JP2018096871A - Range finding sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a range finding sensor capable of detecting a distance to an object over a wide range.SOLUTION: A range finding sensor 1 comprises: a mirror 15 for light projection that changes a travel direction of parallel light made incident from a light projection unit 11 while being kept as the parallel light so as to travel along a prescribed first direction in accordance with rotation around a prescribed rotational axis; a translucent member 3 which is formed of a cylindrical shape with the rotational axis as an axial center, changes the travel direction of the parallel light reflected by the mirror 15 for light projection and changes the travel direction of the reflected light that the parallel light projected to the surroundings strikes against an object and is reflected; and a light-receiving unit 51 for detecting the reflected light whose travel direction has been changed by the translucent member 3. The translucent member 3 includes: a prism unit 21 for light projection that projects the parallel light made incident from the mirror 15 for light projection along a second direction that intersects the first direction; and a prism unit 31 for light reception that changes the travel direction of the reflected light in accordance with incidence on an incidence plane of the reflected light that the parallel light projected from the prism unit 21 for light projection strikes against the object and is reflected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a distance measuring sensor that detects a distance to an object by irradiating light.

  Conventionally, a technique has been used in which a predetermined range set in advance is irradiated with light, the light reflected by the object is acquired, and the distance to the object is detected. As this type of technology, for example, there is one described in Patent Documents 1-3.

  In Patent Document 1, one beam is converted into a plurality of beams, each converted beam is scanned simultaneously, and reflection from the detection target is distinguished for each beam by a plurality of beam receiving means. A receiving position information detecting device is disclosed. This position information detection device performs two-dimensional scanning on a scanning plane including the height direction in one scan, and based on the information on the scanning position and the distance information to the detection target, the position of the detection target in the three-dimensional space Has been identified.

  Patent Document 2 discloses an in-vehicle radar device that includes a polygon mirror having a plurality of light beam reflecting surfaces, and each reflecting surface is configured to have a different tilt angle with respect to the rotation axis of the polygon mirror. This in-vehicle radar device scans the laser incident on the reflection surface of the polygon mirror in the left-right direction by the rotation of the polygon mirror, and scans while shifting in the vertical direction every time the reflection surface on which the laser beam is incident is switched. Two-dimensional scanning is performed on the scanning plane.

  In Patent Document 3, a light beam is irradiated in front of the vehicle, and the reflected wave is received to generate information necessary for measuring the inter-vehicle distance from the preceding vehicle positioned in front of the vehicle, and the elevation angle of the light beam is negative. An in-vehicle radar device is disclosed that detects a white line on a road surface or a traveling band mark line corresponding to the direction change and generates information necessary for lane keeping. This in-vehicle radar device emits a light beam scanned in the horizontal direction to the front of the vehicle, and when the light beam reaches a predetermined horizontal scanning angle directed to a white line on the road surface or a corresponding traveling zone marker line Furthermore, the light beam is refracted by an optical element such as a prism to change the elevation angle in the minus direction.

JP-A-8-248133 JP 2000-147124 A JP 2003-121546 A

  Since the technique described in Patent Document 1 converts a single beam into a plurality of beams via a half mirror, the light amount of each beam after conversion is reduced with respect to the original light amount. As the amount of light decreases, the detection distance of the object is narrowed, and a receiving means (photodiode) is provided for each of a plurality of beams, which causes an increase in cost.

  The technique described in Patent Document 2 depends on the assigned angle of each surface of the polygon mirror with respect to the horizontal scanning angle, and therefore cannot scan all surfaces at a wide angle. In addition, since reflected light with a large light receiving angle with respect to the central axis connecting the centers of the light receiving lens and the photodiode is not condensed on the photodiode, it is necessary to collect light by providing a light receiving mirror on the upper side or the side part, which increases the cost. It becomes a factor.

  Since the technique described in Patent Literature 3 is based on white line detection, the beam angle can be changed only at a specific location, and the vertical angle cannot be detected over a wide angle. Further, since the reflected light of the laser irradiated in the negative direction due to refraction has a large light receiving angle, the amount of light collected on the light receiving element is small, and the detection distance may be shortened or may not be detected properly.

  Therefore, a distance measuring sensor that can detect the distance to an object over a wide range and can be realized at low cost is required.

  The characteristic configuration of the distance measuring sensor according to the present invention includes a light projecting unit provided with a light source that emits light and a light projecting lens that converts light emitted from the light source into parallel light, and is incident from the light projecting unit. A projecting mirror that changes the traveling direction of the parallel light in parallel with the predetermined first direction in accordance with the rotation around the predetermined rotation axis while maintaining the parallel light, and the rotation axis as a center. A translucent member that has a cylindrical shape and changes the traveling direction of the parallel light reflected by the projection mirror and changes the traveling direction of the reflected light reflected by the parallel light projected to the object. And a light receiving portion that detects the reflected light whose traveling direction has been changed by the light transmissive member, and the light transmissive member is a surface formed along a circumferential direction of the light transmissive member. And the surfaces adjacent to each other along the circumferential direction are There are a plurality of projection surfaces arranged so that the angles with respect to the heart are different from each other, and the parallel light incident from the projection mirror provided on the radially inner side of the translucent member intersects the first direction. The angle of the outer peripheral surface of the translucent member with respect to the axial center when the translucent prism portion is projected from the projection surface along the second direction and the translucent member is viewed from the radially outer side. A plurality of incident surfaces formed along the circumferential direction of the translucent member on the outer peripheral surface of the translucent member so as to have the same angle as the angle of the projection surface with respect to the axis; A light receiving prism unit that changes a traveling direction of the reflected light in response to incidence of the reflected light that is reflected by the parallel light projected from the prism unit upon being incident on the object.

  With such a characteristic configuration, it is possible to irradiate by bending in a second direction at a predetermined angle within a range of 360 degrees (horizontal) using one parallel light (light beam). For this reason, it is possible to irradiate a light beam over a wide range without using a complicated polygon mirror. In addition, since one light beam is irradiated without being dispersed, the amount of light is not reduced and the detection distance is not narrowed. Since the light receiving prism section is inclined at the same angle as that of the light projecting prism section, the reflected light from the object, which is the detection target of the distance measuring sensor, is refracted by the light receiving prism section. Incident on the mirror. As a result, the reflected light can be incident on the light receiving mirror at the same angle for the light beam irradiated at any angle, so that it is not necessary to provide a plurality of light receiving portions, and the light is received by one light receiving portion. It becomes possible. Therefore, a distance measuring sensor can be realized at low cost. Furthermore, since the increase / decrease in the amount of light received in a predetermined direction can be controlled by changing the ratio of the area of the light receiving prism portion to be inclined, the detection range in the predetermined direction can be widened or narrowed. .

  The light projecting prism portion is formed in a first axial region that is a part of an end portion on one axial side of the translucent member to an end portion on the other axial side, and It is preferable that the prism portion for use is formed in a second axial region other than the first axial region from the end on one side in the axial direction to the end on the other side in the axial direction of the translucent member. is there.

  With such a configuration, it is possible to avoid arranging adjacent light receiving prism portions having different angles on the incident path to the light receiving prism portion of the reflected light reflected by the object, so that the reflected light is received by the light receiving device. It is possible to prevent the amount of light from being attenuated by being incident on a light receiving prism portion having a different angle before being incident on the prism portion. Therefore, it is possible to prevent the amount of reflected light (light quantity) incident on the light receiving prism portion from being reduced, and to improve the light receiving efficiency.

  Further, it is preferable that the light projecting prism portion is formed on an outer peripheral surface of the translucent member.

  With such a configuration, it is possible to easily form a light projecting prism portion capable of irradiating parallel light in a desired direction on the translucent member. Therefore, it can be configured at low cost.

  A light receiving mirror that reflects the reflected light whose traveling direction has been changed by the light receiving prism unit toward the light receiving unit; and the light receiving mirror rotates integrally with the light projecting mirror. It is preferable to be configured as follows.

  With such a configuration, the power for rotating the light projecting mirror and the power for rotating the light receiving mirror can be shared. Therefore, it is possible to realize a reduction in cost and size.

  The light projecting prism portion may be configured to include a plane formed along the circumferential direction of the translucent member.

  With such a configuration, the light projecting prism portion can be easily formed.

It is a block diagram which shows the structure of a ranging sensor. It is the figure which showed arrangement | positioning of a light projection part and a light-receiving part. It is a side view of a translucent member. It is explanatory drawing of the prism part for light projection. It is the figure which showed the translucent member which concerns on other embodiment. It is the figure which showed the translucent member which concerns on other embodiment. It is the figure which showed the translucent member which concerns on other embodiment. It is the figure which showed the translucent member which concerns on other embodiment. It is the figure which showed the translucent member which concerns on other embodiment. It is a schematic diagram of the ranging sensor which concerns on other embodiment.

  The distance measuring sensor according to the present invention is configured to be able to detect the distance to an object over a wide range with an inexpensive configuration. Hereinafter, the distance measuring sensor 1 of the present embodiment will be described. FIG. 1 is a block diagram schematically showing the configuration of the distance measuring sensor 1 of the present embodiment. FIG. 2 is a diagram showing the arrangement of the light projecting unit 11 and the light receiving unit 51. As shown in FIGS. 1 and 2, the distance measuring sensor 1 includes a control unit 2, a translucent member 3, a light projecting unit 11, a light projecting mirror 15, a light receiving mirror 45, a light receiving unit 51, a motor 60, An encoder 61 is provided.

  The light projecting unit 11 includes a light source 12 and a light projecting lens 13. The light source 12 is configured using, for example, a laser or an LED, and irradiates the surroundings with light. The light emitted from the light source 12 is incident on a light projecting lens 13 described later. A control signal is transmitted from the control unit 2 to the light source 12, and power is supplied thereto. The light source 12 is driven by these control signals and a power source, and irradiates the surroundings with light.

  The light projection lens 13 converts light emitted from the light source 12 into parallel light. The light emitted from the light source 12 travels in a predetermined range. The light projection lens 13 converts such light into parallel light traveling along a predetermined direction. Thereby, the light from the light source 12 can be irradiated only in a predetermined direction. The parallel light from the light projecting lens 13 is irradiated to the outside of the distance measuring sensor 1 with its traveling direction changed. Hereinafter, the parallel light emitted from the light projecting lens 13 will be referred to as a “light projecting beam” as necessary.

  The light projecting mirror 15 changes the traveling direction of the parallel light incident from the light projecting unit 11 while maintaining the parallel light so as to follow the predetermined first direction according to the rotation around the predetermined rotation axis X. . The light projecting mirror 15 has a mirror surface that reflects light. Therefore, the light projecting mirror 15 reflects the parallel light incident from the light projecting unit 11 as parallel light. Further, the light projecting mirror 15 is rotated about the rotation axis X by the drive signal from the control unit 2. Therefore, the parallel light from the light projecting unit 11 is reflected as parallel light in the first direction (horizontal direction in the present embodiment) corresponding to the radial direction of the rotation axis X.

  The translucent member 3 has a cylindrical shape with the rotation axis X as an axis (see FIG. 3), changes the traveling direction of the parallel light reflected by the light projecting mirror 15, and also projects parallel to the surroundings. The traveling direction of the reflected light reflected by the light hitting the object is changed. The rotation axis X is a rotation axis when the projection mirror 15 rotates. Therefore, the translucent member 3 is configured coaxially with the rotation axis X of the light projecting mirror 15. Parallel light is light whose traveling direction has been changed by the light projecting mirror 15. This parallel light is projected around the distance measuring sensor 1. The parallel light projected around the distance measuring sensor 1 is reflected back to the distance measuring sensor 1 when it hits an object. Although details will be described later, the translucent member 3 changes the traveling direction when these parallel light and reflected light are transmitted. Therefore, the translucent member 3 is formed in a cylindrical shape using a material capable of transmitting at least parallel light and reflected light.

  The translucent member 3 includes a light projecting prism portion 21 and a light receiving prism portion 31. The light projecting prism unit 21 is provided in the housing of the distance measuring sensor 1 with a predetermined angle at a position where the light projecting beam is transmitted, and the light projecting beam is refracted according to the angle. Is irradiated around the distance measuring sensor 1. The light projecting prism portion 21 constitutes a housing window 70 as a window portion formed in the housing of the distance measuring sensor 1. The configuration of the light projecting prism unit 21 will be described later.

  The projection beam emitted from the projection prism unit 21 is reflected and becomes reflected light when it hits an object existing around the distance measuring sensor 1. This reflected light is acquired by the distance measuring sensor 1 via the light receiving prism unit 31. The light receiving prism portion 31 is provided at a position where the reflected light is transmitted with a predetermined angle, and the reflected light is refracted according to this angle, whereby the traveling direction of the reflected light is changed. In this embodiment, the traveling direction of the reflected light is changed so as to be directed to the light receiving mirror 45 described later. The light receiving prism portion 31 constitutes a housing window 70 as a window portion formed in the housing of the distance measuring sensor 1 in the same manner as the light projecting prism portion 21 described above. The configuration of the light receiving prism portion 31 will be described later.

  The light receiving mirror 45 reflects the reflected light whose traveling direction has been changed by the light receiving prism unit 31 toward the light receiving unit 51 described later. Similar to the light projecting mirror 15, the light receiving mirror 45 has a mirror surface that reflects light. In the present embodiment, the light receiving mirror 45 is configured to rotate integrally with the light projecting mirror 15. Therefore, the light receiving mirror 45 is configured so that the rotation axis of the light projecting mirror 15 is coaxial. Reflected light from the light receiving prism portion 31 is reflected along the axial direction of the rotation axis X in accordance with the rotation of the light receiving mirror 45.

  The light receiving unit 51 includes a light receiving lens 52 and a light receiving sensor 53. The light receiving lens 52 is provided between the light receiving mirror 45 and the light receiving sensor 53 and condenses the reflected light reflected by the light receiving mirror 45 on the detection surface of the light receiving sensor 53. The light receiving sensor 53 detects the reflected light whose traveling direction has been changed by the translucent member 3. In the present embodiment, the reflected light whose traveling direction is changed by the light receiving prism portion 31 as described above is collected by the light receiving lens 52. Therefore, the light receiving sensor 53 is disposed at the focal position of the light receiving lens 52, and detects reflected light whose traveling direction has been changed by the light receiving prism unit 31 at the focal position. The detection of light by the light receiving sensor 53 is well known and will not be described. The light receiving unit 51 transmits the detection result to the control unit 2 when the light receiving sensor 53 detects the reflected light.

  The control unit 2 calculates the distance from the distance measuring sensor 1 to the object using the transmitted detection result. Specifically, a detection result from the light receiving unit 51 and information indicating that the light projecting unit 11 has emitted light are also transmitted to the control unit 2. The control unit 2 calculates the time from when the light projecting unit 11 irradiates light to when the light receiving sensor 53 receives light, and calculates the distance sensor 1 by the product of the speed of light and 1/2 of the time. The distance from the object to the object is calculated. Of course, it is also possible to correct and use the delay time required for signal processing of each functional unit for the above time. The control unit 2 controls the motor 60 that rotates the light projecting mirror 15 and the light receiving mirror 45, and acquires the detection result of the rotation angle of the motor 60 from the encoder 61. The control unit 2 controls the rotation of the motor 60 based on the detection result from the encoder 61.

  Next, configurations of the light projecting prism unit 21 and the light receiving prism unit 31 will be described. FIG. 3 is a side view of the translucent member 3. The translucent member 3 includes the light projecting prism portion 21 and the light receiving prism portion 31 as described above, and is provided in the housing window 70 of the distance measuring sensor 1.

  In the present embodiment, as described above, the translucent member 3 is formed in a cylindrical shape having the rotation axis X of the light projecting mirror 15 and the light receiving mirror 45 as an axis. The light projecting prism portion 21 is composed of a surface formed along the circumferential direction of such a cylindrical translucent member 3. “The surface formed along the circumferential direction of the cylindrical light-transmissive member 3” means that a plurality of planes are formed along the circumferential direction of the light-transmissive member 3. In the present embodiment, the light projecting prism portion 21 having these planes is formed on the outer peripheral surface of the translucent member 3 over the entire circumference. In this case, these plural planes are divided every several degrees (for example, 3 to 5 degrees) along the circumferential direction when the translucent member 3 is viewed from the outside in the axial direction, and the respective outer circumferential surfaces are flat. It is formed. For this reason, it is preferable that the lengths along the circumferential direction of the respective planes are equal to each other. Of course, the length along the circumferential direction of each plane does not need to be configured equally. In the present embodiment, a plane is taken as an example of the “surface formed along the circumferential direction of the cylindrical translucent member 3”, but not limited to a plane, for example, a cylindrical surface or a conical surface good.

  In addition, the light projecting prism unit 21 has a plurality of projection surfaces arranged so that the angles of the surfaces adjacent to each other along the circumferential direction are different from each other. The “angle with respect to the axis” means an angle difference between the radial direction orthogonal to the axis and the direction of each normal vector of the plurality of planes described above. In the present embodiment, the plane of the light projecting prism portion 21 is a surface facing the radial direction of the translucent member 3 (hereinafter referred to as “A plane”), and is above the radial direction of the translucent member 3. The surface (hereinafter referred to as “B surface”) and the surface facing downward with respect to the radial direction of the translucent member 3 (hereinafter referred to as “C surface”) will be described.

  FIG. 4 is an explanatory diagram of a projection surface of the light projecting prism unit 21. A perspective view of the translucent member 3 is shown in # 01 of FIG. In addition, # 02 shows a side A that is a side view of the part marked with an alternate long and short dash line in # 01, and # 03 shows a B side that is a side view of the part marked with a broken line in # 01. 03 shows a C-plane that is a side view of the part marked with a two-dot chain line in # 01. In order to facilitate understanding, in FIG. 3, the A surface, the B surface, and the C surface of the light projecting prism portion 21 are shown in the same color. As shown in FIGS. 3 and 4, the plane of the light projecting prism portion 21 is such that the A surfaces are not adjacent to each other along the circumferential direction, and the B surfaces are not adjacent to each other. The C planes are not adjacent to each other. In the present embodiment, as shown in FIGS. 3 and 4, the light projecting prism portion 21 is configured so that “A surface, B surface, C surface” repeats along the circumferential direction.

  The light projecting prism portion 21 refracts the parallel light incident from the light projecting mirror 15 provided on the radially inner side of the translucent member 3, and projects from the projection surface along the second direction intersecting the first direction. Project. In other words, the plurality of planes repeatedly arranged as described above constitute a projection surface, along which the parallel light reflected by the projection mirror 15 is incident from the radially inner side and the projection surface faces. To refract and project parallel light. Accordingly, the light projecting prism unit 21 can project the parallel light incident from the light projecting mirror 15 at an angle in the vertical direction with respect to the horizontal direction.

  Such a light projecting prism portion 21 is formed in the first axial region M that is a part of the end of the translucent member 3 from one axial end to the other axial end. . That is, as shown in FIG. 3, when the axial length of the translucent member 3 is L, the light projecting prism portion 21 is a part of the axial length L of the translucent member 3. It is formed in the first axial region M.

  On the other hand, in the light receiving prism portion 31, the angle of the outer peripheral surface of the translucent member 3 with respect to the axis when the translucent member 3 is viewed from the radially outer side is the same angle as the angle of the projection surface with respect to the axis. As described above, the light transmitting member 3 has a plurality of incident surfaces formed on the outer peripheral surface along the circumferential direction of the light transmitting member 3. “An angle of the outer peripheral surface of the translucent member 3 with respect to the axial center when the translucent member 3 is viewed from the outside in the radial direction” refers to the axial center of the translucent member 3 in a side view of the translucent member 3. And the angle difference between the outer peripheral surface of the translucent member 3. In the present embodiment, the projection surface corresponds to the A surface, the B surface, and the C surface. For this reason, the “angle of the projection surface with respect to the axis” corresponds to the angle θ2 of the B surface with respect to the axis and the angle θ3 of the C surface with respect to the axis when the angle θ1 of the A surface is parallel to the axis. .

  Therefore, in the light receiving prism portion 31, in the side view of the translucent member 3, the angle difference between the axial center of the translucent member 3 and the outer peripheral surface of the translucent member 3 is the angle of the A plane with respect to the axial center. It is formed on the outer peripheral surface of the translucent member 3 so as to be equal to θ1, the angle θ2 of the B surface with respect to the axis, and the angle θ3 of the C surface with respect to the axis. Further, in the present embodiment, the light receiving prism portion 31 has an A surface with respect to the axis so that the angular difference from the outer peripheral surface of the translucent member 3 is uniform over the circumferential direction of the translucent member 3. A first outer peripheral portion 71 formed at an angle θ1 of the second surface, a second outer peripheral portion 72 formed at an angle θ2 of the B surface with respect to the shaft center, and a third outer peripheral portion 73 formed at an angle θ3 of the C surface with respect to the shaft center. Is done.

  In addition, the light receiving prism portion 31 is configured so that the first outer peripheral portion 71, the second outer peripheral portion 72, and the third outer peripheral portion 73 are not adjacent to the outer peripheral portion having the same angle, that is, the first outer peripheral portion 71 is The third outer peripheral portion 72 is adjacent to one or both of the first outer peripheral portion 71 and the third outer peripheral portion 73 so as to be adjacent to one or both of the second outer peripheral portion 72 and the third outer peripheral portion 73. The outer peripheral portion 73 is disposed so as to be adjacent to one or both of the first outer peripheral portion 71 and the second outer peripheral portion 72, and the first outer peripheral portion 71, the second outer peripheral portion 72, and the third outer peripheral portion 73 are reflective as described above. It constitutes an incident surface on which light is incident.

  The light receiving prism unit 31 changes the traveling direction of the reflected light according to the incident on the incident surface of the reflected light reflected by the collimated light projected from the light projecting prism unit 21 when it hits the object. That is, as described above, the reflected light is incident on the first outer peripheral portion 71, the second outer peripheral portion 72, and the third outer peripheral portion 73 described above, and the traveling direction of the reflected light in the direction toward the light receiving mirror 45 due to refraction. Is changed.

  Here, as shown in FIG. 3, when the axial length of the translucent member 3 is L, the light projecting prism portion 21 is a part of the axial length L of the translucent member 3. Although formed in a certain first axial region M, the light receiving prism portion 31 is a first axial region of the translucent member 3 from one axial end to the other axial end. It is formed in the second axial region N other than M. In the present embodiment, as shown in FIG. 3, the light projecting prism portion 21 is formed at the central portion in the axial direction of the translucent member 3. An outer peripheral portion 71 is formed. Accordingly, the first outer peripheral portion 71 is arranged in a state of being divided by the light projecting prism portion 21. A second outer peripheral portion 72 is formed on one axial outer side of the first outer peripheral portion 71, and a third outer peripheral portion 73 is formed on the other outer side in the axial direction of the first outer peripheral portion 71.

  By providing the light projecting prism portion 21 in the translucent member 3 configured as described above at a predetermined location in the distance measuring sensor 1, the light projection prism portion 21 has a projection surface according to the angle of the projection surface. It becomes possible to refract the parallel light reflected by the light mirror 15 and to project the parallel light around the distance measuring sensor 1. In addition, by projecting through the light projecting prism unit 21 by tilting a portion of the distance measuring sensor 1 where the light projecting prism unit 21 is not provided at the same angle as the angle of the light projecting prism unit 21. When the reflected light reflected by the object is refracted and the axis of the translucent member 3 is arranged along the vertical direction, the light can be incident on the light receiving mirror 45 in the horizontal direction. Therefore, the reflected light from any direction can be received by the single light receiving sensor 53.

  In addition, the translucent member 3 may be arrange | positioned inside the housing | casing window 70, and may be arrange | positioned outside. In addition, it is preferable that the translucent member 3 is integrally formed of the same material as the housing window 70.

[Other Embodiments]
In the above embodiment, as shown in FIG. 3, the light receiving prism portion 31 has a first outer peripheral portion 71 formed on both outer sides in the axial direction of the light projecting prism portion 21, and one axis of the first outer peripheral portion 71. The second outer peripheral portion 72 is formed on the outer side in the direction, and the third outer peripheral portion 73 is formed on the outer side in the other axial direction of the first outer peripheral portion 71. However, as shown in FIG. 5, a first outer peripheral portion 71, a second outer peripheral portion 72, and a third outer peripheral portion 73 are formed on one side in the axial direction of the light projecting prism portion 21, and the light projecting prism portion 21. The first outer peripheral portion 71, the second outer peripheral portion 72, and the third outer peripheral portion 73 can be formed on the other side in the axial direction of the light source. As shown in FIG. A plurality of first outer peripheral portions 71, second outer peripheral portions 72, and third outer peripheral portions 73 are formed on one axial side of the prism portion 21, and the first outer peripheral portion is also formed on the other axial side of the projecting prism portion 21. It is also possible to form a plurality of sets of 71, second outer peripheral portion 72, and third outer peripheral portion 73. With this configuration, the influence of the light receiving area due to the shape of the light receiving mirror 45 can be reduced, and the amount of received light can be made uniform. Although not shown, the numbers (division numbers) of the first outer peripheral portion 71, the second outer peripheral portion 72, and the third outer peripheral portion 73 are made unequal to strongly receive reflected light from a specific angle. By doing so, it becomes possible to control the detection distance of the distance measuring sensor 1.

  In the above-described embodiment, the light projecting prism portion 21 has been described by taking the example of being arranged at the central portion in the axial direction of the translucent member 3. For example, as shown in FIG. This position can be arranged at a position different from the axial central portion of the translucent member 3 (for example, a position on the axial end side) in accordance with the projection position of the parallel light.

  Further, for example, as shown in FIG. 8, the light receiving prism portion 31 can be formed so as to be divided along the axial direction. Further, as shown in FIG. 9, the light projecting prism portion 21 and the light receiving prism portion 31 can be formed on the inner peripheral surface of the translucent member 3.

  Further, as shown in FIG. 10, by changing the position of the light projecting unit 11 and providing the fixed mirror 16, the light projecting mirror 15 and the light receiving mirror 45 can be shared. Therefore, the distance measuring sensor 1 can be reduced in size.

  In the above embodiment, the light receiving mirror 45 is described as being configured to rotate integrally with the light projecting mirror 15. However, the light receiving mirror 45 is configured to rotate separately from the light projecting mirror 15. It is also possible to configure.

  The present invention can be used in a distance measuring sensor that irradiates light and detects a distance to an object.

1: Distance sensor 3: Translucent member 11: Projection unit 12: Light source 13: Projection lens 15: Projection mirror 21: Projection prism unit 31: Reception prism unit 45: Reception mirror M: First axial region N: Second axial region

Claims (5)

A light projecting unit provided with a light source that emits light and a light projecting lens that converts the light emitted from the light source into parallel light;
A projecting mirror that changes the traveling direction of the parallel light incident from the light projecting unit as parallel light so as to follow a predetermined first direction according to rotation around a predetermined rotation axis;
Progressing of reflected light, which has a cylindrical shape with the rotation axis as an axis, changes the traveling direction of the parallel light reflected by the projection mirror, and reflects the collimated light projected to the surroundings when hitting an object A translucent member that changes direction;
A light receiving unit that detects the reflected light whose traveling direction has been changed by the translucent member,
The translucent member is a surface formed along the circumferential direction of the translucent member, and is disposed so that the angles of the surfaces adjacent to each other along the circumferential direction are different from each other with respect to the axis. A plurality of projection surfaces, and the parallel light incident from the projection mirror provided on the radially inner side of the translucent member is projected from the projection surface along a second direction intersecting the first direction. The angle of the projecting projection prism portion and the angle of the outer peripheral surface of the translucent member with respect to the axis when the translucent member is viewed from the outside in the radial direction are the same as the angle of the projection surface with respect to the axis. The parallel light projected from the light projecting prism unit has a plurality of incident surfaces formed along the circumferential direction of the translucent member on the outer peripheral surface of the translucent member so as to form an angle. In response to the incident light incident on the incident surface reflected by the object Distance measuring sensor comprising: a light receiving prism unit, configured to change a traveling direction of the serial reflected light. The light projecting prism portion is formed in a first axial region that is a part of an end of the translucent member on one side in the axial direction to an end on the other side in the axial direction.
The light-receiving prism portion is formed in a second axial region other than the first axial region from one end in the axial direction to the other end in the axial direction of the translucent member. Item 3. The distance measuring sensor according to Item 1.   The distance measuring sensor according to claim 1, wherein the light projecting prism portion is formed on an outer peripheral surface of the translucent member. A light receiving mirror that reflects the reflected light whose traveling direction has been changed by the light receiving prism unit toward the light receiving unit;
The distance measuring sensor according to any one of claims 1 to 3, wherein the light receiving mirror is configured to rotate integrally with the light projecting mirror.   5. The distance measuring sensor according to claim 1, wherein the light projecting prism portion includes a flat surface formed along a circumferential direction of the translucent member. 6.

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