Sensor device

Abstract

To provide a sensor device that can measure a deflection angle of a movable reflection unit at low cost and with a low temperature dependency.SOLUTION: A reception system 200 includes: a first optical system having a lens 220; and a second optical system having a lens 220, a first reflection unit 232, and a second reflection unit 224. The first optical system causes an electromagnetic wave reflected or scattered by an object outside a sensor device 10 to form an image in a reception unit 210. The second optical system causes an electromagnetic wave reflected or scattered by a structure 300 to form an image in the reception unit 210.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sensor device. [Background technology]

[0002] In recent years, various laser distance measuring devices have been developed. In particular, LiDAR (Light Detection And Ranging) has been developed as a type of laser distance measuring device. The LiDAR reflects electromagnetic waves emitted from an emission unit such as a LD (laser diode) by a movable reflection unit such as a two-axis MEMS (Micro Electro Mechanical Systems) mirror, and emits the electromagnetic waves toward the outside of the LiDAR. The electromagnetic waves emitted from the LiDAR are reflected or scattered by a target such as an object existing outside the LiDAR. The electromagnetic waves reflected or scattered by the target return to the LiDAR and are received by a receiving unit such as an APD (Avalanche Photodiode). The LiDAR measures the distance to the target based on the time from when the electromagnetic waves are emitted from the emission unit to when the electromagnetic waves reflected or scattered by the target are received by the receiving unit.

[0003] Patent Document 1 describes a laser distance measuring device used in FA (factory automation), etc. In this laser distance measuring device, a reflector is used in both the distance measuring optical system and the reference optical system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-174844 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to measure the deflection angle of a movable reflector such as a two-axis MEMS mirror in a sensor device such as LiDAR, a deflection angle sensor may be provided on the movable reflector. However, providing a deflection angle sensor on the movable reflector may lead to increased costs. In addition, the deflection angle sensor provided on the movable reflector generally has temperature dependency, and depending on the operating temperature of the sensor device, it may be difficult to accurately detect the deflection angle of the movable reflector with a temperature sensor. In addition to the deflection angle sensor provided on the movable reflector, other emitters and receivers may be provided for measuring the deflection angle of the movable reflector in addition to the emitters and receivers for measuring the object by the sensor device. However, providing such other emitters and receivers may lead to increased costs.

[0006] One example of a problem to be solved by the present invention is to measure the deflection angle of a movable reflecting part at low cost and with low temperature dependency. [Means for solving the problem]

[0007] The invention described in claim 1 is An emission unit that emits electromagnetic waves; a movable reflecting portion that reflects the electromagnetic wave toward a predetermined scanning range; A receiving unit including at least one receiving element that receives the electromagnetic waves reflected or scattered by at least one of an object present within the scanning range and a structure located within the scanning range closer to the movable reflecting unit than the object; a first optical system that forms an image of the electromagnetic wave reflected or scattered by the object on the receiving unit; a second optical system that forms an image of the electromagnetic wave reflected or scattered by the structure on the receiving unit; The sensor device includes: [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a sensor device according to an embodiment. [Diagram 2]FIG. 2 is a diagram showing details of a receiving system shown in FIG. [Diagram 3] FIG. 2 is a diagram showing a first example of a structure. [Figure 4] 13A and 13B are diagrams for explaining an example of a method in which the measuring unit measures the deflection angle of the movable reflecting unit based on the reception result by the receiving unit of the electromagnetic wave reflected or scattered by the structure. [Diagram 5] FIG. 4 is a diagram showing a modification of FIG. 3. [Figure 6] 1 is a diagram for explaining an example of a relationship between a structure and a spot of an electromagnetic wave irradiated onto the structure; [Figure 7] FIG. 13 is a diagram showing a second example of a structure. [Figure 8] FIG. 13 is a diagram showing a third example of a structure. [Figure 9] FIG. 13 is a diagram showing a fourth example of a structure. [Figure 10] FIG. 13 is a diagram showing a fifth example of a structure. [Figure 11] FIG. 13 is a diagram showing a sixth example of a structure. [Figure 12] FIG. 13 is a diagram showing a seventh example of a structure. [Figure 13] FIG. 13 is a diagram showing an eighth example of a structure. [Figure 14] FIG. 13 is a diagram showing a ninth example of a structure. [Figure 15] FIG. 17 is a diagram showing a tenth example of a structure. [Figure 16] 1 is a graph showing an example of the relationship between a received signal generated at the receiving unit by electromagnetic waves reflected or scattered by an object and a received signal generated at the receiving unit by electromagnetic waves reflected or scattered by a structure. [Figure 17] FIG. 3 is a diagram showing a first modified example of FIG. 2. [Figure 18] FIG. 2 is a diagram showing a second modified example of FIG. [Figure 19] FIG. 11 is a diagram for explaining a receiving system according to the second embodiment. [Figure 20] FIG. 11 is a diagram for explaining a receiving system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0010] FIG. 1 is a diagram showing a sensor device 10 according to an embodiment.

[0011] In FIG. 1, the first direction X and the second direction Y cross each other, specifically, are perpendicular to each other. The first direction X indicates the horizontal direction, and the second direction Y indicates the vertical direction. The positive direction of the first direction X, which is the direction of the arrow indicating the first direction X, is the left direction when viewed from the movable reflector 120 side toward the structure 300 side, which will be described later. The negative direction of the first direction X, which is the opposite direction of the arrow indicating the first direction X, is the right direction when viewed from the movable reflector 120 side toward the structure 300 side. The positive direction of the second direction Y, which is the direction of the arrow indicating the second direction Y, is the upward direction. The negative direction of the second direction Y, which is the opposite direction of the arrow indicating the second direction Y, is the downward direction. The same applies to FIGS. 3 to 15, which will be described later. As will be clear from the following description, the first direction X may be a direction different from the horizontal direction, and the second direction Y may be a direction different from the vertical direction.

[0012] The sensor device 10 includes an emission unit 110 , a movable reflecting unit 120 , a measurement unit 122 , a collimator lens 132 , a beam splitter 134 , and a receiving system 200 .

[0013] In the following description, the measurement unit 122 is not a hardware-based configuration but a functional block. The measurement unit 122 is realized by any combination of hardware and software, centered on the CPU of any computer, memory, a program loaded into the memory, a storage medium such as a hard disk that stores the program, and a network connection interface. There are various modified examples of the method and device for realizing the measurement unit 122.

[0014] The emission unit 110 emits electromagnetic waves such as infrared rays. The emission unit 110 is an element capable of converting electrical energy such as a current into electromagnetic waves such as light, for example, a laser diode (LD). The electromagnetic waves emitted from the emission unit 110 pass through the collimator lens 132, are reflected by the beam splitter 134, and enter the movable reflection unit 120.

[0015] The movable reflector 120 is, for example, a two-axis MEMS mirror. The movable reflector 120 reflects the electromagnetic wave emitted from the emission unit 110 toward a predetermined scanning range S. For example, the movable reflector 120 is driven, for example, sinusoidally along the first direction X, and is driven, for example, sawtooth-shaped along the second direction Y at a frequency lower than the sinusoidal wave along the first direction X. That is, the first direction X is the direction of resonant drive of the movable reflector 120, and the second direction Y is the direction of linear drive of the movable reflector 120. As a result, the electromagnetic wave reflected by the movable reflector 120 follows a scanning trajectory extending in the second direction Y while turning back along the first direction X.

[0016] The electromagnetic wave reflected by the movable reflecting unit 120 is reflected or scattered by at least one of an object such as an object present within the scanning range S and a structure 300 located closer to the movable reflecting unit 120 than the object within the scanning range S. The reflected or scattered electromagnetic wave returns to the movable reflecting unit 120 and is reflected by the movable reflecting unit 120, passes through a beam splitter 134, and is received by a receiving unit 210 of the receiving system 200, which will be described later.

[0017] The measuring section 122 measures the deflection angle of the movable reflecting section 120 based on the reception result of the electromagnetic wave reflected or scattered by the structure 300 by the receiving section 210 described later.

[0018] The sensor device 10 may include a structure 300. Alternatively, the structure 300 may be provided outside the sensor device 10. When the sensor device 10 includes the structure 300, the structure 300 can be provided, for example, in a window portion of a housing that houses members constituting the sensor device 10, such as the emission unit 110, the movable reflecting unit 120, the collimator lens 132, the beam splitter 134, and the receiving system 200, that is, in a portion through which electromagnetic waves pass between the inside and outside of the housing. However, the location where the structure 300 is provided is not limited to the window portion.

[0019] Fig. 2 is a diagram showing details of the receiving system 200 shown in Fig. 1. In the following explanation of Fig. 2, the electromagnetic wave received by the receiving system 200 is assumed to be light. Note that the matters explained below about the receiving system 200 also apply to electromagnetic waves other than light. In Fig. 2, the movable reflecting part 120 and the beam splitter 134 between the lens 220 and the structure 300 are located in an area that is typically omitted by two diagonal slashes.

[0020] The reception system 200 will be outlined with reference to FIG.

[0021] The receiving system 200 includes a receiving section 210 , a lens 220 , a first reflecting section 232 and a second reflecting section 234 .

[0022] The receiving unit 210 is a receiving element, such as an avalanche photodiode (APD), capable of converting electromagnetic waves, such as light, into electric current or the like.

[0023] The first reflecting section 232 is located closer to the receiving section 210 than the second reflecting section 234. Specifically, the first reflecting section 232 is located around the receiving section 210. The first reflecting section 232 is, for example, a mirror.

[0024] The second reflecting section 234 is located closer to the lens 220 than the first reflecting section 232. Specifically, the second reflecting section 234 is provided on the surface of the lens 220 facing the receiving section 210. The second reflecting section 234 is, for example, a partially reflective film coated on the surface of the lens 220. Note that the second reflecting section 234 does not need to have a partially reflective film. Even if the second reflecting section 234 does not have a partially reflective film, it is possible to utilize the partially reflected light generated by the difference between the refractive index of the lens 220 and the refractive index of air.

[0025] In FIG. 2, the solid lines extending parallel to each other from the structure 300 side to the lens 220 and converging from the lens 220 to the receiving unit 210 indicate light rays reflected or scattered by an object present outside the sensor device 10 and imaged by the lens 220 on the receiving unit 210. The dashed lines expanding from the structure 300 toward the lens 220 and traveling back and forth between the first reflecting unit 232 and the second reflecting unit 234 to reach the receiving unit 210 indicate light rays reflected or scattered by the structure 300 and imaged on the receiving unit 210 by the lens 220, the first reflecting unit 232, and the second reflecting unit 234. The dashed lines converging at a position at a distance f2 from the lens 220 on the opposite side of the lens 220 with respect to the receiving unit 210 indicate light rays reflected or scattered by the structure 300 and transmitted through the lens 220 when the first reflecting unit 232 is not provided. Furthermore, the dashed line extending from the structure 300 side to the receiving unit 210 side indicates the optical axis of the lens 220. Furthermore, the hatched area extending from the two diagonal slashes toward the structure 300 side indicates the electromagnetic waves reflected by the structure 300 and irradiated toward the outside of the structure 300 or the sensor device 10. Furthermore, a portion P indicates the intersection of the structure 300 and the optical axis of the lens 220.

[0026] The receiving system 200 has a first optical system including a lens 220, and a second optical system including the lens 220, a first reflecting unit 232, and a second reflecting unit 224. The first optical system forms an image of electromagnetic waves reflected or scattered by an object present outside the sensor device 10 on the receiving unit 210. The second optical system forms an image of electromagnetic waves reflected or scattered by the structure 300 on the receiving unit 210. The measuring unit 122 shown in FIG. 1 measures the deflection angle of the movable reflecting unit 120 by using the electromagnetic waves formed on the receiving unit 210 by the second optical system.

[0027] In this embodiment, the emission section used in the first optical system and the emission section used in the second optical system are shared as emission section 110 shown in Fig. 1. Therefore, the deflection angle of movable reflector 120 can be measured at lower cost than when an emission section used in the first optical system and another emission section used in the second optical system are used.

[0028] Furthermore, in this embodiment, the deflection angle of the movable reflecting unit 120 can be measured using the second optical system without providing a deflection angle sensor in the movable reflecting unit 120. The temperature dependence of the second optical system is generally lower than the temperature dependence of the deflection angle sensor. Therefore, in this embodiment, the deflection angle of the movable reflecting unit 120 can be measured with low temperature dependence compared to the case where a deflection angle sensor is provided in the movable reflecting unit 120. Note that the sensor device 10 may include a deflection angle sensor in addition to the second optical system.

[0029] Furthermore, in this embodiment, the lens 220 is shared by the first optical system and the second optical system. Therefore, the deflection angle of the movable reflector 120 can be measured at a lower cost than when a lens used in the first optical system and another lens used in the second optical system are used.

[0030] Furthermore, in this embodiment, a receiving element where the electromagnetic wave is received by the first optical system and a receiving element where the electromagnetic wave is received by the second optical system are shared as the receiving unit 210. Therefore, it is possible to measure the deflection angle of the movable reflecting unit 120 at a lower cost than when using a receiving element where the electromagnetic wave is received by the first optical system and another receiving element where the electromagnetic wave is received by the second optical system.

[0031] The receiving system 200 will be described in detail with reference to FIG.

[0032] An object existing outside the sensor device 10 is located at infinity of the receiving system 200. Therefore, the light reflected or scattered by the object is substantially parallel light until it enters the lens 220. After transmitting through the lens 220, this light is imaged on the receiving unit 210 located at a position that is the focal length f of the lens 220 away from the lens 220 without being reflected by the first reflecting unit 232 and the second reflecting unit 234.

[0033] 1 is reflected or scattered by structure 300 on the optical axis of lens 220. The electromagnetic wave reflected or scattered by structure 300 and transmitted through lens 220 is reflected by first reflecting section 232 and second reflecting section 234, and then forms an image on receiving section 210.

[0034] If the first reflecting portion 232 is not provided, the electromagnetic wave reflected or scattered by the structure 300 is imaged at a position a distance f2 away from the lens 220. The focal length f of the lens 220, the distance f1 between the lens 220 and the structure 300, and the distance f2 satisfy the relationship of the following formula (1). 1 / f1+1 / f2=1 / f (1) From formula (1), f2>f. Even in this case, in this embodiment, due to reflection by first reflecting portion 232 and reflection by second reflecting portion 234, even an electromagnetic wave reflected or scattered by structure 300 can be imaged on receiving portion 210 located at a position away from lens 220 by focal length f of lens 220.

[0035] The electromagnetic wave reflected or scattered by the structure 300 and transmitted through the lens 220 may be reflected by at least two reflecting sections before being imaged at the receiving section 210. That is, as shown in Fig. 2, the electromagnetic wave may be reflected by two reflecting sections, i.e., by the first reflecting section 232 and the second reflecting section 234, before being imaged at the receiving section 210, or may be reflected by three or more reflecting sections before being imaged at the receiving section 210.

[0036] Furthermore, when the optical distance f2 from the lens 220 to the receiving unit 210 in the second optical system is 1.5 times or more the optical distance from the lens 220 to the receiving unit 210 in the first optical system, i.e., the focal length f of the lens 220, the distance f1 from the lens 220 to the structure 300 is 3 times or less the focal length f. For example, when the structure 300 is attached to a window of a housing that houses the members that constitute the sensor device 10, from the viewpoint of miniaturizing the sensor device 10, for example, the distance f2 can be 1.5 times or more the focal length f1.

[0037] Fig. 3 is a diagram showing a first example of the structure 300. In the example shown in Fig. 3, a scanning range S in the region where the structure 300 is arranged is shown as a region surrounded by a two-dot chain line. The same applies to Figs. 7 to 15 described later.

[0038] 3, the structure 300 is provided such that a plurality of transmission regions 310, which are capable of transmitting electromagnetic waves reflected by the movable reflector 120 and electromagnetic waves reflected or scattered by an object, are arranged in a striped pattern along the first direction X. In the region where the plurality of transmission regions 310 are arranged in a striped pattern, portions of the structure 300 and the plurality of transmission regions 310 are arranged alternately to form a striped portion of the structure 300. The plurality of striped portions of the structure 300 are arranged, for example, at intervals according to the tangent of the deflection angle of the movable reflector 120 along the first direction X.

[0039] The structure 300 may have portions having different reflectivities for the electromagnetic wave irradiated to the structure 300. For example, in the example shown in FIG. 3, the reflectivities of the stripes of the structure 300 may be different in the second direction Y. In detail, the reflectivities of the stripes of the structure 300 may be higher or lower from the top to the bottom of the structure 300. Due to the difference in reflectivities, the measuring unit 122 can measure the deflection angle of the movable reflecting unit 120 along the second direction Y. Note that, in the example shown in FIG. 3, the width of each stripe of the structure 300 in the first direction X is constant regardless of the position in the second direction Y within the structure 300.

[0040] FIG. 4 is a diagram for explaining an example of a method in which the measuring section 122 measures the deflection angle of the movable reflecting section 120 based on the reception result by the receiving section 210 of the electromagnetic wave reflected or scattered by the structure 300.

[0041] In FIG. 4, a circle marked with "iFOI(ta)", a circle marked with "iFOI(tb)", and a circle marked with "iFOI(tc)" indicate the iFOI (instantaneous field of illumination) of the sensor device 10 at the position of the structure 300 at times ta, tb, and tc, respectively. A circle marked with "iFOV(ta)", a circle marked with "iFOV(tb)", and a circle marked with "iFOV(tc)" indicate the iFOV (instantaneous field of view) of the second optical system of the sensor device 10 at times ta, tb, and tc, respectively. Here, times ta, tb, and tc are the instantaneous field of illumination (iFOI) of the sensor device 10 at times ta, tb, and tc, respectively. <tb<tcとなっている。

[0042] 4, similarly to the example shown in FIG 3, the structure 300 has a plurality of stripe portions aligned in the first direction X. A portion of the iFOV of the second optical system at time ta, a portion of the iFOV of the second optical system at time tb, and a portion of the iFOV of the second optical system at time tc each overlap with one stripe portion 300a of the plurality of stripe portions of the structure 300. The area of ​​the portion of the iFOV of the second optical system that overlaps with the stripe portion 300a at time ta, the area of ​​the portion of the iFOV of the second optical system that overlaps with the stripe portion 300a at time tb, and the area of ​​the portion of the iFOV of the second optical system that overlaps with the stripe portion 300a at time tc increase in this order. Therefore, the strength of the signal generated in the receiving unit 210 by each of the iFOV of the second optical system at time ta, the iFOV of the second optical system at time tb, and the iFOV of the second optical system at time tc increases in the order of the iFOV of the second optical system at time ta, the iFOV of the second optical system at time tb, and the iFOV of the second optical system at time tc. Therefore, the measuring unit 122 can measure the deflection angle of the movable reflecting unit 120 based on the strength of the signal generated in the receiving unit 210 by the iFOV of the second optical system.

[0043] FIG. 5 is a diagram showing a modification of FIG.

[0044] In the example shown in FIG. 5, similarly to the example shown in FIG. 3, the structure 300 has a plurality of stripe portions arranged in the first direction X. Furthermore, in the example shown in FIG. 5, the width of at least a portion of the structure 300 differs depending on the position in the structure 300. Specifically, the width in the first direction X of each stripe portion of the structure 300 differs depending on the position in the second direction Y of the structure 300. Specifically, the width in the first direction X of each stripe portion of the structure 300 becomes wider from the top to the bottom of the structure 300. Therefore, the reflectance of each stripe portion of the structure 300 becomes higher from the top to the bottom of the structure 300. Note that the width in the first direction X of each stripe portion of the structure 300 may become narrower from the top to the bottom of the structure 300.

[0045] FIG. 6 is a diagram for explaining an example of the relationship between the structure 300 and the spot of the electromagnetic wave irradiated onto the structure 300. As shown in FIG.

[0046] In FIG. 6, the solid circle labeled "iFOI" indicates the iFOI generated by the emission unit 110 and the collimator lens 132, i.e., the spot of the electromagnetic wave reflected by the movable reflector 120 and irradiated onto the structure 300. The solid circle labeled "iFOV(2)" indicates the iFOV of the second optical system, i.e., the field of view of the second optical system. The dashed circle labeled "iFOV(1)" and outside the iFOV indicates the iFOV of the first optical system. The iFOV of the second optical system is smaller than the iFOI of the second optical system.

[0047] In the example shown in FIG. 6, similarly to the example shown in FIG. 3, the structure 300 has a plurality of stripe portions arranged in the first direction X. The width of each stripe portion of the structure 300 in the first direction X is approximately equal to the width of the iFOV of the second optical system in the first direction X. In this case, the second optical system can detect small shapes of the structure 300 according to the size of the iFOV of the second optical system. In addition, the width of each stripe portion of the structure 300 in the first direction X is much smaller than the width of the iFOV of the first optical system in the first direction X. For example, the width of each stripe portion of the structure 300 in the first direction X is 10% or less of the interval in the first direction X of the iFOV of the first optical system. Therefore, in the conventional example having only the first optical system, it is difficult to detect the structure of the stripe portion of the structure 300.

[0048] 7 is a diagram showing a second example of the structure 300. In this example, the structure 300 is provided such that a plurality of transmission regions 310, which are capable of transmitting the electromagnetic waves reflected by the movable reflector 120 and the electromagnetic waves reflected by the target object, are arranged in a striped pattern along the second direction Y.

[0049] 8 is a diagram showing a third example of the structure 300. In this example, the structure 300 is provided such that a plurality of transmission regions 310, through which the electromagnetic waves reflected by the movable reflector 120 and the electromagnetic waves reflected by the target object can transmit, are arranged in stripes obliquely with respect to both the first direction X and the second direction Y.

[0050] 9 is a diagram showing a fourth example of the structures 300. In this example, a plurality of structures 300 are arranged along two adjacent sides of a scanning range S that is substantially quadrangular, specifically, substantially rectangular. The other areas within the scanning range S are transparent areas 310.

[0051] 10 is a diagram showing a fifth example of the structure 300. In this example, a plurality of structures 300 are arranged along all four adjacent sides of a substantially quadrangular, specifically, substantially rectangular, scanning range S. The other areas within the scanning range S are transparent areas 310.

[0052] 3 to 10 may be replaced with a low reflectance region of the structure 300. As an example, the low reflectance region may be glass that transmits light and reflects it slightly.

[0053] FIG. 11 is a diagram showing a sixth example of structure 300. In the example shown in FIG. 11, structure 300 is configured with light scattering portions such as scratches formed on a substrate such as glass. Also, in the example shown in FIG. 11, a plurality of light scattering portions extending linearly along a first direction X are arranged in a second direction Y. Alternatively, structure 300 may be a light scattering portion of another substance or the like provided on the surface or inside of a substrate such as glass. For example, this substance can be attached, printed, coated or embedded on a substrate such as glass.

[0054] 12 is a diagram showing a seventh example of the structures 300. In this example, a plurality of structures 300 described with reference to FIG.

[0055] Fig. 13 is a diagram showing an eighth example of the structures 300. In this example, a plurality of structures 300 described using Fig. 11 are arranged in stripes along diagonal directions with respect to both the first direction X and the second direction Y.

[0056] Fig. 14 is a diagram showing a ninth example of the structure 300. In this example, the structures 300 described using Fig. 11 are arranged in a lattice shape, specifically a quadrangular lattice shape, more specifically a square lattice shape. Note that the structures 300 may be arranged in a lattice shape other than the quadrangular lattice shape, for example, a triangular lattice shape or a hexagonal lattice shape.

[0057] FIG. 15 is a diagram showing a tenth example of the structure 300. In the example shown in FIG. 15, the structure 300 extends in a meandering shape. Specifically, the structure 300 extends in the second direction Y while folding back in the first direction X. The structure 300 may extend in the first direction X while folding back in the second direction Y. A voltage may be applied between both ends of the structure 300 shown by the black circle to pass a current through the structure 300, causing the structure 300 to generate heat. That is, the structure 300 may be an electric heating wire. The structure 300 may be a light scattering section described with reference to FIG. 11.

[0058] 16 is a graph showing an example of the relationship between a reception signal generated in the receiving unit 210 by an electromagnetic wave reflected or scattered by an object, and a reception signal generated in the receiving unit 210 by an electromagnetic wave reflected or scattered by the structure 300. In the graph of FIG. 16, the horizontal axis represents time, and the vertical axis represents the intensity of the reception signal by the receiving unit 210.

[0059] As shown in Fig. 16, at time t2, a reception signal S1 is generated by the receiving unit 210 of the electromagnetic wave reflected or scattered by the object. Also, at time t1, which is earlier than time t2, a signal S21 is generated by the reception vibration of the electromagnetic wave reflected or scattered by a portion of the structure 300 having a relatively high reflectance, and a signal S22 is generated by the reception vibration of the electromagnetic wave reflected or scattered by a portion of the structure 300 having a relatively low reflectance. The difference between time t1 and time t2 is caused by the difference between the distance from the movable reflecting unit 120 to the object and the distance from the movable reflecting unit 120 to the structure 300. That is, the reception signal S1 by the receiving unit 210 of the electromagnetic wave reflected or scattered by the object and the reception signals S21 and S22 by the receiving unit 210 of the electromagnetic wave reflected or scattered by the structure 300 are separable in time.

[0060] Fig. 17 is a diagram showing a first modified example of Fig. 2. The example shown in Fig. 17 is similar to the example shown in Fig. 2 except for the following points.

[0061] 17, a dotted line extending from the structure 300 side to the second receiving element 214 side described later indicates an optical path that light reflected or scattered by the structure 300 follows when it passes through the center of the lens 220 at the intersection point between the dotted line and the structure 300, that is, the optical axis of the second optical system. Also, a portion P indicates an intersection point between the structure 300 and the optical axis of the first optical system. The optical axis of the first optical system is a line connecting the center of the first receiving element 212 and the center of the lens 220. A portion Q indicates an intersection point between the structure 300 and the optical axis of the second optical system.

[0062] The receiving unit 210 includes a first receiving element 212 and a second receiving element 214. Each of the first receiving element 212 and the second receiving element 214 is, for example, an APD. The first optical system forms an image of the electromagnetic wave reflected or scattered by the object on the first receiving element 212. The second optical system forms an image of the electromagnetic wave reflected or scattered by the structure 300 on the second receiving element 214. In this modification as well, the lens 220 is shared by the first optical system and the second optical system.

[0063] 17, a line connecting the center of the first receiving element 212 and the center of the lens 220, i.e., the optical axis of the first optical system, and the optical axis of the second optical system are disposed at an angle. Therefore, the intersection of the optical axis of the second optical system and the structure 300, i.e., a portion Q of the structure corresponding to the signal detected by the second receiving element 214, is shifted from the intersection of the optical axis of the first optical system and the structure 300, i.e., the portion P. However, the light emitted from the emission unit 110 and reflected by the movable reflecting unit 120 also illuminates the portion Q on the structure 300, and therefore the second receiving element 214 can detect the reflected or scattered light.

[0064] The light reflected or scattered by the structure 300 and imaged on the second receiving element 214 may reach the second receiving element 214 after passing through the lens 220 and being reflected at least once by a reflecting section such as a mirror. The reflecting section can direct the optical path of this light in a direction intersecting with the optical axis of the lens 220. In this case, the second receiving element 214 can be disposed, for example, on the side of the optical axis of the lens 220 between the lens 220 and the receiving section 210, instead of behind the first receiving element 212. In this example, the size of the receiving system 200 in the optical axis direction of the lens 220 can be reduced compared to the example shown in FIG. 17.

[0065] Fig. 18 is a diagram showing a second modified example of Fig. 2. The example shown in Fig. 18 is similar to the example shown in Fig. 2 except for the following points.

[0066] In Figure 18, the dotted line extending from the structure 300 side to the receiving unit 210 side described later indicates the optical path that light reflected or scattered by the structure 300 follows when it passes through the center of the lens 220 at the intersection of the dotted line and the structure 300, i.e., the optical axis of the second optical system.

[0067] The first reflecting section 232 is positioned offset with respect to the receiving section 210 towards the side where the lens 220 is located. The second reflecting section 234 is positioned offset with respect to the lens 220 towards the side where the receiving section 210 is located. In this modification as well, the first reflecting section 232 is positioned closer to the receiving section 210 than the second reflecting section 234. Moreover, the second reflecting section 234 is positioned closer to the lens 220 than the first reflecting section 232. In this modification as well, the receiving element from which the electromagnetic wave is received by the first optical system and the receiving element from which the electromagnetic wave is received by the second optical system are shared as the receiving section 210.

[0068] (Embodiment 2) 19 is a diagram for explaining a receiving system 200A according to embodiment 2. The receiving system 200A according to embodiment 2 is similar to the receiving system 200 according to embodiment 1, except for the following points.

[0069] In Fig. 19, the movable reflecting unit 120 and the beam splitter 134 shown in Fig. 1 are not shown. In Fig. 19, the solid lines extending parallel to each other from the structure 300 side to the first lens 222A described later and converging from the first lens 222A to the receiving unit 210 indicate light rays reflected or scattered by an object present outside the sensor device 10 and imaged by the first lens 222A on the receiving unit 210. In addition, the dashed lines expanding from the structure 300 toward the second lens 224A and converging from the second lens 224A described later toward the receiving unit 210 indicate light rays reflected or scattered by the structure 300 and imaged by the second lens 224A on the receiving unit 210.

[0070] The first optical system has a first lens 222A. The first lens 222A forms an image of the electromagnetic wave reflected or scattered by the object on the receiving unit 210. The second optical system has a second lens 224A. The second lens 224A is located around the first lens 222A. The second lens 224A forms an image of the electromagnetic wave reflected or scattered by the structure 300 on the receiving unit 210.

[0071] In the example shown in FIG. 19, among the electromagnetic waves reflected or scattered by the object, those that reach the first lens 222A are imaged on the receiving unit 210. Among the electromagnetic waves reflected or scattered by the object, those that reach the second lens 224A are not imaged on the receiving unit 210 and become a so-called blurred state, so that they do not affect the reception signal of the receiving unit 210. In contrast, among the electromagnetic waves reflected or scattered by the structure 300, those that reach the second lens 224A are imaged on the receiving unit 210, so that they cause a change in the intensity of the reception signal of the receiving unit 210 according to the structure of the structure 300 having different reflectances. Among the electromagnetic waves reflected or scattered by the structure 300, those that reach the first lens 222A are not imaged on the receiving unit 210 and become a so-called blurred state, so that they do not cause a change in the intensity of the reception signal of the receiving unit 210 according to the structure of the structure 300 having different reflectances according to the parts of the structure 300.

[0072] (Embodiment 3) Fig. 20 is a diagram for explaining a receiving system 200B according to embodiment 3. The receiving system 200B according to embodiment 3 is similar to the receiving system 200 according to embodiment 1, except for the following points. In Fig. 20, the dashed dotted line passing through the center of a first lens 222B (described later) indicates the optical axis of the first lens 222B.

[0073] 20 does not show the movable reflecting unit 120 and the beam splitter 134 shown in FIG. 1. In FIG. 20, the solid lines extending parallel to each other from the structure 300 side to the first lens 222B described later and converging from the lens 220 to the receiving unit 210 indicate light rays reflected or scattered by an object present outside the sensor device 10 and imaged by the first lens 222B on the receiving unit 210. The dashed lines extending from the structure 300 to the receiving unit 210 via the first lens 222B and the second lens 224B described later indicate light rays reflected or scattered by the structure 300 and imaged by the first lens 222B and the second lens 224B on the receiving unit 210.

[0074] The first optical system has a first lens 222B. The first lens 222B forms an image on the receiving unit 210 of the electromagnetic wave reflected or scattered by the object. The second optical system has a second lens 224B. The second lens 224B is arranged offset from the first lens 222B in the optical axis direction of the first lens 222B. Specifically, the second lens 224B is located on the side where the receiving unit 210 is located with respect to the first lens 222B. In addition, the second lens 224B lacks an area that overlaps with a part of the first lens 222B in the optical axis direction of the first lens 222B. The second lens 224B forms an image on the receiving unit 210 of the electromagnetic wave reflected or scattered by the structure 300 and transmitted through the first lens 222B.

[0075] In the example shown in Fig. 20, among the electromagnetic waves reflected or scattered by the object, those that reach the first lens 222B and do not pass through the second lens 224B are imaged at the receiving unit 210. Among the electromagnetic waves reflected or scattered by the object, those that reach the first lens 222B and pass through the second lens 224B are not imaged at the receiving unit 210, and are in a so-called blurred state, so as not to affect the received signal at the receiving unit 210. In contrast, among the electromagnetic waves reflected or scattered by the structure 300, those that reach the first lens 222B and pass through the second lens 224B are imaged at the receiving unit 210, so that a change in the intensity of the received signal at the receiving unit 210 occurs according to the structure of the structure 300 with different reflectances. Of the electromagnetic waves reflected or scattered by structure 300, those that reach first lens 222B and do not pass through second lens 224B are not imaged at receiving unit 210 and become blurred, so as to not cause a change in the intensity of the received signal at receiving unit 210 according to the structure of different reflectivities at different parts of structure 300.

[0076] Although the embodiment and modified examples have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0077] For example, in the first embodiment, the sensor device 10 is a coaxial LiDAR. However, the sensor device 10 may be a biaxial LiDAR. [Explanation of symbols]

[0078] 10 Sensor device 110 Emitter 120 Movable reflector 122 Measuring section 132 Collimator lens 134 Beam splitter 200 Receiving system 200A Receiving system 200B Receiving system 210 Receiving unit 212 First receiving element 214 Second receiving element 220 Lens 222A 1st lens 222B 1st lens 224 2nd reflection section 224A 2nd lens 224B 2nd lens 232 1st reflection section 234 2nd reflection section 300 structures 300a Stripe section 310 Transparent area

Claims

[Claim 1] An emission unit that emits electromagnetic waves; a movable reflecting portion that reflects the electromagnetic wave toward a predetermined scanning range; A receiving unit including at least one receiving element that receives the electromagnetic waves reflected or scattered by at least one of an object present within the scanning range and a structure located within the scanning range closer to the movable reflecting unit than the object; a first optical system that forms an image of the electromagnetic wave reflected or scattered by the object on the receiving unit; a second optical system that forms an image of the electromagnetic wave reflected or scattered by the structure on the receiving unit; a measurement unit that measures a deflection angle of the movable reflector using the intensity of a signal received by the receiver of the electromagnetic wave reflected or scattered by the structure; A sensor device comprising:

Images