Distance measuring device

Abstract

To provide a distance measuring device capable of preventing grease and the like released from a bearing from polluting the inside.SOLUTION: The distance measuring device for measuring the distance to an object by using projection light and reflected light that is the projection light reflected by an object includes: a fixed part; a rotating part that rotates with respect to the fixed part; and a bearing connected to the rotating part. The rotating part includes a rotating fin that rotates together with the rotating part to generate air current.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to distance measuring devices. [Background technology]

[0002] Distance measuring devices that use light to measure the distance to an object are known. Patent Document 1 discloses a distance measuring device that includes a mirror that is tilted with respect to a rotation axis, a drive unit that rotates the mirror about the rotation axis, and a focusing lens that is positioned on the rotation axis and focuses the light reflected by the mirror onto a photodetector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2015-148605A Summary of the Invention [Problem to be solved by the invention]

[0004] In distance measuring devices, bearings are often used to rotate mirrors smoothly. Grease is used on the internal rolling elements of bearings to reduce friction. Some of this grease may volatilize and be released to the outside of the bearing, potentially contaminating the inside of the distance measuring device.

[0005] An object of the present disclosure is to prevent grease and the like released from bearings from contaminating the inside of a distance measuring device. [Means for solving the problem]

[0006] The distance measuring device of the present disclosure is a distance measuring device that measures the distance to an object using projected light and light reflected by the object from the projected light, and comprises a fixed part, a rotating part that rotates relative to the fixed part, and a bearing connected to the rotating part, and the rotating part includes a rotating fin that rotates together with the rotating part and generates an airflow. Effect of the Invention

[0007] According to the present disclosure, it is possible to prevent grease and the like released from the bearing from contaminating the inside of the distance measuring device. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1 is an external perspective view of a distance measuring device according to a first embodiment; [Figure 1B] FIG. 1 is a perspective view showing a configuration of a distance measuring device according to a first embodiment with an outer cover and a tube cover removed; [Diagram 2] FIG. 1 is a vertical cross-sectional view of a distance measuring device according to a first embodiment. [Diagram 3] FIG. 1 is an exploded perspective cross-sectional view of a fixed portion and a rotating portion of a distance measuring device according to a first embodiment; [Figure 4A] FIG. 1 is a diagram showing a rotary fin according to the first embodiment as viewed from diagonally above. [Figure 4B] FIG. 1 is a diagram showing a rotary fin according to the first embodiment as viewed from diagonally below. [Figure 5A] FIG. 1 is a diagram showing a fixed support base according to the first embodiment as viewed from diagonally above; [Figure 5B] FIG. 1 is a diagram showing a fixed support base according to the first embodiment as viewed from diagonally below. [Figure 6] FIG. 1 is a vertical cross-sectional view illustrating an air flow inside a distance measuring device according to a first embodiment; [Figure 7A] FIG. 1 is a top view of a rotating fin, a bearing, and a fixed support base according to the first embodiment. [Figure 7B] FIG. 1 is a bottom view of a rotating fin, a bearing, and a fixed support base according to the first embodiment. [Figure 8A] FIG. 1 is a vertical cross-sectional view showing a configuration example of a bearing according to a first embodiment; [Figure 8B] FIG. 11 is a vertical cross-sectional view showing a modified example of the bearing according to the first embodiment. [Figure 9] FIG. 1 is a perspective view showing a configuration of a distance measuring device with an outer cover and a top cover removed according to a first embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters and duplicated description of substantially the same configuration may be omitted. This is to avoid the following description becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) <Device configuration> Fig. 1A is an external perspective view of a distance measurement device 1 according to embodiment 1. Fig. 1B is a perspective view showing the configuration of the distance measurement device 1 according to embodiment 1 with an outer cover and a tube cover removed. Fig. 2 is a vertical cross-sectional view of the distance measurement device 1 according to embodiment 1. Fig. 2 corresponds to a cross-sectional view of the distance measurement device 1 shown in Fig. 1A taken along line AA.

[0011] As shown in FIG. 1A and FIG. 2, the distance measurement device 1 includes a fixed part 100, a rotating part 300, and an outer cover part 10. The fixed part 100 has a shape of a substantially rectangular parallelepiped, and has a bottom part 111 and an upper part 113 along the bottom part 111. The rotating part 300 is connected to the upper part 113 of the fixed part 100 and has a cylindrical shape that rotates around an axis of rotation C perpendicular to the upper part 113. The outer cover part 10 has a cylindrical shape and covers the rotating part 300 from above. At least a part of the side surface of the outer cover part 10 is formed using a wavelength selection member. The wavelength selection member here is a material that transmits light of a predetermined wavelength (frequency) component used for distance measurement and blocks light of a wavelength (frequency) component in the visible range. The wavelength selection member has a role of blocking disturbance light such as natural light and electric light.

[0012] For convenience of explanation, as shown in FIG. 1A, the axis perpendicular to the bottom surface 111 (or the top surface 113) of the fixed part 100 is defined as the Z axis. The axis perpendicular to the Z axis is defined as the X axis. The axis perpendicular to the Z axis and the X axis is defined as the Y axis. For convenience of explanation, the positive direction of the Z axis may be referred to as "up", the negative direction of the Z axis as "down", and the direction away from the Z axis in the X axis direction or the Y axis direction as "side". These expressions relating to directions are used for convenience of explanation and are not intended to limit the posture of the structure when actually used. For example, the distance measurement device 1 shown in FIG. 1A may be used upside down.

[0013] The fixed portion 100 may be installed such that the bottom surface portion 111 is fixed to a predetermined flat surface (for example, a floor surface or a surface of a housing of a predetermined device, etc.).

[0014] The rotating unit 300 rotates around the central axis in the height direction (Z axis) of the cylinder as the rotation axis C. As the rotating unit 300 rotates, the optical axis of the light (hereinafter referred to as projected light 3A) projected laterally from a part of the side surface of the rotating unit 300 rotates around the rotation axis C. As a result, the projected light 3A and the area where the distance can be measured by the projected light 3A (hereinafter referred to as the distance measurement area) also rotate. As described later, the distance measurement device 1 measures the distance to the object present in the distance measurement area based on the time difference (Time of Flight (ToF)) between the timing when the projected light 3A is projected and the timing when the projected light 3A receives the light (hereinafter referred to as the reflected light 3B) reflected by the object in the distance measurement area. As the rotating unit 300 rotates around the rotation axis C, the distance measurement device 1 can measure the distance to the object present in the distance measurement area of ​​360 degrees around the horizontal direction.

[0015] Fig. 3 is a perspective cross-sectional view of the fixed unit 100 and the rotating unit 300 of the distance measurement device 1 according to the first embodiment, disassembled and cut in the same manner as in Fig. 2. In Fig. 3, in order to make the drawing easier to see, some parts (such as the outer cover unit 10) of the distance measurement device 1 are omitted. Next, the configurations of the fixed unit 100 and the rotating unit 300 of the distance measurement device 1 will be described in detail with reference to Figs. 2 and 3.

[0016] <Fixed part configuration> The fixed portion 100 includes a housing portion 110, a substrate 120, a control portion 130, a fixed support base 140, a yoke 150, a coil 160, a photodetector 170, a bandpass filter 180, a detection lens 190, a light source 200, and a collimator lens 210.

[0017] The housing 110 has a substantially rectangular parallelepiped shape and includes a bottom surface portion 111 that constitutes the bottom surface of the housing 110, a side surface portion 112 that constitutes the side surface of the housing 110, and a top surface portion 113 that constitutes the top surface of the housing 110. The top surface portion 113 has a circular opening. The housing 110 is made of a metal such as aluminum die casting.

[0018] The substrate 120 is, for example, a printed circuit board (PCB), and is disposed within the housing 110 along the bottom surface 111 (for example, parallel to the bottom surface 111). The substrate 120 includes an electronic circuit, electronic components, and the like for controlling the operation of the distance measuring device 1.

[0019] The control unit 130 is provided, for example, on the lower surface side of the substrate 120. The control unit 130 performs processing for controlling the operation of the distance measurement device 1. Examples of the control unit 130 include a Central Processing Unit (CPU), a Field Programmable Gate Array (FPGA), an Application Specific IC (ASIC), and a Large Scale Integration (LSI). The control unit 130 may include a storage unit (not shown) for storing data and / or programs, etc.

[0020] The fixed support base 140 includes an inverted cone portion 141, a base annular portion 142, and an annular recess 143. The inverted cone portion 141 is formed near the center and has a generally inverted cone shape (i.e., a funnel shape) whose inner diameter narrows from top to bottom. The base annular portion 142 surrounds the inverted cone portion 141 and extends laterally in an annular shape. The annular recess 143 connects the base annular portion 142 and the inverted cone portion 141, and has an annular recessed shape. The upper and lower sides of the inverted cone portion 141 are open. The fixed support base 140 is made of, for example, resin.

[0021] The fixed support base 140 is disposed above the substrate 120 such that the inverted cone portion 141 and the annular recess 143 fit into openings in the upper surface portion 113 of the housing portion 110, and a part of the base annular portion 142 is supported from below by a part of the upper surface portion 113 of the housing portion 110. The detailed configuration of the fixed support base 140 will be described later.

[0022] The yoke 150 and the coil 160 wound around the yoke 150 constitute an electromagnet, which generates a magnetic force when a current flows through the coil 160. Hereinafter, the yoke 150 and the coil 160 may be collectively referred to as an electromagnet. A plurality of electromagnets are fixedly arranged in an annular shape on the base annular portion 142 of the fixed support base 140.

[0023] The photodetector 170 is a device that detects the amount of received light, and is configured using, for example, a photodiode. The photodetector 170 is disposed below the lower opening of the inverted cone portion 141 of the fixed support base 140.

[0024] Bandpass filter 180 is disposed so as to cover the lower opening of inverted cone portion 141 of fixed support base 140. Bandpass filter 180 is a filter that transmits light of a predetermined wavelength (frequency) component and blocks light of other wavelength (frequency) components.

[0025] The detection lens 190 is disposed in an upper opening portion of the inverted cone portion 141 of the fixed support base 140. The detection lens 190 is a convex lens having a through hole 191 along the rotation axis C. The detection lens 190 may be interpreted as a condenser lens.

[0026] The light source 200 is embedded in the through-hole 191 of the detection lens 190, and is disposed so as to project the projection light 3A of a predetermined wavelength upward. The projection light 3A of the light source 200 is, for example, a laser pulse light.

[0027] The collimator lens 210 is disposed above the light source 200. The collimator lens 210 corrects the projection light 3A input from the light source 200 to a parallel light beam and outputs the parallel light beam upward.

[0028] <Configuration of rotating part> The rotating portion 300 includes a rotating fin 310 , a bearing 320 , a magnet 330 , a cylindrical portion 340 , a tube portion 350 , a tube cover 360 , a reflecting mirror 370 , a sheet 380 , and an oil adsorption filter 390 .

[0029] The rotating fin 310 has a circular ring shape with a circular opening at the center. The rotating fin 310 is arranged so that the inverted cone portion 141 of the fixed support base 140 is disposed at the opening, and the circular ring-shaped portion covers the base circular portion 142 of the fixed support base 140 from above. The rotating fin 310 is made of, for example, resin. Details of the rotating fin 310 will be described later.

[0030] 3, bearing 320 includes annular outer ring 321 and inner ring 322, and includes a plurality of rolling elements 323, such as balls or rollers, between outer ring 321 and inner ring 322. This allows outer ring 321 to rotate smoothly relative to inner ring 322. Bearing 320 is disposed inside the opening of rotating fin 310, with outer ring 321 connected to rotating fin 310 and inner ring 322 connected to fixed support base 140. Details of the bearing will be described later.

[0031] The magnets 330 are arranged in an annular shape near the outer periphery of the rotating fin 310. The magnets 330 are arranged so that adjacent magnets have opposite polarities. When the rotating fin 310 is arranged, the magnets 330 are positioned so as to laterally face the yoke 150 and the coil 160 (i.e., the electromagnet).

[0032] The cylindrical portion 340 has a cylindrical shape, and its bottom surface is connected (fixed) to the upper surface of the rotating fin 310. The cylindrical portion 340 may be made of resin. Details of the cylindrical portion 340 will be described later. The cylindrical portion and the rotating fin may be integrated.

[0033] The cylindrical portion 350 is a cylindrical space formed inside the cylindrical portion 340 from the rotation axis C of the cylindrical portion 340 to the side surface of the cylindrical portion 340 in order to separate the outgoing light and the returning light. The cylindrical portion 350 prevents light (which is transmitted in principle but contains minute reflected light) that hits a tube cover 360 and / or an outer cover portion 10 (described later) from being reflected and entering the photodetector 170 via the reflector 370.

[0034] Tube cover 360 is a plate that transmits at least light of a predetermined wavelength (frequency) component used for distance measurement, and is disposed so as to cover the opening that tube portion 350 forms on the side surface of columnar portion 340.

[0035] Reflecting mirror 370 is a mirror capable of reflecting light, and is disposed inside cylindrical portion 340 at a position where rotation axis C of cylindrical portion 340 intersects with tube portion 350. Reflecting mirror 370 is disposed at an angle (e.g., 45 degrees) at which light irradiated upward by light source 200 is reflected in the axial direction of tube portion 350 (i.e., the horizontal direction).

[0036] Sheet 380 is a flat, annular sheet with a circular opening at the center, and is disposed between the bottom surface of cylindrical portion 340, bearing 320, and fixed support base 140. Sheet 380 transmits light of a predetermined wavelength (frequency) component, such as reflected light.

[0037] Oil adsorption filter 390 is an annular, flat filter with a circular opening at the center, and is disposed between the bottom surface of cylindrical portion 340 and rotating fins 310. Oil adsorption filter 390 may be disposed closer to bearing 320 than seat 380. Oil adsorption filter 390 is a filter (e.g., a sponge filter) that has the function of adsorbing oil.

[0038] <Optical system behavior> The distance measurement device 1 projects the projection light 3A, receives the reflected light 3B, and measures the distance to the object as follows. (S11) The light source 200 projects light 3A (for example, a pulsed laser) upward. (S12) The projection light 3A emitted from the light source 200 is converted into substantially parallel light by the collimator lens 210 and reflected by the reflecting mirror 370 in the axial direction (horizontal direction) of the tube portion 350. Note that the term "substantially parallel" here includes a range in which the projection light 3A is parallel to the extent that distance measurement is possible. (S13) The projection light 3A reflected by the reflecting mirror 370 passes through the tube portion 350, the tube cover 360, and the outer cover 10, and proceeds to the distance measurement area. (S14) The projected light 3A is reflected by an object in the distance measurement area (that is, becomes reflected light 3B). (S15) At least a portion of the reflected light 3B is input into the spaces on both sides of the tube portion 350, as shown in FIG. 1B. (S16) The reflected light 3B input into the spaces on both sides of the tube portion 350 is reflected downward by the reflecting mirror 370. (S17) Reflected light 3B reflected downward by reflecting mirror 370 is refracted so as to be collected at the position of photodetector 170 located below as it passes through detection lens 190, and passes through bandpass filter 180. Bandpass filter 180 passes light of a predetermined wavelength (frequency) component. (S18) The reflected light 3B that has passed through the bandpass filter 180 is detected by the photodetector 170.

[0039] As a result, when an object is present, the photodetector 170 can detect reflected light 3B with a predetermined amount of light or more. Therefore, the control unit 130 may determine that an object is present when the amount of light detected by the photodetector 170 is equal to or greater than a predetermined threshold, and may determine that an object is not present when the amount of light is less than the predetermined threshold.

[0040] In addition, the control unit 130 may measure (calculate) the distance to the object based on the time (i.e., ToF) until the light (light pulse) emitted by the light source 200 is detected as reflected light 3B (light pulse) by the photodetector 170.

[0041] This enables the distance measurement device 1 to determine the presence or absence of an object and to measure the distance to the object.

[0042] <Operation of rotating part> The distance measurement device 1 rotates the rotating unit 300 as follows.

[0043] When a current is passed through the coil 160, the coil 160 and the yoke 150 function as an electromagnet to generate a magnetic field, and the coil 160 and the yoke 150 move the magnet 330, which is disposed opposite to the coil 160, in a rotational direction about the rotation axis C.

[0044] As a result, the rotating fin 310 to which the magnet 330 is connected, and the cylindrical portion 340 and the like connected to the upper surface of the rotating fin 310 (i.e., the entire rotating portion 300) rotate about the rotation axis C. At this time, the rotating fin 310 rotates smoothly because it is connected to the outer ring 321 of the bearing 320.

[0045] With the rotation of the rotating part 300, the reflecting mirror 370 and the tube part 350 inside the cylindrical part 340 also rotate around the rotation axis C. Therefore, the projection light 3A irradiated from the tube part 350 to the outside also rotates around the rotation axis C. That is, the projection light 3A is projected around the rotation axis C in the entire lateral direction (360 degrees). This allows the control part 130 of the distance measurement device 1 to determine the presence or absence of an object, measure the direction in which the object exists, and measure the distance to the object over almost the entire lateral direction. Note that the rotating part 300 does not necessarily have to rotate 360 ​​degrees for the control of the distance measurement, and may rotate within the rotation range in which the distance is to be measured. This can also extend the life of the light source 200.

[0046] <Issues when using bearings> As shown in FIG. 3, in addition to outer ring 321, inner ring 322, and rolling elements 323, bearing 320 includes a lower surface portion 324 that extends from outer ring 321 toward inner ring 322 on the lower side and has a gap between it and inner ring 322, and an upper surface portion 325 that extends from outer ring 321 toward inner ring 322 on the upper side and has a gap between it and inner ring 322.

[0047] Bearing 320 uses grease (oil) inside to reduce friction between outer ring 321 and inner ring 322 and rolling element 323. Some of this grease evaporates and is released to the outside of bearing 320 through a gap between upper surface portion 325 and inner ring 322. If the grease released from bearing 320 and foreign matter attached thereto (hereinafter referred to as grease, etc.) adhere to optical members such as light source 200, collimator lens 210, detection lens 190, reflector 370, and / or photodetector 170, the detection accuracy and distance measurement accuracy of the target object will decrease.

[0048] Therefore, in this embodiment, a distance measuring device 1 is described that is provided with measures to prevent grease and the like discharged from the bearing 320 from adhering to optical members, the tube cover 360 arranged on the optical paths of the projected light and the reflected light, the outer cover part 10, and the like. The parts listed above are merely examples, and are not intended to limit the objects to which grease and the like are attached. Note that the following measures may be applied alone, two or more of them may be applied in combination, or all of them may be applied.

[0049] <Measure 1> Fig. 4A is a view of the rotary fin 310 according to embodiment 1 as viewed obliquely from above. Fig. 4B is a view of the rotary fin 310 according to embodiment 1 as viewed obliquely from below. Fig. 5A is a view of the fixed support base 140 according to embodiment 1 as viewed obliquely from above. Fig. 5B is a view of the fixed support base 140 according to embodiment 1 as viewed obliquely from below.

[0050] First, the detailed configurations of the rotary fins 310 and the fixed support base 140 will be described.

[0051] As shown in Figures 4A and 4B, rotating fin 310 has a circular ring shape with a circular opening at the center, and has an inner surface portion 311 that forms the side of the opening, an upper surface portion 312 that forms the annular upper surface, and an outer surface portion 313 that forms the side of the outer periphery of the ring.

[0052] Further, rotating fin 310 has a plurality of first holes 314 formed in a circle along the opening at the boundary between inner side surface portion 311 and upper surface portion 312. In addition, rotating fin 310 has a plurality of fins 315 formed at the boundary between inner side surface portion 311 and upper surface portion 312 on the back surface (i.e., the surface of upper surface portion 312 closer to fixed portion 100) (see FIG. 4B).

[0053] Furthermore, the upper surface portion 312 may have an inclined surface 316 approaching the outer surface portion 313 at the boundary portion with the outer surface portion 313 .

[0054] The magnet 330 is provided on the inside of the outer surface portion 313 of the rotating fin 310. The magnet 330 is disposed opposite the yoke 150 and the coil 160 in the lateral direction.

[0055] 5A and 5B, the fixed support base 140 includes the inverted cone portion 141, the base annular portion 142, and the annular recess 143, as described above. In addition, the fixed support base 140 has a plurality of locking portions 144 that lock the inner ring 322 of the bearing 320 on the outer surface of the inverted cone portion 141, second holes 145 formed in the lower portions of the locking portions 144, and one or more third holes 146 formed in the base annular portion 142. The third holes 146 are formed at positions overlapping the coil 160 and the yoke 150 when viewed in the direction of the rotation axis C (i.e., when viewed from above).

[0056] Next, the airflow generated by the rotation of the rotating fins 310 will be described.

[0057] Fig. 6 is a vertical cross-sectional view for explaining the airflow inside distance measurement device 1 according to embodiment 1. In Fig. 6, the airflow is indicated by dotted arrows. The cross section shown in Fig. 6 is the same as the cross section shown in Fig. 2. Fig. 7A is a top view of rotary fin 310, bearing 320, and fixed support base 140 according to embodiment 1. Fig. 7B is a bottom view of rotary fin 310, bearing 320, and fixed support base according to embodiment 1. The following airflow is generated by the rotation of cylindrical portion 340 including rotary fin 310.

[0058] (S21) As rotating fin 310 rotates, an airflow is generated which enters through the gap at the upper end of engaging portion 144, travels in the outer circumferential direction along upper surface portion 325 of bearing 320, and exits through first hole 314 of rotating fin 310. (S22) The airflow coming out of first hole 314 of rotating fin 310 advances in the outer circumferential direction along the lower surface of upper surface 312 of rotating fin 310, and flows downward along inclined surface 316. (S23) This downward airflow passes through the positions where the yoke 150 and the coil 160 are arranged, and passes through the third hole 146 of the base ring portion 142 of the fixed support base 140, and then heads downward. (S24) The downward airflow flows along the lower surface of the substrate 120 and enters the second hole 145 of the fixed support base 140 again. (S25) The airflow entering through second hole 145 of fixed support base 140 passes through the gap between inner ring 322 of bearing 320 and locking portion 144 and flows upward.

[0059] In this way, when the rotating fin 310 is rotated, an airflow is generated that flows from the inner ring 322 side to the outer ring 321 side along the upper surface 325 of the bearing 320. As a result, grease and the like discharged from the gaps in the upper surface 325 of the bearing 320 is carried by the airflow in a direction away from the rotation axis C. Therefore, it becomes difficult for the grease and the like discharged from the gaps in the upper surface 325 of the bearing 320 to reach the optical members arranged near the rotation axis C, and as a result, it is possible to suppress the adhesion of the grease and the like to the optical members.

[0060] In addition, since this airflow passes through the locations where the yoke 150 and the coil 160 are disposed, it also helps to cool the yoke 150 and the coil 160 .

[0061] Even if rotating fins 310 are not provided, a downward airflow is generated by the rotation of rotating part 300. This airflow carries grease and the like discharged from bearing 320 and can flow downward through second hole 145 of fixed support base 140. That is, by providing second hole 145 in fixed support base 140, the airflow mixed with grease and the like discharged from bearing 320 can be released downward away from the optical member.

[0062] <Measure 2> 2, the sheet 380 is an annular sheet disposed between the bottom surface of the cylindrical portion 340 and the upper surface portion 325 of the bearing 320 so as to cover the circular opening portion at the center of the rotating fin 310, except for the central rotation axis C. A gap G1 is provided between the sheet 380 and the upper end of the locking portion 144 of the fixed support base 140.

[0063] 6, air currents generated below sheet 380 are blocked by sheet 380 and flow toward gap G1 instead of toward cylindrical portion 340, passing through upper surface portion 325 of bearing 320. This prevents grease or the like discharged from the gap in upper surface portion 325 of bearing 320 from being carried by the air current and moving toward cylindrical portion 340 and adhering to the optical member.

[0064] 2, the oil adsorption filter 390 is an annular filter (e.g., a sponge sheet) disposed between the bottom surface of the cylindrical portion 340 and the upper surface portion 325 of the bearing 320 so as to cover the first holes 314 of the rotating fin 310. The oil adsorption filter 390 may be disposed closer to the upper surface portion 325 of the bearing 320 than the sheet 380. The oil adsorption filter 390 may be disposed such that the inner periphery of the oil adsorption filter 390 is aligned with the outer periphery of the sheet 380. Alternatively, the oil adsorption filter 390 may be disposed such that at least a portion of the oil adsorption filter 390 overlaps with at least a portion of the sheet 380 when viewed from above.

[0065] As a result, at least a portion of the grease, etc., contained in the airflow that travels in the outer circumferential direction along the upper surface 325 of the bearing 320, passes through the gap G1, and enters the first hole 314 of the rotating fin 310 is adsorbed by the oil adsorption filter 390. Therefore, the amount of grease, etc. traveling with the airflow can be reduced, and as a result, adhesion of the grease, etc. to the optical components can be suppressed.

[0066] <Measure 3> Fig. 8A is a vertical cross-sectional view showing a configuration example of bearing 320 according to embodiment 1. Fig. 8B is a vertical cross-sectional view showing a modified example of bearing 320 according to embodiment 1. The vertical cross sections shown in Fig. 8A and Fig. 8B correspond to the vertical cross section AA in Fig. 1A.

[0067] As shown in FIG. 8A or 8B , an annular upper plate portion 326 may be disposed on upper surface portion 325 of bearing 320, with a gap in the height direction from upper surface portion 325. The upper plate portion 326 covers upper surface portion 325 of bearing 320.

[0068] 8A, in the case of bearing 320 having gap G2 between upper surface portion 325 and inner ring 322, upper plate portion 326 may be disposed such that an inner peripheral portion is connected to inner ring 322 and extends toward outer ring 321. In this case, upper plate portion 326 may form gap G3 near outer ring 321, which is far from gap G2.

[0069] 8B, in the case of bearing 320 having gap G2 between upper surface portion 325 and outer ring 321, upper plate portion 326 may be disposed such that an outer peripheral portion is connected to outer ring 321 and extends toward inner ring 322. In this case, upper plate portion 326 may form gap G3 near inner ring 322, which is far from gap G2.

[0070] As a result, upper surface portion 325 and upper plate portion 326 of bearing 320 form a labyrinth structure. Therefore, grease, etc. discharged from gap G2 of upper surface portion 325 of bearing 320 is blocked by upper plate portion 326 and is less likely to go outside the labyrinth structure. As a result, it is possible to prevent grease, etc. from adhering to optical members.

[0071] 8A or 8B is just an example, and any structure may be used as long as the position of gap G2 formed by upper surface portion 325 and the position of gap G3 formed by upper plate portion 326 do not overlap when viewed from above. Also, the labyrinth structure shown in Fig. 8A or 8B is a two-layer structure made up of upper surface portion 325 and upper plate portion 326, but the labyrinth structure may be a three-layer structure.

[0072] <Measure 4> FIG. 9 is a perspective view showing the configuration of the distance measurement device 1 according to the first embodiment with the outer cover unit 10 and the top lid 342 removed.

[0073] As shown in FIG. 3, the columnar portion 340 includes a columnar main body 341 and a top cover 342 which is a flat plate provided on the upper surface of the columnar main body 341 so that the upper surface of the columnar main body 341 is smooth.

[0074] 9, the inside of the cylindrical body 341 has an uneven structure for the purposes of weight reduction, ease of manufacture, and / or rotation stability. If the top cover 342 is not provided and the cylindrical body 341 is rotated with this uneven structure exposed, this uneven structure will generate turbulence at the top of the cylindrical body 341. This turbulence may carry grease, etc. discharged from the gaps in the upper surface part 325 of the bearing 320, and cause the grease, etc. to adhere to the optical components.

[0075] In contrast, as shown in the present embodiment, by providing a top cover 342 on the upper surface of the cylindrical main body 341, the above-mentioned turbulence caused by the rotation of the cylindrical part 340 is prevented from occurring. As a result, it is possible to prevent grease and the like discharged from the gap in the upper surface part 325 of the bearing 320 from adhering to the optical members, the tube cover 360, the outer cover part 10, and the like.

[0076] <Measure 5> 9, the tube cover 360 is disposed so as to cover the opening of the tube portion 350 formed on the side surface of the cylindrical portion 340. That is, the rotating portion 300 has a generally cylindrical shape with a portion open, and the tube cover 360 is provided so as to cover this open surface. The tube cover 360 may be read as a lid portion. Note that the generally cylindrical shape may be any shape that does not generate turbulence.

[0077] If the cylinder part 340 is rotated without providing the cylinder cover 360 and with the opening of the cylinder part 350 exposed, turbulence will be generated by the air flowing out from the opening of the cylinder part 350. This turbulence may carry grease or the like discharged from the gap in the upper surface part 325 of the bearing 320, and cause the grease or the like to adhere to the optical members.

[0078] In contrast, as shown in the present embodiment, by providing tube cover 360 to cover the opening of tube portion 350, the above-mentioned turbulence caused by the rotation of columnar portion 340 is prevented from occurring. As a result, it is possible to prevent grease and the like discharged from upper surface portion 325 of bearing 320 from adhering to the optical members.

[0079] (Summary of the first embodiment) The above description of the first embodiment discloses the following techniques.

[0080] (Technology A) <Technology A1> A distance measuring device that measures the distance to an object using projected light and light reflected from the object includes a fixed part, a rotating part that rotates relative to the fixed part, and a bearing connected to the rotating part, and the rotating part includes a rotating fin that rotates together with the rotating part and generates an airflow. As a result, grease and other substances released from the bearings are carried away by the air currents generated by the rotating fins, preventing the grease and other substances from adhering to the inside. <Technology A2> In the distance measurement device described in Technology A1, the rotating fin has a plurality of first holes surrounding the bearing. This allows the rotary fin to generate an airflow passing through the first hole. <Technology A3> In the distance measurement device described in Technique A2, when the rotating fin rotates together with the rotating part, an air flow is generated that connects a first surface of the bearing closer to the rotating part and the first hole. As a result, grease and the like released from the first surface of the bearing is carried away by the airflow generated by the rotating fins, thereby preventing the grease and the like from adhering to the inside. <Technology A4> In the distance measurement device described in Technology A2 or A3, the rotating fin has a second surface extending in an outer circumferential direction from the first hole, and a plurality of fins provided on the second surface on the side closer to the fixed portion. This allows the rotating fin to generate airflow through multiple fins. <Technology A5> In the distance measurement device described in Technology A4, the second surface of the rotating fin is inclined from the middle of the direction toward the outer periphery toward the fixed portion. This allows the generated air current to move downwards by the inclined surface. <Technology A6> In the distance measuring device described in Technology A5, the rotating fin further includes a third surface extending from the outer periphery of the second surface in a direction approaching the fixed portion, the rotating portion further includes a magnet provided inside the third surface of the rotating fin, and the fixed portion further includes a coil and a yoke arranged adjacent to the magnet. This allows the air current moving downward by the inclined surface to cool the magnets and coils. <Technology A7> In a distance measuring device described in any one of Technologies A1 to A6, the fixed part includes a light source that projects the projection light in the direction of the rotating part along the rotation axis of the rotating part, and a detection lens through which the reflected light passes, and the rotating part further includes a reflector that reflects the projection light from the light source in a predetermined direction and reflects the reflected light in the direction of the detection lens. As a result, grease and the like released from the bearings is carried by the air currents generated by the rotating fins, making it possible to prevent the grease and the like from adhering to optical components and the like. <Technology A8> In the distance measurement device described in any one of Techniques A1 to A7, the fixed portion includes a fixed support base that supports the bearing and has a second hole in a portion thereof. This makes it possible to generate an airflow connecting the first hole and the second hole. <Technology A9> In a distance measuring device described in any one of Technologies A1 to A8, the rotating part has an approximately cylindrical shape that rotates relative to the fixed part, has an open portion, and is provided with a cover portion arranged to cover the open surface of the rotating part. This makes it possible to suppress the generation of turbulence due to the rotation of the rotating part, thereby suppressing the adhesion of grease and the like released from the bearing to the inside. <Technology A10> In the distance measurement device described in any one of Techniques A1 to A7, a first surface of the bearing closer to the rotating part has a labyrinth structure. This makes it possible to suppress the release of grease and the like from the bearings.

[0081] (Technology B) <Technology B1> A distance measuring device that measures the distance to an object using projected light and light reflected by the object from the projected light comprises a fixed part, a rotating part that rotates relative to the fixed part, and a bearing connected to the rotating part, wherein the fixed part supports the bearing and includes a fixed support base having a first hole in a portion of it. This allows the airflow generated by the rotation of the rotating part to pass through the first hole, and grease and other substances released from the bearing are carried by the airflow, thereby preventing the grease and other substances from adhering to the inside. <Technology B2> In the distance measuring device described in Technique B1, the fixed support base has the first hole in a gap between the fixed support base and the inner ring of the bearing. This allows air to pass near the bearings, preventing grease and other substances released from the bearings from adhering to the inside of the bearings. <Technology B3> In the distance measuring device described in Technique B2, the rotating part includes a rotating fin that rotates together with the rotating part and generates an air flow. As a result, grease and other substances released from the bearings are carried away by the air currents generated by the rotating fins, preventing the grease and other substances from adhering to the inside. <Technology B4> In the distance measuring device described in Technology B3, the rotating fin has a plurality of second holes surrounding the bearing. As a result, grease and the like released from the bearing is carried through the first hole and the second hole by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the inside. <Technology B5> In the distance measurement device described in Technique B4, when the rotating fin rotates together with the rotating part, an airflow is generated that connects a first surface of the bearing closer to the rotating part, the second hole, and the first hole. As a result, grease and the like released from the bearing is carried through the first hole and the second hole by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the inside. <Technology B6> In the distance measurement device described in Technology B5, the rotating fin has a second surface extending in an outer circumferential direction from the second hole, and a plurality of fins provided on the second surface on the side closer to the fixed portion. This allows the rotating fin to generate airflow through multiple fins. <Technology B7> In the distance measurement device described in Technique B6, the second surface of the rotating fin is inclined from the middle of the direction toward the outer periphery toward the fixed portion. This allows the generated air current to move downwards by the inclined surface. <Technology B8> In the distance measuring device described in Technology B7, the rotating fin further includes a third surface extending from the outer periphery of the second surface in a direction approaching the fixed portion, the rotating portion further includes a magnet provided inside the third surface of the rotating fin, the fixed portion further includes a coil and a yoke arranged adjacent to the magnet, and the fixed support base has a third hole at a position overlapping with the coil and yoke when viewed in the direction of the rotation axis of the rotating portion. This allows the air current moving downward by the inclined surface to cool the magnets and coils. <Technology B9> In a distance measuring device described in any one of Technologies B1 to B8, the fixed part includes a light source that projects the projection light in the direction of the rotating part along the rotation axis of the rotating part, and a detection lens through which the reflected light passes, and the rotating part further includes a reflector that reflects the projection light from the light source in a predetermined direction and reflects the reflected light in the direction of the detection lens. As a result, grease and the like released from the bearings is carried by the air currents generated by the rotating fins, making it possible to prevent the grease and the like from adhering to optical components and the like. <Technology B10> In a distance measuring device described in any one of Technologies B1 to B9, the rotating part has a cylindrical shape that rotates relative to the fixed part, has an open portion, and is provided with a cover portion arranged to cover the open surface of the rotating part. This makes it possible to suppress the generation of turbulence due to the rotation of the rotating part, thereby suppressing the adhesion of grease and the like released from the bearing to the inside. <Technology B11> In the distance measurement device according to any one of Techniques B1 to B9, a first surface of the bearing closer to the rotating part has a labyrinth structure. This makes it possible to suppress the release of grease and the like from the bearings.

[0082] (Technology C) <Technology C1> A distance measuring device that measures the distance to an object using projected light and light reflected by the object from the projected light comprises a fixed part, a rotating part that is approximately cylindrical in shape and rotates relative to the fixed part and has an open portion, a cover part that is arranged to cover the open surface of the rotating part, and a bearing connected to the rotating part. This suppresses the generation of turbulence caused by the rotation of the rotating part, thereby preventing grease and other substances released from the bearing from adhering to the inside. <Technology C2> In the distance measurement device described in Technique C1, the cover portion is configured using a member that transmits projected light and / or reflected light. This allows projected light and / or reflected light to pass through the lid. <Technology C3> In the distance measuring device described in Technique C1 or C2, the rotating part includes a rotating fin that rotates together with the rotating part and generates an air flow. As a result, grease and other substances released from the bearings are carried away by the air currents generated by the rotating fins, preventing the grease and other substances from adhering to the inside. <Technology C4> In a distance measuring device described in any one of Technologies C1 to C3, the fixed part includes a light source that projects the projection light in the direction of the rotating part along the rotation axis of the rotating part, and a detection lens through which the reflected light passes, and the rotating part further includes a reflector that reflects the projection light from the light source in a predetermined direction and reflects the reflected light in the direction of the detection lens. This makes it possible to prevent grease and the like discharged from the bearing from adhering to optical members and the like. <Technology C5> In the distance measurement device described in any one of Techniques C1 to C4, the fixed portion includes a fixed support base that supports the bearing and has a first hole in a portion thereof. This allows the airflow to pass through the first hole, preventing grease and other substances released from the bearing from adhering to the inside. <Technology C6> In the distance measurement device according to any one of techniques C1 to C4, a first surface of the bearing closer to the rotating part has a labyrinth structure. This makes it possible to suppress the release of grease and the like from the bearings.

[0083] (Technology D) <Technology D1> A distance measuring device that measures the distance to an object using projected light and light reflected by the object from the projected light comprises a fixed part, a rotating part that rotates relative to the fixed part, and a bearing having an outer ring and an inner ring and connected to the rotating part, the bearing having a labyrinth structure. This makes it possible to suppress the release of grease and the like from the bearings. <Technology D2> In the distance measuring device described in Technology D1, the labyrinth structure has at least one disk, a first disk forming a gap between itself and the inner ring, and a second disk forming a gap between itself and the outer ring. This makes it possible to suppress the release of grease and the like from the bearings. <Technology D3> In the distance measuring device described in Technology D1 or D22, the rotating part includes a rotating fin that rotates together with the rotating part and generates an air flow. As a result, grease and other substances released from the bearings are carried away by the air currents generated by the rotating fins, preventing the grease and other substances from adhering to the inside. <Tech D4> In the distance measurement device described in technique D3, the rotating fin has a plurality of first holes surrounding the outer ring. This allows an airflow to be generated through the first hole by the rotation of the rotating fin. <Technology D5> In the distance measurement device described in Technique D4, when the rotating fin rotates together with the rotating part, an air flow is generated that connects a first surface of the bearing closer to the rotating part and the first hole. As a result, grease and the like released from near the first surface of the bearing is carried away by the airflow generated by the rotating fins, thereby preventing the grease and the like from adhering to the inside. <Technology D6> In a distance measurement device described in any one of Technologies D3 to D5, the rotating fin has a second surface extending in an outer circumferential direction from the first hole, and a plurality of fins provided on the second surface on the side closer to the fixed portion. This allows the rotating fin to generate airflow through multiple fins. <Technology D7> In a distance measuring device described in any one of Technologies D1 to D6, the fixed part includes a light source that projects the projection light in the direction of the rotating part along the rotation axis of the rotating part, and a detection lens through which the reflected light passes, and the rotating part further includes a reflector that reflects the projection light from the light source in a predetermined direction and reflects the reflected light in the direction of the detection lens. This makes it possible to prevent grease and the like discharged from the bearing from adhering to optical members and the like. <Technology D8> In the distance measuring device described in any one of Techniques D1 to D7, the fixed portion includes a fixed support base that supports the bearing and has a second hole in a portion thereof. This allows the airflow to pass through the second hole, preventing grease and other substances released from the bearing from adhering to the inside. <Technology D9> In a distance measuring device described in any one of Technologies D1 to D7, the rotating part has an approximately cylindrical shape that rotates relative to the fixed part, has an open portion, and is provided with a cover portion arranged to cover the open surface of the rotating part. This suppresses the generation of turbulence caused by the rotation of the rotating part, thereby preventing grease and other substances released from the bearing from adhering to the inside.

[0084] Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, corrections, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also belong to the technical scope of the present disclosure. In addition, the components in the above-mentioned embodiments may be arbitrarily combined within the scope of the invention. [Industrial Applicability]

[0085] The technology disclosed herein is useful for distance measuring devices that include bearings or sensing devices that perform optical sensing. [Explanation of symbols]

[0086] 1 Distance measuring device 10 Outer cover part 100 Fixed part 110 Housing 111 Bottom part 112 Side part 113 Top part 120 Substrate 130 Control section 140 Fixed support base 141 Inverted cone 142 Base annular part 143 Circular recess 144 Locking part 145 2nd hole 146 Hole 3 150 York 160 Coil 170 Photodetector 180 Bandpass Filter 190 Detection Lens 191 Through hole 200 light source 210 Collimator lens 300 Rotating Part 310 Rotating Fin 311 Inner side part 312 Top part 313 External surface part 314 Hole 1 315 Finn 316 Slope 320 Bearing 321 Outer Ring 322 Inner Circle 323 Rolling elements 324 Bottom part 325 Top part 326 Upper plate 330 Magnet 340 Cylinder 341 Cylinder Body 342 Top cover 350 Cylinder part 360 Barrel Cover 370 Reflector 380 seats 390 Oil adsorption filter C Rotational Axis G1, G2, G3 Gap

Claims

1. A distance measuring device for measuring a distance to an object using a projected light and a reflected light of the projected light reflected by the object, comprising: A fixed portion; A rotating part that rotates relative to the fixed part; a bearing connected to the rotating part, The rotating part includes a rotating fin that rotates together with the rotating part and generates an air flow. Distance measuring device.

2. The rotating fin has a plurality of first holes surrounding the bearing.

2. A distance measuring device according to claim 1.

3. When the rotating fin rotates together with the rotating part, an airflow is generated that connects a first surface of the bearing that is closer to the rotating part and the first hole.

3. A distance measuring device according to claim 2.

4. The rotating fin is a second surface extending in an outer circumferential direction from the first hole; A plurality of fins are provided on the second surface on a side closer to the fixed portion.

4. A distance measuring device according to claim 3.

5. The second surface of the rotary fin is inclined in a direction approaching the fixed portion from the middle of the direction toward the outer periphery.

5. A distance measuring device according to claim 4.

6. The rotary fin further includes a third surface extending from an outer periphery of the second surface in a direction approaching the fixed portion, The rotating portion further includes a magnet provided on the inside of the third surface of the rotating fin, The fixed portion further includes a coil and a yoke arranged adjacent to the magnet.

6. A distance measuring device according to claim 5.

7. The fixing portion is a light source that projects the projection light in a direction toward the rotating part along a rotation axis of the rotating part; a detection lens through which the reflected light passes; The rotating part is a reflector that reflects the projected light from the light source in a predetermined direction and reflects the reflected light in a direction of the detection lens, A distance measuring device according to any one of claims 1 to 6.

8. the fixed portion includes a fixed support base that supports the bearing and has a second hole in a portion thereof; 8. A distance measuring device according to claim 7.

9. The rotating part has a generally cylindrical shape that rotates relative to the fixed part and has an opening at one end, A lid portion is provided to cover the open surface of the rotating portion.

8. A distance measuring device according to claim 7.

10. The first surface of the bearing has a labyrinth structure.

8. A distance measuring device according to claim 7.

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