JP2017090135A - Distance measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that since a length of a plurality of scanning ranges scanned by distance measuring light is the same, a degree of freedom of the range capable of performing a distance measurement is low.SOLUTION: A distance measurement device includes: a housing; a light source provided inside the housing and emitting distance measuring light; a reflection member provided inside the housing and including a first reflection surface for reflecting distance measuring light emitted by the light source to an outside of the housing and a second reflection surface having a different area from the first reflection surface; a rotation part including a rotation axis for supporting the reflection member and making the reflection member rotate around the rotation axis; and a light receiving member for receiving the distance measuring light reflected by a distance measuring object and reflected on the reflection member so as to be converted into an electrical signal.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a distance measuring device.

  2. Description of the Related Art A distance measuring device that uses a laser beam or the like as distance measuring light to measure a distance to a distance measuring object is known. For example, the distance measuring device projects a distance measuring light by rotating a reflecting member having a plurality of reflecting surfaces, and projects the light onto a distance measuring object. The distance measuring device measures the distance to the distance measuring object by receiving the distance measuring light reflected by the distance measuring object by the light receiving member.

  The distance measuring device can scan the distance measuring light in a plurality of ranges (hereinafter referred to as scanning ranges) along the direction in which the reflecting member rotates by reflecting the distance measuring light by the plurality of reflecting surfaces.

JP 2011-203122 A JP 2009-103482 A

  However, the distance measuring device described above has a problem that the range of distance measurement possible is low because the lengths of the plurality of scanning ranges scanned by the distance measuring light are the same.

  In order to solve the above-described problems and achieve the object, a distance measuring device of the present invention is provided in a housing, a light source for projecting ranging light, and provided in the housing. And a reflection member having a first reflection surface for reflecting the distance measuring light projected from the light source to the outside of the housing and a second reflection surface having an area different from that of the first reflection surface, and supporting the reflection member A rotating unit that rotates the reflecting member around the rotating shaft, and a light receiving unit that receives the ranging light reflected by the object to be measured and reflected by the reflecting member and converts the light into an electrical signal. A member.

  Thus, since the area of the first reflecting surface is different from the area of the second reflecting surface, the distance measuring device reflects the distance measuring range of the distance measuring light reflected on the first reflecting surface and the second reflecting surface. The distance measuring range of the distance measuring light can be made different. Thereby, the distance measuring device can improve the degree of freedom of the distance measuring range.

  In the distance measuring apparatus described above, the rotation axis may be inclined with respect to a light projecting direction of the distance measuring light projected by the light source. Thereby, the distance measuring device can scan the distance measuring light reflected by the first reflecting surface and the second reflecting surface rotating around the rotation axis in a curved shape.

  In the distance measuring apparatus described above, the rotation axis may be inclined with respect to the vertical direction and in the direction of the distance measuring object. Thereby, the distance measuring device scans the distance measuring light reflected by the first reflecting surface and the second reflecting surface rotating around the rotation axis along a line curved in a convex or concave shape in the vertical direction. Can do.

  In the distance measuring apparatus described above, the light source may project the distance measuring light in a light projecting direction that is inclined with respect to a vertical direction and inclined in a direction of the distance measuring target. Thereby, the distance measuring device curves the distance measuring light reflected by the first reflecting surface and the second reflecting surface rotating around the rotation axis inclined with respect to the light projecting direction into a convex shape or a concave shape in the vertical direction. Can be scanned along the line.

  In the distance measuring apparatus described above, the light projecting direction of the distance measuring light projected by the rotating shaft or the light source may be inclined in a direction intersecting the direction of the distance measuring target. As a result, the distance measuring device scans the distance measuring light reflected by the first reflecting surface and the second reflecting surface rotating around the rotation axis in a direction crossing the distance measuring direction. Can do.

FIG. 1 is a longitudinal sectional view illustrating the overall configuration of the distance measuring apparatus according to the first embodiment. FIG. 2 is a perspective view of the reflecting member. FIG. 3 is a perspective view of the light collecting member. FIG. 4 is a plan view for explaining the positional relationship between the optical member and the transmission part of the light collecting member. FIG. 5 is a plan view for explaining the path of the distance measuring light and the distance measuring range. FIG. 6 is a front view for explaining the path of the distance measuring light and the distance measuring range. FIG. 7 is a perspective view of the reflecting member of the first modification. FIG. 8 is a cross-sectional view illustrating the entire configuration of the distance measuring apparatus according to the second modification. FIG. 9 is a cross-sectional view illustrating the overall configuration of a distance measuring apparatus according to Modification 3. FIG. 10 is a cross-sectional view illustrating the overall configuration of the distance measuring apparatus according to the second embodiment. FIG. 11 is a perspective view of a light collecting member according to the second embodiment. FIG. 12 is a plan view of the light collecting member of the second embodiment. FIG. 13 is a cross-sectional view illustrating the overall configuration of a distance measuring apparatus according to Modification 4. FIG. 14 is a diagram illustrating the arrangement of light sources and diaphragms according to the fifth modification. FIG. 15 is a diagram illustrating a light source according to the sixth modification. FIG. 16 is a diagram illustrating the rotation axis of the rotating unit according to the modified example 7.

  Similar components are included in the following exemplary embodiments and modifications. Therefore, below, the same code | symbol is attached | subjected to the same component, and the overlapping description is partially abbreviate | omitted. Portions included in the embodiments and modifications can be configured by replacing corresponding portions in other embodiments and modifications. In addition, the configuration, position, and the like of the parts included in the embodiments and modifications are the same as those in the other embodiments and modifications unless otherwise specified.

  In the distance measuring apparatus of the embodiment, by making the areas of the plurality of reflecting surfaces provided on the reflecting member different from each other, the distance measuring range by the distance measuring light is made different for each reflecting surface, and the degree of freedom of the distance measuring range is increased. .

<First Embodiment>
FIG. 1 is a vertical cross-sectional view illustrating the overall configuration of the distance measuring device 10 according to the first embodiment. FIG. 1 is a view of the distance measuring device 10 as viewed from the side when the direction of the distance measuring object is the front. The distance measuring device 10 is provided, for example, in an outer peripheral portion of an automobile or the like, and measures the distance to a distance measuring object such as a surrounding person or object.

  As illustrated in FIG. 1, the distance measuring device 10 according to the first embodiment includes a housing 12, a light source 14, an optical member 16, a reflecting member 18, a rotating unit 20, a light collecting member 22, and a light receiving member. 24 and a control unit 26.

  The housing 12 includes a main body 30 and a housing window 32.

  The main body 30 is made of resin, for example. The main body 30 is formed in a hollow three-dimensional shape. The main body 30 houses and holds the light source 14, the optical member 16, the reflecting member 18, the rotating unit 20, the light collecting member 22, and the light receiving member 24. The main body 30 includes holding members 34 and 36 that hold the light source 14 and the light receiving member 24.

  The housing window 32 is provided in an area through which the distance measuring light RL is transmitted among the surfaces constituting the main body 30. The housing window 32 is made of resin, glass, or the like that can transmit the distance measuring light RL. The housing window 32 may be opened.

  The light source 14 projects distance measuring light RL for measuring the distance to the distance measuring object. The light source 14 is held and fixed to the holding member 34 and is provided in the housing 12. The light source 14 includes a laser device capable of projecting laser light such as a semiconductor laser element. Based on the light projection signal from the control unit 26, the light source 14 projects laser light in the direction indicated by the arrow AW1 as the distance measuring light RL. The one direction is set as a light projecting direction. The light projecting direction of the present embodiment is parallel to the vertical direction and is downward. A direction perpendicular to the light projecting direction is defined as a horizontal direction. Of the horizontal directions, the direction indicated by the arrow AW2 is a direction to be measured (hereinafter referred to as a ranging direction). More precisely, the distance measuring direction is a direction along the center line in the distance measuring range spreading in a fan shape in plan view.

  The optical member 16 applies an optical action to the distance measuring light RL and projects it onto the reflecting member 18. An example of an optical action is refraction. The optical member 16 is disposed in the light projecting direction of the forward distance measuring light RL that is projected by the light source 14. That is, the optical member 16 is disposed on the path of the distance measuring light RL. In the following description, the course until the distance measurement light RL reaches the distance measurement object is defined as the forward path, and the path after the distance measurement light RL is reflected by the distance measurement object is defined as the return path. The optical member 16 is disposed at a position closer to the light source 14 than the light collecting member 22 in the light projecting direction. An example of the optical member 16 is a collimator lens. The optical member 16 refracts the distance measuring light RL, converts it into parallel light, and projects it onto the reflecting member 18. Thereby, the optical member 16 suppresses dispersion (or diffusion) of the distance measuring light RL.

  The reflection member 18 reflects the distance measurement light RL projected by the light source 14 to the distance measurement target outside the housing 12 and reflects the distance measurement light RL reflected by the distance measurement target 22 and the light receiving member. Reflects in the direction of 24. The reflection member 18 is provided in the housing 12. The reflecting member 18 is disposed on the path of the distance measuring light RL projected from the light source 14. The reflecting member 18 receives the distance measuring light RL that is projected from the light source 14 and passed through the optical member 16 to be parallel light. The reflecting member 18 is constituted by, for example, a polygon mirror that can deflect the received distance measuring light RL. The reflecting member 18 includes a plurality of reflecting surfaces 40 a and reflecting surfaces 40 b that reflect the distance measuring light RL toward a distance measuring object outside the housing 12. The reflective surfaces 40a and 40b are made of a highly reflective material such as metal.

  The reflecting surfaces 40a and 40b are inclined with respect to the traveling direction (that is, the light projecting direction) of the forward distance measuring light RL projected by the light source 14. The reflecting surfaces 40a and 40b reflect the outward distance measuring light RL to the outside where the distance measuring object exists. The reflecting surfaces 40a and 40b are inclined with respect to the traveling direction of the distance measuring light RL on the return path reflected by the external distance measuring target. The reflecting surfaces 40 a and 40 b reflect the distance measuring light RL on the return path toward the light collecting member 22 and the light receiving member 24.

  In the example shown in FIG. 1, the reflecting member 18 has two reflecting surfaces 40a and 40b. By using two reflecting surfaces 40a and 40b, it is possible to increase the distance measuring range in the horizontal direction as compared to the case of using three or more surfaces. The inclination angle θa of the reflection surface 40a is different from the inclination angle θb of the reflection surface 40b. Note that the inclination angles θa and θb are angles between a rotation shaft 46 described later and the reflecting surfaces 40a and 40b. In the present embodiment, the inclination angle θa is larger than the inclination angle θb.

  FIG. 2 is a perspective view of the reflecting member 18. As shown in FIG. 2, the reflecting member 18 is configured in a circular shape in plan view. The reflecting member 18 is configured in a partially cylindrical shape with a part removed along a direction inclined with respect to the central axis. The surface formed by removing the reflection member 18 from the cylindrical shape functions as the reflection surfaces 40a and 40b. The central axis of the reflecting member 18 configured in a partial cylindrical shape coincides with the central axis of the rotation shaft 46.

  The reflecting surfaces 40 a and 40 b are arranged along the circumferential direction of the reflecting member 18. The reflection surfaces 40a and 40b are substantially fan-shaped in a plan view viewed from the direction of the rotation shaft 46. The boundary between the reflecting surface 40 a and the reflecting surface 40 b is substantially along the radial direction of the reflecting member 18. The area of the reflective surface 40a is different from the area of the reflective surface 40b. Thereby, the region (or length) scanned by the distance measuring light RL reflected by the reflecting surface 40a is different from the region (or length) scanned by the distance measuring light RL reflected by the reflecting surface 40b. In the present embodiment, the area of the reflection surface 40a is smaller than the area of the reflection surface 40b.

  The reflecting member 18 further has a correction surface 42. The correction surface 42 reflects the distance measuring light RL projected from the light source 14 to the light receiving member 24 without reflecting the distance measuring light RL to the outside. Thereby, the control part 26 can measure the distance (henceforth correction distance) of the light source 14 and the light-receiving member 24. FIG. The control unit 26 enables more accurate distance measurement by subtracting the correction distance from the value obtained by measuring the distance to the distance measurement object.

  Returning to FIG. 1, the rotating unit 20 rotatably supports the reflecting member 18 and rotates it. The rotating unit 20 includes a base 44, a rotating shaft 46, and a driving member 48.

  The base 44 is fixed to one surface (for example, the bottom surface) of the housing 12.

  The rotating shaft 46 is formed in a cylindrical shape. The rotating shaft 46 is rotatably supported by the base 44. The rotation shaft 46 is inclined with respect to the light projecting direction of the distance measuring light RL projected by the light source 14. For example, the rotation shaft 46 is inclined with respect to the vertical direction, and is inclined in the direction of distance measurement (that is, the direction of the housing window 32). The rotating shaft 46 supports the reflecting member 18. Thereby, the reflecting member 18 is supported by the base 44 and the housing 12 so as to be rotatable by the rotation shaft 46. The rotating shaft 46 is fixed along the central axis of the reflecting member 18, for example.

  The drive member 48 is constituted by a motor, for example. The driving member 48 outputs a rotational driving force to the rotating shaft 46 based on the driving signal output from the control unit 26. Accordingly, the driving member 48 rotates the reflecting member 18 together with the rotating shaft 46 around the central axis of the rotating shaft 46.

  The condensing member 22 condenses the distance measuring light RL on the return path onto the light receiving member 24. The condensing member 22 is disposed on the path of the distance measuring light RL reflected by the reflecting surfaces 40 a and 40 b of the reflecting member 18. The light collecting member 22 receives the distance measuring light RL reflected by the distance measuring object outside the housing 12 and reflected by the reflecting member 18. The condensing member 22 is disposed substantially perpendicular to the light projecting direction. The condensing member 22 is configured by a condensing lens capable of condensing light. The condensing member 22 is composed of, for example, a Fresnel lens. The condensing member 22 condenses the received distance measuring light RL and projects it onto the light receiving member 24.

  The condensing member 22 has a transmission part 50 on the outer peripheral part. The transmission part 50 is provided on the distance measurement target side in the outer peripheral part of the light collecting member 22. The optical member 16 and the transmission part 50 are arranged on one straight line extending from the light source 14 along the light projecting direction. The transmission unit 50 is arranged at a position different from the optical member 16 in the light projecting direction of the distance measuring light RL projected by the light source 14. The transmission part 50 is arrange | positioned rather than the optical member 16 in the downstream of a light projection direction, for example.

  FIG. 3 is a perspective view of the light collecting member 22. As shown in FIG. 3, the condensing member 22 is configured in a substantially disk shape. The transmission part 50 is configured by a notch provided in the outer peripheral part of the light collecting member 22 by removing a part of the outer peripheral part of the light collecting member 22. The outer peripheral side of the transmission part 50 is open. The transmission part 50 is formed in a U shape in plan view. The length of the transmission part 50 along the radial direction of the light collection member 22 is longer than the length of the transmission part 50 along the circumferential direction of the light collection member 22.

  The transmission unit 50 allows transmission (or passage) of the ranging light RL without applying an optical action to the ranging light RL projected from the light source 14 and traveling to the reflecting member 18. That is, the transmission unit 50 transmits the distance measuring light RL without condensing and dispersing the light by refraction.

  The condensing member 22 has a light shielding part 52 formed around the transmission part 50. The light shielding unit 52 is made of a material capable of shielding and absorbing light. For example, the light shielding part 52 is configured by a black member that does not reflect light, for example, black paint. As a result, the light shielding unit 52 absorbs light unnecessary for distance measurement, such as the distance measurement light RL reflected by the inner surface of the housing 12, and suppresses the light receiving member 24 from receiving the light.

  Since the light shielding unit 52 shields light, the transmission unit 50 and the light shielding unit 52 also function as a stop for the distance measuring light RL in the forward path projected from the light source 14. Here, the transmission part 50 and the light shielding part 52 are long in the radial direction of the light collecting member 22 and short in the circumferential direction. Therefore, the transmission part 50 and the light shielding part 52 narrow the cross section of the distance measuring light RL along the surface perpendicular to the light projecting direction into a shape that is long in the radial direction of the light collecting member 22 and short in the circumferential direction. The light is projected onto the reflecting member 18. In other words, in the transmission part 50 and the light shielding part 52, the length of the cross section of the distance measuring light RL in the rotation direction of the reflecting member 18 is shorter than the length of the cross section of the distance measuring light RL in the direction orthogonal to the rotation direction. Thus, the distance measuring light RL is narrowed down. The rotation direction of the reflection member 18 is also the circumferential direction of the reflection member 18 in plan view. The direction orthogonal to the rotation direction of the reflection member 18 is also the radial direction of the reflection member 18 in plan view. Therefore, the reflecting member 18 receives the distance measuring light RL having a short length in a direction intersecting (for example, orthogonal to) the boundary between the reflecting surfaces 40a and 40b.

  FIG. 4 is a plan view for explaining the positional relationship between the optical member 16 and the transmission part 50 of the light collecting member 22. As shown in FIG. 4, the optical member 16 is disposed so as to overlap the transmission part 50 of the light collecting member 22 in plan view. The optical member 16 and the transmission part 50 are arranged at the same position in the direction orthogonal to the light projecting direction.

  Thereby, when the optical member 16 and the transmissive part 50 are arranged at the same position in the light projecting direction, naturally, there is a restriction that the plane area of the transmissive part 50 must be larger than the plane area of the optical member 16. Disappear. Therefore, the plane area of the transmission part 50 can be made smaller than the plane area of the optical member 16. As a result, a region where the condensing member 22 configured by a region other than the transmission part 50 can collect the distance measuring light RL becomes larger.

  Further, the transmission part 50 is provided on the distance measurement target side in the outer peripheral part of the light collecting member 22. As a result, the light source 14 and the optical member 16 are arranged closer to the distance measuring object than the light receiving member 24, and the distance measuring light RL in the forward path is reflected by the outer peripheral portions of the reflecting surfaces 40 a and 40 b close to the housing window 32. Can do. Therefore, the area of the housing window 32 through which the distance measuring light RL in the forward path passes is reduced. As a result, the housing window 32 can be made smaller, so that the distance measuring light RL reflected by the housing window 32 is reflected by the reflecting member 18 and received by the light receiving member 24 as noise, while being designed. Can be improved.

  Returning to FIG. 1, the light receiving member 24 converts the distance measuring light RL in the return path into an electrical signal. The light receiving member 24 is held by the holding member 36 and fixed to the housing 12. The light receiving member 24 is fixed in the vicinity of the light source 14. Thereby, even when the housing 12 is composed of a plurality of components, the light receiving member 24 can be assembled to the same components of the light source 14 and the housing 12. For example, the light receiving member 24 is disposed on the central axis of the light collecting member 22. The light receiving member 24 may be disposed in the vicinity of the focal point on the central axis of the light collecting member 22. The light receiving member 24 is a photodiode that converts received light into an electrical signal, such as an avalanche photodiode. The light receiving member 24 receives the distance measuring light RL that is reflected by the object to be measured and reflected by the reflecting member 18 and then collected by the light collecting member 22. The light receiving member 24 converts the distance measuring light RL into a light receiving signal that is an electrical signal and outputs the light receiving signal to the control unit 26.

  The control unit 26 performs overall control of the distance measuring device 10. The control unit 26 includes an arithmetic device such as a CPU or a circuit and a storage device that can store data. The control unit 26 controls the light source 14 and the driving member 48 based on preset conditions, acquires a light reception signal from the light receiving member 24, and measures the distance to the distance measurement target.

  Next, the distance measuring operation of the distance measuring apparatus 10 described above will be described.

  FIG. 5 is a plan view for explaining the trajectory and distance measurement range of the distance measurement light RL. FIG. 6 is a front view for explaining the locus of the distance measuring light RL and the distance measuring range. FIG. 6 is a front view of the distance measuring device 10 as viewed from the distance measuring object. 5 and 6, the solid line indicates the distance measuring light RLa reflected by the reflecting surface 40a, and the dotted line indicates the distance measuring light RLb reflected by the reflecting surface 40b.

  The control unit 26 outputs a light projection signal to the light source 14. For example, the control unit 26 outputs a pulsed light projection signal at a constant time interval. Further, the control unit 26 outputs a drive signal to the drive member 48 of the rotating unit 20.

  When the light source 14 obtains the light projection signal at a constant time interval, the light source 14 periodically projects laser light onto the optical member 16 as the distance measuring light RL at the time interval. The optical member 16 converts the distance measuring light RL projected by the light source 14 into parallel light and projects it in the direction of the reflecting member 18. The distance measuring light RL passes through the transmission part 50 of the light collecting member 22 and reaches the reflecting member 18.

  On the other hand, when the driving member 48 acquires the driving signal, the driving member 48 rotates the reflecting shaft 18 around the rotating shaft 46 by rotating the rotating shaft 46.

  The reflecting member 18 reflects the distance measuring light RL converted into parallel light by the optical member 16 by the reflecting surfaces 40a and 40b. Here, since the reflecting surfaces 40a and 40b of the reflecting member 18 rotate around the rotation shaft 46, the distance measuring light RL is reflected to different positions in the horizontal direction as shown in FIG. Thereby, the distance measuring device 10 measures the distance to the distance measuring object while moving the distance measuring light RL in the horizontal direction.

  Here, the transmission part 50 is provided on the distance measurement target side in the outer peripheral part of the light collecting member 22. Thereby, the reflecting member 18 reflects the distance measuring light RL in the horizontal direction because the distance measuring light RL in the horizontal direction is reflected by the outer peripheral portions of the reflection surfaces 40a and 40b having a long circumferential length. Can be increased.

  The area of the reflective surface 40b is larger than the area of the reflective surface 40a. Accordingly, the distance measurement range Arb by the distance measurement light RL reflected by the reflection surface 40b is larger than the distance measurement range Ara by the distance measurement light RL reflected by the reflection surface 40a.

  The inclination angle θa is larger than the inclination angle θb. Therefore, as shown in FIG. 6, the reflecting surface 40b reflects the distance measuring light RL below the reflecting surface 40a at most distance measuring positions. For example, the reflecting surface 40b reflects downward so that part of the distance measuring light RL reaches the ground GR. On the other hand, the reflection surface 40a reflects upward so that, for example, the distance measuring light RL does not reach the ground GR, and most of the distance measuring light RL does not rise above the general human height.

  The rotation shaft 46 is inclined with respect to the light projecting direction of the distance measuring light RL projected by the light source 14. Accordingly, the angle between the rotating reflecting surface 40a and the distance measuring light RL changes. Similarly, the angle between the rotating reflecting surface 40b and the distance measuring light RL changes. Thereby, the distance measuring position by the distance measuring light RL reflected by the reflecting surface 40a moves along a curved locus protruding downward. Similarly, the distance measuring position by the distance measuring light RL reflected by the reflecting surface 40b moves along a curved locus protruding downward.

  Since the transmission part 50 has a shape that is long in the radial direction of the light collecting member 22, the cross section of the distance measuring light RL that is transmitted has a shape that is long in the radial direction of the light collecting member 22. In other words, the transmission unit 50 makes the length of the cross section of the distance measuring light RL in the rotation direction of the reflection member 18 shorter than the length of the distance measurement light RL in the direction orthogonal to the rotation direction of the reflection member 18. Thereby, the shape of the cross section of the distance measuring light RL along the plane perpendicular to the traveling direction is long along the boundary between the reflective surface 40a, the reflective surface 40b, and the correction surface 42, and short in the direction orthogonal to the boundary. Become. As a result, the time during which the distance measurement light RL cannot measure the distance while straddling the boundary is shortened.

  The distance measuring light RL reaches the reflecting member 18 after being reflected by the distance measuring object. The reflecting member 18 reflects the distance measuring light RL to the light collecting member 22 by the reflecting surface 40a or the reflecting surface 40b. The condensing member 22 condenses the distance measuring light RL and projects it onto the light receiving member 24. The light receiving member 24 converts the distance measuring light RL into an electrical light reception signal and outputs it to the control unit 26.

  The control unit 26 calculates a distance from the time from when the light source 14 projects the distance measuring light RL to when the light receiving member 24 receives the distance measuring light RL to the distance measuring object. In addition, the control unit 26 calculates the direction and distance of the distance measurement target by calculating the direction in which the distance measurement light RL reflected by the reflection surfaces 40a and 40b travels from the rotational position of the reflection member 18.

  As described above, since the distance measuring device 10 is provided with the reflecting surfaces 40a and 40b having different areas on the reflecting member 18, the distance measuring range Ara by the distance measuring light RL reflected by the reflecting surface 40a and the reflecting surface 40b. The distance measurement range Arb by the distance measurement light RL reflected by can be made different. As a result, the distance measuring device 10 can improve the degree of freedom of the distance measurement range by the reflecting surfaces 40a and 40b.

  In the distance measuring device 10, since the rotation shaft 46 is inclined with respect to the light projecting direction, the scanning surface of the distance measurement light RL reflected by the reflecting surfaces 40a and 40b rotating around the rotation shaft 46 is set in the vertical direction. Can be curved. Furthermore, since the rotation shaft 46 is inclined in the vertical direction and is inclined toward the distance measuring object, the scanning surface of the distance measuring light RL can be curved in a convex shape protruding downward. As a result, the distance measuring device 10 can detect the distance measurement objects in the front and the side by one scanning of the distance measurement light RL in the horizontal direction, and can detect the distance measurement objects having different heights. .

  In the distance measuring device 10, since the scanning surface is curved by inclining the rotation shaft 46 with respect to the light projecting direction of the light source 14, compared with the case where the light source 14 or the light receiving member 24 is inclined with respect to the rotation shaft 46. The inclination angle can be made small, for example, ½. As a result, the distance measuring device 10 can be miniaturized and can reduce the amount of protrusion from the automobile when it is provided in an automobile or the like.

  In the distance measuring device 10, since the reflecting member 18 is provided with two reflecting surfaces 40a and 40b, the distance measuring range in the horizontal direction is increased and the reflecting surface is increased as compared with the case where three or more reflecting surfaces are provided. The time during which distance measurement cannot be performed at the boundary between 40a and 40b can be reduced.

  As described above, in the distance measuring device 10, the optical member 16 is disposed at a position different from the transmission unit 50 in the light projecting direction. Thereby, since it is not necessary to make the size of the plane area of the transmission part 50 larger than the size of the plane area of the optical member 16, for example, it is smaller than the magnitude of the distance measuring light RL that transmits the plane area of the transmission part 50. can do. Accordingly, in the condensing member 22 in which the transmission part 50 is formed, the area in which the ranging light RL can be condensed can be increased, and thus the ranging light RL in which the light receiving member 24 is condensed by the condensing member 22. The distance measuring device 10 can improve the distance measuring performance.

  In the distance measuring device 10, since the transmissive part 50 is configured by a notch, the transmissive part 50 can be easily provided on the outer peripheral part of the light collecting member 22. Furthermore, by providing the transmission part 50 on the light collecting member 22, the path of the distance measuring light RL projected onto the distance measuring object and the path of the received distance measuring light RL can be made closer. Thereby, the condensing member 22 receives the distance measuring light RL reflected by the distance measuring object after being transmitted through the transmission unit 50 with respect to a wider area and more efficiently, and receives the light receiving member 24. The light can be condensed. As a result, the distance measuring device 10 can improve the distance measuring performance of a distance measuring object in the distance where the amount of the reflected distance measuring light RL is small, and can further reduce the blind spot in a short distance region where distance measurement is difficult. .

  In the distance measuring device 10, since the optical member 16 suppresses dispersion of the distance measuring light RL, the distance measuring light RL can be used more efficiently.

  In the distance measuring device 10, the transmission part 50 and the light shielding part 52 configured by notches have the length of the cross section of the distance measuring light RL in the rotation direction of the reflection member 18 in a direction orthogonal to the rotation direction of the reflection member 18. It is shorter than the length of the cross section of the distance measuring light RL. Thereby, since the time during which the distance measuring light RL cannot be measured while straddling the boundary between the reflecting surfaces 40a and 40b can be shortened, the range in which the distance can be measured can be further increased.

<Modification 1>
FIG. 7 is a perspective view of the reflecting member 118 of the first modification. As shown in FIG. 7, the reflective member 118 of Modification 1 has three reflective surfaces 140 a, 140 b, 140 c and a correction surface 42. The reflective surfaces 140a, 140b, and 140c have different areas. The reflection surfaces 140a, 140b, and 140c have different inclination angles that are angles between the reflection surfaces 140a, 140b, and 140c. The reflecting member 118 of the first modification can scan the distance measuring light RL at three positions in a direction intersecting (for example, orthogonal) with the scanning direction of the distance measuring light RL. Thereby, the reflection member 118 can improve the ranging performance in the direction intersecting with the scanning direction, for example.

<Modification 2>
FIG. 8 is a cross-sectional view illustrating the overall configuration of the distance measuring device 210 of the second modification. As shown in FIG. 8, the distance measuring device 210 includes a light receiving reflection member 260. The light receiving reflection member 260 is, for example, a total reflection mirror. The light receiving reflection member 260 is disposed on the path of the distance measuring light RL on the return path collected by the light collecting member 222. The light receiving member 24 is disposed on the path of the distance measuring light RL reflected by the light receiving reflecting member 260. In the distance measuring device 210 of the second modification, the light receiving reflecting member 260 reflects the distance measuring light RL collected by the light collecting member 222 to the light receiving member 24. The light receiving member 24 converts the distance measuring light RL reflected by the light receiving reflecting member 260 into a light receiving signal and outputs the light receiving signal to the control unit 26.

  In the distance measuring device 210 according to the second modification, the light receiving reflection member 260 can improve the degree of freedom of arrangement of the light receiving member 24. For example, by disposing the light receiving member 24 closer to the reflecting member 18 than the light source 14, the height of the distance measuring device 210 can be reduced and downsizing can be realized.

<Modification 3>
FIG. 9 is a cross-sectional view illustrating the overall configuration of the distance measuring apparatus 310 of the third modification. As shown in FIG. 9, the light condensing member 322 may be constituted by a convex lens having a transmission part 350 formed on the outer periphery. The transmission part 350 is configured by a notch obtained by partially removing the outer peripheral part of the light collecting member 322.

Second Embodiment
FIG. 10 is a cross-sectional view illustrating the overall configuration of the distance measuring apparatus 410 according to the second embodiment. FIG. 11 is a perspective view of the light collecting member 422 of the second embodiment. FIG. 12 is a plan view of the light collecting member 422 of the second embodiment.

  As shown in FIG. 10, the distance measuring device 410 of the second embodiment includes a light collecting member 422. As shown in FIGS. 11 and 12, the condensing member 422 has a condensing mirror surface 423. The condensing mirror surface 423 is made of a highly reflective metal or the like. The condensing mirror surface 423 is configured as a curved surface. Thereby, the condensing mirror surface 423 reflects the distance measuring light RL toward the light receiving member 24 while condensing the distance measuring light RL. A transmission portion 450 constituted by a notch is formed on the outer peripheral portion of the light collecting member 422. The transmission unit 450 transmits the forward distance measuring light RL. Also in the second embodiment, the transmission unit 450 is disposed at a position different from the optical member 16 in the light projecting direction.

<Modification 4>
FIG. 13 is a cross-sectional view illustrating the overall configuration of a distance measuring apparatus 510 according to Modification 4. As shown in FIG. 13, the distance measuring device 510 according to Modification 4 includes a light receiving reflection member 560. The light receiving reflection member 560 is, for example, a total reflection mirror. The light receiving reflection member 560 is disposed on the path of the return distance measuring light RL collected by the light collecting member 422. The light receiving member 24 is disposed on the path of the distance measuring light RL reflected by the light receiving reflecting member 560.

  In the distance measuring device 510 of Modification 4, the light receiving reflection member 560 is reflected by the light collecting member 422 and reflects the collected distance measuring light RL to the light receiving member 24. The light receiving member 24 converts the distance measuring light RL reflected by the light receiving reflecting member 560 into a light receiving signal and outputs the light receiving signal to the control unit 26.

  In the distance measuring device 510 of Modification 4, the light receiving reflection member 560 can improve the degree of freedom of the arrangement of the light receiving member 24. For example, the ranging device 510 can be downsized by arranging the light receiving member 24 in an empty space.

<Modification 5>
FIG. 14 is a diagram illustrating the arrangement of the light source 14 and the diaphragm 62 according to the fifth modification. In the above-described embodiment, the transmission unit 50 and the light shielding unit 52 function as a diaphragm, but the diaphragm 62 may be provided separately. For example, the diaphragm 62 is disposed between the optical member 16 and the transmission part 50 of the light collecting member 22 and on the path of the forward distance measuring light RL. The diaphragm 62 makes the length of the cross section of the distance measuring light RL in the rotation direction of the reflecting member 18 having the plurality of reflecting surfaces 40a and 40b shorter than the length of the cross section of the distance measuring light RL in the direction orthogonal to the rotation direction. Thus, the distance measuring light RL is narrowed down.

<Modification 6>
FIG. 15 is a diagram illustrating the light source 14 according to the sixth modification. As shown in FIG. 15, the light source 14 may project the distance measuring light RL in the light projecting direction inclined with respect to the vertical direction.
For example, the light source 14 may project the distance measuring light RL in a light projecting direction that is tilted with respect to the vertical direction and tilted in the direction of the distance measuring target. In this case, the rotating shaft 46 may be parallel to the vertical direction or may be inclined. Thereby, for example, when the rotating shaft 46 is arranged in parallel to the vertical direction, it is possible to suppress damage to the rotating unit 20 due to rotation.

<Modification 7>
FIG. 16 is a diagram for explaining the rotating shaft 46 of the rotating unit 20 according to the modified example 7. FIG. 16 is a diagram of a main part of the distance measuring device 710 as viewed from the distance measuring object side. The rotating shaft 46 of the rotating unit 20 may be inclined in a direction intersecting (for example, orthogonal) with the distance measuring direction. Thereby, the distance measuring device 710 can make the scanning line of the distance measuring light RL into a curved shape such as rising to the right or rising to the left, and the distance measuring light in the direction intersecting the distance measuring direction. The range can be biased. For example, when two distance measuring devices 710 are provided on the left and right sides of the front end of the vehicle, the distance measuring range of the distance measuring device 710 provided on the left side is biased to the left front of the vehicle and provided on the right side. The distance measuring range of the distance measuring device 710 can be biased to the front right of the automobile. As a result, the overlapping ranging ranges of the left and right ranging devices 710 can be reduced, and the ranging ranges by the two ranging devices 710 can be expanded. Note that the light projecting direction of the light source 14 may be inclined in a direction intersecting (for example, orthogonal) with the distance measuring direction.

  Although embodiments and modifications of the present invention have been described, these embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These novel embodiments and modifications can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  The arrangement, shape, number, and the like of the configurations in the above-described embodiments and modifications may be changed as appropriate. Moreover, you may combine each embodiment and a modified example suitably.

  In the above-described embodiment and the modification, the example in which the control unit 26 is provided inside the distance measuring device 10 has been described. However, the control unit 26 may be provided outside the distance measuring device 10. It may be different from 10.

  In the above-described embodiment and modification, the transmissive part 50 is configured as a notch, but the transmissive part 50 may be configured to transmit the distance measuring light RL without applying an optical action such as refraction. . Therefore, the transmission part 50 may be made of a material that has a surface that is perpendicular to the light projecting direction (that is, the traveling direction) of the distance measuring light RL and is capable of transmitting light.

  In the above-described embodiment and modification, the example in which the condensing members 22, 322, and 422 are configured by a Fresnel lens, a convex lens, and a condensing mirror is shown, but the condensing member is configured by other optical components that can collect light. May be. For example, the condensing member may be constituted by a refractive lens, a free-form surface lens, or the like.

  In the embodiment and the modification described above, the example in which the reflecting member has one to three reflecting surfaces has been described, but the reflecting member may have four or more reflecting surfaces. Further, when the reflecting member has a plurality of reflecting surfaces, it is preferable to adjust the balance by the area of the reflecting surface and the like so that rotation unevenness and vibration do not occur during the rotating operation by a driving member such as a motor.

  In the above-described embodiment, the light source having the laser device is taken as an example, but the light source may be provided with an LED (Light Emitting Diode) or the like.

10, 210, 310, 410, 510, 610, 710 ... distance measuring device, 14 ... light source, 16 ... optical member, 18, 118, 618 ... reflecting member, 20 ... rotating part, 22, 322, 422 ... condensing member , 24 ... Light receiving member, 40a, 40b, 140a, 140b, 140c, 640 ... Reflecting surface, 46 ... Rotating shaft, 48 ... Driving member, 50, 350, 450 ... Transmission part, 52 ... Light shielding part, 62 ... Aperture, RL ... ranging light

Claims (5)

A housing,
A light source provided in the housing and for projecting ranging light;
A reflecting member provided in the housing and having a first reflecting surface for reflecting the distance measuring light projected by the light source to the outside of the housing and a second reflecting surface having a different area from the first reflecting surface; ,
A rotating part that supports the reflecting member and rotates the reflecting member around the rotating axis;
A light receiving member that receives the distance measuring light reflected by the object to be measured and reflected by the reflecting member, and converts the light into an electrical signal;
Ranging device comprising. The distance measuring device according to claim 1, wherein the rotation axis is inclined with respect to a light projecting direction of the distance measuring light projected by the light source. The distance measuring device according to claim 1, wherein the rotation axis is inclined with respect to a vertical direction and is inclined in a direction of the distance measuring object. The ranging device according to any one of claims 1 to 3, wherein the light source projects the ranging light in a projection direction that is inclined with respect to a vertical direction and inclined in a direction of the ranging object. . The distance measuring method according to any one of claims 1 to 4, wherein a light projecting direction of the distance measuring light projected by the rotation axis or the light source is inclined in a direction intersecting with a direction of the distance measuring object. apparatus.

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