Distance measuring device

Abstract

A distance measuring device (1) that measures a distance to an object by scanning light to the outside and detecting light reflected by the object, the distance measuring device (1) being provided with: a swing shaft (13) that is driven by an actuator (50); a mirror (18) that is swingably driven by the actuator (50) and that scans light to the outside; and a holder (21-28). The holder (21-28) has: a shaft holding section (31) in which a hole (311) into which the swing shaft (13) is press-fitted is formed; and mirror holding sections (32, 33) which are integrally formed with the shaft holding section (31) and to which the mirror (18) is adhered by means of an adhesive member (29). Mirror contact sections (41-48) that protrude toward the mirror (18) and come into contact with the mirror (18) are formed on the mirror holding sections (32, 33).

Description

[0001] Cross-referencing of related applications This application is based on patent application number 2023-116539, filed on July 18, 2023, the contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to a ranging device. Background Technology

[0003] Conventional ranging devices are known that detect the distance to an object by illuminating it with a transmitted wave and detecting the reflected wave from the object. These ranging devices utilize optical scanning devices; for example, in the optical scanning device of Patent Document 1, a mirror is driven to reciprocate in rotation to scan light.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2021-96295 Summary of the Invention

[0005] In Patent Document 1, a plate-shaped reflector is mounted on one side of a substrate. However, when attaching the reflector to a holding component such as the substrate, it is difficult to adjust the thickness of the bonding component when using adhesives or double-sided tape. Therefore, thickness deviations may affect the ranging accuracy. The object of this disclosure is to provide a ranging device capable of suppressing deviations in the reflector's position.

[0006] The distance measuring device disclosed herein measures the distance to an object by scanning light outward and detecting light reflected by the object. The distance measuring device includes: a swing shaft driven by an actuator; a reflector driven by the actuator to swing and scan light outward; and a holding member.

[0007] The retaining member includes: a shaft retaining portion having a hole for pressing in a swing shaft; and a mirror retaining portion integrally formed with the shaft retaining portion, wherein the mirror is attached by an adhesive component. A mirror abutting portion is formed in the mirror retaining portion, protruding towards the mirror and abutting against the mirror. This suppresses deviations in the mirror surface position. Attached Figure Description

[0008] The foregoing and other objects, features, and advantages of this disclosure will become more apparent with reference to the accompanying drawings and through the following detailed description. The accompanying drawings are as follows: Figure 1 This is a cross-sectional view showing the oscillating actuator of the ranging device according to the first embodiment.

[0009] Figure 2 This is a perspective view showing the spindle, holding member, and reflector of the first embodiment.

[0010] Figure 3 This is a top view showing the retaining member of the first embodiment.

[0011] Figure 4 yes Figure 3 The IV direction view.

[0012] Figure 5 This is an enlarged view of the fourth part, V.

[0013] Figure 6 This is a top view showing the retaining member of the second embodiment.

[0014] Figure 7 This is a top view showing the retaining member of the third embodiment.

[0015] Figure 8 This is a top view showing the retaining member of the fourth embodiment.

[0016] Figure 9 This is a top view showing the retaining member of the fifth embodiment.

[0017] Figure 10 yes Figure 9 The X-direction view.

[0018] Figure 11 This is a top view showing the retaining member of the sixth embodiment.

[0019] Figure 12 yes Figure 11 The XII direction view.

[0020] Figure 13 This is a top view showing the retaining member of the seventh embodiment.

[0021] Figure 14 yes Figure 13 The XIV direction view.

[0022] Figure 15 This is a top view showing the retaining member of the eighth embodiment.

[0023] Figure 16 yes Figure 15 The XVI direction view.

[0024] Figure 17 This is a schematic diagram illustrating the ranging device of the embodiment. Detailed Implementation

[0025] The ranging device of this disclosure will now be described with reference to the accompanying drawings. In several embodiments, the same reference numerals will be used to denote substantially the same configurations, and descriptions will be omitted.

[0026] (First Implementation) Figures 1-5 The first embodiment is shown. Additionally, Figure 17 The approximate structure of the distance measuring device is shown. For example... Figure 17 As shown, the ranging device 1 is a LiDAR (Light Detection and Ranging) device that determines the distance to an object by illuminating it with light and detecting the reflected light from the illuminated object. The ranging device 1 is, for example, mounted on a vehicle to detect objects present in front of the vehicle.

[0027] The ranging device 1 includes a light-emitting unit 91, a light-receiving unit 92, and a oscillating actuator 5, and is housed in a frame 93. The light-emitting unit 91 intermittently outputs a light beam B. The output light beam B is reflected at a mirror 18 that is driven by oscillation and exits to the outside through an optical window 94. The light-receiving unit 92 receives the reflected light from an object irradiated by the light beam B. The light detected by the light-receiving unit 92 is converted into an electrical signal, which is used to calculate the distance between the device and the object.

[0028] like Figure 1 As shown, the oscillating actuator 5 includes a reflector section 10, an oscillating motor 50, and an encoder 60, etc. The reflector section 10 has a base 11, a main shaft 13, a reflector 18, and a retaining member 21, etc. The base 11 has a mounting part 111 and retaining walls 112 and 113, and is integrally formed, for example, from metal. The mounting part 111 is mounted to the frame by bolts or the like. The retaining walls 112 and 113 are erected substantially vertically at both ends of the mounting part 111.

[0029] The main shaft 13 is arranged substantially parallel to the mounting portion 111, and the main shaft 13 is rotatably held in the base 11 by bearings 14 and 15 provided in the retaining walls 112 and 113. In this embodiment, the bearings 14 and 15 are ball bearings, but bearings other than ball bearings may also be used. The main shaft 13 is formed to extend to the side of the oscillating motor 50 and the encoder 60. Hereinafter, the axis of the main shaft 13 will be appropriately referred to as the oscillating axis Ax, and the oscillating axis will be simply referred to as the "axial direction". Furthermore, in the configuration of the retaining member 21, etc., the side closer to the oscillating axis Ax is designated as the inner side in the oscillating direction, and the side farther from the oscillating axis Ax is designated as the outer side. The E-ring 16 is provided on the axially outer side of the bearing 14 and functions as an anti-disengagement member for the main shaft 13.

[0030] like Figure 1 and Figure 2As shown, the reflector 18 is formed into a rectangular flat plate when viewed from above, and is mounted symmetrically to the holder 21 with respect to the swing axis Ax. The reflector 18 can also be any shape other than a rectangle, as long as it is symmetrical with respect to the swing axis Ax. The holder 21 and the reflector 18 are arranged inside the base 11 with the reflector surface 181 facing the side opposite to the mounting portion 111, and are driven to swing by the swing motor 50. The reflector 18 reflects the light beam B output from the light-emitting portion 91 using the reflector surface 181, and emits the light beam B to the outside in a direction corresponding to the swing position of the reflector 18, thereby scanning the light beam within a predetermined scanning range.

[0031] The retainer 21 has a press-in portion 31 and a mirror retaining portion 32, and is integrally formed, for example, from metal. A hole 311 is formed in the press-in portion 31 for inserting the main shaft 13, and the main shaft 13 is press-fitted and fixed therein. The press-in portion 31 is configured to protrude further to the opposite side of the mirror 18 than the mirror retaining portion 32. In other words, the thickness of the mirror retaining portion 32 is smaller than that of the press-in portion 31.

[0032] The mirror 18 is attached to the mirror mounting surface, on the side of the mirror holding portion 32 opposite to the side protruding from the press-in portion 31, using an adhesive or the like. The mirror holding portion 32 is formed symmetrically on both sides of the press-in portion 31 with respect to the swing axis Ax. This ensures that the moment of inertia during swing is equal in both directions. The axial length of the mirror holding portion 32 is longer than that of the press-in portion 31, and the holding member 21 is generally formed in a roughly H-shape when viewed from above. By making the axial length of the press-in portion 31 shorter than that of the mirror holding portion 32, the holding member 21 can be made lighter, and the mounting area of ​​the mirror 18 can be ensured. Details regarding the mounting of the mirror 18 to the holding member 21 will be described later.

[0033] like Figure 1 As shown, the swing motor 50 is disposed on one side of the reflector section 10 along its axial direction. The swing 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 by bolts, etc. The stator 51 is provided with an electromagnetic coil (not shown) and a fixing magnet.

[0034] The rotor magnet 52 is formed as a cylinder with a shaft hole 521 at the center, which is inserted through the main shaft 13 and fixed to the main shaft 13 by the rotor fixing component 53. One end of the preload spring 54 abuts against the bearing 15, and the other end abuts against the rotor magnet 52.

[0035] The rotor magnet 52 is disposed inside the stator 51 and oscillates around a stationary position by energizing the electromagnetic coil. Here, oscillation refers to the periodic repetition of forward and reverse rotation within a specified angular range of less than 360°. When the energizing of the electromagnetic coil is disconnected, the rotor magnet 52 returns to the stationary position and comes to rest by the magnetic force of the stationary magnet.

[0036] The encoder 60 includes a disk 61 and a detection element 63, and is housed in a housing 65. The disk 61 is mounted on a hub (not shown) that is pressed and fixed to the encoder 60 side of the main shaft 13, and rotates integrally with the main shaft 13. The detection element 63 is mounted on a base plate 64 and detects the rotational position of the disk 61. Thus, the encoder 60 can detect the oscillation position of the oscillating motor 50 and the reflector 18. A through hole 641 is formed in the base plate 64, through which the main shaft 13 is inserted.

[0037] In this embodiment, an adhesive component 29 (see reference 29) is used as an adhesive, double-sided tape, etc. Figure 5 The reflector 18 is attached to the retainer 21. When the reflector 18 is attached using the adhesive part 29, it is difficult to adjust the thickness of the adhesive part 29, which may cause a deviation in the distance between the reflector surface 181 and the main shaft 13.

[0038] Furthermore, when the spindle 13 is pressed into the hole 311 of the retainer 21, the pressed-in portion 31 may bulge towards the reflector 18. If the retainer 21 bulges due to the pressing, the surface accuracy of the reflector mounting surface deteriorates, which may cause a deviation in the distance between the reflector surface 181 and the spindle 13. If a deviation occurs in the distance between the reflector surface 181 and the spindle 13, it will affect the ranging accuracy.

[0039] Therefore, in this embodiment, as Figures 3-5 As shown, a mirror abutment portion 41 is formed protruding from the surface of the retainer 21 on the mirror 18 side, abutting against the mirror 18 at its front end. In this embodiment, the mirror abutment portion 41 is formed extending axially along the end of the mirror retainer 32 on the press-in portion 31 side. The protrusion height of the mirror abutment portion 41 is set to ensure the necessary mounting strength when the mirror is mounted using the adhesive member 29 (e.g., about 0.1 mm). The adhesive member 29 is provided on the outside of the mirror abutment portion 41, and the mirror 18 is adhered thereto. The thickness of the adhesive member 29 is limited by the contact between the mirror abutment portion 41 and the mirror 18. Figure 5 In the illustration, the pear-skin surface is used to represent the adhesive component 29. Figure 10 The same applies to waiting.

[0040] Furthermore, by forming the mirror abutment portion 41 at the end of the press-in portion 31, the mirror abutment portion 41 functions as a limiting wall to prevent the adhesive member 29 from flowing out towards the press-in portion 31. By abutting the retainer 21 against the mirror 18 at the mirror abutment portion 41, and bonding the mirror 18 to the retainer 21 at the mirror retainer portion 32 located outside the press-in portion 31, a gap is formed between the press-in portion 31 and the mirror 18. Therefore, even if the press-in portion 31 deforms due to the pressing of the main shaft 13, the gap absorbs the expansion, preventing interference between the press-in portion 31 and the mirror 18. This suppresses deviations in the distance between the mirror surface 181 and the main shaft 13, ensuring ranging accuracy.

[0041] As described above, the distance measuring device 1 is a device that measures the distance to an object by scanning light outward and detecting the light reflected by the object. It includes a main shaft 13 driven by a swing motor 50, a reflector 18 that is driven by the swing motor 50 to scan light outward, and a holding member 21.

[0042] The retainer 21 has: a press-in portion 31 having a hole 311 for pressing in the spindle 13; and a mirror retainer 32 integrally formed with the press-in portion 31, which is used to attach the mirror 18 by means of the adhesive member 29. The mirror retainer 32 has a mirror abutment portion 41 that protrudes toward the mirror 18 and abuts against the mirror 18.

[0043] In this embodiment, a protruding mirror abutment 41 is formed on the mirror mounting surface of the mirror holding portion 32. The holding member 21 abuts against the mirror 18 without passing through the adhesive member 29 at the mirror abutment 41, thereby suppressing deviations in the distance between the mirror surface 181 and the swing axis Ax. Furthermore, by placing the mirror abutment 41 outside the press-in portion 31, it is possible to prevent deterioration of the surface accuracy of the mirror surface 181 caused by deformation of the press-in portion 31 due to the press-in spindle 13. This ensures the positional accuracy of the mirror surface and improves ranging accuracy.

[0044] The press-in portion 31 and the reflector holding portion 32 are divided by the reflector abutment portion 41. The reflector 18 is attached to the holding member 21 by an adhesive member 29 provided on the reflector holding portion 32, and is separated from the press-in portion 31. Since the adhesive member 29 is not provided on the press-in portion 31, the influence of the thickness of the adhesive member 29 does not need to be considered, and even after pressing, the press-in portion 31 will not interfere with the reflector 18. As a result, the ranging accuracy can be further improved.

[0045] The direction of the swing axis of the mirror holding part 32 (i.e., for example) Figure 3The length of the portion (in the vertical direction on the paper) is greater than that of the pressing portion 31. Therefore, the bonding area with the reflector 18 can be ensured regardless of the pressing length.

[0046] (Second Implementation) Figure 6 The second embodiment is shown. The shapes of the retaining members in the second to eighth embodiments differ, so this will be the focus of the description. In the mirror retaining portion 32 of the retaining member 22, in addition to the mirror abutment portion 41 formed on the side of the press-in portion 31, a mirror abutment portion 42 is also provided on the outer side in the swing direction. The adhesive member 29 is provided between the mirror abutment portions 41 and 42, and the mirror 18 (in...) Figure 6 (Not shown in the figure) is attached to the retainer 22. The reflector abutment portions 41 and 42 are formed at the same height and abut against the reflector 18 at the front end face. By also forming the reflector abutment portion 42 on the outer side, deformation of the reflector 18 caused by swinging can be suppressed. In addition, it can prevent the adhesive part 29 from overflowing to the outside. In addition, the same effect as the above embodiment can be achieved.

[0047] (Third implementation method) Figure 7 A third embodiment is shown. A mirror abutment 43 is provided in the mirror holding portion 32 of the retainer 23. The mirror abutment 43 is formed along the outer edge of the mirror holding portion 32. An adhesive member 29 is provided in the inner region surrounded by the mirror abutment 43, and the mirror 18 is adhered to the retainer 23. The retainer 23 abuts against the mirror 18 at the front end face of the mirror abutment 43. By providing the mirror abutment 43 along the outer edge of the mirror holding portion 32, deformation of the mirror 18 caused by oscillation can be suppressed. In addition, overflow of the adhesive member 29 can be prevented.

[0048] An opening 435 is formed in the reflector abutment portion 43. In this embodiment, the opening 435 is formed on the side of the press-in portion 31, and functions as an vent during bonding and an escape portion when the bonding component 29 expands due to heat, etc. As a result, the decrease in ranging accuracy caused by temperature changes, etc., can be suppressed. In addition, the same effect as in the embodiment described above can be achieved.

[0049] (Fourth Implementation) Figure 8A fourth embodiment is shown. A mirror abutment 44 is provided in the mirror holding portion 32 of the retainer 24. The mirror abutment 44 is formed along the end of the mirror holding portion 32 on the press-in portion 31 side and both ends in the axial direction, and opens outward. An adhesive member 29 is provided in the area surrounded by the mirror abutment 44, and the mirror 18 is adhered to the retainer 24. This prevents the adhesive member 29 from flowing into the press-in portion 31 side. In addition, it can suppress the deformation of the mirror 18 caused by swinging. Furthermore, the same effects as the embodiment described above can be achieved.

[0050] (Fifth Implementation) Figure 9 and Figure 10 This describes the fifth embodiment. The retaining member 25 integrally forms a press-in portion 31 and a mirror retaining portion 33. The mirror retaining portion 33 is generally rectangular in plan view. The press-in portion 31 protrudes further from the mirror 18 than the mirror retaining portion 33. The axial length of the press-in portion 31 is shorter than that of the mirror retaining portion 33, similar to the embodiment described above. A groove 312 is formed on the surface of the mirror retaining portion 33 opposite to the mirror 18 to avoid interference with the spindle 13 inserted into the hole 311.

[0051] A mirror abutment portion 45 is formed protruding from the surface of the retainer 25 on the side of the mirror 18. The mirror abutment portion 45 is formed on the mirror mounting surface, extending axially outward along the swing direction of the projection area of ​​the press-in portion 31. An adhesive member 29 is provided on the outside of the mirror abutment portion 45, and the mirror 18 is adhered to the retainer 25. The mirror 18 abuts against the retainer 25 at the front end face of the mirror abutment portion 45. In this embodiment, the mirror 18 is separated from the mirror retainer 33 in the area where the press-in portion 31 is formed. Even with this configuration, the same effect as in the embodiment described above is achieved.

[0052] (Sixth Implementation Method) Figure 11 and Figure 12 This describes the sixth embodiment. In this sixth embodiment, a mirror abutment 46 is formed protruding outward in the swing direction from the mirror mounting surface of the mirror holder 33 in the retainer 26. An adhesive member 29 is provided in the area clamped by the mirror abutment 46, and the mirror 18 is adhered to the retainer 26. The mirror 18 abuts against the retainer 26 at the front end face of the mirror abutment 46. By providing the mirror abutment 46 outward in the swing direction, deformation of the mirror 18 caused by swinging can be suppressed. Furthermore, the same effects as in the embodiments described above can be achieved.

[0053] (Seventh Implementation) like Figure 13 and Figure 14As shown, in the seventh embodiment, the mirror abutment portion 47 of the retainer 27 protrudes from the mirror mounting surface of the mirror retainer 33. The mirror abutment portion 47 extends along both ends of the axial direction ( Figure 13 The mirror 18 is formed at four locations on the outer side of the oscillation direction, beyond the area where the pressing portion 31 extends axially. An adhesive member 29 is provided on the area on the mirror mounting surface where the mirror abutment portion 47 is not formed, and the mirror 18 is adhered to the retainer 27. The mirror 18 abuts against the retainer 27 at the front end face of the mirror abutment portion 47. By forming the mirror abutment portion 47 axially outward, deformation of the mirror 18 caused by vibrations accompanying oscillation can be suppressed. Furthermore, the same effect as in the above embodiment can be achieved.

[0054] (Eighth Implementation) like Figure 15 and Figure 16 As shown, in the eighth embodiment, the mirror abutment portion 48 of the retainer 28 protrudes outward in the axial direction from the middle region where the press-in portion 31 is formed. An adhesive member 29 is provided on the mirror mounting surface side where the mirror abutment portion 48 is not formed, and the mirror 18 is adhered to the retainer 28. The mirror 18 abuts against the retainer 28 at the front end face of the mirror abutment portion 48. Even with this configuration, the same effect as the embodiment described above is achieved. Furthermore, in Figure 16 In order to avoid complicating the process, the adhesive component 29 has been omitted.

[0055] In this embodiment, the main shaft 13 corresponds to the "swing shaft", the pressing part 31 corresponds to the "shaft holding part", and the swing motor 50 corresponds to the "actuator".

[0056] (Other implementation methods) In the above embodiments, the mirror abutment portions are formed at two or four locations on the mirror mounting surface side of the retainer. In other embodiments, the shape and number of mirror abutment portions may differ from those in the above embodiments.

[0057] In the above embodiment, the press-in portion is formed to protrude to the opposite side of the mirror mounting surface. In other embodiments, the shape of the press-in portion can be arbitrary. For example, depending on the spindle diameter and the thickness of the retainer plate, the press-in portion can be formed without protrusion, and the press-in hole can penetrate the interior of the retainer. In this case, the area projected by the press-in hole in a direction perpendicular to the swing axis is regarded as the "shaft retaining portion," and the outer area of ​​the shaft retaining portion is regarded as the "mirror retaining portion." The mirror abutment portion can be formed at any part of the mirror retaining portion.

[0058] Furthermore, the shapes of the retainer and the reflector may differ from those described in the above embodiment. Moreover, from the viewpoint of ensuring equal inertial torque during oscillation, it is preferable that the retainer and the reflector be formed symmetrically with respect to the oscillation axis. Additionally, the configuration and arrangement of the oscillation motor and the reflector section may differ from those described in the above embodiment, as long as they enable the reflector to oscillate.

[0059] The present disclosure is not limited to the above-described embodiments and can be implemented in various ways without departing from its spirit.

[0060] This disclosure has been described with reference to embodiments. However, this disclosure is not limited to these embodiments and constructions. This disclosure also includes various modifications and equivalent variations. In addition, various combinations and methods, as well as other combinations and methods that include only one element, more or fewer elements, also fall within the scope and spirit of this disclosure.

Claims

1. A ranging device that measures the distance to an object by scanning light outward and detecting light reflected from the object, characterized in that, The ranging device includes: The swing shaft (13) is driven by the actuator (50); The reflector (18), driven by the actuator to swing, scans light outward; and The retaining member (21-28) has a shaft retaining part (31) and a mirror retaining part (32, 33). The shaft retaining part has a hole (311) for pressing the swing shaft into it. The mirror retaining part is integrally formed with the shaft retaining part and the mirror is attached to it by an adhesive member (29). The mirror holding portion has a mirror abutment portion (41-48) that protrudes toward the mirror side and abuts against the mirror.

2. The ranging device according to claim 1, characterized in that, The shaft holding portion and the mirror holding portion are divided into areas by the mirror abutment portion (41, 44, 45). The reflector is attached to the retainer by the adhesive component provided in the reflector retaining part, and is separated from the shaft retaining part.

3. The ranging device according to claim 1 or 2, characterized in that, The length of the swing axis of the mirror holding part is greater than that of the shaft holding part.

Images