based on the reflected light. Thereby, the rotational position of the magnet 32 and the mirror part 12 can be detected accurately with high resolution.

The photosensor 76 is mounted on the back surface of the sensor substrate 72 . The sensor substrate 72 is attached to the substrate holding portion 73 , so that the photosensor 76 is disposed in the sensor arrangement portion 701 so as to face the encoder disk 74 in the axial direction. The photosensor 76 is arranged in the photosensor arrangement portion 701 so as to be able to detect the number of revolutions and the rotational position of the encoder disk 74 .

The sensor substrate 72 is arranged so as to block the opening 732 of the substrate holding portion 73 from the one end 131 side, thereby forming a closed sensor arrangement portion 701 .

The sensor substrate 72 has an opening 724 in the center. The mounting shaft portion (encoder hub) 742 for mounting the encoder disk 74 and the rotation shaft 13 are inserted into the opening 724 so that the sensor substrate 72 can support them. The fixing member 84 is fixed to the fixing hole 703 of the substrate holding part 73 via the fixing hole 723 , so that the sensor substrate 72 is fixed to the substrate holding part 73 . Thereby, the sensor substrate 72 is fixed to the substrate holding part 73 fixed to the wall part 212, and is fixed to the wall part 212 via the board holding part 73.

In addition, the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 are provided with positioning holes 205, 705, and 725 and position adjustment holes 207, 707, and 727 for positioning and fixing the angle sensor portion 70 in an appropriate position on the wall portion 212. .

The positioning holes 205 , 705 , and 725 are arranged on the same axis parallel to the rotation axis 13 so as to have the same diameter (including substantially the same diameter). The position adjustment holes 207 , 707 , and 727 are arranged in the same shape and coaxially parallel to the rotation axis 13 , and have a shape capable of forming a gap when a rod-shaped adjustment member (not shown) is inserted.

According to this structure, before the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 are fixed with the fixing member 84, the adjustment member (not shown) is inserted into the position adjustment holes 207, 707, and 727. In this state, the rod-shaped positioning member can be inserted through the positioning holes 205, 705, and 725 while moving and adjusting the wall portion 212, the substrate holding portion 73, and the sensor substrate 72 to appropriate positions. Thereby, the substrate holding part 73 and the sensor substrate 72 are positioned at appropriate positions with respect to the wall part 212 with the rotation axis 13 as the center. In this state, the substrate holding portion 73 and the sensor substrate 72 can be fixed at appropriate positions on the wall portion 212 .

The sensor substrate 72 is fixed to the substrate holding portion 73 via the fixing member 84 inserted through the fixing hole 703 so that the attached photosensor 76 faces the encoder disk 74 in the opening 732 .

The sensor substrate 72 can prevent unnecessary external objects such as garbage from intruding into the sensing portion of the angle sensor unit 70 including the optical sensor 76 and the encoder disk 74 simply by being attached to the substrate holding portion 73 .

Hereinafter, the operation of the rotational reciprocating drive actuator 1 will be described using FIGS. 3 and 15 . FIG. 15 is a diagram for explaining the operation of the magnetic circuit of the rotational reciprocating drive actuator 1 .

The magnetic poles 410a and 410b of the two rod-shaped portions 411a and 411b of the core body 400 of the core assembly 40 are arranged so as to sandwich the magnet 32 with the air gap G vacated. As shown in FIG. 3 , when the coils 44 and 45 are not energized, the magnet 32 is held in the neutral position by the magnetic attraction force between the magnet 32 and the rotation angle position holding part 48 .

In this neutral position, one of the S pole 32 a and the N pole 32 b of the magnet 32 (the S pole 32 a in FIG. 20 ) is attracted to the rotation angle position holding part 48 (see the magnetic spring torque FM in FIG. 20 ). At this time, the magnetic pole switching portions 32c and 32d face the center positions of the magnetic poles 410a and 410b of the core 400. In addition, the auxiliary pole portion 414 and the other of the S pole 32a and the N pole 32b of the magnet 32 (the N pole 32b in FIG. 20 ) attract each other. Thereby, the magnet 32 moves to the neutral position more efficiently.

When the coils 44 and 45 are energized, the core 400 is excited, and the magnetic poles 410a and 410b generate polarities corresponding to the direction of energization. For example, when the coils 44 and 45 are energized as shown in FIG. 20 , magnetic flux is generated inside the core 400 , and the magnetic pole 410 a becomes the N pole, and the magnetic pole 410 b becomes the S pole.

Thereby, the magnetic pole 410a magnetized to the N pole and the S pole 32a of the magnet 32 attract each other, and the magnetic pole 410b magnetized to the S pole and the N pole 32b of the magnet 32 attract each other. Then, the magnet 32 generates torque in the F direction around the rotation axis 13, and the magnet 32 rotates in the F direction. Along with this, the rotating shaft 13 also rotates in the F direction, and the mirror portion 12 fixed to the rotating shaft 13 also rotates in the F direction.

Then, when the coils 44 and 45 are energized in opposite directions, the magnetic flux generated inside the core 400 flows in the opposite direction to that shown in FIG. 15 , and the magnetic pole 410a becomes the S pole, and the magnetic pole 410b becomes the N pole. . The magnetic pole 410a magnetized to the S pole and the N pole 32b of the magnet 32 attract each other, and the magnetic pole 410b magnetized to the N pole and the S pole 32a of the magnet 32 attract each other. Then, the magnet 32 generates a torque -F in the direction opposite to the F direction around the rotation axis 13, and the magnet 32 rotates in the -F direction. Along with this, the rotating shaft 13 also rotates, and the mirror portion 12 fixed to the rotating shaft 13 also rotates in the opposite direction to the direction shown in FIG. 15 .

The rotational reciprocation drive actuator 1 performs the rotational reciprocation drive of the mirror portion 12 by repeating the above operation.

Actually, the rotational reciprocating drive actuator 1 is driven by an AC wave input to the coils 44 and 45 from a power supply unit (for example, equivalent to the drive signal supply unit 103 in FIG. 21 ). That is, the energization directions of the coils 44 and 45 are periodically switched. When the energization direction is switched, the magnetic attraction force between the rotation angle position holding part 48 and the magnet 32, that is, the restoring force of the magnetic spring (the magnetic spring torque FM shown in FIG. 20 and the torque in the opposite direction "-FM"), the magnet 32 is urged to return to the neutral position. As a result, the torque in the F direction and the torque in the direction opposite to the F direction (-F direction) alternately act on the movable body 10 around the axis. Thereby, the movable body 10 is driven to rotate and reciprocate.

The driving principle of the rotary reciprocating drive actuator 1 will be briefly described below. In the rotary reciprocating drive actuator 1 of the present embodiment, the moment of inertia of the movable body (movable body 10) is set to J [kg·m ² ], and the magnetic spring (magnetic poles 410a, 410b, rotation angle position When the spring constant in the torsional direction of the holding portion 48 and the magnet 32 is K _sp [N·m/rad], the movable body resonates with the fixed body (fixed body 20 ) at the resonance calculated by equation (1) Frequency Fr [Hz] vibration (reciprocating rotation).

[Formula 1]

Fr: Resonance frequency [Hz]

J: Moment of inertia [kg·m ² ]

K _sp : Spring constant [N·m/rad]

The movable body constitutes the mass part in the vibration model of the spring-mass system. Therefore, when an alternating current wave with a frequency equal to the resonance frequency Fr of the movable body is input to the coils 44 and 45 , the movable body enters the resonance state. That is, by inputting an AC wave of a frequency substantially equal to the resonance frequency Fr of the movable body into the coils 44 and 45 from the power supply unit, the movable body can be vibrated efficiently.

The motion equation and circuit equation representing the driving principle of the rotary reciprocating drive actuator 1 are shown below. 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).

[Formula 2]

J: Moment of inertia [kg·m ² ]

θ(t): angle [rad]

K _t : Torque constant [N·m/A]

i(t): current [A]

K _sp : Spring constant [N·m/rad]

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

T _Loss : Load torque [N·m]

[Formula 3]

e(t): voltage [V]

R: Resistance [Ω]

L: Inductance [H]

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

That is, the moment of inertia J [kg·m ² ], the rotation angle θ (t) [rad], the torque constant Kt [N·m/A], and the current i (t )[A], spring constant Ksp[N·m/rad], attenuation coefficient D[N·m/(rad/s)], load torque TLoss[N·m], etc. can be in the range that satisfies equation (2) Make appropriate changes within. In addition, the voltage e(t) [V], resistance R [Ω], inductance L [H], and back electromotive force constant Ke [V/(rad/s)] can be appropriately changed within the range satisfying equation (3).

In this way, the rotary reciprocating drive actuator 1 can obtain high efficiency when the coil is energized by an AC wave corresponding to the resonance frequency Fr determined by the inertial moment J of the movable body and the spring constant K _sp of the magnetic spring. And large vibration output.

＜Modification 1＞

FIG. 16 is an external perspective view of a modified example 1 of the rotary reciprocating drive actuator, and FIG. 17 is a longitudinal sectional view through the axis center of the modified example 1 of the rotary reciprocated drive actuator. In addition, FIG. 18 is an exploded perspective view of the modification 1 of the rotation reciprocating drive actuator, and FIG. 19 is a perspective view of the wall portion on the one end side of the modification 1 of the rotation reciprocating drive actuator. In addition, FIG. 20 is an exploded perspective view of the sensor portion disposed on the wall portion on the one end side.

Compared with the rotary reciprocating drive actuator 1 having a substantially similar configuration, the rotary reciprocating drive actuator 1A of the modified example 1 has only the substrate of the angle sensor portion 70A attached to the wall portion 212A side of the one end side of the base portion 21A. The structure in which the holding portion is provided on the wall portion 212A is different, but the other structures are the same. Therefore, the same names with the same functions are labeled with the same symbols, and explanations are omitted, and only the differences are explained.

In the rotation reciprocating drive actuator 1A shown in FIGS. 16 to 20 , the movable body 10A is attached to the base portion 21A to form a main body unit 2A. In addition, the movable body 10 is attached to the base portion 21A to form the main body unit 2A. In addition, the base portion 21A and the drive unit 4 constitute a fixed body 20A that supports the movable body 10 in a reciprocating and rotatable manner. The rotation reciprocating drive actuator 1A has an angle sensor portion 70A on the wall portion 212A that is one end of the main body unit 2A, and has the drive unit 4 on the wall portion 211A of the main body unit 2A that is disposed on the other end side. In addition, the angle sensor unit 70A includes an encoder disk 74 , a photosensor 76 , and a sensor substrate 72 .

Compared with the rotational reciprocation drive actuator 1 , the rotational reciprocation drive actuator 1A does not have a substrate holding portion, and the function of the substrate holding portion is integrally provided in the wall portion 212A. The wall portion 212A and the wall portion 211A are vertically erected from both ends of the flat bottom 213A configured similarly to the bottom 213 and are spaced apart from each other and opposed to each other. The wall portion 212A of the base portion 21A is provided with a concave sensor placement portion 230 opening toward the other end portion 131 .

Specifically, the wall portion 212A on the other end side of the base portion 21A configured similarly to the base portion 21 has a frame-shaped peripheral wall portion 240 that has the same function as the substrate holding portion 73 . In the outer surface 21 a of the wall portion 212A, a concave sensor placement portion 230 is provided in a central portion surrounded by the frame-shaped peripheral wall portion 240 . One end portion 131 of the rotation shaft 13 inserted into the wall portion 212A protrudes toward the sensor placement portion 230 .

This sensor arrangement part 230 has the same structure as that of the embodiment, and inside, the encoder disk 74 is fixed to the rotating shaft 13 via the mounting shaft part 742 . In addition, the sensor substrate 72 is mounted on the wall portion 212A in the sensor arrangement portion 230 so that the photosensor 76 mounted on the sensor substrate 72 faces the encoder disk 74 .

The sensor substrate 72 is mounted on the outer surface 21 a of the wall portion 212A via the fixing holes 723 and 215 by the fixing member 84 so as to cover the sensor placement portion 230 . The structure of the rotary reciprocating drive actuator 1A has the same effect as the embodiment, and it is not necessary to use a separate component as the substrate holding portion. Therefore, the number of parts can be reduced and the manufacturing time can be shortened. In addition, when the sensor substrate 72 is mounted on the wall portion 212A, the sensor substrate 72 can be positioned on the wall portion 212A through the positioning holes 205 and 725 and the position adjustment holes 207 and 727 provided in the wall portion 212 and the sensor substrate 72. The axis of rotation 13 is in a suitable position as the center.

<Scanner System 100>

FIG. 21 is a block diagram showing the main structure of the scanner system 100 using the rotary reciprocating drive actuator 1 .

The scanner system 100 has any one of the rotary reciprocating drive actuators 1 and 1A. In addition to the rotary reciprocating drive actuators 1 and 1A, it also has a laser light emitting unit 101, a laser control unit 102, a drive signal supply unit 103, and a position control unit. Signal calculation unit 104.

The laser light emitting unit 101 includes, for example, an LD (laser diode) serving as a light source, a lens system for condensing laser light output from the light source, and the like. The laser control unit 102 controls the laser light emitting unit 101. The laser light emitted from the laser light emitting unit 101 is incident on the reflecting mirror 121 of the rotational reciprocating drive actuator 1 .

The position control signal calculation unit 104 refers to the angular position of the rotating shaft 13 (mirror 121 ) acquired by the angle sensor unit 70 and the target angular position, and generates and outputs a drive for controlling the rotating shaft 13 (mirror 121 ) to reach the target angular position. Signal. For example, the position control signal calculation unit 104 generates a position based on the acquired angular position of the rotation axis 13 (mirror 121) and a signal indicating a target angular position converted using sawtooth waveform data or the like stored in a waveform memory not shown. control signal. The position control signal calculation unit 104 outputs the generated position control signal to the drive signal supply unit 103 .

The drive signal supply unit 103 supplies a drive signal for setting the angular position of the rotation shaft 13 (mirror 121) to a desired angular position to the coils 44 and 45 of the rotational reciprocating drive actuator 1 based on the position control signal. This allows the scanner system 100 to emit scanning light from the rotary reciprocating drive actuator 1 to a predetermined scanning area.

＜Summary＞

As explained above, the rotational reciprocating drive actuator 1 of this embodiment has the movable body 10 having the rotation shaft (shaft part) 13 to which the mirror part (movable object) is connected, and the fixed Magnet 32 on the rotating shaft 13. In addition, the magnet 32 is a ring-shaped magnet in which S poles 32a and N poles 32b are alternately arranged in the circumferential direction on the outer peripheral surface. Furthermore, the rotary reciprocating drive actuator 1 has a fixed body 20 having a core assembly 40 .

The rotating shaft 13 is rotatably supported by a pair of wall portions 211 and 212 of the base portion 21 . The core assembly 40 is mounted on the other wall portion 211 of the pair of wall portions 211 and 212 , and an angle sensor portion that detects the rotation angle of the rotation shaft 13 is arranged on the one wall portion 212 of the pair of wall portions 211 and 212 . 70. A sensor (photo sensor) 76 is mounted on the angle sensor portion 70 , and the sensor substrate 72 is mounted on the one wall portion 212 from the one end portion 131 side toward the one wall portion side.

In this way, the angle sensor member (encoder disk, etc.) is disposed near the bearing 23 at a position separated from the core assembly 40. Therefore, there is no concern about electromagnetic noise, heat generation influence, or mechanical influence from the core assembly during driving, and there is no rotation. The angle of the shaft 13 can be appropriately detected due to the influence of shaft wobble. Therefore, the rotation of the shaft connected to the movable object can be accurately detected, and the movable object can be driven with a high amplitude more appropriately.

The sensor substrate 72 covers the detection part (encoder disk) of the sensor member outside the sensor placement parts 701 and 230 . This allows the sensor substrate 72 to prevent contamination of the sensor arrangement portions 701 and 230 . In this way, it is possible to prevent foreign matter from being mixed into the sensor arrangement portions 701 and 230, and to drive the movable object in a manner suitable for accurate rotation angle detection.

The angle sensor unit 70 is configured by arranging the encoder disk 74 as a detected portion at one end 131 of the rotating shaft 13 and facing the photosensor 76 mounted on the sensor substrate 72 in the axial direction of the rotating shaft 13 . According to this structure, a layout is achieved that minimizes the size of the structure in which the angle sensor unit 70 is arranged, and the rotational reciprocating drive actuator 1 itself can be miniaturized and the photosensor 76 can be stably held.

In addition, when repairing the angle sensor unit 70 , only the fixing member 84 is removed, so that the sensor member, which is a costly member when in a defective condition, is exposed to the outside and can be easily recovered or replaced.

In addition, when the sensor unit is an optical sensor, it is possible to prevent light from interfering with the sensor arrangement portions (which may also be accommodating portions for accommodating the sensors) 701 and 230 without using additional light shielding members.

When the drive unit 4 is fixed to the main body unit 2, when the rotation axis 13 is used as a reference, it is preferable to fix it at a position where the dimensions can be determined based on the reference. In addition, when the shaft is vertically erected and the rotary reciprocating drive actuator is fixed to the product case, the rotary reciprocating drive actuator can be positioned and fixed in a direction parallel to the shaft, and the rotary reciprocating drive actuator can be assembled and the rotary reciprocating drive actuator can be assembled. Install the device 1 to the box. This enables high-precision positioning and fixing with less additional dimensions than when assembled in a direction different from the axial direction.

In addition, a gap (gap) narrower than the air gap between the magnet 32 and the core assembly 40 may be provided between the bushing 39 and the outer periphery of the rotating shaft 13 . In this case, the sliding movement between the bushing 39 and the rotating shaft 13 disappears, and impact resistance can be ensured. In addition, if the bush 39 and the rotating shaft 13 are configured to slide, impact can be reliably received, impact on the sensor portion can be prevented, unnecessary vibration of the movable body can be attenuated, and noise can be reduced.

In addition, the movable object is the mirror portion 12 (especially the mirror 121) that reflects the scanning light. Thereby, the rotation reciprocating drive actuator 1 can be used as a scanner for performing optical scanning.

In addition, as shown in FIG. 22 , in the annular magnet 32 of the rotary reciprocating drive actuators 1 and 1A of this embodiment, the magnetic pole switching portions 32 c and 32 d are constituted by U-shaped grooves formed on the end surface 322 of one side. , but it does not need to be composed of U-shaped grooves. The magnetic pole switching part can be configured arbitrarily as long as it indicates the position where the magnetic pole changes in the magnet 32 . Modifications of the magnet 32 will be described with reference to FIGS. 22 to 26 .

FIGS. 22 to 26 show modifications 1 to 4 of the magnets in the rotational reciprocating drive actuators 1 and 1A. In addition, Figures A and B of Figures 23 to 25 respectively show a front view and a right side view of a magnet as a modification, and Figure 26 is a diagram showing a core assembly having a rotational reciprocating drive actuator according to Modification 4. , corresponding to the end view of the line A-A portion of FIG. 2 of the rotary reciprocating drive actuator having the magnet 32 .

The magnets 320, 320A, and 320B shown in FIGS. 23 to 25 are each annular and have an opening 321 in the center through which the rotation shafts 13 and 13A are inserted.

The magnet 320 shown in FIG. 23 has protruding magnetic pole switching portions 32e and 32f integrally with the diameter portion of one end surface 322. The magnetic pole switching portions 32e and 32f are protrusions (projections) formed on the same straight line across the opening 321 on the end surface 322, and their front end surfaces may be rounded or flat.

The magnetic pole switching portions 32e and 32f allow the magnet 320 to determine the switching position of the magnetic pole in the magnet 320 based on its shape.

In addition, compared with the magnet 320, the magnet 320A shown in FIG. 24 has magnetic pole switching portions 32g and 32h with a V-shaped cross section on the end surface 322 of the annular main body instead of having a U-shaped cross section.

The magnetic pole switching portions 32g and 32h allow the magnet 320A to determine the switching position of the magnetic pole in the magnet 320A based on its shape.

Here, in addition to the magnet 32 , the assembly accuracy of the magnetic pole directions of the magnets 320 and 320A is preferably arranged in a well-balanced manner in conjunction with the angle reference of the mirror unit 12 as a movable object and the angle reference of the angle sensor unit 70 . If each angle reference deviates, there is a problem that the characteristics change due to the rotation angle of the rotating shaft 13, which becomes a main cause of performance variation.

On the other hand, in the present embodiment, in the magnets 32, 320, and 320A, the magnetic pole switching portions 32c to 32h are formed in a U-shape, a protruding shape, a V-shape, etc., and the magnets 32, 320, and 320A have a shape in the magnetization direction. concave and convex shape.

Therefore, it is possible to assemble other components based on these magnetic pole switching parts 32c, 32d, 32e, 32f, 32g, 32h using a positioning jig having pins corresponding to U-shaped, protruding, V-shaped, etc., or assemble Rotating reciprocating drive actuator.

That is, based on the concave and convex portions (magnetic pole switching portions 32c, 32d, 32e, 32f, 32g, 32h), each member fixed to the rotating shaft 13 can be adjusted during assembly or maintenance of the rotational reciprocating drive actuator 1 positional relationship. In the rotary reciprocating drive actuator 1 , the angle reference of the mirror portion 12 , the angle reference of the angle sensor portion 70 , and the magnetic pole reference of the magnet 32 can be easily aligned, and high-precision assembly can be easily achieved.

In addition, if the magnet 32 is configured to have concavities and convexities in the magnetization direction, the influence on the magnetic poles 410a and 410b facing each other on the outer peripheral surface and the rotation angle position holding portion (magnetic spring) 48 will be small, and the torque will be reduced. The influence is small, and there is no variation in the characteristics of the magnetic attraction force of the rotation angle position holding portion 48 .

For example, the magnet 320B shown in FIG. 25 has a flat surface 328 in a shape in which a part of the outer peripheral surface 326 is notched. The flat surface 328 is a part of the outer peripheral surface of one of the magnets 320B having different magnetic poles.

For example, when the core assembly 40B having the magnet 320B is provided in the rotational reciprocating drive actuator 1 , the magnetic pole is disposed on the opposite side of the magnetic pole 32 a facing the rotation angle position holding portion 48 shown in FIG. 26 32b has a flat surface 328. The flat surface 328 faces the curved surface of the auxiliary pole portion 414 . Specifically, when the magnet 320B is located at the reference position, the flat surface 328 is disposed so that the center of its length in the circumferential direction (horizontal direction) and the center of the circumferential direction (horizontal direction) of the auxiliary pole portion 414 are located through the opening 321 (or the center of the rotation axis 13 ) and on a line orthogonal to the flat surface 328 .

In the magnet 320B, for example, if the flat surface 328 is arranged to face the rotation angle position holding part 48 or the core (magnetic poles 410a, 410b) side, only a part of the magnet 320B is a flat part, so the flow of magnetic flux is generated. Imbalance is considered to affect magnetic circuit characteristics and degrade performance.

On the other hand, in the present embodiment, the flat surface 328 of the magnet 320B is arranged on the opposite side to the rotation angle holding portion 48 across the rotation shaft 13 in the non-energized state, for example, when it is located at the reference position. Therefore, the flat surface 328 can avoid the influence on the rotation angle holding part 48 , that is, avoid the imbalance caused by the torque, and generate a magnetic attraction force between the flat surface 328 and the auxiliary pole part 414 . In addition, it is also possible to assemble other components using the flat surface 328 based on the magnet 320B, or to assemble the rotational reciprocating drive actuator.

The invention proposed by the present inventors has been specifically described above based on the embodiments. However, the invention is not limited to the above-described embodiments and can be modified within the scope without departing from the gist of the invention.

For example, in the embodiment, the case where the movable object is the mirror unit 12 has been described, but the movable object is not limited to this. The movable object may be, for example, an imaging device such as a camera.

In addition, for example, in the embodiment, the case where the rotational reciprocating drive actuator 1 is driven with resonance has been described, but the present invention can also be applied to the case of non-resonant driving.

In addition, the structure of the drive unit 4 is not limited to the structure demonstrated in embodiment. For example, it suffices that the core has a magnetic pole portion that is excited by energizing the coil to generate a polarity, and that the magnetic pole portion and the outer peripheral surface of the magnet face each other via an air gap when the rotating shaft is attached to the fixed body. In addition, the coil may be configured so as to appropriately generate magnetic flux from one of the magnetic pole portions of the core toward the other when energized.

Furthermore, although the rotation angle position holding part 48 provided in the fixed body 20 is attached to the second core 42, it is not limited to this, and the structure of other components provided in the fixed body 20 may also be adopted. In addition, for example, the rotation angle position holding portion 48 may be provided to protrude from the surface of the cover body 52 or the back surface of the top cover body 62 so as to be disposed at the same position as that attached to the second core 42 . In addition, in the above case, the rotation angle position holding part 48 may be accommodated in the drive unit 4 .

It should be understood that the embodiments disclosed this time are illustrative and not restrictive in every respect. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all changes within the meaning and scope of the claims be equal to those of the claims.

Industrial availability

The present invention is applicable to, for example, LiDAR devices, scanner systems, and the like.

Claims (5)

1. A rotary reciprocation drive actuator is characterized by comprising:

a movable body having a shaft portion to which a movable object is connected at one end portion side and a magnet fixed to the shaft portion at the other end portion side, and supported so as to be capable of reciprocating rotation about an axis;

a base portion rotatably supporting the shaft portion via a bearing on the one end portion side, the base portion having a pair of wall portions disposed so as to sandwich the movable object;

a core assembly having a core body, a coil body, and a magnet position holding portion, the core body having a plurality of magnetic poles facing an outer periphery of the magnet with the magnet interposed therebetween, the coil body being wound around the core body and configured to reciprocate the movable body by generating magnetic flux interacting with the magnet by energization, the magnet position holding portion generating magnetic attraction force with the magnet to define a reference position of the reciprocation; and

And a sensor board attached to one of the pair of wall portions, and having a sensor for detecting a rotation angle of the shaft portion, wherein the sensor is disposed on the one wall portion from the one end portion side toward the one wall portion side.

2. The rotary reciprocating drive actuator of claim 1 wherein,

the number of the plurality of magnetic poles is two.

3. The rotary reciprocating drive actuator of claim 1 wherein,

the sensor is a photosensor.

4. The rotary reciprocating drive actuator of claim 1 wherein,

the one end portion side of the one wall portion has a substrate holding portion that surrounds the sensor and that mounts and holds the sensor substrate.

5. The rotary reciprocating drive actuator of claim 1 wherein,

the movable object is a mirror that reflects the scanning light.