Mirror oscillation device and lidar device

Abstract

A mirror part (10) has a mirror surface (11) that reflects light. An extension part (20) extends from a rear surface (12) of the mirror part (10) to a side opposite to the mirror surface (11). A shaft (30) is fixed to the extension part (20). A pedestal (40) is provided in a region on the side opposite to the mirror surface (11) relative to the mirror part (10). A bearing (50) is provided on the pedestal (40) in the axis direction of the shaft (30) relative to the extension part (20), and supports the shaft (30) so as to be rotatable with respect to the pedestal (40). The mirror part (10) can oscillate together with the shaft (30) and the extension part (20) within a prescribed angle range around the axis (CL) of the shaft (30). At least a part of the bearing (50) and at least a part of the pedestal (40) are provided in a height range (H1) of the mirror part (10) in the axis direction of the shaft (30) in a region on the side opposite to the mirror surface (11) relative to the mirror part (10).

Description

Mirror oscillation device and LiDAR device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2023-108420, filed on June 30, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a mirror oscillation device and a LiDAR device including the same.

[0003] Conventionally, mirror oscillating devices used as components of LiDAR devices and the like have been known. LiDAR stands for Light Detection and Ranging or Laser Imaging Detection and Ranging. LiDAR is a technology that irradiates a laser beam and measures the distance to an object, the shape of the object, and the like based on information from the reflected light. The mirror oscillating device described in Patent Document 1 has a configuration in which a shaft is fixed to a hole provided in the center of the mirror in the thickness direction, and two bearings, an actuator, and a rotation angle sensor are provided on a portion of the shaft that protrudes from the mirror. Specifically, a bearing and an actuator are provided on one side of the shaft that protrudes from the mirror, and a bearing and a rotation angle sensor are provided on the other side of the shaft that protrudes from the mirror. Note that in Patent Document 1, the shaft is referred to as a shaft portion, and the actuator is referred to as a drive unit.

[0004] JP 2022-30904 A

[0005] However, the mirror rocking device described in Patent Document 1 has an actuator, a bearing on one side, a mirror unit, a bearing on the other side, and a rotation angle sensor arranged in series in the direction in which the axis of the shaft extends (hereinafter referred to as the "axial direction"), which results in a large axial size. Also, the proportion of the mirror surface of the mirror unit to the axial size of the mirror rocking device is small.

[0006] Therefore, in a LiDAR device using the mirror oscillation device described in Patent Document 1, as the mirror oscillation device becomes larger, the size of the mirror section in the axial direction of oscillation becomes larger, and furthermore, the proportion of the mirror surface of the mirror section relative to the size becomes smaller. If such a LiDAR device is mounted on the roof of a vehicle, for example, the size of the LiDAR device causes the rooftop to have a convex shape that protrudes significantly above the vehicle, resulting in problems such as increased air resistance when the vehicle is traveling and reduced fuel or electricity efficiency. Alternatively, the LiDAR device protrudes significantly from the roof into the vehicle interior, impairing the driver's forward visibility.

[0007] One possible solution to these two problems is to reduce the size of the mirror in the axial direction. However, reducing the size of the mirror reduces the spot diameter of the laser light, which can result in performance degradation such as a worsening of the signal-to-noise ratio and a reduced distance measurement range.

[0008] The present disclosure aims to reduce the size of a mirror rocking device in the axial direction of rocking of a mirror section, and to increase the proportion of the mirror section in the axial direction of the mirror rocking device.

[0009] According to one aspect of the present disclosure, a mirror oscillation device comprises: a mirror portion having a mirror surface that reflects light; an extension portion extending from the surface of the mirror portion opposite the mirror surface to the opposite side of the mirror surface; a shaft fixed to the extension portion; a base provided in an area opposite the mirror surface from the mirror portion; and a bearing provided on the base in the axial direction of the shaft relative to the extension portion, and supporting the shaft rotatably relative to the base; the mirror portion can oscillate together with the shaft and the extension portion around the axial center of the shaft within a predetermined angular range; and at least a part of the bearing and at least a part of the base are provided in the area opposite the mirror surface from the mirror portion, in the height range of the mirror portion in the axial direction of the shaft.

[0010] According to this, by utilizing the area of ​​the mirror unit opposite the mirror surface to arrange the bearing and the base, the size of the mirror oscillating device in the axial direction of the mirror oscillating can be reduced. Furthermore, the proportion of the mirror surface of the mirror unit to the axial size of the mirror oscillating device can be increased. Therefore, a LiDAR device using this mirror oscillating device can reduce the size of the mirror unit in the axial direction, in other words, the size in the direction perpendicular to the direction in which the mirror oscillates. Therefore, when the LiDAR device is mounted on, for example, the roof of a vehicle, it is possible to prevent the rooftop from becoming a convex shape that protrudes significantly above the vehicle, or to prevent the LiDAR device from protruding significantly from the roof into the vehicle cabin. Furthermore, a LiDAR device using this mirror oscillating device can increase the spot diameter of the laser light by increasing the size of the mirror surface of the mirror unit, thereby improving the signal-to-noise ratio and expanding the ranging range.

[0011] According to another aspect of the present disclosure, a LiDAR device comprises: a housing having a window that transmits laser light; a mirror oscillating device described in the above one aspect that is provided inside the housing; a light source device that is provided inside the housing and irradiates laser light onto the mirror surface of a mirror portion provided in the mirror oscillating device; and a light receiving device that is provided inside the housing and receives the laser light that is scanned by the mirror surface of the mirror portion provided in the mirror oscillating device and irradiated to the outside through the window of the housing, then reflected by an external object, returns through the window of the housing, and is reflected again by the mirror surface of the mirror portion.

[0012] According to this, by including the mirror oscillation device described in one aspect above, the LiDAR device can reduce the size of the LiDAR device in the axial direction of the oscillation of the mirror unit, in other words, the size in the direction perpendicular to the direction of the oscillation of the mirror unit. Therefore, when this LiDAR device is mounted on the roof of a vehicle, for example, it is possible to prevent the rooftop from becoming a convex shape that protrudes significantly above the vehicle, or to prevent the LiDAR device from protruding significantly from the roof into the vehicle cabin. Furthermore, by including the mirror oscillation device described in one aspect above, the LiDAR device can increase the spot diameter of the laser light, thereby improving the signal-to-noise ratio and expanding the ranging range.

[0013] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below.

[0014] 11 is a perspective view showing the internal configuration of a LiDAR device using a mirror rocking device according to the first embodiment. FIG. 12 is a diagram showing an example of a LiDAR device mounted on the roof of a vehicle. FIG. 13 is a diagram showing another example of a LiDAR device mounted on the roof of a vehicle. FIG. 14 is a perspective view of a mirror rocking device according to the first embodiment. FIG. 15 is a side view of the mirror rocking device as seen from direction V in FIG. 4. FIG. 16 is a front view of the mirror rocking device as seen from direction VI in FIG. 4. FIG. 17 is a plan view of the mirror rocking device as seen from direction VII in FIG. 4. FIG. 18 is a bottom view of the mirror rocking device as seen from direction VIII in FIG. 4. FIG. 19 is a cross-sectional view of the mirror rocking device taken along line IX-IX in FIG. 6. FIG. 20 is a cross-sectional view of the mirror rocking device taken along line X-X in FIG. 5. FIG. 21 is a rear view of the mirror section and the extension section provided in the mirror rocking device according to the first embodiment. FIG. 22 is a side view of the mirror section and the extension section as seen from direction XII in FIG. 11. FIG. 23 is a plan view of the mirror section and the extension section as seen from direction XIII in FIG. 11. FIG. 24 is a plan view for explaining the operation of the mirror rocking device according to the first embodiment. FIG. 25 is a plan view for explaining the operation of the mirror rocking device according to the first embodiment. 21. A plan view for explaining the operation of the mirror rocking device according to the first embodiment when used in a LiDAR device. FIG. 22 is a plan view for explaining the operation of the mirror rocking device according to the first embodiment when used in a LiDAR device. FIG. 23 is a plan view for explaining the operation of the mirror rocking device according to the first embodiment when used in a LiDAR device. FIG. 24 is a plan view for explaining the operation of the mirror rocking device according to the first embodiment when used in a LiDAR device. FIG. 25 is a rear view of the mirror section, extension section, and counterweight provided in the mirror rocking device according to the second embodiment. FIG. 26 is a side view of the mirror section, extension section, and counterweight as seen from the XXII direction of FIG. 21. FIG. 27 is a plan view of the mirror section, extension section, and counterweight as seen from the XXIII direction of FIG. 21. FIG. 28 is a plan view of the mirror section, extension section, and counterweight provided in the mirror rocking device according to the third embodiment.

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, identical or equivalent parts will be denoted by the same reference numerals, and description thereof will be omitted.

[0016] (First embodiment) A first embodiment will be described with reference to the drawings. As shown in Fig. 1 , a mirror oscillating device 1 of the first embodiment is used in a LiDAR device 2 or the like. Inside a housing 3 provided in the LiDAR device 2, the mirror oscillating device 1, a light source device 4 that irradiates laser light, and a light receiving device 5 that receives the laser light are provided. Note that in Fig. 1 , only the outline of the housing 3 is shown so that the interior of the housing 3 can be seen.

[0017] The LiDAR device 2 emits laser light emitted from the light source device 4 through a window 8 of the housing 3 while reflecting and scanning the laser light on the mirror surface 11 of the mirror unit 10 provided in the mirror oscillation device 1. The laser light reflected by an external object and returning through the window 8 of the housing 3 is reflected again by the mirror surface 11 of the mirror unit 10 and received by the light receiving device 5. The LiDAR device 2 detects the distance and direction to the object from the time difference between the time the laser light is emitted and the time it is received. The LiDAR device 2 may also detect the moving speed of the object from the change in frequency between the transmitted wave and the received wave.

[0018] Incidentally, in the LiDAR device 2, if the spot diameter 7 where the laser light hits the mirror surface 11 of the mirror unit 10 is small, for example, if raindrops or the like adhere to the window 8 of the housing 3 of the LiDAR device 2, the laser light may be diffused and not be irradiated to the outside. In contrast, if the mirror surface 11 of the mirror unit 10 is made larger and the spot diameter 7 of the laser light is accordingly increased, the spot diameter 7 of the laser light can be made larger than the raindrops or the like, and it becomes possible to irradiate at least a portion of the laser light to the outside. Therefore, by increasing the spot diameter 7 of the laser light, the LiDAR device 2 can improve the signal-to-noise ratio.

[0019] As shown in Figures 2 and 3, the LiDAR device 2 may be mounted on, for example, the roof 6 of a vehicle. In this case, if the size LH of the LiDAR device 2 is increased using a mirror oscillation device such as that described in Patent Document 1, the roof top will have a convex shape that protrudes significantly above the vehicle, as shown in Figure 2. This increases air resistance while the vehicle is running, resulting in problems such as reduced fuel economy or power consumption. Alternatively, as shown in Figure 3, the LiDAR device 2 protrudes significantly from the roof 6 into the vehicle interior, impairing the driver's forward visibility. Note that, as shown in Figure 1, the size LH of the LiDAR device 2 refers to the size LH in the axial direction of the mirror unit 10 in the LiDAR device 2, in other words, the size LH in the direction perpendicular to the direction in which the mirror unit 10 oscillates.

[0020] To solve these problems, if the mirror surface 11 of the mirror unit 10 were to be reduced, the spot diameter 7 of the laser light would be reduced, resulting in performance degradation such as a worsening of the signal-to-noise ratio and a reduced ranging range. Therefore, the mirror oscillating device 1 used in the LiDAR device 2 is required to have a reduced size in the axial direction of the oscillation of the mirror unit 10 and to increase the proportion of the mirror unit 10 in the size. In the following description, the size of the mirror oscillating device 1 in the axial direction of the oscillation of the mirror unit 10 may be simply referred to as the "size of the mirror oscillating device 1 in the axial direction." Reducing the size of the mirror oscillating device 1 in the axial direction allows the size LH of the mirror unit 10 in the LiDAR device 2 to be reduced in the axial direction, in other words, the size LH in the direction perpendicular to the direction in which the mirror unit 10 oscillates.

[0021] As shown in FIGS. 4 to 10, the mirror rocking device 1 according to the first embodiment of the present disclosure includes a mirror portion 10, an extension portion 20, a shaft 30, a base 40, a bearing 50, an actuator 60, and a sensor .

[0022] The mirror portion 10 is formed in a plate shape, and has a mirror surface 11 that reflects light over the entire surface of one of its surfaces facing in the thickness direction.

[0023] As shown in Figures 5, 9, and 11 to 13, an extension portion 20 is provided on the surface of the mirror portion 10 opposite the mirror surface 11 (hereinafter referred to as the "rear surface 12 of the mirror portion 10"). The extension portion 20 extends from the rear surface 12 of the mirror portion 10 to the side opposite the mirror surface 11. When viewed from the direction in which the axis CL of the shaft 30 extends, the extension portion 20 has a shape in which the area of ​​the portion that connects to the rear surface 12 of the mirror portion 10 is large and the area gradually decreases with increasing distance from the rear surface 12 of the mirror portion 10. A hole 21 through which the shaft 30 is inserted is provided in the extension portion 20 at a position away from the rear surface 12 of the mirror portion 10.

[0024] The shaft 30 is inserted through the hole 21 in the extension portion 20 and fixed to the extension portion 20. A predetermined distance D1 is provided between the rear surface 12 of the mirror portion 10 and the shaft 30. In the following explanation, the direction in which the axis CL of the shaft 30 extends will be simply referred to as the "axial direction." For ease of explanation, the upper side of the paper in FIGS. 4 to 6, 9, 11, and 12 will be referred to as "one side of the axial direction," and the lower side of the paper will be referred to as "the other side of the axial direction."

[0025] As shown in FIGS. 4 , 8 , and 9 , the bearings 50 are provided on one axial side of the extending portion 20 and the other axial side of the extending portion 20. Of the two bearings 50, the one provided on one axial side of the extending portion 20 is referred to as the first bearing 51, and the one provided on the other axial side of the extending portion 20 is referred to as the second bearing 52. Both the first bearing 51 and the second bearing 52 are provided on the base 40 and rotatably support the shaft 30 relative to the base 40. The radial thickness D2 of the bearing 50 is smaller than the distance D1 between the rear surface 12 of the mirror portion 10 and the shaft 30. Therefore, the bearing 50 can be provided in a region of the mirror portion 10 opposite the mirror surface 11, within a height range H1 of the mirror portion 10 in the axial direction. In the following description, the region of the mirror portion 10 opposite the mirror surface 11 is referred to as the "rear surface region of the mirror portion 10."

[0026] The base 40 is provided in the rear surface region of the mirror unit 10. The base 40 has a first base portion 41 on which a first bearing 51 is provided, a second base portion 42 on which a second bearing 52 is provided, and a connecting portion 43 that connects the first base portion 41 and the second base portion 42. The connecting portion 43 connects a portion of the first base portion 41 opposite the mirror unit 10 to a portion of the second base portion 42 opposite the mirror unit 10. The connecting portion 43 extends further to one side in the axial direction than the first base portion 41.

[0027] Here, by providing at least a portion of the bearing 50 and at least a portion of the base 40 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be made smaller than the configuration of the above-mentioned Patent Document 1. Preferably, as in the first embodiment, by providing all of the bearing 50 and all of the base 40 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be made even smaller. Specifically, with respect to the outer edge 13 on one side of the mirror unit 10 in the axial direction, the outer edge 46 on one side of the axial direction of the connecting portion 43 of the base 40 and the outer edge 56 on one side of the axial direction of the first bearing 51 are positioned at the same height or on the other side in the axial direction. Furthermore, the outer edge 47 of the second base 42 on the other side in the axial direction and the outer edge 57 of the second bearing 52 on the other side in the axial direction are located at the same height or on one side in the axial direction relative to the outer edge 14 of the mirror part 10. This allows the axial size of the mirror rocking device 1 to be further reduced. Note that in this disclosure, "the same height" includes not only being exactly the same height, but also being substantially the same height, for example, taking into account manufacturing tolerances, etc.

[0028] As shown in Figures 4, 5, 7, 9, and 10, the actuator 60 is provided in the rear surface region of the mirror unit 10. The actuator 60 is a drive device that drives the mirror unit 10, together with the shaft 30 and the extension 20, to oscillate within a predetermined angular range around the axis CL of the shaft 30. That is, by driving the actuator 60, the mirror unit 10, together with the shaft 30 and the extension 20, can oscillate within a predetermined angular range around the axis CL of the shaft 30. The actuator 60 is disposed in an area of ​​the first pedestal 41 on the opposite side from the second pedestal 42. This allows the actuator 60 to be easily assembled to a sub-assembly that includes the pedestal 40, bearing 50, shaft 30, and mirror unit 10 during the manufacturing process of the mirror oscillation device 1.

[0029] The actuator 60 includes a magnet 61, a stator 62, and an electromagnetic coil 63. The magnet 61 is formed in an annular shape, and the shaft 30 is inserted through a central hole 64 thereof. The magnet 61 is fixed to the shaft 30. Specifically, the magnet 61 is fixed to a portion of the shaft 30 that extends from the first bearing 51 to one side in the axial direction. The magnet 61 may be fixed directly to the shaft 30, or may be fixed to the shaft 30 via a holder 73. The magnet 61 is magnetized with alternating south and north poles in the circumferential direction about the axis CL of the shaft 30. In the first embodiment, the magnet 61 is magnetized with one south pole and one north pole in the circumferential direction about the axis CL of the shaft 30.

[0030] The stator 62 is made of a magnetic material and forms a magnetic circuit between the electromagnetic coil 63 and the magnet 61. The stator 62 has a core portion 65 and a yoke portion 66. The electromagnetic coil 63 is provided outside the core portion 65. The yoke portion 66 connects one end of the core portion 65 to the other end of the core portion 65 and has a hole 67 where the magnet 61 is disposed. The inner wall of the hole 67 in the yoke portion 66 does not contact the magnet 61. The yoke portion 66 is fixed to a portion of the connecting portion 43 of the base 40 that extends further toward one side in the axial direction than the first base portion 41.

[0031] When current is applied to the electromagnetic coil 63, a magnetic field generated in the electromagnetic coil 63 causes magnetic flux to flow in the stator 62. Specifically, when current is passed in a predetermined direction through wiring (not shown) of the electromagnetic coil 63, magnetic flux flows from one side of the core portion 65 through the yoke portion 66 to the other side of the core portion 65, as shown by solid arrows A and B in Fig. 10, causing the magnet 61 to rotate. Note that in Fig. 10, as shown by solid arrow C, the north pole of the magnet 61 rotates toward the part of the yoke portion 66 on the right side in Fig. 10. Therefore, as shown by solid arrow D, the mirror portion 10 swings by a predetermined angle together with the shaft 30.

[0032] On the other hand, when a current is passed through the wiring of the electromagnetic coil 63 in the direction opposite to the predetermined direction, magnetic flux flows from the other side of the core portion 65 through the yoke portion 66 to one side of the core portion 65, as shown by dashed arrows E and F in Fig. 10, thereby rotating the magnet 61. Note that in Fig. 10, as shown by dashed arrow G, the north pole of the magnet 61 rotates toward the part of the yoke portion 66 on the left side in Fig. 10. Therefore, as shown by dashed arrow H, the mirror portion 10 swings by a predetermined angle together with the shaft 30.

[0033] 14 to 16 show the angular range of oscillation of the mirror unit 10. As indicated by arrow I in FIG. 14, the maximum angle at which the mirror unit 10 oscillates counterclockwise as viewed from one side of the axial direction is referred to as the first angle. Furthermore, as indicated by arrow J in FIG. 16, the maximum angle at which the mirror unit 10 oscillates clockwise is referred to as the second angle. Furthermore, as shown in FIG. 15, the angle midway between the first and second angles is referred to as the third angle. In the mirror oscillation device 1 of the first embodiment, the first angle shown in FIG. 14 is, for example, −35°, the second angle shown in FIG. 16 is, for example, +35°, and the third angle shown in FIG. 15 is, for example, 0°. Therefore, the mirror oscillation device 1 of the first embodiment is configured so that the mirror unit 10 oscillates within a range of, for example, −35° to +35°.

[0034] As shown in Figures 4 and 8, surfaces 44, 45 of the base 40 facing the mirror unit 10 are inclined from a portion closer to the shaft 30 to a portion farther from the shaft 30, in a direction away from the mirror unit 10 at the third angle. This prevents interference between the base 40 and the mirror unit 10 when the actuator 60 drives the mirror unit 10 to swing. Note that the surfaces 44, 45 of the base 40 facing the mirror unit 10 are not limited to flat inclined surfaces as shown in Figures 4 and 8, but may also be curved inclined surfaces. Note that, although not shown, a magnetic or mechanical stopper may be provided between the inclined surfaces of the base 40 and the back surface 12 of the mirror unit 10.

[0035] 4, 7, and 10, the surface 68 of the stator 62 facing the mirror unit 10 is inclined from the portion closer to the shaft 30 to the portion farther from the shaft 30, in a direction away from the mirror unit 10 at the third angle. This prevents interference between the stator 62 and the mirror unit 10 when the actuator 60 drives the mirror unit 10 to swing. Note that the surface 68 of the stator 62 facing the mirror unit 10 is not limited to a flat inclined surface as shown in FIGS. 4, 7, and 10, but may be a curved inclined surface.

[0036] Here, by providing at least a portion of the actuator 60 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be reduced compared to the configuration of Patent Document 1. Preferably, as in the first embodiment, by providing the entire actuator 60 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be further reduced. Specifically, the outer edge 601 on one side of the axial direction of the actuator 60 is located at the same height as or on the other side of the outer edge 13 on one side of the axial direction of the mirror unit 10. Furthermore, the outer edge 602 on the other side of the axial direction of the actuator 60 is located at the same height as or on one side of the outer edge 14 on the other side of the axial direction of the mirror unit 10. This allows the axial size of the mirror rocking device 1 to be further reduced.

[0037] The sensor 70 is provided in the rear surface region of the mirror unit 10. The sensor 70 is a rotation angle sensor that detects the angle of the mirror unit 10 relative to the base 40. In the first embodiment, for example, a rotary encoder is used as the sensor 70. As shown in FIGS. 5 and 9 , the rotary encoder includes a rotating disk 71 and a detecting element 72. The rotating disk 71 is fixed to a holder 73 provided on a portion of the shaft 30 that extends from the magnet 61 to one side in the axial direction, and rotates together with the shaft 30 and the holder 73. The detecting element 72 is, for example, a photo IC, and is mounted on a substrate 74. The substrate 74 is fixed to a portion of the connecting portion 43 of the base 40 that extends further from the first base portion 41 to one side in the axial direction. Note that the substrate 74 and the detecting element 72 are shown only in FIGS. 5 and 9 and are omitted in the other figures.

[0038] Here, by providing at least a portion of the sensor 70 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be reduced compared to the configuration of Patent Document 1. Preferably, as in the first embodiment, by providing the entire sensor 70 within the height range H1 of the mirror unit 10 in the axial direction, the axial size of the mirror rocking device 1 can be further reduced. Specifically, the outer edge 75 of the sensor 70 on one side in the axial direction is located at the same height as or on the other side of the outer edge 13 of the mirror unit 10 on one side in the axial direction. Furthermore, the outer edge 76 of the sensor 70 on the other side in the axial direction is located at the same height as or on one side of the outer edge 14 of the mirror unit 10 on the other side in the axial direction. This allows the axial size of the mirror rocking device 1 to be further reduced.

[0039] 17 , the LiDAR device 2 using the mirror oscillating device 1 of the first embodiment can irradiate the laser light to the outside while scanning it within a predetermined angular range θ (e.g., a maximum range of 140°). As indicated by arrow K, the light source device 4 provided within the housing 3 irradiates the laser light onto the mirror unit 10 from outside the predetermined angular range in which the laser light is scanned. Note that the controllable range in which the LiDAR device 2 scans the laser light is set to a range smaller than the maximum oscillation range of the mirror unit 10 (e.g., 120° or less).

[0040] Specifically, as shown by arrows K and L in FIGS. 17 and 18 , when the mirror unit 10 is at a first angle (e.g., −35°), the laser light emitted from the light source device 4 is reflected at an acute angle by the mirror surface 11 of the mirror unit 10 and irradiated to the outside. Note that in FIGS. 18 to 20 , the dashed line O indicates the normal to the mirror surface 11. As shown by arrows K and M in FIGS. 17 and 19 , when the mirror unit 10 is at a third angle (e.g., 0°), the laser light emitted from the light source device 4 is reflected at a right angle by the mirror surface 11 of the mirror unit 10 and irradiated to the outside. As shown by arrows K and N in FIGS. 17 and 20 , when the mirror unit 10 is at a second angle (e.g., +35°), the laser light emitted from the light source device 4 is reflected at an obtuse angle by the mirror surface 11 of the mirror unit 10 and irradiated to the outside. The mirror portion 10 of the mirror swinging device 1 swings repeatedly between the first angle, the second angle, and the third angle, thereby scanning the laser light.

[0041] The mirror rocking device 1 of the first embodiment described above has the following advantages. (1) In the first embodiment, at least a portion of the bearing 50 and at least a portion of the base 40 are provided in a region of the mirror unit 10 opposite the mirror surface 11, within a height range H1 of the mirror unit 10 in the axial direction of the shaft 30. By arranging the bearing 50 and the base 40 by utilizing the region of the mirror unit 10 opposite the mirror surface 11, the size of the mirror rocking device 1 in the axial direction of the rocking of the mirror unit 10 can be reduced. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 in the axial direction of the rocking of the mirror rocking device 1 can be increased. Therefore, the LiDAR device 2 using this mirror rocking device 1 can be reduced in size LH in the axial direction of the mirror unit 10, in other words, in the direction perpendicular to the rocking direction of the mirror unit 10. Therefore, when the LiDAR device 2 is mounted on the roof 6 of a vehicle, for example, it is possible to prevent the rooftop from protruding significantly above the vehicle, or to prevent the LiDAR device 2 from protruding significantly into the vehicle interior from the roof 6. Furthermore, the LiDAR device 2 using this mirror oscillating device 1 can increase the spot diameter 7 of the laser light by increasing the size of the mirror surface 11 of the mirror section 10, thereby improving the signal-to-noise ratio and expanding the ranging range.

[0042] (2) In the first embodiment, the outer edge 56 of the bearing 50 on one side in the axial direction and the outer edge 46 of the base 40 on one side in the axial direction are located at the same height as or on the other side of the outer edge 13 of the mirror unit 10 on one side in the axial direction. Furthermore, the outer edge 57 of the bearing 50 on the other side in the axial direction and the outer edge 47 of the base 40 on the other side in the axial direction are located at the same height as or on one side of the outer edge 14 of the mirror unit 10 on the other side in the axial direction. This allows the entire bearing 50 and the base 40 to be located in the region of the mirror unit 10 opposite the mirror surface 11, within the height range H1 of the mirror unit 10 in the axial direction. This allows the mirror rocking device 1 to be further miniaturized in the axial direction. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 to the axial size of the mirror rocking device 1 can be increased. In this disclosure, "the same height" includes not only exactly the same height, but also substantially the same height, for example, taking into account manufacturing tolerances.

[0043] (3) In the first embodiment, at least a portion of the actuator 60 is provided in a region of the mirror unit 10 opposite the mirror surface 11, in a height range H1 of the mirror unit 10 in the axial direction. By arranging the actuator 60 by utilizing the region of the mirror unit 10 opposite the mirror surface 11, the size of the mirror rocking device 1 including the actuator 60 in the axial direction of the rocking of the mirror unit 10 can be reduced. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 in the axial direction of the mirror rocking device 1 can be increased.

[0044] (4) In the first embodiment, the outer edge 601 of the actuator 60 on one side in the axial direction is located at the same height as or on the other side of the outer edge 13 of the mirror unit 10 on one side in the axial direction. The outer edge 602 of the actuator 60 on the other side in the axial direction is located at the same height as or on one side of the outer edge 14 of the mirror unit 10 on the other side in the axial direction. This allows the entire actuator 60 to be provided in a region of the mirror unit 10 opposite the mirror surface 11, within the height range H1 of the mirror unit 10 in the axial direction. Therefore, the size of the mirror oscillation device 1 including the actuator 60 in the axial direction of the oscillation of the mirror unit 10 can be further reduced. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 to the size of the mirror oscillation device 1 in the axial direction can be increased.

[0045] (5) In the first embodiment, at least a portion of the sensor 70 is provided in a region of the mirror unit 10 opposite the mirror surface 11, in a height range H1 of the mirror unit 10 in the axial direction. By arranging the sensor 70 by utilizing the region of the mirror unit 10 opposite the mirror surface 11, the size of the mirror rocking device 1 including the sensor 70 in the axial direction of the rocking of the mirror unit 10 can be reduced. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 in the axial size of the mirror rocking device 1 can be increased.

[0046] (6) In the first embodiment, the outer edge 75 of the sensor 70 on one axial side is located at the same height as or on the other side of the outer edge 13 of the mirror unit 10 on one axial side. The outer edge 76 of the sensor 70 on the other axial side is located at the same height as or on one side of the outer edge 14 of the mirror unit 10 on the other axial side. This allows the entire sensor 70 to be provided in a region of the mirror unit 10 opposite the mirror surface 11, within the height range H1 of the mirror unit 10 in the axial direction. Therefore, the size of the mirror oscillation device 1 including the sensor 70 in the axial direction of the oscillation of the mirror unit 10 can be further reduced. Furthermore, the proportion of the mirror surface 11 of the mirror unit 10 to the size of the mirror oscillation device 1 in the axial direction can be increased.

[0047] (7) In the first embodiment, the sensor 70 is a rotary encoder having a rotating disk 71 that rotates together with the shaft 30 and a detection element 72 that detects the position of the rotating disk 71 relative to the base 40. By using a rotary encoder as the sensor 70, the size in the axial direction can be reduced.

[0048] (8) In the first embodiment, the surfaces 44 and 45 of the base 40 facing the mirror unit 10 are inclined from the portion closer to the shaft 30 to the portion farther from the shaft 30, in a direction away from the mirror unit 10 at the third angle. Therefore, when the actuator 60 drives the mirror unit 10 to swing, interference between the base 40 and the mirror unit 10 is prevented. This ensures an angular range over which the mirror swings. Note that the surfaces 44 and 45 of the base 40 facing the mirror unit 10 may be flat inclined surfaces or curved inclined surfaces.

[0049] (9) In the first embodiment, the surface 68 of the stator 62 of the actuator 60 facing the mirror unit 10 is inclined from the portion closer to the shaft 30 to the portion farther from the shaft 30, in a direction away from the mirror unit 10 at the third angle. Therefore, when the actuator 60 drives the mirror unit 10 to swing, interference between the stator 62 and the mirror unit 10 is prevented. This ensures an angular range in which the mirror swings. Note that the surface 68 of the stator 62 facing the mirror unit 10 may be a flat inclined surface or a curved inclined surface.

[0050] Second Embodiment A second embodiment will be described. In the second embodiment, the configuration of the mirror rocking device 1 is partially changed from that of the first embodiment, and the rest of the configuration is the same as that of the first embodiment. Therefore, only the parts that are different from the first embodiment will be described.

[0051] 21 to 23, the mirror rocking device 1 of the second embodiment includes a counterweight 22. The counterweight 22 is provided so as to extend from a portion of the extension portion 20 on the opposite side from the mirror portion 10 to the opposite side from the mirror portion 10. When viewed from the axial direction of the shaft 30, the counterweight 22 is formed in a fan shape centered on the axis CL of the shaft 30. The counterweight 22 is formed integrally with the extension portion 20 and the mirror portion 10. The counterweight 22 may be formed as a separate member from the extension portion 20 and fixed to the extension portion 20.

[0052] The shape and weight of the counterweight 22 are set so that the center of gravity of the integrated part including the mirror section 10, the extension section 20, and the counterweight 22 is close to or coincides with the axis center CL of the shaft 30. It is preferable that the center of gravity of the integrated part including the mirror section 10, the extension section 20, and the counterweight 22 coincides with the axis center CL of the shaft 30. In this disclosure, "coincidence" includes not only perfect coincidence but also substantial coincidence, for example, with manufacturing tolerances.

[0053] The mirror rocking device 1 of the second embodiment described above includes the counterweight 22, which reduces the moment of inertia when the mirror section 10 is rocked, thereby reducing the generation of vibrations and abnormal noise.

[0054] Third Embodiment A third embodiment will be described. In the third embodiment, the configuration of the counterweight 22 is changed from that of the second embodiment, but the other parts are the same as those of the second embodiment, so only the parts that are different from the second embodiment will be described.

[0055] 24 , the counterweight 22 included in the mirror oscillation device 1 of the third embodiment has a resin body 23 and a weight portion 24. The resin body 23 is made of resin and is integrally formed with the extension portion 20 and the mirror portion 10. The resin body 23 may be formed as a separate member from the extension portion 20 and fixed to the extension portion 20. The weight portion 24 is made of a material with a specific weight greater than that of the resin body 23 and is fixed to the resin body 23. Specifically, the weight portion 24 is made of, for example, metal and is molded into the resin body 23.

[0056] In the mirror rocking device 1 of the third embodiment described above, the counterweight 22 is made up of the resin body 23 and the weight portion 24, which allows the size of the counterweight 22 to be reduced. In addition, the amount of expensive resin used can be reduced, thereby reducing manufacturing costs.

[0057] (Other embodiments) (1) In each of the above embodiments, the mirror oscillating device 1 has been described as being used in a LiDAR device 2, but it is not limited to this and may also be used in various optical scanning devices, such as a multifunction device or a laser beam printer.

[0058] (2) In each of the above embodiments, the LiDAR device 2 using the mirror rocking device 1 is described as being mounted on the roof 6 of a vehicle, but this is not limiting and the LiDAR device 2 may be mounted, for example, on the back side of a vehicle's bumper or grille. Alternatively, the LiDAR device 2 may be mounted on something other than a vehicle.

[0059] (3) In the above embodiments, at least a portion of each of the base 40, bearing 50, actuator 60, and sensor 70 is described as being provided within the height range H1 of the mirror unit 10. However, this is not limiting. For example, a configuration may be adopted in which at least a portion of the base 40 and at least a portion of the bearing 50 are provided within the height range H1 of the mirror unit 10, and the actuator 60 and sensor 70 are not provided within the height range H1 of the mirror unit 10.

[0060] Alternatively, for example, at least a portion of the base 40, at least a portion of the bearing 50, and at least a portion of the actuator 60 may be provided in the height range H1 of the mirror unit 10, and the sensor 70 may not be provided in the height range H1 of the mirror unit 10.

[0061] Alternatively, for example, at least a portion of the base 40, at least a portion of the bearing 50, and at least a portion of the sensor 70 may be provided in the height range H1 of the mirror unit 10, and the actuator 60 may not be provided in the height range H1 of the mirror unit 10.

[0062] (3) In the above embodiments, it has been described that the base 40, bearing 50, actuator 60, and sensor 70 are preferably all provided within the height range H1 of the mirror unit 10, but this is not limited thereto. For example, it is sufficient that a portion of each of the base 40, bearing 50, actuator 60, and sensor 70 is within the height range of the mirror unit 10, and other portions may protrude beyond the height range H1 of the mirror unit 10. The configuration described in Patent Document 1 above has the entire first and second bases, the entire bearings, the entire actuators, and the entire sensor protruding beyond the height range of the mirror unit. Compared to the configuration of Patent Document 1, the mirror oscillation device 1 of the present disclosure can reduce the axial size of the mirror unit 10. Furthermore, compared to the configuration of Patent Document 1, the mirror oscillation device 1 of the present disclosure can increase the proportion of the mirror surface 11 of the mirror unit 10 to the axial size of the mirror oscillation device 1.

[0063] (4) In each of the above embodiments, the mirror rocking device 1 has been described as including the actuator 60, but this is not limiting, and for example, the mirror rocking device 1 may be configured not to include the actuator 60. In that case, for example, the mirror rocking device 1 may be configured to rock the mirror unit 10 using the actuator 60 installed in the housing 3 of the LiDAR device 2, for example.

[0064] (5) In each of the above embodiments, the actuator 60 is positioned in the area opposite the second base portion 42 from the first base portion 41. However, this is not limited to this. For example, the actuator 60 may be positioned between the first base portion 41 and the second base portion 42.

[0065] (6) In each of the above embodiments, the mirror rocking device 1 has been described as including a sensor 70 that detects the angle of the mirror unit 10. However, this is not limiting, and the mirror rocking device 1 may be configured, for example, without including a sensor 70. In this case, the angle of the mirror unit 10 may be detected by a sensor 70 installed, for example, inside the housing 3 of the LiDAR device 2.

[0066] (7) In each of the above embodiments, a rotary encoder was used as an example of the sensor 70 provided in the mirror oscillation device 1, but this is not limited to this. Various non-contact or contact sensors, such as a Hall IC, a magnetic resistance element, or an inductive sensor, may also be used.

[0067] (8) In each of the above embodiments, the counterweight 22 is fixed to the extension portion 20 . However, the present invention is not limited to this. For example, the counterweight 22 may be fixed to the shaft 30 .

[0068] (9) In the above embodiments, the shaft 30, the extension 20, and the mirror 10 are swingably supported on the base 40 via the bearings 50. However, the present invention is not limited to this. For example, the base 40 and the shaft 30 may be fixed, and the extension 20 and the mirror 10 may be swingably supported on the shaft 30 via the bearings 50.

[0069] The present disclosure is not limited to the above-described embodiments and can be modified as appropriate. Furthermore, the above-described embodiments and portions thereof are not unrelated to each other and can be combined as appropriate unless the combination is clearly impossible. It goes without saying that, in each of the above embodiments, the elements constituting the embodiments are not necessarily essential unless specifically stated as essential or clearly considered essential in principle. Furthermore, in each of the above embodiments, when numerical values ​​such as the number, values, amounts, and ranges of components of the embodiments are mentioned, they are not limited to the specific numbers unless specifically stated as essential or clearly limited to a specific number in principle. Furthermore, in each of the above embodiments, when the shape, positional relationship, etc. of components, etc. are mentioned, they are not limited to the shape, positional relationship, etc., unless specifically stated or limited to a specific shape, positional relationship, etc. in principle.

[0070] (Aspects of the Present Disclosure) The above-described present disclosure can be understood from the following aspects, for example. [First Aspect] A mirror oscillation device comprising: a mirror section (10) having a mirror surface (11) that reflects light; an extension section (20) extending from a surface (12) of the mirror section opposite the mirror surface to the opposite side of the mirror surface; a shaft (30) fixed to the extension section; a pedestal (40) provided in an area of ​​the mirror section opposite the mirror surface; and a bearing (50) provided on the pedestal in an axial direction of the shaft with respect to the extension section, the bearing supporting the shaft rotatably with respect to the pedestal, the mirror section being oscillating together with the shaft and the extension section within a predetermined angular range around an axial center (CL) of the shaft; and at least a part of the bearing and at least a part of the pedestal being provided in an area of ​​the mirror section opposite the mirror surface, within a height range (H1) of the mirror section in the axial direction of the shaft. [Second Aspect] The mirror oscillation device according to the first aspect, wherein an outer edge (56) of the bearing on one side in the axial direction and an outer edge (46) of the base on one side in the axial direction are located at the same height as or on the other side of an outer edge (13) of the mirror section on one side in the axial direction, and an outer edge (57) of the bearing on the other side in the axial direction and an outer edge (47) of the base on the other side in the axial direction are located at the same height as or on one side of an outer edge (14) of the mirror section on the other side in the axial direction. [Third Aspect] The mirror oscillation device according to the first or second aspect, further comprising an actuator (60) that drives the mirror section to oscillate together with the shaft and the extension section within a predetermined angular range around the axis of the shaft, and at least a portion of the actuator is provided in a region of the mirror section on the opposite side from the mirror surface, within the height range of the mirror section in the axial direction of the shaft.[Fourth Aspect] The mirror oscillation device according to the third aspect, wherein an outer edge (601) of the actuator on one side in the axial direction is located at the same height as or on the other side of an outer edge of the mirror section on one side in the axial direction, and an outer edge (602) of the actuator on the other side in the axial direction is located at the same height as or on one side of an outer edge of the mirror section on the other side in the axial direction. [Fifth Aspect] The mirror oscillation device according to any one of the first to fourth aspects, further comprising a sensor (70) that detects the angle of the mirror section with respect to the base, and at least a part of the sensor is provided in an area of ​​the mirror section on the opposite side from the mirror surface, within a height range of the mirror section in the axial direction of the shaft. [Sixth Aspect] The mirror oscillation device according to the fifth aspect, wherein an outer edge (75) of the sensor on one side in the axial direction is located at the same height as or on the other side of an outer edge of the mirror section on one side in the axial direction, and an outer edge (76) of the sensor on the other side in the axial direction is located at the same height as or on one side of an outer edge of the mirror section on the other side in the axial direction. [Seventh Aspect] The mirror oscillation device according to the first or second aspect, further comprising: an actuator that drives the mirror section together with the shaft and the extension section to oscillate within a predetermined angular range around the axis of the shaft; and a sensor that detects the angle of the mirror section with respect to the base, wherein at least a part of the actuator and at least a part of the sensor are provided in an area of ​​the mirror section on the opposite side from the mirror surface, within the height range of the mirror section in the axial direction of the shaft. [Eighth Aspect] A mirror oscillation device according to the seventh aspect, wherein an outer edge of the actuator on one side in the axial direction and an outer edge of the sensor on one side in the axial direction are located at the same height in the axial direction as or on the other side of the outer edge of the mirror section on one side in the axial direction, and an outer edge of the actuator on the other side in the axial direction and an outer edge of the sensor on the other side in the axial direction are located at the same height in the axial direction as or on one side of the outer edge of the mirror section on the other side in the axial direction.[Ninth Aspect] The mirror oscillation device according to any one of the fifth to eighth aspects, wherein the sensor is a rotary encoder having a rotating disk (71) that rotates together with the shaft and a detection element (72) that detects the position of the rotating disk with respect to the base. [Tenth Aspect] The mirror oscillation device according to the third, fourth, seventh, or eighth aspect, wherein, when a maximum angle at which the mirror section oscillates counterclockwise as viewed from one side in the axial direction is called a first angle, a maximum angle at which the mirror section oscillates clockwise as viewed from one side in the axial direction is called a second angle, and an angle midway between the first angle and the second angle is called a third angle, a surface (44, 45) of the base facing the mirror section is inclined in a direction from a portion closer to the shaft to a portion farther from the shaft, and away from the mirror section in a state where it is at the third angle, thereby preventing interference between the base and the mirror section when the actuator drives the mirror section to oscillate. [Eleventh Aspect] The mirror oscillation device according to the third, fourth, seventh, eighth or tenth aspect, wherein the actuator includes: a magnet (61) fixed to the shaft; an electromagnetic coil (63) that generates a magnetic field when current is applied; and a stator (62) that forms a magnetic circuit between the electromagnetic coil and the magnet and causes magnetic flux generated by the electromagnetic coil to flow around the magnet, wherein a maximum angle at which the mirror section oscillates counterclockwise when viewed from one side in the axial direction is called a first angle, a maximum angle at which the mirror section oscillates clockwise when viewed from one side in the axial direction is called a second angle, and an angle midway between the first angle and the second angle is called a third angle, a surface (68) of the stator facing the mirror section is inclined in a direction from a portion closer to the shaft to a portion farther from the shaft, and away from the mirror section in a state where it is at the third angle, thereby preventing interference between the stator and the mirror section when the actuator drives the mirror section to oscillate. [Twelfth Aspect] The mirror oscillation device according to any one of the first to eleventh aspects, further comprising a counterweight (22) provided on the opposite side of the axis from the mirror portion and fixed to the extension portion or the shaft.[Thirteenth Aspect] The mirror oscillation device according to the twelfth aspect, wherein the counterweight has a resin body (23) fixed to the extension or the shaft, and a weight portion (24) formed of a material having a specific weight greater than that of the resin body and fixed to the resin body. [Fourteenth Aspect] The mirror oscillation device according to the twelfth or thirteenth aspect, wherein the center of gravity of a part in which the mirror portion, the extension, and the counterweight are integrated coincides with the axis of the shaft. [Fifteenth Aspect] A LiDAR device comprising: a housing (3) having a window (8) that transmits laser light; the mirror oscillating device (1) according to any one of the first to fourteenth aspects that is provided inside the housing; a light source device (4) that is provided inside the housing and that irradiates laser light onto the mirror surface of the mirror section provided in the mirror oscillating device; and a light receiving device (5) that is provided inside the housing and that receives laser light that is scanned by the mirror surface of the mirror section provided in the mirror oscillating device, irradiated to the outside from the window of the housing, reflected by an external object, returns from the window of the housing, and is again reflected on the mirror surface of the mirror section.

Claims

1. A mirror oscillating device comprising: a mirror section (10) having a mirror surface (11) that reflects light; an extension section (20) extending from a surface (12) of the mirror section opposite the mirror surface to the opposite side of the mirror surface; a shaft (30) fixed to the extension section; a base (40) provided in an area of ​​the mirror section opposite the mirror surface; and a bearing (50) provided on the base in the axial direction of the shaft relative to the extension section, for rotatably supporting the shaft relative to the base, wherein the mirror section can oscillate together with the shaft and the extension section within a predetermined angular range around the axis (CL) of the shaft, and at least a part of the bearing and at least a part of the base are provided in the area of ​​the mirror section opposite the mirror surface, within a height range (H1) of the mirror section in the axial direction of the shaft.

2. A mirror rocking device as described in claim 1, wherein an outer edge (56) of the bearing on one side in the axial direction and an outer edge (46) of the base on one side in the axial direction are located at the same height in the axial direction or on the other side of an outer edge (13) of the mirror part on one side in the axial direction, and an outer edge (57) of the bearing on the other side in the axial direction and an outer edge (47) of the base on the other side in the axial direction are located at the same height in the axial direction or on one side of an outer edge (14) of the mirror part on the other side in the axial direction.

3. A mirror oscillation device as described in claim 1 or 2, further comprising an actuator (60) that drives the mirror section, together with the shaft and the extension section, to oscillate within a predetermined angular range around the axis of the shaft, and at least a portion of the actuator is provided in an area of ​​the mirror section opposite the mirror surface and within the height range of the mirror section in the axial direction of the shaft.

4. A mirror oscillation device as described in claim 3, wherein an outer edge (601) on one side of the actuator in the axial direction is located at the same height or on the other side in the axial direction as an outer edge of the mirror section on one side in the axial direction, and an outer edge (602) on the other side of the actuator in the axial direction is located at the same height or on one side in the axial direction as an outer edge of the mirror section on the other side in the axial direction.

5. A mirror oscillation device as described in claim 1 or 2, further comprising a sensor (70) for detecting the angle of the mirror portion relative to the base, at least a portion of the sensor being provided in an area of ​​the mirror portion opposite the mirror surface, within the height range of the mirror portion in the axial direction of the shaft.

6. A mirror oscillation device as described in claim 5, wherein an outer edge (75) of the sensor on one side in the axial direction is located at the same height in the axial direction or on the other side of the outer edge of the mirror section on one side in the axial direction, and an outer edge (76) of the sensor on the other side in the axial direction is located at the same height in the axial direction or on one side of the outer edge of the mirror section on the other side in the axial direction.

7. A mirror oscillation device as described in claim 1 or 2, further comprising an actuator that drives the mirror section to oscillate together with the shaft and the extension section within a predetermined angular range around the axis of the shaft, and a sensor that detects the angle of the mirror section relative to the base, wherein at least a part of the actuator and at least a part of the sensor are provided in an area of ​​the mirror section opposite the mirror surface, within the height range of the mirror section in the axial direction of the shaft.

8. A mirror oscillation device as described in claim 7, wherein an outer edge of one side of the actuator in the axial direction and an outer edge of one side of the sensor in the axial direction are located at the same height in the axial direction or on the other side of the outer edge of one side of the mirror section in the axial direction, and an outer edge of the other side of the actuator in the axial direction and an outer edge of the other side of the sensor in the axial direction are located at the same height in the axial direction or on one side of the outer edge of the other side of the mirror section in the axial direction.

9. A mirror oscillation device as described in claim 5, wherein the sensor is a rotary encoder having a rotating disk (71) that rotates together with the shaft and a detection element (72) that detects the position of the rotating disk relative to the base.

10. A mirror oscillation device as described in claim 3, wherein the maximum angle at which the mirror section oscillates counterclockwise when viewed from one side in the axial direction is called the first angle, the maximum angle at which the mirror section oscillates clockwise when viewed from one side in the axial direction is called the second angle, and the angle midway between the first angle and the second angle is called the third angle, the surface (44, 45) of the base facing the mirror section is inclined in a direction away from the mirror section at the third angle, from a portion closer to the shaft to a portion farther from the shaft, and wherein interference between the base and the mirror section is prevented when the actuator drives the mirror section to oscillate.

11. The mirror oscillation device described in claim 3, wherein the actuator has a magnet (61) fixed to the shaft, an electromagnetic coil (63) which generates a magnetic field when current is passed through it, and a stator (62) which forms a magnetic circuit between the electromagnetic coil and the magnet and causes magnetic flux generated by the electromagnetic coil to flow around the magnet, wherein the maximum angle at which the mirror section oscillates counterclockwise when viewed from one side in the axial direction is called a first angle, the maximum angle at which the mirror section oscillates clockwise when viewed from one side in the axial direction is called a second angle, and the midpoint between the first angle and the second angle is called a third angle, a surface (68) of the stator facing the mirror section is inclined from a portion closer to the shaft to a portion farther from the shaft, in a direction away from the mirror section which is at the third angle, and interference between the stator and the mirror section is prevented when the actuator drives the mirror section to oscillate.

12. A mirror rocking device as claimed in claim 1 or 2, further comprising a counterweight (22) provided on the opposite side of the axis from the mirror portion and fixed to the extension portion or the shaft.

13. A mirror oscillation device as described in claim 12, wherein the counterweight has a resin body (23) fixed to the extension portion or the shaft, and a weight portion (24) formed of a material having a specific weight greater than that of the resin body and fixed to the resin body.

14. The mirror rocking device according to claim 12, wherein the center of gravity of a part in which the mirror portion, the extension portion and the counterweight are integrated coincides with the axis of the shaft.

15. A LiDAR device comprising: a housing (3) having a window (8) that transmits laser light; the mirror oscillating device (1) as described in claim 1 that is provided inside the housing; a light source device (4) that is provided inside the housing and irradiates laser light onto the mirror surface of the mirror section provided by the mirror oscillating device; and a light receiving device (5) that is provided inside the housing and receives laser light that is scanned by the mirror surface of the mirror section provided by the mirror oscillating device and irradiated to the outside through the window of the housing, then reflected by an external object, returns through the window of the housing, and is again reflected by the mirror surface of the mirror section.

Images