Distance measurement device

Abstract

A distance measurement device (1) performs light scanning toward the outside and detects light reflected by an object, thereby measuring the distance to the object. The distance measurement device (1) comprises a rotary shaft (13-16), a mirror (18), and a mirror fixing member (21-30). The rotary shaft (13-16) is driven by an actuator (50). The mirror (18) is driven by the actuator (50) to perform light scanning toward the outside. The mirror fixing member (21-30) fixes the mirror (18) to the rotary shaft (13-16). The mirror fixing member (21-30) covers a part of the rotary shaft (13-16) in the circumferential direction and is bonded to the rotary shaft (13-16).

Description

Distance measuring device Cross-reference to related applications

[0001] This application is based on Patent Application No. 2024-168469 filed on September 27, 2024, the contents of which are incorporated herein by reference.

[0002] This disclosure relates to a distance measuring device.

[0003] Conventionally, a distance measuring device that irradiates a transmission wave and detects the reflected wave of the irradiated transmission wave from an object to detect the distance to the object, etc. is known. An optical scanning device is used in the distance measuring device. For example, in the optical scanning device of Patent Document 1, light is scanned by reciprocally rotating and driving a mirror.

[0004] Japanese Patent Application Laid-Open No. 2021-96295

[0005] In Patent Document 1, a plate-like mirror is attached to a substrate and fixed by inserting a shaft portion into an insertion hole of the substrate. For example, when a rotating shaft is fixed to a member for attaching the mirror by press-fitting or the like, the surface accuracy of the mirror may deteriorate due to deformation of the mirror caused by press-fitting. An object of the present disclosure is to provide a distance measuring device capable of appropriately fixing a mirror to a rotating shaft.

[0006] The distance measuring device of the present disclosure measures the distance to an object by scanning light externally and detecting the light reflected by the object, and includes a rotating shaft, a mirror, and a mirror fixing member.

[0007] The rotating shaft is driven by an actuator. The mirror is driven by an actuator to scan light externally. The mirror fixing member fixes the mirror to the rotating shaft. The mirror fixing member covers a part of the circumferential direction of the rotating shaft and is adhered to the rotating shaft. Thereby, the mirror can be appropriately fixed to the rotating shaft.

[0008] The above-mentioned and other purposes, features, and benefits of this disclosure will be further clarified by the following detailed description with reference to the attached drawings. The drawings are as follows: Figure 1 is a schematic diagram showing a distance measuring device according to the first embodiment; Figure 2 is a schematic cross-sectional view showing a rocking actuator according to the first embodiment; Figure 3 is a perspective view showing a spindle, holder, and mirror according to the first embodiment; Figure 4 is a cross-sectional view showing the spindle bonding configuration according to the first embodiment; Figure 5 is an enlarged view of section V in Figure 4; Figure 6 is a perspective view showing a holder according to the first embodiment; Figure 7 is a plan view showing a holder according to the first embodiment; Figure 8 is a cross-sectional view showing a holder and spindle according to the first embodiment; Figure 9 is a plan view showing a holder according to the second embodiment; Figure 10 is a cross-sectional view showing the spindle bonding configuration according to the third embodiment; Figure 11 is an enlarged view of section XI in Figure 10; Figure 12 is a perspective view showing a holder according to the third embodiment; Figure 13 is a cross-sectional view showing a holder and spindle according to the third embodiment; Figure 14 is a cross-sectional view showing a holder and spindle according to the fourth embodiment. Figure 15 is a perspective view showing a holder according to the fifth embodiment, Figure 16 is a cross-sectional view showing a holder and spindle according to the fifth embodiment, Figure 17 is a perspective view showing a holder according to the sixth embodiment, Figure 18 is a cross-sectional view showing a holder and spindle according to the sixth embodiment, Figure 19 is a cross-sectional view showing a spindle bonding configuration according to the seventh embodiment, Figure 20 is a cross-sectional view showing a spindle bonding configuration according to the eighth embodiment, Figure 21 is a cross-sectional view showing a spindle bonding configuration according to the ninth embodiment, Figure 22 is a cross-sectional view showing a spindle bonding configuration according to the tenth embodiment, Figure 23 is a cross-sectional view showing a spindle bonding configuration according to the eleventh embodiment, Figure 24 is a cross-sectional view showing a spindle bonding configuration according to the twelfth embodiment, Figure 25 is a cross-sectional view showing a spindle bonding configuration according to the thirteenth embodiment, and Figure 26 is a cross-sectional view showing a spindle bonding configuration according to the thirteenth embodiment.

[0009] The distance measuring device described herein will be described below with reference to the drawings. In the following embodiments, substantially identical components will be denoted by the same reference numerals and their descriptions will be omitted.

[0010] (First Embodiment) The first embodiment is shown in Figures 1 to 8. As shown in Figure 1, the distance measuring device 1 is a LiDAR (Light Detection and Ranging) device that measures the distance to an object by irradiating it with light and detecting the reflected light from the object to which the light was irradiated. The distance measuring device 1 is mounted on a vehicle, for example, and used to detect objects present around the vehicle.

[0011] The distance measuring device 1 comprises a light-emitting unit 91, a light-receiving unit 92, and a oscillating actuator 5, and is housed in a housing 93. The light-emitting unit 91 intermittently outputs a light beam B. The output light beam B is reflected by a mirror 18 that is driven to oscillate as shown by the dashed arrow, and is emitted to the outside through an optical window 94. The light-receiving unit 92 receives the reflected light from the object irradiated by the light beam B. The light detected by the light-receiving unit 92 is converted into an electrical signal and used to calculate the distance to the object.

[0012] As shown in Figure 2, the oscillating actuator 5 comprises a mirror section 10, an oscillating motor 50, and an encoder 60, etc. The mirror section 10 includes a base 11, a spindle 13, a mirror 18, and a holder 21, etc. The base 11 has a mounting section 111 and retaining walls 112 and 113, and is integrally formed from, for example, metal. The mounting section 111 is attached to the housing 93 (see Figure 1) by bolts or the like. The retaining walls 112 and 113 are erected substantially vertically at both ends of the mounting section 111.

[0013] The spindle 13 is positioned approximately parallel to the mounting portion 111 and is rotatably held on the base 11 by bearings 114 and 115 provided on the retaining walls 112 and 113. In this embodiment, the bearings 114 and 115 are ball bearings, but other types of bearings may also be used. The spindle 13 extends from the retaining wall 113 side to the oscillating motor 50 and encoder 60 side.

[0014] The spindle 13 has a stepped portion 131 formed at the fixing point with the holder 21. Details of the stepped portion 131 will be described later. The E-ring 116 is provided on the axially outer side of the bearing 114 and functions as a retainer for the spindle 13 to come off.

[0015] As shown in Figures 2 to 4, the mirror 18 is formed in the shape of a rectangular flat plate in plan view and is attached to the holder 21 with adhesive or the like so as to be symmetrical with respect to the axis of rotation. The mirror 18 may have a shape other than rectangle as long as it is symmetrical with respect to the axis of rotation.

[0016] The holder 21 is fixed to the spindle 13. The fixing of the spindle 13 and the holder 21 will be described later. The holder 21 and the mirror 18 are arranged inside the base 11 such that the mirror surface 181 faces away from the mounting portion 111, and are oscillating together with the spindle 13 by the oscillating motor 50. The mirror 18 reflects the light beam B output from the light-emitting portion 91 (see Figure 1) with its mirror surface 181 and emits the light beam B outwards in a direction corresponding to the oscillating position of the mirror 18, thereby scanning the light beam within a preset scanning range.

[0017] As shown in Figure 2, the oscillating motor 50 is provided on one axial side of the mirror section 10. The oscillating motor 50 includes a stator 51, a rotor magnet 52, and a preload spring 54, etc. The stator 51 is fixed to the retaining wall 113 with bolts or the like. The stator 51 is provided with an electromagnetic coil and a fixed magnet (not shown).

[0018] The rotor magnet 52 is formed in a cylindrical shape with a central shaft hole 521 through which the spindle 13 is inserted. The rotor magnet 52 is fixed to the spindle 13 by a rotor fixing member 53. The preload spring 54 has one end in contact with the bearing 115 and the other end in contact with the rotor magnet 52.

[0019] The rotor magnet 52 is located inside the stator 51 and oscillates around its resting position when the electromagnetic coil is energized. Here, oscillation refers to a motion that periodically repeats forward and reverse rotation within a predetermined angular range of less than 360°. When the energization to the electromagnetic coil is turned off, the rotor magnet 52 returns to its resting position and comes to rest due to the magnetic force of a fixed magnet (not shown).

[0020] The encoder 60 has a disk 61 and a detection element 63, and is housed in a case 65. The disk 61 is attached to a disk hub (not shown) which is press-fitted and fixed to the spindle 13, and rotates together with the spindle 13. The detection element 63 is mounted on a substrate 64 and detects the rotational position of the disk 61. As a result, the encoder 60 can detect the oscillation position of the oscillating motor 50 and the mirror 18. A through hole 641 is formed in the substrate 64, through which the spindle 13 is inserted.

[0021] For high-precision sensing to be performed by the distance measuring device 1, it is desirable that the flatness of the mirror surface 181, which is the reflective surface of the mirror 18, is high and that the distance between the rotation axis and the mirror surface 181 is small. As an example, if the holder is made thin and the spindle is press-fitted in order to reduce the distance between the rotation axis and the mirror surface, the deformation of the holder will increase, and there is a risk that the surface accuracy of the mirror bonded to the holder will deteriorate. Therefore, in this embodiment, in order to avoid partial deformation due to press-fitting, the circumferential direction of the spindle 13 is partially covered with the holder 21, and the holder 21 and the spindle 13 are fixed with adhesive 40.

[0022] As shown in Figures 4 to 8, the holder 21 has a mirror holding portion 211 and a shaft holding portion 215 that are integrally formed from metal or the like. In the holder 21, the axial direction of the spindle 13 to which it is mounted is called the "axial direction," and the direction perpendicular to the axial direction is called the "width direction." Figure 4 corresponds to the cross-section along line VI-VI in Figure 2, and is drawn so that the mirror 18 is on the upper side of the paper. The same applies to Figure 10 and others in the embodiment described later.

[0023] The mirror holding portion 211 is formed in a substantially rectangular flat plate shape, and the mirror 18 is attached to the mirror adhesive surface 212, which is the surface opposite to the shaft holding portion 215, with adhesive or the like. A slit 213 is formed in the mirror adhesive surface 212.

[0024] The shaft holding portion 215 is provided on the side opposite to the mirror bonding surface 212, rising up to cover a portion of the circumferential direction of the spindle 13. The shaft holding portion 215 is formed symmetrically with respect to the center line Lc that divides the width direction of the holder 21 into two. In this embodiment, the inclined surface rising from the mirror holding portion 211 is formed continuously in the axial direction, but it may also be formed as a discontinuous rib shape in the axial direction.

[0025] The inner surface of the shaft holder 215 is formed in an arc shape. The shaft holder 215 has a hole 216 that penetrates in the thickness direction along the center line Lc. Adhesive 40 is applied to both outer sides in the width direction of the hole 216 on the inner circumferential surface of the shaft holder 215, and the spindle 13 is bonded to it. The area where the adhesive 40 is applied is designated as the adhesive application area 217, and is shown by hatching in Figures 6 and 7. The area where the spindle 13 and the holder 21 are bonded with adhesive 40 is designated as the bonded area AP (see Figure 5).

[0026] In this embodiment, the spindle 13 may be bonded to the holder 21 with the mirror 18 already attached, or the mirror 18 may be bonded to the holder 21 after the spindle 13 has been bonded to the holder 21. By fixing the holder 21 and the spindle 13 with adhesive 40, the amount of deformation of the mirror bonding surface 212 can be suppressed even if the holder 21 is made thinner, compared to, for example, the case where the spindle 13 is press-fitted. In addition, it is easy to guarantee the bonding strength.

[0027] As shown in Figure 5, the inner circumferential surface of the shaft holder 215 is formed in an arc shape with a larger diameter than the spindle 13, and the axis center C1 of the spindle 13 is located on the mirror 18 side (upper side of the paper in Figure 5) than the arc center C2 of the shaft holder 215. This allows the adhesive 40 to be thicker on the side of the axis center C1. By increasing the thickness of the adhesive 40, the tensile stress caused by the adhesive 40 increases, so that the areas with greater adhesive thickness approach point-symmetric positions (3 o'clock and 9 o'clock directions in Figure 5), and the tensile stress can be equalized.

[0028] The amount of adhesive 40 applied is set so that it overflows when the spindle 13 and the holder 21 are bonded together. As a result, the adhesive 40 overflows on both sides in the circumferential direction of the bonding area between the spindle 13 and the holder 21. If the overflowing portion of adhesive 40 is called the overflow portion 401, the overflow portion 401 is formed on the end face side of the holder 21 opposite to the mirror 18. In addition, in this embodiment, a hole 216 is formed along the adhesive application portion 217, so the overflow portion 401 is also formed on the hole 216 side.

[0029] In this embodiment, the adhesive portion AP can be controlled by the shape of the part by forming the hole 216. Furthermore, by making the adhesive 40 as close to point symmetry as possible with respect to the rotation axis and making it uniform, the tensile stress generated by the difference in linear expansion coefficients between the spindle 13 and the holder 12, and the shrinkage force of the adhesive 40 itself (e.g., curing shrinkage during thermal curing) are equalized. Note that the adhesive 40 is not limited to a thermosetting type. This makes it possible to suppress deformation of the spindle 13 caused by uneven tensile stress and prevent a decrease in detection accuracy.

[0030] As shown in Figures 3 and 8, the spindle 13 has two annular stepped portions 131. The axially inner side of the two stepped portions 131 has a smaller diameter than the axially outer side, and is concave in cross-section. In the spindle 13, the space formed in a concave shape on the axially inner side is the adhesive holding chamber 132, and the axially outer side of the adhesive holding chamber 132 is the contact portion 133. No adhesive 40 is applied to the contact portion 133, and it comes into direct contact with the holder 21.

[0031] By providing the contact portion 133, the thickness of the adhesive 40 can be controlled according to the dimensions of the part. This makes it possible to suppress variations in adhesive strength caused by variations in the thickness of the adhesive 40. In the axial direction, the adhesive 40 is applied within the range where the hole 216 is formed. In Figure 6, the axial length of the hole 216 is made shorter than the adhesive holding chamber 132 of the spindle 13 in order to increase the adhesive length. However, there are no constraints on the axial length, and the adhesive holding chamber 132 may be longer.

[0032] Note that although the spindle 13 is not shown in Figure 6, Figure 8 corresponds to the VIII-VIII section of Figure 6 with the spindle 13 assembled, and is shown so that the spindle 13 is on the lower side of the paper. Also, the adhesive 40 is not shown in Figure 8. The same applies to Figure 13, which is the XIII-XIII section of Figure 12, Figure 16, which is the XVI-XVI section of Figure 15, and Figure 18, which is the XVIII-XVIII section of Figure 17.

[0033] As described above, the distance measuring device 1 of this embodiment measures the distance to an object by scanning light to the outside and detecting the light reflected by the object, and comprises a spindle 13, a mirror 18, and a holder 21.

[0034] The spindle 13 is driven by the oscillating motor 50. The mirror 18 is driven to oscillate by the oscillating motor 50 to scan light outwards. The holder 21 fixes the mirror 18 to the spindle 13. The holder 21 covers a portion of the circumferential direction of the spindle 13 and is bonded to the spindle 13. In other words, the holder 21 does not cover the entire circumference of the spindle 13.

[0035] This allows the mirror 18 to be properly fixed to the spindle 13. Specifically, compared to the case where the spindle 13 is fixed by press-fitting or the like, even if the holder 21 is made thinner, the amount of deformation of the mirror surface 181 can be suppressed, and high-precision measurements can be performed.

[0036] The adhesive portion AP between the holder 21 and the spindle 13 is provided symmetrically on both sides of the center line Lc passing through the axis of the spindle 13 and the center of the mirror 18. Here, "symmetry" means that a certain degree of manufacturing tolerance is acceptable. The holder 21 has a hole 216 formed between the adhesive portion AP. This makes it possible to suppress deformation of the spindle 13 due to uneven tensile stress in the adhesive 40 caused by the difference in linear expansion coefficients between the adherend spindle 13 and the holder 21, and the contraction force of the adhesive 40 itself, thereby enabling high-precision measurement.

[0037] The spindle 13 has a stepped portion 131 that separates the adhesive holding chamber 132, which is bonded with adhesive 40, from the contact portion 133. The contact portion 133 is adjacent to the adhesive holding chamber 132 in the axial direction and protrudes toward the holder 21, which is the member to be bonded, and contacts the holder 21 without the adhesive 40 in between. As a result, the orientation of the mirror 18 can be determined by the dimensions of the part by making metal-to-metal contact between the spindle 13 and the holder 21 via the contact portion 133. Furthermore, by defining the thickness of the adhesive 40 by the height of the stepped portion 131, variations in adhesive strength due to variations in the thickness of the adhesive 40 can be reduced.

[0038] The holder 21 covers a portion of the circumferential direction of the spindle 13 in an arc shape. By forming the surface of the holder 21 facing the spindle 13 in an arc shape, processing is made easier and manufacturability is improved.

[0039] The axis center C1 of the spindle 13 is on the mirror 18 side than the arc center C2 of the surface of the holder 21 facing the spindle 13. As a result, the areas where the thickness of the adhesive 40 is relatively large are nearly point-symmetric with respect to the axis center C1, thereby equalizing the tensile stress applied to the adhesive 40 and the shrinkage force of the adhesive 40 itself.

[0040] An overhang portion 401 is formed in the area adjacent to the bonding portion AP between the spindle 13 and the holder 21. The overhang portion 401 is formed so as to be exposed in at least one location where the spindle 13 and the holder 12 are not in contact. By applying an overhanging amount of adhesive 40 to bond the spindle 13 and the holder 21, it is possible to ensure that the adhesive 40 is applied to the required area. Furthermore, since the required precision for the amount of adhesive 40 applied can be relaxed, manufacturability is improved.

[0041] (Second Embodiment) The second embodiment is shown in Fig. 9. As shown in Fig. 9, holes 221 and 222 are formed between the adhesive application portions 217 of the holder 22. A beam 223 extending in the axial direction is provided between the holes 221 and 222. That is, in the present embodiment, two holes 221 and 222 are provided in the holder 22 corresponding to the two adhesive application portions 217 respectively. As long as there is a space adjacent to the adhesive application portion 217 where the adhesive 40 (not shown in Fig. 9) protrudes, the shape of the beam and the number of holes are not limited, for example, the beam may be orthogonal to the axial direction and the width direction.

[0042] By providing the beam 223, the rigidity of the holder 22 can be increased. Also, when forming the holes 221 and 222 by cutting or the like, the cutting amount can be reduced. Further, the same effects as those of the above embodiment are achieved.

[0043] (Third Embodiment) The third to twelfth embodiments are variations of the bonding form between the spindle and the holder. Therefore, the description will focus on this point, and the description of other points will be omitted as appropriate.

[0044] The third embodiment is shown in Figs. 10 to 13. No hole is formed in the shaft holding portion 235 of the holder 23 of the present embodiment. As shown in Fig. 11, when no hole is formed in the holder 23, the adhesive 40 protrudes to the side opposite to the mirror 18 (the lower side of the paper surface in Fig. 11), and the protruding portion 401 is formed. Thereby, the adhesive area can be ensured by the part dimensions.

[0045] As shown in Fig. 13, the spindle 13 has a stepped portion 131 formed in the same manner as in the first embodiment, and the contact portion 133 is provided outside the axial direction of the adhesive holding chamber 132. Even with such a configuration, the same effects as those of the above embodiment are achieved.

[0046] (Fourth Embodiment) The fourth embodiment is shown in Fig. 14. In this embodiment, the shape of the spindle 14 is different from that of the above embodiment. A stepped portion 141 is provided on the spindle 14, and in the portion facing the holder 23, the outer side in the axial direction has a smaller diameter than the inner side in the axial direction. In the spindle 14, the portion formed in a concave shape on the outer side in the axial direction is the adhesive holding chamber 142, and the inner side in the axial direction of the adhesive holding chamber 142 is the contact portion 143. No adhesive 40 is applied to the contact portion 143, and the spindle 14 and the holder 23 directly contact each other.

[0047] By providing the contact portion 143, the thickness of the adhesive 40 can be managed by the part dimensions, and the variation in the adhesive strength due to the variation in the thickness of the adhesive 40 can be suppressed. Note that, as in the first and second embodiments, the holder may be provided with a hole portion. The same applies to the fifth and sixth embodiments.

[0048] (Fifth Embodiment, Sixth Embodiment) The fifth embodiment is shown in Figs. 15 and 16, and the sixth embodiment is shown in Figs. 17 and 18. As shown in Figs. 15 and 16, in the fifth embodiment, a stepped portion 241 is provided on the surface of the spindle holding portion 245 of the holder 24 facing the spindle 15, and the inner side in the axial direction is concave in a cross-sectional view. In the holder 24, the space formed in a concave shape on the inner side in the axial direction is the adhesive holding chamber 242, and the outer side in the axial direction of the adhesive holding chamber 242 is the contact portion 243. No adhesive 40 is applied to the contact portion 243, and it directly contacts the spindle 15.

[0049] As shown in Figs. 17 and 18, in the sixth embodiment, a stepped portion 251 is provided on the surface of the spindle holding portion 255 of the holder 25 facing the spindle 15, and the outer side in the axial direction is concave in a cross-sectional view. In the holder 25, the portion formed in a concave shape on the outer side in the axial direction is the adhesive holding chamber 252, and the outer side in the axial direction of the adhesive holding chamber 252 is the contact portion 253. No adhesive 40 is applied to the contact portion 253, and it directly contacts the spindle 15.

[0050] In the fifth embodiment, the holder 24 has a stepped portion 241 that separates the adhesive holding chamber 242, which is bonded with adhesive 40, from the contact portion 243. The contact portion 243 is adjacent to the adhesive holding chamber 242 in the axial direction and protrudes toward the spindle 15, which is the member to be bonded, and contacts the spindle 15 without the adhesive 40 in between.

[0051] In the sixth embodiment, the holder 25 has a stepped portion 251 that separates the adhesive holding chamber 252, which is bonded with adhesive 40, from the contact portion 253. The contact portion 253 is adjacent to the adhesive holding chamber 252 in the axial direction and protrudes toward the spindle 15, contacting the spindle 15 without the adhesive 40. This configuration also produces the same effects as the above embodiments. In addition, although the spindle 15 in the sixth and seventh embodiments does not have a stepped portion, the adhesive holding chamber and the contact portion may be formed by providing stepped portions on both the spindle and the holder.

[0052] (Seventh and Eighth Embodiments) In the seventh embodiment shown in Figure 19, the shaft holding portion 265 of the holder 26 is formed in a U-shape in cross-section, opening towards the mirror bonding surface 262. The opening of the shaft holding portion 265 is formed to allow insertion of the spindle 13, and the bottom of the shaft holding portion 265 is formed to cover the outer circumferential surface of the inserted spindle 13 opposite to the mirror 18. The adhesive 40 is applied to the bottom of the shaft holding portion 265, and the spindle 13 and the holder 26 are bonded together by inserting the spindle 13 into the shaft holding portion 265 with the adhesive 40 applied. In this embodiment, the holder 26 and the mirror 18 are bonded together after the spindle 13 and the holder 26 are bonded together.

[0053] Furthermore, as shown in the eighth embodiment in Figure 20, a hole 266 may be provided in the holder 26, dividing the area to which the adhesive 40 is applied into two locations. Although Figures 19 and 20 show a spindle 13 as an example, the stepped shape in the axial direction of the spindle and holder may be combined with any of the embodiments described above. The same applies to the embodiments described later. Even with this configuration, the same effects as the embodiments described above can be achieved.

[0054] (Ninth and Tenth Embodiments) In the ninth embodiment shown in Figure 21, a projection 161 is formed on the spindle 16 on the surface facing the holder 27. The shaft holding portion 275 of the holder 27 is formed to cover the mirror 18 side of the spindle 16, similar to the first embodiment. A rotation restricting portion 276, which is a recess that accommodates the projection 161, is formed at a position corresponding to the projection 161 of the shaft holding portion 275. By inserting the projection 161 into the rotation restricting portion 276, the relative rotation between the spindle 16 and the holder 27 is restricted. This makes it possible to suppress the rotational torque applied to the adhesive 40.

[0055] Furthermore, in the tenth embodiment shown in Figure 22, the holder 28 is formed to cover the spindle 16 on the side opposite to the mirror 18, similar to the seventh embodiment, and the shaft holding portion 285 has a rotation restricting portion 286 into which the projection 161 is inserted. Similar to the ninth embodiment, the insertion of the projection 161 into the rotation restricting portion 286 restricts relative rotation, thereby suppressing the rotational torque applied to the adhesive 40. This also provides the same effects as the above embodiments.

[0056] (Eleventh Embodiment) In the eleventh embodiment shown in Figure 23, a recess 296 is formed in the shaft holding portion 295 of the holder 29, and a cylindrical spindle 13 is held therein. This configuration also produces the same effects as the above embodiment.

[0057] (Twelfth Embodiment) In the twelfth embodiment shown in Figure 24, the holder 30 is formed in a substantially flat shape, and a recess is formed in the shaft holding portion 305 that opens on the opposite side from the mirror 18, and the spindle 13 is inserted into the recess and bonded with adhesive 40. As in this embodiment, the bonding portion between the spindle 13 and the holder 30 may be 180° or less. This configuration also produces the same effects as the above embodiment.

[0058] (Third Embodiment) The thirteenth embodiment is shown in Figures 25 and 26. As shown in Figure 25, in the thirteenth embodiment, a cover 35 is provided on the spindle 13 opposite to the mirror 18. The cover 35 is a separate component from the holder 23 and is formed in a substantially semi-cylindrical shape so as to cover the surface of the spindle 13 opposite to the mirror 18. Also, as shown in Figure 26, the outer shape of the cover 35 may be a shape other than cylindrical, such as a polygonal prism (a rectangular prism in the example of Figure 26).

[0059] Adhesive 40 is applied to the inner circumferential surface of the cover 35 and bonded to the spindle 13. Preferably, the bonding portion between the cover 35 and the spindle 13 is provided symmetrically with respect to the axis of the spindle 13 and the bonding portion between the holder 23 and the spindle 13. The surface of the cover 35 on the mirror 18 side is in contact with the holder 23.

[0060] In this embodiment, the distance measuring device 1 (see Figure 1) further includes a cover 35 that covers the portion of the spindle 13 not covered by the holder 23, and to which the spindle 13 is bonded. This allows for a larger bonding area and improves the bonding strength.

[0061] The bonding points between the spindle 13 and the holder 23, and between the spindle 13 and the cover 35, are arranged symmetrically with respect to the axial center C1 of the spindle 13. By dividing the fixing points with adhesive 40 into two or more locations and symmetrically arranging them, the tensile stress of the adhesive 40 and the contraction force of the adhesive 40 itself, caused by the difference in linear expansion coefficients between the adherends, the spindle 13 and the holder 23, are equalized, thereby suppressing deformation of the spindle 13. Furthermore, the same effects as in the above embodiment are achieved.

[0062] In this embodiment, the spindles 13-15 correspond to the "rotating shaft," the holders 21-30 correspond to the "mirror fixing members," the protruding portion 401 corresponds to the "adhesive overflow portion," and the oscillating motor 50 corresponds to the "actuator."

[0063] (Other Embodiments) In the above embodiment, the mirror is attached to a mirror holder formed in the shape of a substantially rectangular flat plate using adhesive. In other embodiments, the shape of the mirror holder may differ, and the mirror may be attached to the mirror holder member by means other than adhesive. Also, the shapes of the holder and the mirror may differ from those in the above embodiment. Furthermore, it is desirable that the holder and the mirror be formed symmetrically with respect to the axis of rotation from the viewpoint of equalizing the moment of inertia during oscillation. Moreover, the configuration and arrangement of the oscillation motor, mirror holder structure, etc., may differ from those in the above embodiment, as long as the mirror can be oscillated.

[0064] (Disclosure of Technical Ideas) This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0065] (Technical Concept 1) A distance measuring device that measures the distance to an object by scanning light to the outside and detecting the light reflected by the object, comprising: a rotating shaft (13-16) driven by an actuator (50); a mirror (18) driven by the actuator to scan light to the outside; and a mirror fixing member (21-30) that fixes the mirror to the rotating shaft, wherein the mirror fixing member covers a part of the circumferential direction of the rotating shaft and is bonded to the rotating shaft. (Technical Concept 2) The distance measuring device according to Technical Concept 1, wherein the bonding portion between the rotating shaft and the mirror fixing member is provided symmetrically on both sides of the axis of the rotating shaft and the center line passing through the center of the mirror, and the mirror fixing member has holes (216, 221, 222) formed between the bonding portions. (Technical Idea 3) A distance measuring device according to Technical Idea 1 or 2, wherein at least one of the rotating shaft and the mirror fixing member has stepped portions (131, 141, 241, 251) that separate adhesive holding chambers (132, 142, 242, 252) and contact portions (133, 143, 243, 253) that are adjacent to the adhesive holding chambers in the axial direction and protrude toward the member to be bonded, and contact the member to be bonded without the use of adhesive. (Technical Idea 4) A distance measuring device according to any one of Technical Ideas 1 to 3, wherein the mirror fixing member covers a part of the circumferential direction of the rotating shaft in an arc shape. (Technical Idea 5) A distance measuring device according to Technical Idea 4, wherein the axis center of the rotating shaft is on the mirror side of the arc center of the surface of the mirror fixing member facing the rotating shaft. (Technical Idea 6) A distance measuring device according to any one of Technical Ideas 1 to 5, further comprising a cover (35) that covers the portion of the rotating shaft not covered by the mirror fixing member and to which the rotating shaft is bonded. (Technical Idea 7) A distance measuring device according to Technical Idea 6, wherein the bonding location between the rotating shaft and the mirror fixing member and the bonding location between the rotating shaft and the cover are provided symmetrically with respect to the axis center of the rotating shaft. (Technical Idea 8) A distance measuring device according to any one of Technical Ideas 1 to 7, wherein an adhesive overflow portion (401) is formed in a location adjacent to the bonding portion between the rotating shaft and the mirror fixing member.

[0066] The present invention is not limited in any way to the embodiments described above, and can be implemented in various forms without departing from its spirit.

[0067] This disclosure is described in accordance with embodiments. However, this disclosure is not limited to such embodiments and structures. This disclosure also includes various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and idea of ​​this disclosure.

Claims

1. A distance measuring device that measures the distance to an object by scanning light to the outside and detecting the light reflected by the object, comprising: a rotating shaft (13-16) driven by an actuator (50); a mirror (18) driven by the actuator to scan light to the outside; and a mirror fixing member (21-30) that fixes the mirror to the rotating shaft, wherein the mirror fixing member covers a part of the circumferential direction of the rotating shaft and is bonded to the rotating shaft.

2. The distance measuring device according to claim 1, wherein the adhesive portion between the rotating shaft and the mirror fixing member is provided symmetrically on both sides of the axis of the rotating shaft and the center line passing through the center of the mirror, and the mirror fixing member has holes (216, 221, 222) formed between the adhesive portions.

3. The distance measuring device according to claim 1 or 2, wherein at least one of the rotating shaft and the mirror fixing member has stepped portions (131, 141, 241, 251) that separate adhesive holding chambers (132, 142, 242, 252) from contact portions (133, 143, 243, 253) that are adjacent to the adhesive holding chambers in the axial direction and protrude toward the member to be bonded, and contact the member to be bonded without the use of adhesive.

4. The distance measuring device according to claim 1, wherein the mirror fixing member covers a part of the circumferential direction of the rotation axis in an arc shape.

5. The distance measuring device according to claim 4, wherein the axis of the rotation shaft is on the mirror side of the arc center of the surface of the mirror fixing member facing the rotation shaft.

6. The distance measuring device according to claim 1, further comprising a cover (35) that covers the portion of the rotating shaft not covered by the mirror fixing member and to which the rotating shaft is bonded.

7. The distance measuring device according to claim 6, wherein the bonding location between the rotating shaft and the mirror fixing member and the bonding location between the rotating shaft and the cover are provided symmetrically with respect to the axis center of the rotating shaft.

8. The distance measuring device according to claim 1, wherein an adhesive overflow portion (401) is formed at a location adjacent to the adhesive portion between the rotating shaft and the mirror fixing member.

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