Distance measurement device

Abstract

The purpose of the present disclosure is to prevent grease or the like released from a bearing from contaminating the inside of a distance measurement device.　A distance measurement device (1) according to the present disclosure measures the distance to an object using projected light (3A) and reflected light (3B), which is the projected light reflected by the object. The distance measurement device (1) comprises: a fixed unit (100); a rotation unit (300) that rotates with respect to the fixed unit; a lid unit (10) having an affinity for oils and provided so as to cover the rotation unit; and a bearing (320) connected to the rotation unit.

Description

Distance measuring device

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

[0002] Distance measurement devices that use light to measure the distance to an object are known. Patent Document 1 discloses a distance measurement device that includes a mirror that is tilted relative to a rotation axis, a drive unit that rotates the mirror about the rotation axis, and a condenser lens that is arranged on the rotation axis and condenses light reflected by the mirror onto a photodetector.

[0003] Japanese Patent Application Publication No. 2015-148605

[0004] In distance measurement devices, bearings are often used to ensure smooth rotation of mirrors. Grease is used on the internal rolling elements of bearings to reduce friction. Some of this grease can volatilize and be released outside the bearing, potentially contaminating the inside of the distance measurement 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.

[0006] The distance measuring device of the present disclosure is a distance measuring device that measures the distance to an object using the projected light reflected by the object, and comprises a fixed part, a rotating part that rotates relative to the fixed part, a lipophilic cover part that is arranged to cover the rotating part, and a bearing connected to the rotating part.

[0007] 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 from the object when the projected light is reflected, 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.

[0008] The distance measuring device according to the present disclosure is a distance measuring device that measures the distance to an object using projected light and light reflected from the object when the projected light is reflected from the object, and includes 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, wherein a first surface of the bearing has a labyrinth structure.

[0009] 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 measurement device.

[0010] 1. A perspective view of the appearance of the distance measurement device according to embodiment 1. 2. A perspective view showing the configuration of the distance measurement device according to embodiment 1 with the outer cover part and the tube cover removed. 3. A longitudinal sectional view of the distance measurement device according to embodiment 1. 4. A perspective sectional view of the fixed part and the rotating part of the distance measurement device according to embodiment 1 disassembled. 5. A view of the rotary fin according to embodiment 1, seen from diagonally above. 6. A view of the rotary fin according to embodiment 1, seen from diagonally below. 7. A view of the fixed support base according to embodiment 1, seen from diagonally above. 8. A view of the fixed support base according to embodiment 1, seen from diagonally below. 9. A longitudinal sectional view for explaining the air flow inside the distance measurement device according to embodiment 1. 10. A view of the rotary fin, bearing, and fixed support base according to embodiment 1, seen from above. FIG. 1 is a diagram showing a ring and a fixed support base as viewed from below. FIG. 2 is a longitudinal section showing an example of the configuration of a bearing according to embodiment 1. FIG. 3 is a longitudinal section showing a modified example of the bearing according to embodiment 1. FIG. 4 is a perspective view showing the configuration of a distance measurement device with the outer cover part and top cover removed according to embodiment 1. FIG. 5 is a diagram showing a lens cover as viewed diagonally from above according to embodiment 1. FIG. 6 is a diagram showing the lens cover as viewed diagonally from below according to embodiment 1. FIG. 7 is a diagram for explaining the refraction of light when (a) grease adheres to an oil-repellent member and (b) grease adheres to an lipophilic member. Graph showing the relationship between the contact angle of grease on the reflector according to embodiment 1 and the signal reduction level. Graph showing the relationship between the contact angle of grease on the outer cover part according to embodiment 1 and the signal reduction level.

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with appropriate reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description 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.

[0012] (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 the outer cover and 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 A-A.

[0013] As shown in FIGS. 1A and 2 , the distance measurement device 1 includes a fixed unit 100, a rotating unit 300, and an outer cover unit 10. The fixed unit 100 has a substantially rectangular parallelepiped shape and includes a bottom surface 111 and an upper surface 113 that aligns with the bottom surface 111. The rotating unit 300 is connected to the upper surface 113 of the fixed unit 100 and has a cylindrical shape that rotates around a rotation axis C that is perpendicular to the upper surface 113. The outer cover unit 10 has a cylindrical shape and covers the rotating unit 300 from above. At least a portion of the side surface of the outer cover unit 10 is formed using a wavelength-selecting member. Note that the wavelength-selecting member referred to here is a material that transmits light of a predetermined wavelength (frequency) component used in distance measurement and blocks light of a wavelength (frequency) component in the visible range. The wavelength-selecting member has the role of blocking ambient light, such as natural light and electric light.

[0014] For ease of explanation, as shown in FIG. 1A, the axis perpendicular to the bottom surface 111 (or top surface 113) of the fixed unit 100 is referred to as the Z axis. The axis perpendicular to the Z axis is referred to as the X axis. The axis perpendicular to the Z axis and the X axis is referred to as the Y axis. For ease 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 "sideways." Note that these directional expressions are used for ease of explanation and are not intended to limit the orientation of the structure during actual use. For example, the distance measurement device 1 shown in FIG. 1A may be used upside down.

[0015] The fixed part 100 may be installed such that the bottom part 111 is fixed to a predetermined plane (for example, a floor surface or the surface of a housing of a predetermined device).

[0016] The rotating unit 300 rotates around a rotation axis C, which is the central axis in the height direction (Z axis) of the cylinder. As the rotating unit 300 rotates, the optical axis of light (hereinafter referred to as projected light 3A) projected laterally from a portion of the side surface of the rotating unit 300 rotates around the rotation axis C. Accordingly, the projected light 3A and the area where distance measurement can be performed using the projected light 3A (hereinafter referred to as the distance measurement area) also rotate. As described below, the distance measurement device 1 measures the distance to an object 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 light reflected from the projected light 3A by an object in the distance measurement area (hereinafter referred to as reflected light 3B) is received. As the rotating unit 300 rotates around the rotation axis C, the distance measurement device 1 can measure the distance to an object in a 360-degree horizontal distance measurement area.

[0017] 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 embodiment 1, disassembled and cut in the same manner as in Fig. 2. In Fig. 3, in order to make the drawing easier to see, some components (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.

[0018] <Configuration of fixed part> The fixed part 100 includes a housing part 110, a substrate 120, a control part 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, a collimator lens 210, and a lens cover 400.

[0019] The housing 110 has a substantially rectangular parallelepiped shape and includes a bottom surface 111 that forms the bottom surface of the housing 110, a side surface 112 that forms the side surface of the housing 110, and a top surface 113 that forms the top surface of the housing 110. The top surface 113 has a circular opening. The housing 110 is made of metal such as aluminum die-cast.

[0020] The board 120 is, for example, a printed circuit board (PCB), and is arranged inside the housing 110 along the bottom surface 111 (for example, parallel to the bottom surface 111). The board 120 includes electronic circuits, electronic components, and the like for controlling the operation of the distance measurement device 1.

[0021] 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), a Large Scale Integration (LSI), etc. The control unit 130 may include a storage unit (not shown) for storing data and / or programs, etc.

[0022] 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) with an inner diameter that 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.

[0023] 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 113 of the housing 110, and a portion of the base annular portion 142 is supported from below by a portion of the upper surface 113 of the housing 110. The detailed configuration of the fixed support base 140 will be described later.

[0024] 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 the electromagnet. The multiple electromagnets are fixedly arranged in a ring shape on the base ring portion 142 of the fixed support base 140.

[0025] 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.

[0026] The bandpass filter 180 is disposed so as to cover the lower opening of the inverted cone portion 141 of the fixed support base 140. The bandpass filter 180 is a filter that transmits light of a predetermined wavelength (frequency) component and blocks light of other wavelength (frequency) components.

[0027] The detection lens 190 is disposed in the upper opening 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 also be referred to as a condenser lens.

[0028] The light source 200 is embedded in the through-hole 191 of the detection lens 190 and is disposed so as to project projection light 3A of a predetermined wavelength upward. The projection light 3A from the light source 200 is, for example, laser pulse light.

[0029] 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 parallel light and outputs it upward.

[0030] The lens cover 400 has an annular shape with a circular opening in the center. The lens cover 400 is supported and positioned on the fixed support base 140 so that the circular opening in the center corresponds to the opening above the inverted cone portion 141 of the fixed support base 140. The lens cover 400 is made of, for example, resin. Details of the lens cover 400 will be described later.

[0031] <Configuration of Rotating Section> The rotating section 300 includes rotating fins 310 , bearings 320 , magnets 330 , a cylindrical section 340 , a tube section 350 , a tube cover 360 , a reflecting mirror 370 , a sheet 380 , and an oil absorption filter 390 .

[0032] 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 placed in the opening, and the ring-shaped portion covers the base ring 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.

[0033] 3, the bearing 320 includes an annular outer ring 321 and an inner ring 322, and includes a plurality of rolling elements 323, such as balls or rollers, between the outer ring 321 and the inner ring 322. This allows the outer ring 321 to rotate smoothly relative to the inner ring 322. The bearing 320 is disposed inside the opening of the rotary fin 310, with the outer ring 321 connected to the rotary fin 310 and the inner ring 322 connected to the fixed support base 140. Details of the bearing 320 will be described later.

[0034] The magnets 330 are arranged in a circular 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).

[0035] The cylindrical portion 340 has a cylindrical shape, and its bottom surface is connected (fixed) to the top surface of the rotary fin 310. However, the cylindrical portion 340 and the rotary fin 310 may be integral with each other. The cylindrical portion 340 is made of, for example, resin. Details of the cylindrical portion 340 will be described later.

[0036] 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 reflects light (which is transmitted in principle, but contains minute reflected light) that strikes the cylindrical cover 360 and / or the outer cover portion 10, which will be described later, and prevents it from entering the photodetector 170 via the reflecting mirror 370.

[0037] The tube cover 360 is a plate that transmits at least light of a predetermined wavelength (frequency) component used for distance measurement, and is arranged so as to cover the opening that the tube portion 350 forms in the side surface of the columnar portion 340 .

[0038] 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) such that light emitted upward by light source 200 is reflected in the axial direction of tube portion 350 (i.e., the horizontal direction).

[0039] Sheet 380 is a flat, annular sheet with a circular opening in the center, and is disposed between the bottom surface of cylindrical portion 340 and bearing 320 and / or lens cover 400. Sheet 380 transmits light of a predetermined wavelength (frequency) component, such as reflected light.

[0040] The oil adsorption filter 390 is a flat, annular filter with a circular opening in the center, and is disposed between the bottom surface of the cylindrical portion 340 and the rotary fins 310. The oil adsorption filter 390 may be disposed closer to the bearing 320 than the seat 380. Alternatively, the oil adsorption filter 390 may be disposed between the bottom surface of the cylindrical portion 340 and the bearing 320 and / or the lens cover 400. The oil adsorption filter 390 is a filter (e.g., a sponge filter) that has the function of absorbing oil.

[0041] <Behavior of the Optical System> 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 the projection light 3A (e.g., an optical pulse laser) upward. (S12) The projection light 3A emitted from the light source 200 is converted into approximately parallel light by the collimator lens 210 and reflected by the reflector 370 in the axial direction (horizontal direction) of the tube portion 350. Note that "approximately parallel" here includes the 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 reflector 370 passes through the tube portion 350, the tube cover 360, and the outer cover portion 10, and proceeds to the distance measurement area. (S14) The projection light 3A is reflected by the object in the distance measurement area (i.e., becomes reflected light 3B). (S15) As shown in FIG. 1B , at least a portion of the reflected light 3B is input into the spaces on both sides of the cylindrical portion 350. (S16) The reflected light 3B input into the spaces on both sides of the cylindrical portion 350 is reflected downward by the reflecting mirror 370. (S17) The reflected light 3B reflected downward by the reflecting mirror 370 is refracted so as to be collected at the position of the photodetector 170 located below as it passes through the detection lens 190, and passes through the bandpass filter 180. The bandpass filter 180 passes light of a predetermined wavelength (frequency) component. (S18) The amount of reflected light 3B that has passed through the bandpass filter 180 is detected by the photodetector 170.

[0042] As a result, if an object is present, the photodetector 170 can detect a predetermined amount of reflected light 3B or more. Therefore, the control unit 130 may determine that an object is present if the amount of light detected by the photodetector 170 is a predetermined threshold or more, and may determine that an object is not present if the amount of light is less than the predetermined threshold.

[0043] In addition, the control unit 130 may measure (calculate) the distance to the target 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.

[0044] This allows the distance measurement device 1 to determine whether or not an object is present and to measure the distance to the object.

[0045] <Operation of Rotating Unit> The distance measurement device 1 rotates the rotating unit 300 as follows.

[0046] When a current is passed through the coil 160, the coil 160 and the yoke 150 function as electromagnets to generate a magnetic field, and the coil 160 and the yoke 150 move the magnet 330, which is arranged opposite to the coil 160 and the yoke 150, in a rotational direction around the rotation axis C.

[0047] As a result, the rotating fin 310 to which the magnet 330 is connected, and the cylindrical portion 340 and other parts connected to the upper surface of the rotating fin 310 (i.e., the entire rotating portion 300) rotate around 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.

[0048] As the rotating unit 300 rotates, the reflecting mirror 370 and the cylindrical unit 350 inside the cylindrical unit 340 also rotate around the rotation axis C. Therefore, the projection light 3A emitted from the cylindrical unit 350 to the outside also rotates around the rotation axis C. In other words, the projection light 3A is projected over the entire horizontal circumference (360 degrees) around the rotation axis C. This allows the control unit 130 of the distance measurement device 1 to determine the presence or absence of an object, measure the direction in which the object is located, and measure the distance to the object over almost the entire horizontal circumference. Note that the rotating unit 300 does not necessarily have to rotate 360 ​​degrees to control the distance measurement, and may rotate within the rotation range that is the target of distance measurement. This can extend the life of the light source 200.

[0049] <Issues when a bearing is provided> As shown in Figure 3, in addition to the outer ring 321, the inner ring 322, and the rolling elements 323, the bearing 320 is equipped with a lower surface portion 324 that extends from the outer ring 321 toward the inner ring 322 on the lower side and has a gap between it and the inner ring 322, and an upper surface portion 325 that extends from the outer ring 321 toward the inner ring 322 on the upper side and has a gap between it and the inner ring 322.

[0050] The bearing 320 uses a lubricant inside to reduce friction between the outer ring 321, the inner ring 322, and the rolling elements 323. Examples of lubricants include oil and grease. Lubricants (oil or grease) are made from base oil. Hereinafter, grease will be referred to as a specific example of a lubricant. Some of this grease evaporates and is released to the outside of the bearing 320 through the gap between the upper surface portion 325 and the inner ring 322. If the grease released from the bearing 320 and any foreign matter adhering thereto (hereinafter referred to as grease, etc.) adheres to optical components including at least one of the light source 200, the collimator lens 210, the detection lens 190, the reflector 370, and the photodetector 170, or to a light-transmitting component including at least one of the tube cover 360 and the outer cover portion 10, the detection accuracy and ranging accuracy of the target object will be reduced.

[0051] Therefore, in this embodiment, a distance measurement device 1 will be described that is equipped with measures to prevent grease and the like released from the bearing 320 from adhering to optical components and translucent components such as the tube cover 360 and the outer cover part 10 that are arranged on the optical paths of the projected light and the reflected light. The components listed above are merely examples, and are not intended to limit the objects to which grease and the like may be attached. Note that the following measures may be applied alone, in combination with two or more, or all at once.

[0052] <Countermeasure 1> Fig. 4A is a view of rotary fin 310 according to embodiment 1 as viewed obliquely from above. Fig. 4B is a view of rotary fin 310 according to embodiment 1 as viewed obliquely from below. Fig. 5A is a view of fixed support base 140 according to embodiment 1 as viewed obliquely from above. Fig. 5B is a view of fixed support base 140 according to embodiment 1 as viewed obliquely from below.

[0053] First, the detailed configuration of the rotary fin 310 and the fixed support base 140 will be described.

[0054] As shown in Figures 4A and 4B, the rotary 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.

[0055] Furthermore, the rotating fin 310 has a plurality of first holes 314 formed in a circle along the opening at the boundary between the inner side surface portion 311 and the upper surface portion 312. In addition, the rotating fin 310 has a plurality of fins 315 formed at the boundary between the inner side surface portion 311 and the upper surface portion 312 on the back surface (i.e., the surface of the upper surface portion 312 closer to the fixed portion 100) (see FIG. 4B ).

[0056] Furthermore, the upper surface portion 312 may have an inclined surface 316 that approaches the outer surface portion 313 at the boundary with the outer surface portion 313 .

[0057] The magnet 330 is provided on the inside of the outer surface portion 313 of the rotary fin 310. The magnet 330 is disposed opposite the yoke 150 and the coil 160 in the horizontal direction.

[0058] 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 extending upward from the outer surface of the inverted cone portion 141 for locking the inner ring 322 of the bearing 320, second holes 145 formed in the lower portion of each locking portion 144, one or more third holes 146 formed in the base annular portion 142, and a plurality of support portions 147 extending upward from the outer surface of the inverted cone portion 141 for supporting the lens cover 400. The third holes 146 are formed at positions overlapping with the coil 160 and the yoke 150 when viewed in the direction of the rotation axis C (i.e., when viewed from above).

[0059] Next, the airflow generated by the rotation of the rotary fins 310 will be described.

[0060] Fig. 6 is a longitudinal cross-sectional view illustrating airflow inside the distance measurement device 1 according to the first embodiment. 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 the rotary fin 310, bearing 320, and fixed support base 140 according to the first embodiment. Fig. 7B is a bottom view of the rotary fin 310, bearing 320, and fixed support base according to the first embodiment. The following airflow is generated by the rotation of the cylindrical portion 340 including the rotary fin 310.

[0061] (S21) As the rotating fin 310 rotates, an airflow is generated that enters through the gap at the upper end of the locking portion 144, travels circumferentially along the upper surface 325 of the bearing 320, and exits through the first hole 314 of the rotating fin 310. (S22) This airflow exiting the first hole 314 of the rotating fin 310 travels circumferentially along the lower surface of the upper surface 312 of the rotating fin 310, and then flows downward along the inclined surface 316. (S23) This downward airflow passes through the position where the yoke 150 and the coil 160 are disposed, passes through the third hole 146 of the base annular portion 142 of the fixed support base 140, and then flows downward. (S24) This downward airflow flows along the underside of the substrate 120 and enters the second hole 145 of the fixed support base 140 again. (S25) The airflow entering through the second hole 145 of the fixed support base 140 passes through the gap between the inner ring 322 of the bearing 320 and the locking portion 144 and heads upward.

[0062] In this way, when rotating fin 310 is rotated, an air current is generated that flows from inner ring 322 to outer ring 321 along upper surface 325 of bearing 320. As a result, grease and the like released from gaps in upper surface 325 of bearing 320 is carried by the air current in a direction away from rotation axis C. Therefore, it becomes difficult for grease and the like released from gaps in upper surface 325 of bearing 320 to reach optical elements arranged near rotation axis C, and as a result, adhesion of grease and the like to optical elements can be suppressed.

[0063] In addition, this airflow also helps to cool the yoke 150 and the coil 160 because it passes through the positions where the yoke 150 and the coil 160 are arranged.

[0064] Even if rotating fins 310 are not provided, a downward air current is generated by the rotation of rotating unit 300. This air current carries grease and other materials released from bearings 320 and can flow downward through second holes 145 of fixed support base 140. In other words, by providing second holes 145 in fixed support base 140, the air current mixed with grease and other materials released from bearings 320 can be released downward, away from the optical components.

[0065] 2 , sheet 380 is an annular sheet that is disposed between the bottom surface of cylindrical portion 340, upper surface portion 325 of bearing 320, and the upper surface of lens cover 400 so as to cover the circular opening at the center of rotating fin 310, excluding the central rotation axis C. A gap G1 is provided between sheet 380 and the upper surface of lens cover 400.

[0066] 6, air currents generated below sheet 380 are blocked by sheet 380 and do not flow toward columnar portion 340. This prevents grease or the like released from gaps in upper surface portion 325 of bearing 320 from being carried by the air current toward columnar portion 340 and adhering to the optical element.

[0067] 2 , the oil adsorption filter 390 is an annular filter (e.g., a sponge sheet) that is disposed between the bottom surface of the cylindrical portion 340 and the upper surface 325 of the bearing 320 and the upper surface of the lens cover 400 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 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.

[0068] As a result, at least a portion of the grease and other substances contained in the airflow that flows outward along the upper surface 325 of the bearing 320 and then passes through the gap G1 toward the rotation axis C is adsorbed by the oil adsorption filter 390. This reduces the amount of grease and other substances carried by the airflow, and as a result, prevents the grease and other substances from adhering to the optical components.

[0069] <Countermeasure 3> Figure 8A is a vertical cross-sectional view showing an example configuration of bearing 320 according to embodiment 1. Figure 8B is a vertical cross-sectional view showing a modified example of bearing 320 according to embodiment 1. The vertical cross-sections shown in Figures 8A and 8B correspond to the vertical cross-section A-A in Figure 1A.

[0070] As shown in Figure 8A or 8B, an annular upper plate portion 326 may be arranged on the upper surface portion 325 of the bearing 320, with a gap in the height direction from the upper surface portion 325 and covering the upper surface portion 325 of the bearing 320.

[0071] 8A , in the case of bearing 320 having a gap G2 between upper surface portion 325 and inner ring 322, upper plate portion 326 may be disposed so that its inner peripheral portion is connected to inner ring 322 and extends toward outer ring 321. In this case, upper plate portion 326 may form a gap G3 near outer ring 321, which is far from gap G2.

[0072] 8B , in the case of bearing 320 having a gap G2 between upper surface portion 325 and outer ring 321, upper plate portion 326 may be disposed so that its outer peripheral portion is connected to outer ring 321 and extends toward inner ring 322. In this case, upper plate portion 326 may form a gap G3 near inner ring 322, which is far from gap G2.

[0073] As a result, the upper surface portion 325 and the upper plate portion 326 of the bearing 320 form a labyrinth structure. Therefore, grease and the like released from the gap G2 of the upper surface portion 325 of the bearing 320 is blocked by the upper plate portion 326, making it difficult for the grease and the like to escape from the labyrinth structure. As a result, it is possible to prevent the grease and the like from adhering to the optical member.

[0074] 8A or 8B is 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, while the labyrinth structure shown in Fig. 8A or 8B is a two-layer structure consisting of upper surface portion 325 and upper plate portion 326, the labyrinth structure may also be a three-layer structure. Also, upper surface portion 325 may be a separate structure from outer ring 321 or inner ring 322, or may be an integral structure.

[0075] <Countermeasure 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.

[0076] As shown in FIGS. 1B and 3, the columnar portion 340 includes a columnar main body 341 and a top cover 342 which is a flat plate provided on the top surface of the columnar main body 341 so that the top surface is smooth.

[0077] 9, the inside of the cylindrical body 341 has an uneven structure for the purposes of weight reduction, ease of manufacturing, and / or rotational stability. If the cylindrical body 341 is rotated with the outer cover 10 attached and the top cover 342 not provided, leaving the uneven structure exposed, turbulence will be generated at the top of the cylindrical body 341 inside the outer cover 10 due to the uneven structure. This turbulence may carry grease or the like released from gaps in the upper surface 325 of the bearing 320, and cause the grease or the like to adhere to the optical components.

[0078] In contrast to this, 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 portion 340 is prevented from occurring. As a result, it is possible to prevent grease and the like released from the gap in the upper surface portion 325 of the bearing 320 from adhering to the optical members and the translucent members such as the tube cover 360 and the outer cover portion 10. The outer cover portion 10 is provided, for example, to protect the cylindrical portion 340.

[0079] <Measure 5> As shown in Figure 9, the tube cover 360 is arranged to cover the opening of the tube portion 350 formed on the side surface of the cylindrical portion 340. In other words, the rotating portion 300 has a generally cylindrical shape with a partial opening, and the tube cover 360 is provided 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.

[0080] If the cylindrical portion 340 is rotated without providing the tube cover 360 and with the opening of the tube portion 350 exposed, turbulence will be generated by the air flowing out from the opening of the tube portion 350. This turbulence may carry grease or the like that has been released from the gap in the upper surface portion 325 of the bearing 320, and cause the grease or the like to adhere to the optical members and the light-transmitting members.

[0081] In contrast to this, as shown in the present embodiment, by providing a tube cover 360 to close the opening of the tube portion 350, the turbulence described above due to the rotation of the columnar portion 340 is prevented from occurring. As a result, it is possible to prevent grease and the like released from the upper surface portion 325 of the bearing 320 from adhering to the optical members and the light-transmitting member.

[0082] <Measure 6> Fig. 10A is a view of lens cover 400 according to embodiment 1 as seen obliquely from above. Fig. 10B is a view of lens cover 400 according to embodiment 1 as seen obliquely from below.

[0083] Lens cover 400 has an annular shape with a circular opening at the center. Lens cover 400 has an annular portion 401 that forms the annular shape, and a circular convex portion 402 that protrudes downward from the circumference of the opening inside annular portion 401.

[0084] The annular portion 401 of the lens cover 400 is supported and disposed on the support portion 147 of the fixed support base 140. The circular convex portion 402 of the lens cover 400 fits inside the circumference formed by the locking portion 144 and support portion 147 of the fixed support base 140, and faces the outer periphery of the detection lens 190 disposed in the inverted cone portion 141 of the fixed support base 140. This allows the lens cover 400 to be assembled to the fixed support base 140.

[0085] A protrusion 403 is provided on a part of the circular convex portion 402 of the lens cover 400, and the protrusion 403 is adapted to fit into a predetermined gap formed by two support portions 147 of the fixed support base 140. This restricts rotation of the lens cover 400 in the XY plane.

[0086] The annular portion 401 of the lens cover 400 has a reservoir hole 404 formed in a position corresponding to the support portion 147 of the fixed support base 140. By injecting adhesive into the reservoir hole 404, the annular portion 401 of the lens cover 400 is fixed to the support portion 147 of the fixed support base 140.

[0087] When the lens cover 400 is fixed to the fixed support base 140, at least a portion of the annular portion 401 of the lens cover 400 is positioned above the upper plate portion 326 of the bearing 320, forming a narrow gap G1 between the sheet 380 and the lower surface of the oil absorption filter 390. In other words, the bearing 320, the lens cover 400, the sheet 380, and the oil absorption filter 390 form a labyrinth structure. As a result, airflow containing grease and other contaminants flowing from the opening of the second hole 145 through the upper surface portion 325 of the bearing 320 toward the periphery is blocked by the annular portion 401 of the lens cover 400, making it difficult for the airflow to move toward the gap G1 and the optical components. Furthermore, the sheet 380 prevents the airflow flowing toward the rotating unit 300, and at least a portion of the grease and other contaminants contained in the airflow are adsorbed by the oil absorption filter 390. As a result, grease and other contaminants released from the upper surface portion 325 of the bearing 320 from adhering to the optical components and the translucent components can be prevented.

[0088] <Countermeasure 7> Figure 11 is a diagram for explaining the refraction of light when grease adheres to an oil-repellent member and when grease adheres to an oil-philic member. Figure 11(a) shows the case when grease adheres to an oil-repellent member, and Figure 11(b) shows the case when grease adheres to an oil-philic member.

[0089] As shown in Figure 11(a), when grease adheres to an oil-repellent member, the contact angle of the grease becomes relatively large, the grease acts as a lens with a relatively large thickness, and the scattering of light becomes relatively large. On the other hand, as shown in Figure 11(b), when grease adheres to an oil-philic member, the contact angle of the grease becomes smaller than the contact angle of the grease adhered to an oil-repellent member, the grease acts as a lens with a relatively small thickness, and the scattering of light becomes relatively small.

[0090] Therefore, in this embodiment, by increasing the lipophilicity of the optical member and / or the light-transmitting member, even if grease or the like discharged from the bearing 320 adheres to the optical member and / or the light-transmitting member, scattering of light due to the adhesion of the grease or the like is reduced, thereby suppressing a decrease in the amount of light received by the photodetector 170 (i.e., a decrease in the detection level of the light-receiving signal).

[0091] 12 is a graph showing the relationship between the contact angle of grease on reflecting mirror 370 and the signal reduction level according to embodiment 1. In the graph shown in Fig. 12, the horizontal axis represents the contact angle (degrees) of grease attached to reflecting mirror 370, and the vertical axis represents the signal reduction level (%). The signal reduction level represents the percentage reduction in the level of the received light signal compared to when no grease is attached.

[0092] 12, it can be seen that when the target signal degradation level is "10% or less," the contact angle of grease adhering to reflecting mirror 370 needs to be 40 degrees or less. Therefore, when the target signal degradation level is "10% or less," reflecting mirror 370 may be configured to have lipophilic properties such that the contact angle of grease adhering to reflecting mirror 370 is 40 degrees or less. For example, reflecting mirror 370 may be coated with an lipophilic coating such that the contact angle of grease adhering to reflecting mirror 370 is 40 degrees or less.

[0093] Fig. 13 is a graph showing the relationship between the contact angle of grease on the outer cover part 10 and the signal reduction level according to embodiment 1. In the graph shown in Fig. 13, the horizontal axis represents the contact angle (degrees) of grease attached to the outer cover part 10, and the vertical axis represents the signal reduction level (%).

[0094] For example, the graph shown in Figure 13 shows that when the target signal degradation level is "10% or less," the contact angle of grease adhering to the outer cover unit 10 needs to be 28 degrees or less. Therefore, when the target signal degradation level is "10% or less," the outer cover unit 10 may be configured to have lipophilicity such that the contact angle of grease adhering to the outer cover unit 10 is 28 degrees or less. For example, the outer cover unit 10 may be coated with a lipophilic coating such that the contact angle of grease adhering to the outer cover unit 10 is 28 degrees or less.

[0095] 12 and 13, the outer cover unit 10 and the reflecting mirror 370 may each have lipophilic properties (for example, may be coated with an lipophilic coating) such that the contact angle of grease adhering to the outer cover unit 10 is smaller than the contact angle of grease adhering to the reflecting mirror 370. This is because the distance between the outer cover unit 10 and the detection lens 190 is longer than the distance between the reflecting mirror 370 and the detection lens 190, and therefore the effect of light scattering by the grease (i.e., loss of light reception) is large.

[0096] The above-described lipophilicity of the outer cover portion 10 can also be applied to other optical members and / or translucent members such as the tube cover 360, the bandpass filter 180, and the detection lens 190.

[0097] (Summary of First Embodiment) The above description of the first embodiment discloses the following techniques.

[0098] (Technology A) <Technology A1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, and a bearing (320) connected to the rotating part. The rotating part includes a rotating fin (310) that rotates with the rotating part and generates an airflow. As a result, grease and other substances released from the bearing are carried by the airflow generated by the rotating fin, thereby preventing the grease and other substances from adhering to the interior. <Technology A2> In the distance measurement device described in Technology A1, the rotating fin has a plurality of first holes (314) surrounding the bearing. As a result, the rotating fin can generate an airflow passing through the first holes. <Technology A3> In the distance measurement device described in Technology A2, when the rotating fin rotates with the rotating part, an airflow is generated connecting the first surface of the bearing closer to the rotating part and the first holes. As a result, grease and the like released from the first surface of the bearing is carried by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the interior. <Technology A4> In the distance measurement device described in Technology A2 or A3, the rotating fin has a second surface extending from the first hole in the outer circumferential direction, and a plurality of fins (315) provided on the second surface closer to the fixed part. This allows the rotating fin to generate an airflow by the plurality of fins. <Technology A5> In the distance measurement device described in Technology A4, the second surface of the rotating fin is inclined from midway toward the outer periphery toward the fixed part. This allows the generated airflow to move downward by the inclined surface. <Technology A6> In the distance measurement 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 part, the rotating part further includes a magnet (330) provided inside the third surface of the rotating fin, and the fixed part further includes a coil (160) and a yoke (150) arranged adjacent to the magnet. This allows the airflow moving downward by the inclined surface to cool the magnet and the coil.<Technology A7> In the distance measurement device described in any one of Technologies A1 to A6, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes, and the rotating unit further includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This makes it possible to control the optical paths of the projection light and the reflected light. <Technology A8> In the distance measurement device described in any one of Technologies A1 to A7, the fixed unit includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This makes it possible to generate an airflow connecting the first hole (314) and the second hole (145). <Technology A9> In the distance measurement device described in any one of Technologies A1 to A8, the rotating part has a generally cylindrical shape that rotates relative to the fixed part, is partially open, and includes a lid part (e.g., tube cover 360) that is provided 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 interior. <Technology A10> In the distance measurement device described in any one of Technologies A1 to A7, a first surface of the bearing that is closer to the rotating part has a labyrinth structure. This makes it possible to suppress the release of grease and the like from the bearing.

[0099] (Technology B) <Technology B1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, and a bearing (320) connected to the rotating part. The fixed part includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This allows airflow generated by rotation of the rotating part to pass through the second hole, and grease and other substances released from the bearing are carried by the airflow, thereby preventing grease and other substances from adhering to the interior. <Technology B2> In the distance measurement device described in Technology B1, the fixed support base has the second hole (145) in a gap between the fixed support base and the inner ring of the bearing. This allows airflow to pass near the bearing, preventing grease and other substances from adhering to the interior. <Technology B3> In the distance measurement device described in Technology B2, the rotating part includes a rotating fin (310) that rotates with the rotating part and generates an airflow. As a result, grease and the like released from the bearing are carried by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the interior. <Technology B4> In the distance measurement device described in Technology B3, the rotating fin has a plurality of first holes (314) surrounding the bearing. As a result, grease and the like released from the bearing are carried by the airflow generated by the rotating fin through the first holes (314) and the second holes (145), preventing the grease and the like from adhering to the interior. <Technology B5> In the distance measurement device described in Technology B4, when the rotating fin rotates with the rotating part, an airflow is generated that connects the first surface of the bearing closer to the rotating part with the first holes and the second holes. In the distance measuring device described in Technology B5, the rotating fin has a second surface extending from the second hole in the outer circumferential direction, and a plurality of fins (315) provided on a surface of the second surface closer to the fixed portion.This allows the rotating fin to generate an airflow through the multiple fins. <Technology B7> In the distance measurement device described in Technology B6, the second surface of the rotating fin is inclined from midway toward the outer periphery toward the fixed part. This allows the generated airflow to move downward by the inclined surface. <Technology B8> In the distance measurement device described in Technology B7, the rotating fin further includes a third surface extending from the outer periphery of the second surface toward the fixed part, the rotating part further includes a magnet (330) provided inside the third surface of the rotating fin, the fixed part further includes a coil (160) and a yoke (150) arranged adjacent to the magnet, and the fixed support base has a third hole (146) at a position overlapping the coil and yoke when viewed in the direction of the rotation axis of the rotating part. This allows the airflow moving downward by the inclined surface to cool the magnet and coil. <Technology B9> In the distance measurement device described in any one of Techniques B1 to B8, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes. The rotating unit further includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This allows for control of the optical paths of the projection light and the reflected light. <Technology B10> In the distance measurement device described in any one of Techniques B1 to B9, the rotating unit has a cylindrical shape that rotates relative to the fixed unit, is partially open, and includes a lid (e.g., a tube cover 360) that is provided to cover the open surface of the rotating unit. This prevents turbulence caused by the rotation of the rotating unit, thereby preventing grease, etc., released from bearings from adhering to the interior. <Technology B11> In the distance measurement device according to any one of Techniques B1 to B9, a first surface of the bearing that is closer to the rotating part has a labyrinth structure, thereby making it possible to suppress the release of grease or the like from the bearing.

[0100] (Technology C) <Technology C1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed portion (100), a rotating portion (300) that is approximately cylindrical and has an open portion and rotates relative to the fixed portion, a lid (e.g., a tube cover 360) that covers the open surface of the rotating portion, and a bearing (320) connected to the rotating portion. This suppresses the generation of turbulence caused by the rotation of the rotating portion, thereby preventing grease and other substances released from the bearing from adhering to the interior. <Technology C2> In the distance measurement device described in Technology C1, the lid is made of a material that transmits projected light and / or reflected light. This allows the projected light and / or reflected light to pass through the lid. <Technology C3> In the distance measurement device described in Technology C1 or C2, the rotating portion includes a rotating fin (310) that rotates with the rotating portion and generates an airflow. This allows grease and other contaminants released from the bearing to be carried by the airflow generated by the rotating fins, thereby preventing the grease and other contaminants from adhering to the interior. <Technology C4> In the distance measurement device described in any one of Techniques C1 to C3, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes. The rotating unit further includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This allows the optical paths of the projection light and the reflected light to be controlled. <Technology C5> In the distance measurement device described in any one of Techniques C1 to C4, the fixed unit includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This allows the airflow to pass through the second hole (145), preventing the grease and other contaminants released from the bearing from adhering to the interior. <Technology C6> In the distance measurement device according to any one of Techniques C1 to C4, the first surface of the bearing that is closer to the rotating part has a labyrinth structure, which makes it possible to suppress the release of grease and the like from the bearing.

[0101] (Technology D) <Technology D1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, and a bearing (320) that has an outer ring and an inner ring and is connected to the rotating part, and the first surface of the bearing has a labyrinth structure. This makes it possible to suppress the release of grease and other substances from the bearing. <Technology D2> In the distance measurement device described in Technology D1, the labyrinth structure includes at least one disk: a first circular ring (e.g., upper plate portion 326 in FIG. 8A ) that forms a gap with the inner ring (322), and a second circular ring (e.g., upper plate portion 326 in FIG. 8B ) that forms a gap with the outer ring (321). This makes it possible to suppress the release of grease and other substances from the bearing. <Technology D3> In the distance measurement device described in Technology D1 or D2, the rotating part includes a rotating fin (310) that rotates with the rotating part and generates an airflow. As a result, grease and the like released from the bearing are carried by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the interior. <Technology D4> In the distance measurement device described in Technology D3, the rotating fin has a plurality of first holes (314) surrounding the outer ring. As a result, an airflow passing through the first holes can be generated by the rotation of the rotating fin. <Technology D5> In the distance measurement device described in Technology D4, when the rotating fin rotates with the rotating part, an airflow is generated that connects a first surface of the bearing closer to the rotating part with the first hole (314). As a result, grease and the like released from near the first surface of the bearing are carried by the airflow generated by the rotating fin, thereby preventing the grease and the like from adhering to the interior. <Technology D6> In the distance measurement device according to any one of Technologies D3 to D5, the rotating fin includes a second surface extending from the first hole in an outer circumferential direction, and a plurality of fins (315) provided on a surface of the second surface closer to the fixed portion, whereby the rotating fin can generate an airflow by the plurality of fins.<Technology D7> In the distance measurement device described in any one of Techniques D1 to D6, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes, and the rotating unit further includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This makes it possible to control the optical paths of the projection light and the reflected light. <Technology D8> In the distance measurement device described in any one of Techniques D1 to D7, the fixed unit includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This makes it possible to prevent airflow from passing through the second hole and to prevent grease, etc., released from the bearing from adhering to the interior. <Technology D9> In the distance measurement device described in any one of Technologies D1 to D7, the rotating part has a generally cylindrical shape that rotates relative to the fixed part, is partially open, and includes a lid part (e.g., a tube cover 360) that is provided to cover the open surface of the rotating part. This suppresses the generation of turbulence due to the rotation of the rotating part, and therefore prevents grease and the like released from the bearing from adhering to the inside.

[0102] (Technology E) <Technology E1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, an outer cover part (10) that covers the rotating part, and a bearing (320) connected to the rotating part, and the rotating part includes a top cover (342) on its top surface. By providing the top cover in this manner, the generation of turbulence due to the rotation of the rotating part inside the outer cover part can be suppressed. This prevents grease and other materials released from the bearing from adhering to the interior due to turbulence. <Technology E2> In the distance measurement device described in Technology E1, the rotating part has a generally cylindrical shape that rotates relative to the fixed part and has an internal uneven structure. Even if the internal uneven structure is thus achieved, the rotation of the rotating part is blocked by the top cover, thereby suppressing the generation of turbulence due to the rotation of the rotating part inside the outer cover part. This prevents grease and other substances released from the bearing from adhering to the interior due to turbulence. <Technology E3> In the distance measurement device described in Technology E1 or E2, the rotating unit includes a rotating fin (310) that rotates with the rotating unit and generates an airflow. The rotation of the rotating fin generates an airflow. <Technology E4> In the distance measurement device described in any one of Technology E1 to E3, the rotating unit has an opening in a portion thereof and includes a lid (e.g., a tube cover 360) that covers the open surface of the rotating unit. This prevents turbulence from being generated by the rotation of the rotating unit, thereby preventing grease and other substances released from the bearing from adhering to the interior. <Technology E5> In the distance measurement device described in any one of Technology E1 to E4, the fixed unit includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This allows airflow to pass near the bearing, thereby preventing grease and other substances released from the bearing from adhering to the interior. <Technology E6> In the distance measurement device according to any one of technologies E1 to E5, a first surface of the bearing that is closer to the rotating part has a labyrinth structure, thereby making it possible to suppress the release of grease or the like from the bearing.<Technology E7> In the distance measurement device described in any one of Techniques E1 to E6, the fixed part includes a lens cover (400) at least a portion of which is arranged between the bearing and the rotating part. As a result, the lens cover prevents grease and the like released from the bearing from flowing toward the rotating part. <Technology E8> The distance measurement device described in Technique E7 further includes a sheet (380) arranged between the lens cover and the rotating part. As a result, the sheet prevents grease and the like released from the bearing from flowing toward the rotating part. <Technology E9> The distance measurement device described in Technique E7 further includes an adsorption filter (e.g., oil adsorption filter 390) capable of adsorbing oil, arranged between the lens cover and the rotating part. As a result, a portion of the grease and the like released from the bearing is adsorbed by the adsorption filter and is prevented from flowing toward the rotating part. <Technology E10> In the distance measurement device according to any one of technologies E1 to E9, the fixed unit includes a light source (200) that projects the projection light in the direction of the rotating unit along the rotation axis of the rotating unit, and a detection lens (190) through which the reflected light passes, and the rotating unit includes a reflector (370) 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 control the optical paths of the projection light and the reflected light.

[0103] (Technology F) <Technology F1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, and a bearing (320) connected to the rotating part. The fixed part includes a lens cover (400), at least a portion of which is disposed between the bearing and the rotating part. As a result, grease and other substances released from the bearing are prevented from flowing toward the rotating part by the lens cover. This prevents grease and other substances released from the bearing from adhering to components of the rotating part. <Technology F2> In the distance measurement device described in Technology F1, the lens cover includes a circular ring part (401) with an opening in the center and a circular convex part (402) protruding from the inner circumference of the circular ring part. As a result, grease and other substances released from the bearing are prevented from flowing toward the rotating part by the circular ring part of the lens cover. This prevents grease and other substances released from the bearing from adhering to the rotating part. <Technology F3> The distance measurement device described in Technology F1 or F2 further includes a sheet (380) disposed between the fixed part and the rotating part. This prevents grease and other substances released from the bearing from flowing toward the rotating part. <Technology F4> The distance measurement device described in any one of Technology F1 to F3 further includes an adsorption filter (e.g., oil adsorption filter 390) capable of adsorbing oil disposed between the fixed part and the rotating part. This prevents a portion of the grease and other substances released from the bearing from adsorbing to the adsorption filter and flowing toward the rotating part. <Technology F5> The distance measurement device described in any one of Technology F1 to F4, wherein the rotating part includes a rotating fin that rotates with the rotating part and generates an airflow. The rotation of the rotating fin generates an airflow. <Technology F6> In the distance measurement device according to any one of technologies F1 to F5, the fixed portion includes a fixed support base (140) that supports the bearing and the lens cover and has a second hole (145) in a part thereof.This allows the airflow passing through the second hole to flow along the lens cover toward the bearing, and grease and other contaminants released from the bearing are carried by the airflow, preventing the grease and other contaminants from adhering to the interior. <Technology F7> The distance measurement device described in any one of Techniques F1 to F6 includes an outer cover (10) that covers the rotating unit, and the rotating unit includes a top cover (342) on its top surface. By providing such a top cover, it is possible to prevent turbulence caused by the rotation of the rotating unit inside the outer cover. This prevents grease and other contaminants from adhering to the interior due to turbulence. <Technology F8> In the distance measurement device described in any one of Techniques F1 to F8, the first surface of the bearing closer to the rotating unit has a labyrinth structure. This prevents the release of grease and other contaminants from the bearing. <Technology F9> In the distance measurement device described in any one of Techniques F1 to F8, the rotating unit has a generally cylindrical shape that rotates relative to the fixed unit, is partially open, and includes a lid (e.g., a tube cover 360) that covers the open surface of the rotating unit. This suppresses turbulence caused by the rotation of the rotating unit, thereby preventing grease and other substances released from bearings from adhering to the interior. <Technology F10> In the distance measurement device described in any one of Techniques F1 to F9, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes. The rotating unit includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This allows for control of the optical paths of the projection light and the reflected light.

[0104] (Technology G) <Technology G1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, a bearing (320) connected to the rotating part, and a sheet (380) disposed between the fixed part and the rotating part. The sheet prevents grease and other substances released from the bearing from flowing toward the rotating part. This prevents grease and other substances released from the bearing from adhering to components of the rotating part. <Technology G2> In the distance measurement device described in Technology G1, the sheet is a flat, annular sheet with a circular opening at its center that transmits at least the reflected light. This prevents at least the reflected light from being obstructed by the sheet. <Technology G3> In the distance measurement device described in Technology G1 or G2, the rotating part includes a rotating fin (310) that rotates with the rotating part and generates an airflow. As a result, grease and the like released from the bearing are carried by the airflow generated by the rotating fins, thereby preventing the grease and the like from adhering to the interior. <Technology G4> In the distance measurement device described in any one of Technologies G1 to G3, the fixed part includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. As a result, the airflow passes through the second hole (145), preventing the grease and the like released from the bearing from adhering to the interior. <Technology G5> In the distance measurement device described in any one of Technologies G1 to G4, the first surface of the bearing closer to the rotating part has a labyrinth structure. As a result, the release of grease and the like from the bearing is prevented. <Technology G6> In the distance measurement device described in any one of Technologies G1 to G5, the rotating part has a generally cylindrical shape that rotates relative to the fixed part, is partially open, and includes a lid part (e.g., a tube cover 360) that is provided 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 interior.<Technology G7> In the distance measurement device described in any one of Technologies G1 to G6, the fixed part includes a lens cover (400) at least a portion of which is disposed between the bearing and the rotating part. This prevents grease and other substances released from the bearing from flowing toward the rotating part by the lens cover. This prevents grease and other substances released from the bearing from adhering to components of the rotating part. <Technology G8> In the distance measurement device described in any one of Technologies G1 to G7, an adsorption filter (e.g., oil adsorption filter 390) capable of adsorbing oil is disposed between the fixed part and the rotating part. This prevents a portion of the grease and other substances released from the bearing from adsorbing to the adsorption filter and flowing toward the rotating part. <Technology G9> In the distance measurement device described in any one of Technologies G1 to G8, an outer cover part (10) covering the rotating part is further provided, and the rotating part is provided with a top lid (342) on its top surface. By providing this top lid, it is possible to prevent turbulence caused by the rotation of the rotating part inside the outer cover part. This prevents grease and the like released from the bearing from adhering to the interior due to turbulence. <Technology G10> In the distance measurement device described in any one of Technologies G1 to G9, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit, and a detection lens (190) through which the reflected light passes, and the rotating unit includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This makes it possible to control the optical paths of the projection light and the reflected light.

[0105] (Technology H) <Technology H1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, a bearing (320) connected to the rotating part, and an adsorption filter (e.g., oil adsorption filter 390) that is disposed between the fixed part and the rotating part and is capable of adsorbing oil. As a result, a portion of grease and other contaminants released from the bearing is adsorbed by the adsorption filter, preventing them from flowing toward the rotating part. <Technology H2> In the distance measurement device described in Technology H1, the rotating part includes a rotating fin (310) that rotates with the rotating part and generates an airflow. As a result, grease and other contaminants released from the bearing are carried by the airflow generated by the rotating fin, preventing the grease and other contaminants from adhering to the interior. <Technology H3> In the distance measurement device described in Technology H1 or H2, the fixed part supports the bearing and includes a fixed support base having a second hole (145) in a portion thereof. This allows airflow to pass through the second hole (145), preventing grease and other substances released from the bearing from adhering to the interior. <Technology H4> In the distance measurement device described in any one of Technology H1 to H3, the first surface of the bearing closer to the rotating part has a labyrinth structure. This prevents grease and other substances from being released from the bearing. <Technology H5> In the distance measurement device described in any one of Technology H1 to H4, the rotating part has a generally cylindrical shape that rotates relative to the fixed part, is partially open, and includes a lid part (e.g., a tube cover 360) that is provided to cover the open surface of the rotating part. This prevents turbulence caused by the rotation of the rotating part, preventing grease and other substances released from the bearing from adhering to the interior. <Technology H6> In the distance measurement device according to any one of technologies H1 to H5, the fixed part includes a lens cover (400) at least a portion of which is disposed between the bearing and the rotating part. This prevents grease or the like released from the bearing from flowing toward the rotating part by the lens cover. This prevents grease or the like released from the bearing from adhering to components of the rotating part.<Technology H7> The distance measurement device described in any one of Technologies H1 to H6 further includes an outer cover (10) that covers the rotating unit, and the rotating unit includes a top lid (342) on its top surface. By providing a top lid in this manner, it is possible to suppress the generation of turbulence inside the outer cover due to the rotation of the rotating unit. This prevents grease and other substances released from the bearing from adhering to the interior due to turbulence. <Technology H8> The distance measurement device described in any one of Technologies H1 to H7 further includes a sheet (380) arranged between the fixed unit and the rotating unit. This prevents grease and other substances released from the bearing from flowing toward the rotating unit by the sheet. This prevents grease and other substances released from the bearing from adhering to components of the rotating unit. <Technology H9> In the distance measurement device according to any one of Technologies H1 to H8, the fixed unit includes a light source (200) that projects the projection light in the direction of the rotating unit along the rotation axis of the rotating unit, and a detection lens (190) through which the reflected light passes, and the rotating unit includes a reflector (370) 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 control the optical paths of the projection light and the reflected light.

[0106] (Technology I) <Technology I1> A distance measurement device (1) that measures the distance to an object using projected light and light reflected from the object includes a fixed part (100), a rotating part (300) that rotates relative to the fixed part, a lipophilic lid part (e.g., a tube cover 360) that covers the rotating part, and a bearing (320) connected to the rotating part. This reduces the contact angle of the lubricant, even if a lubricant such as grease released from the bearing adheres to the lid part, thereby reducing light scattering due to the lubricant. <Technology I2> In the distance measurement device described in Technology I1, the lid part is made of a material that transmits projected light and / or reflected light. This allows the lid part to transmit projected light and / or reflected light. <Technology I3> In the distance measurement device described in Technology I1 or Technology I2, the fixed unit includes a light source (200) that projects the projection light toward the rotating unit along the rotation axis of the rotating unit and a detection lens (190) through which the reflected light passes. The rotating unit includes a reflector (370) that reflects the projection light from the light source in a predetermined direction and reflects the reflected light toward the detection lens. This allows for control of the optical paths of the projection light and the reflected light. <Technology I4> In the distance measurement device described in Technology I3, the reflector is lipophilic. This reduces the contact angle of the lubricant, even if lubricant such as grease released from a bearing adheres to the reflector, thereby reducing light scattering due to the lubricant. <Technology I5> In the distance measurement device described in Technology I4, the cover and the reflector are each lipophilic enough that the contact angle of the lubricant adhering to the cover is smaller than the contact angle of the lubricant adhering to the reflector. The influence of light scattering due to the lubricant adhering to the lid is large, but this configuration can suppress the influence of light scattering due to the lubricant adhering to the lid. <Technology I6> In the distance measurement device described in any one of Technologies I1 to I5, the lid has lipophilicity such that the contact angle of the lubricant adhering to the lid is 28 degrees or less. This can sufficiently suppress the influence of light scattering due to the lubricant adhering to the lid.<Technology I7> In the distance measurement device described in any one of Techniques I3 to I6, the reflecting mirror has lipophilicity such that the contact angle of a lubricant adhering to the reflecting mirror is 40 degrees or less. This sufficiently suppresses the effect of light scattering caused by the lubricant adhering to the reflecting mirror. <Technology I8> In the distance measurement device described in any one of Techniques I1 to I7, the rotating unit includes a rotating fin (310) that rotates with the rotating unit and generates an airflow. This allows grease and other substances released from the bearing to be carried by the airflow generated by the rotating fin, thereby preventing the grease and other substances from adhering to the interior. <Technology I9> In the distance measurement device described in any one of Techniques I1 to I8, the fixed unit includes a fixed support base (140) that supports the bearing and has a second hole (145) in a portion thereof. This allows the airflow to pass through the second hole (145), preventing the grease and other substances released from the bearing from adhering to the interior. <Technology I10> In the distance measurement device described in any one of Techniques I1 to I9, the first surface of the bearing closer to the rotating unit has a labyrinth structure. This prevents grease and other contaminants from being released from the bearing. <Technology I11> In the distance measurement device described in any one of Techniques I1 to I10, the rotating unit has a generally cylindrical shape that rotates relative to the fixed unit, has a portion open, and the cover is arranged to cover the open surface of the rotating unit. This prevents turbulence caused by the rotation of the rotating unit, thereby preventing grease and other contaminants from being released from the bearing from adhering to the interior. <Technology I12> In the distance measurement device described in any one of Techniques I1 to I11, the fixed unit includes a lens cover (400) at least partially disposed between the bearing and the rotating unit. This prevents grease and other contaminants from being released from the bearing from flowing toward the rotating unit by the lens cover. This prevents grease and other contaminants from being released from the bearing from adhering to components of the rotating unit. <Technology I13> The distance measurement device according to any one of Techniques I1 to I12 further comprises an outer cover (10) that covers the rotating part, and the rotating part comprises a top cover (342) on the top surface.By providing a top cover in this manner, it is possible to suppress the generation of turbulence caused by the rotation of the rotating part inside the outer cover part. This prevents grease and other substances released from the bearings from adhering to the interior due to turbulence. <Technology I14> The distance measurement device described in any one of Technologies I1 to I13 is provided with a sheet (380) arranged between the fixed part and the rotating part. This prevents grease and other substances released from the bearings from flowing toward the rotating part by the sheet. This prevents grease and other substances released from the bearings from adhering to components of the rotating part. <Technology I15> The distance measurement device described in any one of Technologies I1 to I14 is provided with an adsorption filter (e.g., oil adsorption filter 390) arranged between the fixed part and the rotating part, capable of adsorbing oil. This prevents a portion of the grease and other substances released from the bearings from adsorbing to the rotating part.

[0107] 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, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components in the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0108] In addition, this application is based on Japanese patent applications filed on June 30, 2023 (Patent Application Nos. 2023-108930, 2023-108931, 2023-108932, 2023-108933) and Japanese patent applications filed on September 25, 2023 (Patent Application Nos. 2023-161648, 2023-161649, 2023-161651, 2023-161652, 2023-161650), the contents of which are incorporated by reference into this application.

[0109] The technology of the present disclosure is useful for distance measurement devices that include bearings or sensing devices that perform optical sensing.

[0110] 1 Distance measuring device 10 Outer cover part 100 Fixed part 110 Housing part 111 Bottom part 112 Side part 113 Top part 120 Substrate 130 Control part 140 Fixed support base 141 Inverted cone part 142 Base annular part 143 Annular recess 144 Locking part 145 Second hole 146 Third hole 150 Yoke 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 surface part 312 Top surface part 313 Outer surface part 314 First hole 315 Fin 316 Inclined surface 320 Bearing 321 Outer ring 322 Inner ring 323 Rolling element 324 Lower surface portion 325 Upper surface portion 326 Upper plate portion 330 Magnet 340 Cylinder portion 341 Cylinder main body 342 Top cover 350 Cylinder portion 360 Cylinder cover 370 Reflector 380 Sheet 390 Oil absorption filter 400 Lens cover 401 Annular portion 402 Circular convex portion 403 Protrusion 404 Reservoir hole C Rotating shaft G1, G2, G3 Clearance

Claims

1. A distance measuring device that measures the distance to an object using projected light and light reflected by the object from the projected light, comprising: a fixed part; a rotating part that rotates relative to the fixed part; a lipophilic cover part that is provided to cover the rotating part; and a bearing connected to the rotating part.

2. A distance measuring device that measures a distance to an object using projected light and light reflected by the object from the projected light, comprising: a fixed part; a rotating part that rotates relative to the fixed part; and a bearing connected to the rotating part, wherein the rotating part rotates together with the rotating part and includes a rotating fin that generates an airflow.

3. A distance measuring device that measures a distance to an object using projected light and light reflected by the object from the projected light, comprising: 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, wherein a first surface of the bearing has a labyrinth structure.

4. A distance measuring device according to claim 1, wherein the rotating part includes a rotating fin that rotates together with the rotating part and generates an air flow.

5. A distance measuring device according to claim 1, wherein the bearing has an outer ring and an inner ring, and the first surface of the bearing has a labyrinth structure.

6. A distance measuring device according to claim 2, wherein the bearing has an outer ring and an inner ring, and the first surface of the bearing has a labyrinth structure.

7. A distance measuring device according to claim 2, wherein 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 2, further comprising a sheet disposed between the fixed part and the rotating part.

9. A distance measuring device according to claim 2, wherein the fixed portion includes a lens cover, at least a portion of which is disposed between the bearing and the rotating portion.

10. A distance measuring device according to claim 2, further comprising an outer cover part that covers the rotating part, the rotating part being provided with a top cover on the top surface.

11. A distance measuring device as claimed in claim 2, wherein the rotating part has a generally cylindrical shape, has an opening at one end, and further comprises a lid part arranged to cover the opening at the other end of the rotating part.

12. A distance measuring device according to claim 3, further comprising an adsorption filter capable of adsorbing oil, disposed between said fixed part and said rotating part.

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