Electromagnetic wave detection device and electromagnetic wave detection method

Abstract

To provide an electromagnetic wave detector and an electromagnetic wave detection method that can reduce the influence of noise generated in a detection element on which an electromagnetic wave arriving from an object to be detected is not incident.SOLUTION: An electromagnetic wave detector 10 comprises a radiation unit 12, a first detection unit 20, a traveling unit 18, and a control unit 14. The radiation unit 12 radiates an electromagnetic wave. The first detection unit 20 has a plurality of detection elements 22 outputting results of detection of an electromagnetic wave. The traveling unit 18 has a plurality of traveling elements 180 that can be switched to a first state for causing the electromagnetic wave to travel to the first detection unit 20 and a second state for not causing the electromagnetic wave to travel to the first detection unit 20. The control unit 14 switches the state of a first traveling element 181 on which the electromagnetic wave is incident to the first state, and switches the state of a second traveling element 182 on which the electromagnetic wave is not incident to the second state. The control unit 14 does not acquire a detection result output from a detection element 22b on which the electromagnetic wave is not incident as a result of detection of the electromagnetic wave.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an electromagnetic wave detection device and an electromagnetic wave detection method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a configuration in which the traveling direction of an electromagnetic wave is switched to detect the electromagnetic wave that has traveled in a predetermined direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-200927 A Summary of the Invention [Problem to be solved by the invention]

[0004] When electromagnetic waves coming from a detection target are detected by a plurality of detection elements, noise may occur in detection elements that are not irradiated with the electromagnetic waves coming from the detection target, and it is necessary to reduce the effect of noise.

[0005] An object of the present disclosure is to provide an electromagnetic wave detection device and an electromagnetic wave detection method that can reduce the influence of noise generated in a detection element that is not incident on an electromagnetic wave arriving from a detection target. [Means for solving the problem]

[0006] An electromagnetic wave detection device according to an embodiment of the present disclosure includes an emission unit, a first detection unit, a traveling unit, and a control unit. The emission unit emits an irradiated electromagnetic wave toward a space in which a detection target exists. The first detection unit has a plurality of detection elements that output a detection result of a reflected electromagnetic wave generated when the irradiated electromagnetic wave is reflected by the detection target. The traveling unit has a plurality of traveling elements that can be switched to one of a first state in which the reflected electromagnetic wave travels to the first detection unit and a second state in which the reflected electromagnetic wave does not travel to the first detection unit. The control unit switches the state of a first traveling element, of the plurality of traveling elements, on which the reflected electromagnetic wave is incident, to the first state, and switches the state of a second traveling element, of the plurality of traveling elements, on which the reflected electromagnetic wave is not incident, to the second state. The control unit acquires the detection result output from a detection element, of the plurality of detection elements, on which the reflected electromagnetic wave is incident, as the detection result of the reflected electromagnetic wave. The control unit does not acquire the detection result output from a detection element, of the plurality of detection elements, on which the reflected electromagnetic wave is not incident, as the detection result of the reflected electromagnetic wave.

[0007] An electromagnetic wave detection device according to an embodiment of the present disclosure includes an emission unit, a first detection unit, and a control unit. The emission unit emits an irradiated electromagnetic wave toward a space in which a detection target exists. The first detection unit has a plurality of detection elements that output a detection result of the electromagnetic wave incident from the space. The control unit acquires, as a detection result of the reflected electromagnetic wave, a detection result output from a detection element, among the plurality of detection elements, on which a reflected electromagnetic wave generated by reflection of the irradiated electromagnetic wave by the detection target is incident. The control unit does not acquire, as a detection result of the reflected electromagnetic wave, a detection result output from a detection element, among the plurality of detection elements, on which the reflected electromagnetic wave is not incident.

[0008] An electromagnetic wave detection method according to an embodiment of the present disclosure includes irradiating an irradiated electromagnetic wave toward a space in which a detection target exists. The electromagnetic wave detection method includes switching the states of a plurality of traveling elements included in a traveling section that causes a reflected electromagnetic wave generated by reflection of the irradiated electromagnetic wave by the detection target to travel to a first detection section that detects the reflected electromagnetic wave. The electromagnetic wave detection method includes switching the state of a first traveling element, of the plurality of traveling elements, on which the reflected electromagnetic wave is incident, to a first state that causes the reflected electromagnetic wave to travel to the first detection section. The electromagnetic wave detection method includes switching the state of a second traveling element, of the plurality of traveling elements, on which the reflected electromagnetic wave is not incident, to a second state that does not cause the reflected electromagnetic wave to travel to the first detection section. The electromagnetic wave detection method includes acquiring a detection result output from a detection element, of the plurality of detection elements included in the first detection section, on which the reflected electromagnetic wave is incident, as a detection result of the reflected electromagnetic wave. The electromagnetic wave detection method includes not acquiring a detection result output from a detection element, of the plurality of detection elements, on which the reflected electromagnetic wave is not incident, as a detection result of the reflected electromagnetic wave.

[0009] An electromagnetic wave detection method according to an embodiment of the present disclosure includes irradiating an irradiated electromagnetic wave toward a space in which a detection target exists, acquiring, as a detection result of the reflected electromagnetic wave, a detection result output from a detection element on which a reflected electromagnetic wave generated by reflection of the irradiated electromagnetic wave by the detection target is incident, among a plurality of detection elements included in a first detection unit that detects the electromagnetic wave incident from the space, and not acquiring, as a detection result of the reflected electromagnetic wave, a detection result output from a detection element on which the reflected electromagnetic wave is not incident, among the plurality of detection elements. Effect of the Invention

[0010] According to an electromagnetic wave detection device and an electromagnetic wave detection method according to an embodiment of the present disclosure, the influence of noise generated in a detection element to which electromagnetic waves coming from a detection target are not incident can be reduced. [Brief description of the drawings]

[0011] [Figure 1]1 is a diagram illustrating an example of the configuration of an electromagnetic wave detection device according to an embodiment. [Diagram 2] FIG. 4 is a diagram illustrating an example of the configuration of a detection unit. [Diagram 3] FIG. 13 is a diagram showing an example of correspondence between traveling elements and detecting elements. [Figure 4] 1 is a diagram showing an example of the correspondence between the position at which a reflected electromagnetic wave is incident and the states of a traveling element and a detecting element. FIG. [Diagram 5] 1 is a table that defines the relationship between the orientation of the reflecting surface of the radiating portion and each of the drive signal, detection element, and traveling element. [Figure 6] 10 is a flowchart showing an example of a procedure of an adjustment method according to an embodiment. [Figure 7] FIG. 13 is a diagram showing a configuration example in which the output of each detection element is switched by a switch. [Figure 8] 1A and 1B are diagrams illustrating an example of the configuration of a microlens that converges an electromagnetic wave incident on a detection element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The drawings used in the following description are schematic. The dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0013] (Configuration example of electromagnetic wave detection device 10) As shown in FIG. 1, an electromagnetic wave detection device 10 according to an embodiment includes a detection unit 11, an emission unit 12, a scanning unit 13, and a control unit 14. The electromagnetic wave detection device 10 emits electromagnetic waves by the emission unit 12. The electromagnetic waves emitted from the emission unit 12 are radiated into a space in which the detection target ob exists by changing the traveling direction of the electromagnetic waves by the scanning unit 13. The electromagnetic waves radiated into the space are scanned over the detection target ob by changing the traveling direction of the electromagnetic waves by the scanning unit 13. In FIG. 1, the electromagnetic waves radiated to the detection target ob are represented by solid arrows and are also referred to as radiated electromagnetic waves 200. The traveling direction of the radiated electromagnetic waves 200 is also referred to as the irradiation direction. At least a part of the radiated electromagnetic waves 200 is reflected by the detection target ob and travels toward the detection unit 11. The electromagnetic wave detection device 10 detects at least a part of the electromagnetic waves reflected by the detection target ob by the detection unit 11, and acquires information about the detection target ob. The electromagnetic wave generated when the irradiated electromagnetic wave 200 is reflected by the detection object ob is represented by a dashed arrow, and is also called a reflected electromagnetic wave 210.

[0014] The control unit 14 can determine the irradiation direction of the electromagnetic wave by controlling the emission unit 12 and the scanning unit 13. That is, the control unit 14 can irradiate the electromagnetic wave emitted from the emission unit 12 in a predetermined direction. The irradiated electromagnetic wave 200 irradiated to the detection target ob reaches a predetermined part of the detection target ob, is reflected by the detection target ob, and proceeds toward the detection unit 11 as a reflected electromagnetic wave 210. The control unit 14 can obtain information on the predetermined part of the detection target ob by detecting the reflected electromagnetic wave 210 generated by the irradiated electromagnetic wave 200 irradiated to the predetermined part of the detection target ob with the detection unit 11. That is, the control unit 14 can obtain information on any part of the detection target ob by determining the irradiation direction of the irradiated electromagnetic wave 200. The control unit 14 can obtain information on the detection target ob as two-dimensionally mapped information by scanning the detection target ob with the irradiated electromagnetic wave 200.

[0015] Each component of the electromagnetic wave detection device 10 will be described in detail below.

[0016] <Control unit 14> The control unit 14 includes one or more processors and a memory. The processor may include at least one of a general-purpose processor that loads a specific program to execute a specific function and a dedicated processor specialized for a specific process. The dedicated processor may include an application specific integrated circuit (ASIC). The processor may include a programmable logic device (PLD). The PLD may include a field programmable gate array (FPGA). The control unit 14 may include at least one of a system-on-a-chip (SoC) and a system-in-a-package (SiP) in which one or more processors work together.

[0017] <Radiation Unit 12 and Scanning Unit 13> The emitter 12 emits electromagnetic waves. The emitter 12 may emit at least one of infrared rays, visible light, ultraviolet rays, and radio waves. The emitter 12 may include, for example, an LED (Light Emitting Diode) or an LD (Laser Diode).

[0018] The scanning unit 13 scans the detection object ob with the electromagnetic waves by changing the traveling direction of the electromagnetic waves emitted from the emission unit 12. The scanning unit 13 may have a scanning reflecting surface that reflects the electromagnetic waves emitted by the emission unit 12, and may scan the detection object ob with the electromagnetic waves by changing the orientation of the scanning reflecting surface. The scanning unit 13 may include at least one of a MEMS mirror, a polygon mirror, and a galvanometer mirror. The scanning unit 13 may be included in the emission unit 12.

[0019] The radiation unit 12 may scan the detection object ob with electromagnetic waves by a phased scan method that can change the radiation direction of the electromagnetic waves by controlling the phase of the radiated electromagnetic waves. In this case, the electromagnetic wave detection device 10 does not need to include the scanning unit 13.

[0020] <Detection unit 11> As shown in FIG. 2, the detection unit 11 includes a traveling unit 18 and a first detection unit 20.

[0021] The traveling section 18 has a plurality of traveling elements 180 arranged along the reference surface 18a. Each traveling element 180 is configured to be switchable between two states in which the reflected electromagnetic wave 210 travels in mutually different directions. Specifically, each traveling element 180 is configured to be switchable to a first state in which the electromagnetic wave travels in a direction in which the incident electromagnetic wave, such as the reflected electromagnetic wave 210, is incident on the first detection section 20. Each traveling element 180 is configured to be switchable to a second state in which the incident electromagnetic wave, such as the reflected electromagnetic wave 210, is caused to travel in a direction that is not incident on the first detection section 20. In other words, each traveling element 180 is configured to be switchable between the first state and the second state.

[0022] The control unit 14 can control the direction of travel of the reflected electromagnetic wave 210 incident on each traveling element 180 by determining the state of each traveling element 180 to be either the first state or the second state. The traveling element 180 switched to the first state is represented as the first traveling element 181. The traveling element 180 switched to the second state is represented as the second traveling element 182.

[0023] 2, the reflected electromagnetic wave 210 is represented by a solid arrow. The direction in which the reflected electromagnetic wave 210 is incident toward the traveling unit 18 is represented by D0. When the reflected electromagnetic wave 210 is incident on the first traveling element 181, the traveling direction of the reflected electromagnetic wave 210 is changed by the first traveling element 181 to a direction represented by D1. The reflected electromagnetic wave 210, whose traveling direction has been changed by the first traveling element 181, travels toward the first detection unit 20 as the first detection electromagnetic wave 212.

[0024] Electromagnetic waves from the space in which the detection object ob exists may be incident on the detection unit 11. The electromagnetic waves incident on the detection unit 11 may include not only the reflected electromagnetic waves 210 but also background electromagnetic waves 220. The background electromagnetic waves 220 are electromagnetic waves incident on the detection unit 11 from the detection object ob or its background, regardless of the irradiation direction of the irradiated electromagnetic waves 200. The background electromagnetic waves 220 may include light from a light source such as the sun, or light from a light source reflected by the detection object ob. The background electromagnetic waves 220 are represented by dashed arrows and are incident on the detection unit 11. When the background electromagnetic waves 220 are incident on the second traveling element 182 along the direction represented by D0, the traveling direction of the background electromagnetic waves 220 is changed by the second traveling element 182 to the direction represented by D2. As a result, the background electromagnetic waves 220 incident on the second traveling element 182 may travel outside the detection unit 11 as undetected electromagnetic waves 224. If the reflected electromagnetic wave 210 is incident on the second traveling element 182, the traveling direction of the reflected electromagnetic wave 210 is changed by the second traveling element 182 to a direction represented by D2.

[0025] A portion of the background electromagnetic wave 220 incident on the second traveling element 182 may be incident on the first detection unit 20 as a noise electromagnetic wave 226 due to scattering in the traveling unit 18. The noise electromagnetic wave 226 is represented by a two-dot chain line arrow.

[0026] The first detection unit 20 has a plurality of detection elements 22 arranged along the detection surface 20a. A first detection electromagnetic wave 212 (reflected electromagnetic wave 210) incident from the first traveling element 181 of the traveling unit 18 is incident on at least one detection element 22. The detection element 22 detects the first detection electromagnetic wave 212 and outputs the detection result to the control unit 14. The detection element 22 may detect the intensity of the first detection electromagnetic wave 212 and output it to the control unit 14. The control unit 14 can acquire the detection result from the detection element 22.

[0027] The first detection unit 20 is an active sensor that detects a reflected electromagnetic wave 210 that is generated when an irradiated electromagnetic wave 200 is irradiated from the emission unit 12 or the scanning unit 13 to the detection object ob and is reflected by the detection object ob.

[0028] The detection unit 11 may further include a prism 16 and a second detection unit 17. The prism 16 has a reflecting surface 16a. A reflected electromagnetic wave 210 that has entered the detection unit 11 is incident on the reflecting surface 16a from the outside of the prism 16. At least a part of the reflected electromagnetic wave 210 passes through the reflecting surface 16a and proceeds to the traveling unit 18. A part of the reflected electromagnetic wave 210 may be reflected by the reflecting surface 16a and enter the second detection unit 17. A first detection electromagnetic wave 212 is incident on the reflecting surface 16a from the inside of the prism 16, is reflected by the reflecting surface 16a, and proceeds toward the first detection unit 20.

[0029] Background electromagnetic waves 220 incident on the detection unit 11 are incident on the reflecting surface 16a from the outside of the prism 16. At least a part of the background electromagnetic waves 220 is reflected by the reflecting surface 16a and is incident on the second detection unit 17 as second detection electromagnetic waves 222. The second detection unit 17 detects the background electromagnetic waves 220. The second detection unit 17 may capture an image formed by the second detection electromagnetic waves 222 (the reflected background electromagnetic waves 220).

[0030] The detection unit 11 may further include a first imaging unit 15. The first imaging unit 15 is configured to form an image on a reference plane 18a of the traveling unit 18 when the reflected electromagnetic wave 210 is incident on the traveling unit 18. The first imaging unit 15 is also configured to form an image on a detection plane of the second detection unit 17 when the background electromagnetic wave 220 is incident on the second detection unit 17. In other words, the reference plane 18a of the traveling unit 18 and the detection plane of the second detection unit 17 are located at the image forming point of the first imaging unit 15.

[0031] The first imaging unit 15 forms an image of the incident electromagnetic wave on the reference surface 18a. The first imaging unit 15 may be an optical member whose imaging point is located on the reference surface 18a. The first imaging unit 15 may be an optical member including at least one of a lens and a mirror.

[0032] The detection unit 11 may further include a second imaging unit 19. The second imaging unit 19 is configured so that the first detection electromagnetic wave 212 incident on the first detection unit 20 forms an image on the detection surface 20a of the detection element 22 of the first detection unit 20. In other words, the detection element 22 of the first detection unit 20 is disposed at the imaging point of the second imaging unit 19.

[0033] (Operation example of the electromagnetic wave detection device 10) In order to obtain information on the detection object ob, the control unit 14 may control the emission unit 12 or the scanning unit 13, the traveling unit 18, and the first detection unit 20 as described below.

[0034] The control unit 14 controls the emission unit 12 to irradiate electromagnetic waves. The control unit 14 can irradiate an irradiated electromagnetic wave 200 to a predetermined portion of the detection target ob by controlling the scanning unit 13. The control unit 14 can obtain information about the predetermined portion of the detection target ob by detecting, with the detection unit 11, a reflected electromagnetic wave 210 generated when the irradiated electromagnetic wave 200 is reflected at the predetermined portion of the detection target ob. The control unit 14 can obtain information about the detection target ob that exists over a wide range of space by scanning the space in which the detection target ob exists with the irradiated electromagnetic wave 200.

[0035] The reflected electromagnetic wave 210 is incident on at least one traveling element 180 of the traveling unit 18. At the same time as the reflected electromagnetic wave 210 is incident on the traveling element 180, the background electromagnetic wave 220 is also incident on the traveling element 180. The control unit 14 switches the state of the traveling element 180 on which the reflected electromagnetic wave 210 is incident to a first state in advance. By switching the state of the traveling element 180 on which the reflected electromagnetic wave 210 is incident to the first state, the reflected electromagnetic wave 210 can travel toward the first detection unit 20. The control unit 14 switches the state of the traveling element 180 on which the reflected electromagnetic wave 210 is not incident to a second state. By switching the state of the traveling element 180 on which the reflected electromagnetic wave 210 is not incident to the second state, electromagnetic waves other than the reflected electromagnetic wave 210 incident on the traveling unit 18 are less likely to travel toward the first detection unit 20. For example, the background electromagnetic wave 220, which is different from the reflected electromagnetic wave 210 incident on the second traveling element 182, travels in the direction represented by D2. Most of the electromagnetic wave that travels in the direction represented by D2 does not enter the first detection unit 20 as undetectable electromagnetic wave 224. Undetectable electromagnetic wave 224 may be caused to travel outside the detection unit 11 by being caused to travel in the direction represented by D2 by the second traveling element 182.

[0036] As described above, by switching the state of each traveling element 180 to the first state or the second state, noise caused by the first detection unit 20 detecting electromagnetic waves other than the reflected electromagnetic wave 210 can be reduced. As a result, most of the background electromagnetic wave 220 does not enter the first detection unit 20. However, a part of the background electromagnetic wave 220 that enters the second traveling element 182 may enter the first detection unit 20 as a scattered component. The background electromagnetic wave 220 that enters the first detection unit 20 may become noise when the first detection unit 20 detects the reflected electromagnetic wave 210.

[0037] The control unit 14 is configured to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is incident as the detection result of the reflected electromagnetic wave 210. On the other hand, the control unit 14 is configured not to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is not incident as the detection result of the reflected electromagnetic wave 210. Furthermore, the control unit 14 is configured not to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 (reflected electromagnetic wave 210) is not incident as the detection result of the reflected electromagnetic wave 210 at the time when the first detection electromagnetic wave 212 (reflected electromagnetic wave 210) is incident on the first detection unit 20. More specifically, when an electromagnetic wave is incident on the detection element 22, the detection result is supplied to the control unit 14 as a detection signal. Electromagnetic waves from a space in which the detection target ob exists are simultaneously incident on each of the multiple detection elements 22 of the first detection unit 20. The control unit 14 acquires only the detection signal from the detection element 22 on which the reflected electromagnetic wave 210 is incident as the detection result of the reflected electromagnetic wave 210, and does not acquire the detection signal from the other detection elements 22. Alternatively, the control unit 14 uses only the detection signal from the detection element 22 on which the reflected electromagnetic wave 210 is incident for processing based on the detection signal. For example, when the electromagnetic wave detection device 10 is a distance measuring device, the distance to the detection target ob is measured based on the detection signal from the detection element 22 on which the reflected electromagnetic wave 210 is incident, and the detection signal from the other detection elements 22 is not used for measuring the distance. It is possible to determine which detection element 22 the reflected electromagnetic wave 210 is incident on by a table described later. By selectively acquiring the detection result, the control unit 14 becomes less likely to acquire the detection result of the electromagnetic wave other than the reflected electromagnetic wave 210. As a result, the influence of noise on the detection result of the reflected electromagnetic wave 210 acquired by the control unit 14 can be reduced.

[0038] Specifically, the control unit 14 may be configured to operate as described below so as not to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is not incident, as the detection result of the reflected electromagnetic wave 210. For example, the control unit 14 may be configured not to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is not incident. In other words, the control unit 14 may be configured not to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is not incident. For example, the control unit 14 may be configured to control the detection element 22 on which the first detection electromagnetic wave 212 is incident to output the detection result, while controlling the detection element 22 on which the first detection electromagnetic wave 212 is not incident to not output the detection result. For example, the control unit 14 may be configured to acquire the detection result output from the detection element 22 on which the first detection electromagnetic wave 212 is not incident, but not to acquire the detection result as the detection result of the reflected electromagnetic wave 210.

[0039] 3 shows the positional relationship between the position of the traveling element 180 on which the reflected electromagnetic wave 210 is incident and the positional relationship between the detecting element 22 on which the reflected electromagnetic wave 210 is incident by the traveling element 180 in the first state. In FIG. 3, the reflected electromagnetic waves 210a, 210b, 210c, and 210x are images of the reflected electromagnetic wave 210 on the traveling section 18 by the first imaging section 15. As illustrated in FIG. 3, the reflected electromagnetic wave 210 incident on each traveling element 180 of the traveling section 18 corresponds to the first detected electromagnetic wave 212 incident on each detecting element 22 of the first detecting section 20. In other words, the traveling element 180 in the first state on which the first detected electromagnetic wave 212 is incident and the detecting element 22 on which the traveling element 180 makes the first detected electromagnetic wave 212 incident are determined in advance. For example, the reflected electromagnetic wave 210a incident on the traveling portion 18 corresponds to the first detected electromagnetic wave 212a incident on the first detector 20. Moreover, the reflected electromagnetic waves 210b, 210c, and 210x correspond to the first detected electromagnetic waves 212b, 212c, and 212x, respectively.

[0040] The control unit 14 controls the state of each traveling element 180 based on the position of the traveling unit 18 where the reflected electromagnetic wave 210 is incident, and determines how to handle the detection results output from each detection element 22 of the first detection unit 20. Hereinafter, the operation of the control unit 14 will be described with reference to FIG.

[0041] In FIG. 4, the reflected electromagnetic wave 210a is incident on the traveling elements 180 located in the first and second columns from the left and the first to fourth rows from the top, among the multiple traveling elements 180 of the traveling unit 18. The control unit 14 has switched the state of the traveling elements 180 on which the reflected electromagnetic wave 210a is incident to the first state in advance. That is, the control unit 14 has switched the traveling element 180 on which the reflected electromagnetic wave 210 is incident to the first traveling element 181. The first traveling element 181 corresponds to the cell hatched with diagonal lines. On the other hand, the control unit 14 switches the state of the traveling element 180 on which the reflected electromagnetic wave 210 is not incident to the second state. That is, the control unit 14 has switched the traveling element 180 on which the reflected electromagnetic wave 210 is not incident to the second traveling element 182. The second traveling element 182 corresponds to the cell not hatched.

[0042] Here, background electromagnetic waves 220 different from the reflected electromagnetic waves 210a may be incident on the second traveling element 182. The second traveling element 182 does not allow the incident electromagnetic waves to travel toward the first detection unit 20, so that the background electromagnetic waves 220 are less likely to be incident on the first detection unit 20. As a result, noise caused by the background electromagnetic waves 220 can be reduced in the detection result of the reflected electromagnetic waves 210a.

[0043] In Fig. 4, the reflected electromagnetic wave 210a incident on the first traveling element 181 is incident on the first detection unit 20 as the first detection electromagnetic wave 212a. The first detection electromagnetic wave 212a is incident on the detection elements 22 located in the first and second rows from the left among the multiple detection elements 22 of the first detection unit 20. The detection elements 22 on which the first detection electromagnetic wave 212a is incident are also referred to as detection elements 22a, and correspond to cells hatched with diagonal lines. On the other hand, the detection elements 22 on which the first detection electromagnetic wave 212a is not incident are also referred to as detection elements 22b, and correspond to cells not hatched.

[0044] The control unit 14 acquires the detection result output from the detection element 22a on which the first detection electromagnetic wave 212a is incident as the detection result of the reflected electromagnetic wave 210a. On the other hand, the control unit 14 does not acquire the detection result output from the detection element 22b on which the first detection electromagnetic wave 212a is not incident as the detection result of the reflected electromagnetic wave 210a. The control unit 14 does not need to acquire the detection result output from the detection element 22b. The control unit 14 may control the detection element 22b so as not to cause the detection element 22b to output the detection result. In other words, the control unit 14 may switch the state of the detection element 22a on which the first detection electromagnetic wave 212 is incident to a state in which the detection result is output. The control unit 14 may switch the state of the detection element 22b on which the first detection electromagnetic wave 212 is not incident to a state in which the detection result is not output. Note that the detection elements 22 switched to the state in which the detection result is output may not be all the detection elements 22 on which the first detection electromagnetic wave 212 is incident. Of the detection elements 22, one or more detection elements in which the incident amount of the first detection electromagnetic wave 212 is greater than a predetermined value may be switched to a state in which the detection result is output. Similarly, the detection elements 22 switched to a state in which the detection result is not output need not be all detection elements 22 in which the first detection electromagnetic wave 212 is not incident. Of the detection elements 22, detection elements in which the incident amount of the first detection electromagnetic wave 212 is less than a predetermined value may be switched to a state in which the detection result is not output.

[0045] Here, a part of the background electromagnetic wave 220 incident on the second traveling element 182 may be incident on the first detection unit 20 as a noise electromagnetic wave 226 due to scattering or the like. By not acquiring the detection result output from the detection element 22b as the detection result of the reflected electromagnetic wave 210a, noise caused by the noise electromagnetic wave 226 can be reduced in the detection result of the reflected electromagnetic wave 210a.

[0046] The electromagnetic wave detection device 10 is configured to determine the traveling element 180 on which the reflected electromagnetic wave 210 is incident and the detection element 22 on which the first detected electromagnetic wave 212 is incident based on the irradiation direction of the irradiated electromagnetic wave 200. The control unit 14 may specify whether each traveling element 180 should be the first traveling element 181 or the second traveling element 182 based on the irradiation direction of the irradiated electromagnetic wave 200. Based on the specified result, the control unit 14 may switch the state of each traveling element 180 prior to the emission of the electromagnetic wave by the emission unit 12. Based on the irradiation direction of the irradiated electromagnetic wave 200, the control unit 14 may specify whether each detection element 22 corresponds to the detection element 22 on which the first detected electromagnetic wave 212 is incident or the detection element 22 on which the first detected electromagnetic wave 212 is not incident. Based on the specified result, the control unit 14 may determine how to handle the detection result output from each detection element 22.

[0047] The control unit 14 may acquire in advance a table that specifies the correspondence between the irradiation direction of the irradiated electromagnetic wave 200 and the detection elements 22 onto which the reflected electromagnetic wave 210 generated when the irradiated electromagnetic wave 200 is reflected by the detection object ob is incident. The control unit 14 may store the table in the storage unit. The control unit 14 may further specify, based on the table, whether each detection element 22 corresponds to a detection element 22 onto which the first detection electromagnetic wave 212 is incident or a detection element 22 onto which the first detection electromagnetic wave 212 is not incident.

[0048] The control unit 14 may obtain a table as illustrated in FIG. 5. The table as illustrated in FIG. 5 specifies the correspondence between the orientation of the scanning reflecting surface described in the first column from the left and the position of the detection element 22 described in the third column from the left. The orientation of the scanning reflecting surface determines the irradiation direction of the irradiated electromagnetic wave 200. Therefore, the table as illustrated in FIG. 5 associates the irradiation direction of the irradiated electromagnetic wave 200 with the detection element 22 into which the first detection electromagnetic wave 212 generated by the irradiated electromagnetic wave 200 is incident. In the table, the orientation of the scanning reflecting surface is represented by two angles, θ and φ, which specify the direction in a spherical coordinate system. In addition, the detection element 22 is represented by x coordinates and y coordinates which specify the position on a planar coordinate system set on the detection surface 20a of the first detection unit 20. The control unit 14 can specify the detection element 22 into which the first detection electromagnetic wave 212 is incident based on the table as illustrated in FIG. 5.

[0049] The table illustrated in Fig. 5 further specifies the correspondence between the orientation of the scanning reflective surface described in the first column from the left and the signal value of the drive signal of the scanning unit 13 described in the second column from the left. The signal value of the drive signal corresponds to the signal value output to the emission unit 12 or the scanning unit 13 to control the orientation of the scanning reflective surface. In the table, the signal value of the drive signal is represented by a value that counts up in binary. Based on the table illustrated in Fig. 5, the control unit 14 can control the scanning unit 13 so that the irradiated electromagnetic wave 200 can be irradiated in a predetermined direction.

[0050] The table illustrated in FIG. 5 further specifies the correspondence between the orientation of the scanning reflection surface described in the first column from the left and the position of the traveling element 180 described in the fourth column from the left. In the table, the traveling element 180 is represented by x and y coordinates that specify the position on the plane coordinate system set on the reference surface 18a of the traveling unit 18. A dash (') is added to the characters that indicate the coordinates of the traveling element 180 to distinguish them from the characters that indicate the coordinates of the detection element 22. The control unit 14 can specify the traveling element 180 on which the reflected electromagnetic wave 210 is incident based on the table illustrated in FIG. 5.

[0051] As described above, the control unit 14 can identify the detection element 22 on which the first detection electromagnetic wave 212 is incident based on the table, so that the processing load of the control unit 14 can be reduced.

[0052] <Flowchart showing an example of a procedure for an electromagnetic wave detection method> The control unit 14 of the electromagnetic wave detection device 10 may execute an electromagnetic wave detection method including the steps of the flowchart illustrated in Fig. 6. The electromagnetic wave detection method may be realized as an electromagnetic wave detection program executed by a processor constituting the control unit 14. The electromagnetic wave detection program may be stored in a non-transitory computer-readable medium.

[0053] The control unit 14 determines the direction of irradiation of the irradiated electromagnetic wave 200 (step S1).

[0054] The control unit 14 identifies the traveling element 180 and the detection element 22 corresponding to the irradiation direction of the irradiated electromagnetic wave 200 (step S2). The control unit 14 may identify the traveling element 180 on which the reflected electromagnetic wave 210 is incident. The control unit 14 may identify the detection element 22 on which the first detection electromagnetic wave 212 is incident.

[0055] The control unit 14 switches the states of the identified traveling element 180 and detection element 22 (step S3). The control unit 14 switches the state of the traveling element 180 on which the reflected electromagnetic wave 210 is incident to a first state, while switching the state of the traveling element 180 on which the reflected electromagnetic wave 210 is not incident to a second state. The control unit 14 may switch the state of the detection element 22 on which the first detection electromagnetic wave 212 is incident to a state in which the detection result is output. The control unit 14 may switch the state of the detection element 22 on which the first detection electromagnetic wave 212 is not incident to a state in which the detection result is not output.

[0056] The control unit 14 controls the emission unit 12 and the scanning unit 13 to irradiate the irradiated electromagnetic wave 200 in the irradiation direction determined in step S1 (step S4). The control unit 14 may control the orientation of the scanning reflection surface of the scanning unit 13 based on the determined irradiation direction.

[0057] The control unit 14 acquires the detection result of the reflected electromagnetic wave 210 reflected by the detection object ob (step S5). After completing the procedure of step S5, the control unit 14 ends the execution of the procedure shown in the flowchart of Fig. 6. After completing the procedure of step S5, the control unit 14 may return to the procedure of step S1.

[0058] <Summary> As described above, the electromagnetic wave detection device 10 of this embodiment obtains information about the detection object ob by irradiating the detection object ob with an irradiated electromagnetic wave 200 and detecting the reflected electromagnetic wave 210 that is reflected by the detection object ob.

[0059] The control unit 14 of the electromagnetic wave detection device 10 selectively acquires the detection result output from the detection element 22 of the first detection unit 20 as the detection result of the reflected electromagnetic wave 210. Specifically, the control unit 14 acquires the detection result output from the detection element 22 on which the reflected electromagnetic wave 210 is incident as the detection result of the reflected electromagnetic wave 210. On the other hand, the control unit 14 does not acquire the detection result output from the detection element 22 on which the reflected electromagnetic wave 210 is not incident as the detection result of the reflected electromagnetic wave 210. By doing so, even if other electromagnetic waves such as the background electromagnetic wave 220 are incident on the first detection unit 20, the detection result can be ignored. On the other hand, the detection result of the reflected electromagnetic wave 210 is selectively acquired. As a result, noise can be reduced from the detection result of the reflected electromagnetic wave 210.

[0060] Furthermore, by controlling the traveling unit 18, the control unit 14 can allow the reflected electromagnetic wave 210 to be incident on the first detection unit 20 while making it difficult for other electromagnetic waves such as the background electromagnetic wave 220 to be incident on the first detection unit 20. In this manner, electromagnetic waves that cause noise are less likely to be incident on the first detection unit 20. As a result, noise can be reduced in the detection result of the reflected electromagnetic wave 210 in the first detection unit 20.

[0061] (Other configuration examples) Various configuration examples that can be employed as each component of the electromagnetic wave detection device 10 will be described below.

[0062] <Progress section 18> The traveling unit 18 may include a mirror device such as a DMD or a MEMS (Micro Electro Mechanical Systems) mirror. The traveling element 180 may be a mirror element. The reference surface 18a may be an array surface of the mirror elements.

[0063] The traveling element 180 may have a reflecting surface that reflects the electromagnetic wave incident on the reference surface 18a. The traveling unit 18 may determine the direction in which the electromagnetic wave incident on the reference surface 18a is reflected by controlling the orientation of the reflecting surface of each traveling element 180. The orientation of the reflecting surface of each traveling element 180 may be associated with the first state and the second state, respectively. In other words, the traveling unit 18 may determine the direction in which the electromagnetic wave is reflected by making the orientation of the reflecting surface of the traveling element 180 different when it is switched to the first state and when it is switched to the second state. The first state may be associated with a first reflecting state in which the electromagnetic wave is reflected in a first direction. The second state may be associated with a second reflecting state in which the electromagnetic wave is reflected in a second direction.

[0064] The traveling element 180 may have a shutter including a reflective surface that reflects the electromagnetic wave. When the shutter is open, the electromagnetic wave is transmitted and travels in a predetermined direction. The state in which the shutter is open is associated with a first state. When the shutter is closed, the electromagnetic wave is reflected and travels in a direction different from the predetermined direction. The state in which the shutter is closed is associated with a second state. When the traveling element 180 has a shutter, the traveling section 18 may be equipped with a MEMS shutter or the like having shutters that can be controlled to be opened and closed and arranged in an array along the reference surface 18a.

[0065] The traveling element 180 may include a liquid crystal shutter. The liquid crystal shutter transitions to either a transmissive state that transmits electromagnetic waves or a reflective state that reflects electromagnetic waves by controlling the orientation state of the liquid crystal. The transmissive state and the reflective state are respectively associated with a first state and a second state.

[0066] <First detection unit 20> The first detection unit 20 may be configured to selectively output the detection result to the control unit 14. As shown in FIG. 7, the first detection unit 20 may further include an amplifier 24 that outputs the detection result to the control unit 14, and a switch 26 connected between the detection element 22 and the amplifier 24. The switch 26 is configured to output a signal output by the detection element 22 to the amplifier 24 when it is on, and not output a signal output by the detection element 22 to the amplifier 24 when it is off. In other words, when the switch 26 is on, the state of the detection element 22 connected to the switch 26 is a state in which the detection result is output. On the other hand, when the switch 26 is off, the state of the detection element 22 connected to the switch 26 is a state in which the detection result is not output. In other words, the switch 26 can switch whether or not the detection result is output from each detection element 22. The control unit 14 can switch the state of each detection element 22 by switching the state of the switch 26 on or off.

[0067] Each detection element 22 of the first detection unit 20 may be configured to be switchable between an ON state in which a signal corresponding to an incident electromagnetic wave is output, and an OFF state in which no signal is output regardless of whether an electromagnetic wave is incident. The control unit 14 may switch the detection element 22 to an ON state, thereby switching the detection element 22 to a state in which the detection element 22 outputs a detection result to the amplifier 24. The control unit 14 may switch the detection element 22 to an OFF state, thereby switching the detection element 22 to a state in which the detection element 22 does not output a detection result to the amplifier 24.

[0068] The control unit 14 may simultaneously turn on two detection elements 22 at a time and turn off the other detection elements 22. In this manner, the signal output as the detection result from the first detection unit 20 may be stable and have an intensity equal to or greater than a predetermined value. The number of detection elements 22 that are simultaneously turned on is not limited to two and may be changed depending on the circuit configuration.

[0069] 8, the first detection unit 20 may include a microlens array 30. The microlens array 30 includes a plurality of microlenses 32. Each microlens 32 may be associated with a corresponding detection element 22 and configured to converge the first detection electromagnetic wave 212 incident on each detection element 22. This can increase the detection efficiency of the first detection electromagnetic wave 212 in the detection element 22. As a result, noise can be reduced in the detection result of the reflected electromagnetic wave 210 (first detection electromagnetic wave 212).

[0070] The detection element 22 of the first detection unit 20 may be configured to include an APD (Avalanche Photo-Diode), a PD (Photo-Diode), a SPAD (Single Photon Avalanche Diode), etc. The detection element 22 may be configured to include a millimeter wave sensor, a sub-millimeter wave sensor, a distance measurement image sensor, etc.

[0071] The detector elements 22 may be arranged in a single line or in a two-dimensional array.

[0072] The first detection unit 20 may be configured as a distance measurement sensor. When the first detection unit 20 is configured as a distance measurement sensor, the electromagnetic wave detection device 10 can obtain image-like distance information by the first detection unit 20.

[0073] When the first detection unit 20 is a distance measurement sensor, the control unit 14 may acquire distance information. The control unit 14 may acquire distance information regarding the detection target ob by a ToF (Time of Flight) method based on the detection result acquired from the first detection unit 20. The control unit 14 may execute, as the ToF method, a DirectToF method that directly measures the time from emitting an electromagnetic wave to detecting a reflected wave. The control unit 14 may execute, as the ToF method, a FlashToF method that periodically radiates an electromagnetic wave and indirectly measures the time from emitting an electromagnetic wave to detecting a reflected wave based on the phase of the radiated electromagnetic wave and the phase of the reflected wave. The control unit 14 may execute, as the ToF method, other methods such as PhasedToF. The control unit 14 may execute the ToF method by making the radiator 12 radiate an electromagnetic wave.

[0074] The control unit 14 may include, for example, a time measurement LSI (Large Scale Integrated circuit). The control unit 14 may calculate the time elapsed from the time when the emission unit 12 is caused to emit electromagnetic waves to the time when the first detection unit 20 detects reflected waves from the detection target ob as the response time. The control unit 14 may calculate the distance to the detection target ob based on the response time. When the control unit 14 is causing the emission unit 12 or the scanning unit 13 to scan the detection target ob with electromagnetic waves, the control unit 14 may create image-like distance information by synchronizing the emission direction of the electromagnetic waves with the detection result acquired from the first detection unit 20.

[0075] When the first detection unit 20 is a thermosensor, the control unit 14 may acquire temperature information. The control unit 14 may acquire information about the surroundings of the electromagnetic wave detection device 10 based on the detection result of the electromagnetic waves acquired from the first detection unit 20. The information about the surroundings may include at least one of image information, distance information, and temperature information.

[0076] <Prism 16> The reflecting surface 16a of the prism 16 may be configured to have different transmittance or reflectance for the incident electromagnetic wave depending on the wavelength. The reflecting surface 16a may be configured so that the transmittance or reflectance when the electromagnetic wave is incident on the reflecting surface 16a from the outside of the prism 16 is different from the transmittance or reflectance when the electromagnetic wave is incident on the reflecting surface 16a from the inside of the prism 16.

[0077] The reflecting surface 16a may reflect the electromagnetic wave with a predetermined reflectance. If the predetermined reflectance is constant regardless of the wavelength of the electromagnetic wave, the image formed on the detection surface of the second detection unit 17 may be an image in which the intensity of the electromagnetic wave as a whole has changed by a predetermined ratio with respect to the image formed on the reference surface 18a of the traveling section 18.

[0078] For example, the reflecting surface 16a may reflect electromagnetic waves having wavelengths within a predetermined range with a reflectance equal to or greater than a predetermined value, and may reflect electromagnetic waves having wavelengths outside the predetermined range with a reflectance less than a predetermined value. In this way, electromagnetic waves having wavelengths within the predetermined range are reflected toward the second detection unit 17 and are more likely to be incident on the second detection unit 17. On the other hand, electromagnetic waves having wavelengths outside the predetermined range are more likely to be transmitted through the reflecting surface 16a and be incident on the traveling unit 18. As a result, the electromagnetic waves can be separated based on their wavelengths. That is, the reflecting surface 16a can separate the electromagnetic waves based on the wavelengths of the electromagnetic waves. The predetermined range may be a range specified as a value equal to or greater than the predetermined wavelength, or a value greater than the predetermined wavelength. The predetermined range may be a range specified as a value equal to or less than the predetermined wavelength, or a value less than the predetermined wavelength. The predetermined range may be a range specified as a value equal to or greater than the first predetermined wavelength and equal to or less than the second predetermined wavelength. The predetermined range may be a range specified as a value equal to or less than the first predetermined wavelength, or a value equal to or greater than the second predetermined wavelength.

[0079] The reflection surface 16a separates the electromagnetic waves based on wavelengths, so that images are formed on the detection surface of the second detection unit 17 and the reference surface 18a of the traveling section 18, each of which is composed of electromagnetic waves of different wavelengths, but whose coordinates within the image are the same. The image information detected by the first detection unit 20, or image-like distance information or temperature information, can be easily superimposed on the image information detected by the second detection unit 17, because the reflection surface 16a separates the electromagnetic waves based on wavelengths. The first detection unit 20 and the second detection unit 17 can each be configured as a sensor that detects electromagnetic waves of a specific wavelength.

[0080] The reflective surface 16a may include at least one of a visible light reflective coating, a half mirror, a beam splitter, a dichroic mirror, a cold mirror, a hot mirror, a metasurface, and a deflection element.

[0081] <Second detection unit 17> The second detection unit 17 may include detection elements arranged in an array along the detection surface. The second detection unit 17 may include an imaging element such as an image sensor or an imaging array. In this case, the second detection unit 17 may capture an image composed of electromagnetic waves incident on the detection surface and generate image information.

[0082] The second detection unit 17 may capture an image composed of visible light. The second detection unit 17 may capture an image composed of not only visible light but also infrared light, ultraviolet light, other radio waves, etc. The second detection unit 17 may include a distance measurement sensor. When the second detection unit 17 includes a distance measurement sensor, the electromagnetic wave detection device 10 may obtain image-like distance information by the second detection unit 17. The second detection unit 17 may include a thermosensor. When the second detection unit 17 includes a thermosensor, the electromagnetic wave detection device 10 may obtain image-like temperature information by the second detection unit 17.

[0083] The second detection unit 17 may include a single detection element. The single detection element may include an APD (Avalanche Photo-Diode), a PD (Photo-Diode), a SPAD (Single Photon Avalanche Diode), or the like. The single detection element may include a millimeter wave sensor, a sub-millimeter wave sensor, a ranging image sensor, or the like. The second detection unit 17 may include a detection element array. The detection element array may be an APD array, a PD array, an MPPC (Multi Photon Pixel Counter), a ranging imaging array, a ranging image sensor, or the like.

[0084] Although the present disclosure has been described based on the drawings and examples, it should be noted that a person skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each functional unit can be rearranged so as not to be logically inconsistent. Multiple functional units may be combined into one or divided. Each embodiment of the present disclosure described above is not limited to being implemented faithfully to each of the embodiments described above, and may be implemented by combining each feature or omitting a part as appropriate.

[0085] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. Configurations distinguished by descriptions such as "first" and "second" in this disclosure may exchange numbers in the configuration. For example, the first imaging unit 15 may exchange identifiers "first" and "second" with the second imaging unit 19. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the exchange of identifiers. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. The descriptions of identifiers such as "first" and "second" in this disclosure should not be used solely to interpret the order of the configuration or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0086] 10 Electromagnetic wave detection device (12: Radiation unit, 13: Scanning unit, 14: Control unit) 11 detection unit (15: first imaging unit, 19: second imaging unit) 16 Prism (16a: reflective surface) 17 Second detection section 18 Progression section (18a: reference surface, 180: progression element, 181: first progression element, 182: second progression element) 20 first detection unit (20a: detection surface, 22: detection element, 24: amplifier, 26: switch) 30 Microlens array (32: Microlens) 200 Irradiation electromagnetic waves 210(210a, 210b, 210c, 212x) Reflected electromagnetic waves 212 (212a, 212b, 212c, 212x) First detection electromagnetic wave 220 Background electromagnetic waves 222 Second Detected Electromagnetic Wave 224 Undetectable Electromagnetic Waves 226 Noise Electromagnetic Waves ob detection target

Claims

1. An emission unit that emits an electromagnetic wave toward a space in which a detection target is present; a first detection unit having a plurality of detection elements that output a detection result of a reflected electromagnetic wave generated when the irradiated electromagnetic wave is reflected by the detection target and is included in the electromagnetic wave incident from the space; a traveling unit having a plurality of traveling elements that can be switched to either a first state in which the reflected electromagnetic wave travels to the first detection unit or a second state in which the reflected electromagnetic wave does not travel to the first detection unit; a control unit that switches a state of a first traveling element, of the plurality of traveling elements, onto which the reflected electromagnetic wave is incident, to the first state, and switches a state of a second traveling element, of the plurality of traveling elements, onto which the reflected electromagnetic wave is not incident, to the second state; Equipped with The control unit is Identifying a first detection element on which the reflected electromagnetic wave is incident based on a correspondence relationship between an irradiation direction of the irradiated electromagnetic wave and a detection element on which the reflected electromagnetic wave is incident; an electromagnetic wave detection device which acquires, as the detection result of the reflected electromagnetic wave, a detection result output from a first detection element which has been identified as having received the reflected electromagnetic wave among the plurality of detection elements, and does not acquire, as the detection result of the reflected electromagnetic wave, a detection result output from a second detection element which has not been identified as having received the reflected electromagnetic wave among the plurality of detection elements, and which receives an electromagnetic wave resulting from scattering within the device of a portion of the background electromagnetic wave contained in the electromagnetic wave received from the space.

2. An emission unit that irradiates electromagnetic waves toward a space in which a detection target exists; a first detection unit having a plurality of detection elements that output a detection result of the electromagnetic wave incident from the space; a control unit that identifies a first detection element onto which the reflected electromagnetic wave is incident, based on a correspondence relationship between an irradiation direction of the irradiated electromagnetic wave irradiated from the emission unit and a detection element onto which a reflected electromagnetic wave generated when the irradiated electromagnetic wave is reflected by the detection target and is included in the electromagnetic wave incident from the space, and acquires a detection result output from the first detection element identified as the first detection element onto which the reflected electromagnetic wave is incident, as a detection result of the reflected electromagnetic wave, and does not acquire a detection result output from a second detection element that is a detection element not identified as the second detection element onto which the reflected electromagnetic wave is incident, and into which an electromagnetic wave resulting from scattering inside the device of a part of a background electromagnetic wave included in the electromagnetic wave incident from the space is incident, as a detection result of the reflected electromagnetic wave; An electromagnetic wave detection device comprising:

3. 3. The electromagnetic wave detection device according to claim 1, wherein the control unit causes the first detection element on which the reflected electromagnetic wave is incident to output a detection result, while not causing the second detection element on which the reflected electromagnetic wave is not incident to output a detection result.

4. The electromagnetic wave detection device according to claim 1 , wherein the control unit does not acquire a detection result output from the second detection element on which the reflected electromagnetic wave is not incident.

5. the first detection unit has a switch for switching whether or not to output the detection result from each of the detection elements, 5. The electromagnetic wave detection device according to claim 1, wherein the control unit controls the switch to obtain a detection result from the first detection element onto which the reflected electromagnetic wave is incident, and does not obtain a detection result from the second detection element onto which the reflected electromagnetic wave is not incident.

6. 6. The electromagnetic wave detection device according to claim 1, wherein the control unit acquires, as the detection result of the reflected electromagnetic wave, a detection result output from a detection element, among the first detection elements identified as having been incident on the reflected electromagnetic wave, in which an incident value of the reflected electromagnetic wave is greater than a predetermined value.

7. A scanning unit having a reflecting surface, the scanning unit changing an orientation of the reflecting surface to change an irradiation direction of the electromagnetic wave emitted by the radiation unit and outputting the electromagnetic wave into the space; a storage unit that stores a correspondence relationship between the orientation of the reflection surface of the scanning unit and the detection element on which the reflected electromagnetic wave is incident; Further comprising: The electromagnetic wave detection device according to claim 1 , wherein the control unit is further configured to identify the first detection element on which the reflected electromagnetic wave is incident, based on the correspondence relationship.

8. The electromagnetic wave detection device according to claim 1 , further comprising a microlens array that converges the reflected electromagnetic wave traveling toward the first detection unit onto the detection element.

9. 9. The electromagnetic wave detection device according to claim 1, wherein the control unit does not acquire a detection result from the second detection element on which the reflected electromagnetic wave is not incident as a detection result of the reflected electromagnetic wave at a time point when the reflected electromagnetic wave is incident on the first detection unit.

10. The electromagnetic wave detection device according to claim 1 , further comprising: a detection unit configured to detect the reflected electromagnetic wave and detect the distance to the detection target based on the detection result obtained as a result of the detection of the reflected electromagnetic wave.

11. Irradiating an electromagnetic wave toward a space in which a detection target is present; Among a plurality of traveling elements included in a traveling section that causes a reflected electromagnetic wave generated when the irradiated electromagnetic wave is reflected by the detection object and that is included in the electromagnetic wave incident from the space to travel to a first detection section that detects the reflected electromagnetic wave, switching the state of a first traveling element onto which the reflected electromagnetic wave is incident to a first state that causes the reflected electromagnetic wave to travel to the first detection section, and switching the state of a second traveling element onto which the reflected electromagnetic wave is not incident to a second state that does not cause the reflected electromagnetic wave to travel to the first detection section; Identifying a first detection element on which the reflected electromagnetic wave is incident based on a correspondence relationship between an irradiation direction of the irradiated electromagnetic wave and a detection element on which the reflected electromagnetic wave is incident; Among the plurality of detection elements included in the first detection unit, a detection result output from the first detection element that has been specified as having received the reflected electromagnetic wave is acquired as the detection result of the reflected electromagnetic wave, and a detection result output from a second detection element that has not been specified as having received the reflected electromagnetic wave among the plurality of detection elements and into which an electromagnetic wave resulting from scattering inside the device of a part of a background electromagnetic wave included in the electromagnetic wave incident from the space is incident is not acquired as the detection result of the reflected electromagnetic wave.

13. An electromagnetic wave detection method comprising:

12. Irradiating an electromagnetic wave toward a space in which a detection target is present; a detection result output from a first detection element, which is identified as a detection element into which a reflected electromagnetic wave generated by the irradiated electromagnetic wave being reflected by the detection target and included in the electromagnetic wave incident from the space is incident, based on a correspondence relationship between an irradiation direction of the irradiated electromagnetic wave and a detection element into which a reflected electromagnetic wave generated by the irradiated electromagnetic wave being reflected by the detection target and included in the electromagnetic wave incident from the space is incident, is acquired as the detection result of the reflected electromagnetic wave; and a detection result output from a second detection element, which is a detection element into which an electromagnetic wave generated by scattering within the device of a part of a background electromagnetic wave included in the electromagnetic wave incident from the space is incident, is not acquired as the detection result of the reflected electromagnetic wave.

13. An electromagnetic wave detection method comprising:

Images