Electromagnetic wave radiation device and electromagnetic wave radiation method

Abstract

This electromagnetic wave radiation device comprises: a second radiation unit (32) that radiates second electromagnetic waves; a detection unit that detects the second electromagnetic waves; a change unit that changes the travel direction of the second electromagnetic waves so that the irradiation position when a detection surface of the detection unit is irradiated with the second electromagnetic waves changes along a first direction and a third direction intersecting the first direction; and an optical system that reduces the change in the irradiation position of the second electromagnetic waves in the third direction on the detection surface of the detection unit.

Description

Electromagnetic wave irradiation device and electromagnetic wave irradiation method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from Japanese Patent Application No. 2023-193104 (filed November 13, 2023), the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to an electromagnetic wave irradiation device and an electromagnetic wave irradiation method.

[0003] In recent years, devices have been developed that obtain information about surrounding objects, etc. from the results of detecting electromagnetic waves. For example, Patent Document 1 discloses a LIDAR (Light Detection and Ranging) system that includes a collimator lens that converts laser light into parallel light and a prism that emits the laser light incident on a first surface from a second surface.

[0004] Japanese Patent Application Laid-Open No. 2022-059924

[0005] (1) An electromagnetic wave irradiation device according to an embodiment of the present disclosure includes: a second irradiation unit that irradiates a second electromagnetic wave; a detection unit that detects the second electromagnetic wave; a change unit that changes the direction of travel of the second electromagnetic wave so that the irradiation position when the second electromagnetic wave is irradiated onto a detection surface of the detection unit changes along a first direction and a third direction intersecting the first direction; and an optical system that reduces the change in the irradiation position of the second electromagnetic wave in the third direction on the detection surface of the detection unit.

[0006] (2) As an embodiment of the present disclosure, in (1), the optical system reduces a spot diameter of the second electromagnetic wave on the detection surface of the detection unit in the third direction.

[0007] (3) As an embodiment of the present disclosure, in (1) or (2), the optical system includes a second optical element disposed in the optical path of the second electromagnetic wave from the change unit to the detection unit, the second optical element having a stronger power in the third direction than in the first direction.

[0008] (4) As an embodiment of the present disclosure, in any one of (1) to (3), the optical system includes a first optical member that is arranged in the optical path of the second electromagnetic wave from the second irradiation unit to the modification unit and has a power that changes the spot shape of the second electromagnetic wave on the detection surface in the third direction greater than a power that changes the spot shape in the first direction.

[0009] (5) As one embodiment of the present disclosure, in (4), a first irradiation unit that irradiates a first electromagnetic wave to irradiate an object, and a synthesis unit that causes the first electromagnetic wave to travel in the same direction as the second electromagnetic wave and make it incident on the modification unit, wherein the modification unit is positioned at a position where the first electromagnetic wave is not blocked by the first optical member due to a change in the traveling direction of the first electromagnetic wave.

[0010] (6) As an embodiment of the present disclosure, in (3), the second optical member includes a cylindrical lens having a greater power to change the spot shape of the second electromagnetic wave on the detection surface in the third direction than in the first direction.

[0011] (7) As an embodiment of the present disclosure, in any one of (1) to (6), the range in which the detection unit can detect the second electromagnetic wave in the third direction is greater than the range in which the irradiation position of the second electromagnetic wave changes in the third direction.

[0012] (8) As an embodiment of the present disclosure, in (5), a second anamorphic lens is provided between the first irradiation unit and the synthesis unit.

[0013] (9) As one embodiment of the present disclosure, in (8), the second anamorphic lens has a power in a direction corresponding to the first direction on the detection surface that is greater than a power in a direction corresponding to the third direction on the detection surface.

[0014] (10) An electromagnetic wave irradiation method according to an embodiment of the present disclosure includes: an irradiation unit irradiating a second electromagnetic wave; a modification unit changing the direction of travel of the second electromagnetic wave so that the irradiation position when the second electromagnetic wave is irradiated on a detection surface of a detection unit changes along a first direction and a third direction intersecting the first direction; an optical system adjusting the direction of travel of the second electromagnetic wave so as to reduce the change in the irradiation position of the second electromagnetic wave in the third direction on the detection surface of the detection unit; and a detection unit detecting the second electromagnetic wave.

[0015] FIG. 1 is a diagram showing a schematic configuration of an electromagnetic wave irradiation device according to an embodiment of the present disclosure. FIG. 2A is a partially enlarged view of the electromagnetic wave irradiation device, showing the schematic configuration as viewed from one direction. FIG. 2B is a partially enlarged view of the electromagnetic wave irradiation device, showing the schematic configuration as viewed from another direction. FIG. 3 is a diagram showing the schematic configuration of an electromagnetic wave irradiation device according to an embodiment of the present disclosure. FIG. 4A is a diagram illustrating a second electromagnetic wave on a detection surface and a substrate when neither a first optical member nor a second optical member is provided. FIG. 4B is a diagram illustrating a second electromagnetic wave on a detection surface and a substrate when a second optical member is provided but the first optical member is not provided. FIG. 4C is a diagram illustrating a second electromagnetic wave on a detection surface and a substrate when both a first optical member and a second optical member are provided. FIG. 5 is a diagram for explaining detection of electromagnetic waves including reflected waves.

[0016] An electromagnetic wave irradiation device and an electromagnetic wave irradiation method according to an embodiment of the present disclosure will be described below with reference to the drawings. In each drawing, identical or corresponding parts are designated by the same reference numerals. In the description of this embodiment, the description of identical or corresponding parts will be omitted or simplified as appropriate.

[0017] 1 and 3 are diagrams showing the schematic configuration of an electromagnetic wave irradiation device according to this embodiment. The electromagnetic wave irradiation device includes a first irradiation unit 31, a second irradiation unit 32, a lens group, a change unit, and a detection unit 66 (see FIG. 4A ) provided on a substrate 65. FIG. 1 is a diagram showing the electromagnetic wave irradiation device as tracing the optical path of a first electromagnetic wave irradiated from the first irradiation unit 31. FIG. 3 is a diagram showing the electromagnetic wave irradiation device as tracing the optical path of a second electromagnetic wave irradiated from the second irradiation unit 32. The lens group is an irradiation optical system of the electromagnetic wave irradiation device and includes a first optical element and a combining unit 40. The first optical element includes a first anamorphic lens 42. The lens group may further include a second anamorphic lens 41. The lens group may further include a collimator lens 43. The change unit includes a scanning unit 50. The change unit may further include a waveguide 60, a mirror 61, and an emission unit 70. Here, the electromagnetic wave irradiation device may include a second optical member arranged in the optical path of the second electromagnetic wave from the change unit to the detection unit 66. The second optical member includes a cylindrical lens 64. The second optical member may further include a mirror 62 and a mirror 63, as in this embodiment. The configuration of the electromagnetic wave irradiation device shown in FIGS. 1 and 3 is an example. The electromagnetic wave irradiation device may include all of the functional units shown in FIGS. 1 and 3, or may include functional units other than those shown in FIGS. 1 and 3, or may not include some of the functional units shown in FIGS. 1 and 3.

[0018] Here, for convenience of explanation, the functional units are shown sufficiently spaced apart from one another. In the actual configuration of the electromagnetic wave irradiation device, the functional units constituting the electromagnetic wave irradiation device may be more densely packed than the state shown in Figures 1 and 3. For example, the functional units may be arranged so that the electromagnetic wave irradiation device is configured to be small enough to fit within an area of ​​several centimeters square.

[0019] The electromagnetic wave irradiation device can irradiate electromagnetic waves and output the irradiated electromagnetic waves while changing the irradiation direction. At least a portion of the electromagnetic waves whose irradiation direction has been changed by the electromagnetic wave irradiation device may be reflected by a predetermined target (such as an object). The electromagnetic waves reflected by the predetermined target (such as an object) (reflected waves) may be detected and used for distance measurement. In this embodiment, the electromagnetic wave irradiation device is used as part of a LIDAR device that irradiates electromagnetic waves that are laser light and measures the distance to, the shape of, and the like of a predetermined target based on the reflected waves.

[0020] FIG. 5 is a diagram illustrating the detection of electromagnetic waves including reflected waves. For example, the LIDAR device may include an electromagnetic wave irradiation device, an incident unit 15, a separation unit 16, an image sensor 17, a switching unit 18, a post-stage optical system 19, and a photodiode 20. In the example of FIG. 5 , a region R exists within a range in which the LIDAR device can irradiate irradiation waves. Electromagnetic waves irradiated from the electromagnetic wave irradiation device are incident as irradiation waves on one region R in a space where a predetermined object exists. The irradiation waves are, for example, infrared rays. Electromagnetic waves including reflected waves, which are irradiated by a predetermined object existing in region R, are incident on the incident unit 15 of the LIDAR device. The electromagnetic waves including reflected waves may include not only infrared rays but also visible light, which is external light reflected by a predetermined object existing in region R. The separation unit 16 separates visible light from the electromagnetic waves including reflected waves, and the separated visible light is detected by the image sensor 17. The separation unit 16 also separates infrared rays from the electromagnetic waves including reflected waves. The separated infrared light is reflected by the switching unit 18, passes through a post-stage optical system 19, and is detected by a photodiode 20. As the irradiation direction of the irradiation wave changes (deflection, optical scanning), the area R in space onto which the irradiation wave is irradiated changes. Furthermore, the LIDAR device uses the detected reflected wave to calculate the distance to a predetermined object, for example, using a ToF method.

[0021] Referring again to FIG. 1 , the components of the electromagnetic wave irradiation device will be described. As described above, the first irradiation unit 31 irradiates the first electromagnetic wave. In this embodiment, the first irradiation unit 31 irradiates infrared rays as the first electromagnetic wave for scanning a predetermined object. However, the first electromagnetic wave irradiated by the first irradiation unit 31 is not limited to infrared rays. In this embodiment, the first irradiation unit 31 is configured to include a semiconductor laser (laser diode) that functions as a laser utilizing semiconductor recombination light emission. However, the first irradiation unit 31 may be configured to include a laser light source other than a semiconductor laser. The first irradiation unit 31 may irradiate, for example, a pulsed first electromagnetic wave.

[0022] In this embodiment, multiple light-emitting regions are arranged in an array on the irradiation surface of the first irradiation unit 31. That is, the first irradiation unit 31 is configured as a multi-channel laser diode in which multiple light-emitting regions are arranged in one direction (array direction). Here, the light-emitting region may be one laser diode, and the first irradiation unit 31 may be configured with multiple laser diodes. The number of light-emitting regions arranged may be two or more, but is not limited to a specific number. The irradiation surface of the first irradiation unit 31 generally has a shape that is elongated overall in the array direction. Furthermore, to increase the amount of light, the light-emitting region may have a multilayer structure. One light-emitting region may have a multilayer structure including multiple light-emitting layers formed side by side in a layer direction perpendicular to the array direction. When the light-emitting region has a multilayer structure, the number of layers may be two or more, but is not limited to a specific number.

[0023] In the first irradiation unit 31, in which a plurality of light-emitting regions are arranged in an array, the spread of the first electromagnetic wave (infrared light in this embodiment) varies depending on the direction. The length of each light-emitting layer is short. Therefore, the spread angle of the first electromagnetic wave in the layer direction is large. Here, the spread angle indicates the spread of the irradiated first electromagnetic wave as an angle relative to the case where the wave travels straight (in a direction perpendicular to the array direction and the layer direction). In contrast, the length of the light-emitting region in the array direction is longer than the length of one light-emitting layer in the layer direction. Therefore, the spread angle of the first electromagnetic wave in the array direction is narrow. The lens group onto which the first electromagnetic wave irradiated from the first irradiation unit 31 is incident is preferably configured to reduce light loss in accordance with the difference in the spread angle of the first electromagnetic wave depending on the direction. The electromagnetic wave irradiation device according to this embodiment, with the lens group having the configuration described below, can reduce light loss and increase the laser light density, thereby improving ranging accuracy when used in a LIDAR device.

[0024] 2A is an enlarged view of a portion of the electromagnetic wave irradiation device including a lens group, showing the schematic configuration when viewed in the positive x-axis direction. FIG. 2B is an enlarged view of a portion of the electromagnetic wave irradiation device including a lens group, showing the schematic configuration when viewed in the negative y-axis direction. Here, the x- and y-coordinates correspond to the arrangement of the laser diodes of the first irradiation unit 31. The x-axis direction corresponds to the array direction. The y-axis direction corresponds to the layer direction. In FIGS. 2A and 2B, the thin solid lines indicate the first electromagnetic wave irradiated from the first irradiation unit 31 and refracted through the lens group before reaching the scanning unit 50. In FIG. 2B, the first irradiation unit 31 has multiple light-emitting regions in the x-axis direction (array direction), and the first electromagnetic wave is irradiated from each light-emitting region.

[0025] The lens group includes a first anamorphic lens 42 and a second anamorphic lens 41. The second anamorphic lens 41 is located between the first irradiator 31 and the combiner 40, but is disposed closer to the first irradiator 31 than the first anamorphic lens 42. For example, the second anamorphic lens 41 may be configured to output the first electromagnetic wave incident from the first irradiator 31, and the first anamorphic lens 42 may be configured to receive the first electromagnetic wave from the second anamorphic lens 41 and output it toward the converter. Anamorphic lenses have different powers depending on the direction. Here, the power in a certain direction is the refractive power that refracts the first electromagnetic wave in that direction.

[0026] As described above, the spread angle of the first electromagnetic wave in the y-axis direction is larger than the spread angle in the x-axis direction. If the first electromagnetic wave continues to travel with a large spread angle, the amount of light that does not reach the scanning unit 50 (loss) will increase. Therefore, it is preferable to correct the propagation direction of the first electromagnetic wave in the y-axis direction at a position close to the first irradiation unit 31. The second anamorphic lens 41 has a power greater in the y-axis direction, which is perpendicular to the optical axis of the first electromagnetic wave, than in the x-axis direction, which is perpendicular to the optical axis and the y-axis direction. Therefore, by arranging the second anamorphic lens 41 closer to the first irradiation unit 31, light loss can be reduced.

[0027] The first anamorphic lens 42 has a symmetrical structure with the second anamorphic lens 41 so that the exit pupil is formed on the scanning unit 50. That is, the power of the first anamorphic lens 42 in the y-axis direction is smaller than the power in the x-axis direction. Here, the power of the second anamorphic lens 41 in the y-axis direction and the power of the first anamorphic lens 42 in the x-axis direction may be determined based on, for example, the difference between the divergence angle of the first electromagnetic wave in the y-axis direction and the divergence angle in the x-axis direction. Here, the power of the second anamorphic lens 41 in the y-axis direction may be set to be larger than the power of the first anamorphic lens 42 in the x-axis direction. In this case, the beam diameter in the scanning unit 50 can be reduced. This is expected to have the effect of suppressing the first electromagnetic wave, whose direction of travel has been changed by the scanning unit 50, from entering the first anamorphic lens 42.

[0028] The second anamorphic lens 41 may have zero power in the x-axis direction. Also, the first anamorphic lens 42 may have zero power in the y-axis direction. In this case, the design of the second anamorphic lens 41 and the first anamorphic lens 42 becomes easier, and installation accuracy can be improved. Also, instead of the first anamorphic lens 42 and the second anamorphic lens 41, the lens group may include another lens having lens performance that satisfies the above-mentioned power in the x-axis direction and power in the y-axis direction.

[0029] 2A and 2B , the lens group may further include a collimator lens 43 that is rotationally symmetric with respect to the optical axis. The inclusion of the collimator lens 43 in the lens group suppresses the occurrence of aberrations. In this case, the lens group may be configured such that the second anamorphic lens 41, the collimator lens 43, and the first anamorphic lens 42 are arranged in this order from the first irradiation unit 31 side. Furthermore, the second anamorphic lens 41, the first anamorphic lens 42, and the collimator lens 43 may each include an aspherical surface. In this case, the effect of reducing light loss can be further improved compared to when the lens group is configured with spherical lenses.

[0030] Furthermore, each of the second anamorphic lens 41, the first anamorphic lens 42, and the collimator lens 43 may have one of its object-side and image-side surfaces flat and the other convex. In this case, the second anamorphic lens 41, the first anamorphic lens 42, and the collimator lens 43 can be easily designed and installation accuracy can be improved. Furthermore, the second anamorphic lens 41 may be integrated with the collimator lens 43, for example, by bonding flat surfaces together. In this case, installation accuracy can be further improved.

[0031] Here, the lens group includes a combiner 40. The combiner 40 causes the incident first electromagnetic wave and second electromagnetic wave to travel (in the same direction) toward the changer. In this embodiment, the combiner 40 combines two electromagnetic waves (the first electromagnetic wave and the second electromagnetic wave) input from different directions and outputs the combined electromagnetic wave toward the scanning unit 50. The combiner 40 may be, for example, a prism or a cold mirror, but may have any configuration as long as it can combine two electromagnetic waves and output them in a predetermined direction.

[0032] As shown in Fig. 3, the second irradiating unit 32 irradiates the second electromagnetic wave, and the combining unit 40 combines the second electromagnetic wave and the first electromagnetic wave. In this embodiment, the second irradiating unit 32 irradiates, for example, visible light as the second electromagnetic wave for detecting the irradiation direction of the first electromagnetic wave for scanning. However, the second electromagnetic wave irradiated by the second irradiating unit 32 is not limited to visible light. The direction in which the second irradiating unit 32 irradiates the second electromagnetic wave toward the combining unit 40 is determined so that the spot diameter of the second electromagnetic wave can be adjusted as described below.

[0033] The second irradiating unit 32 may be configured to include, for example, a semiconductor laser (laser diode). Alternatively, the second irradiating unit 32 may be configured to include, for example, a light-emitting diode (LED) that irradiates visible light. The second irradiating unit 32 may irradiate, for example, constant light.

[0034] 1 again, the configuration of the change unit will be described below. The change unit performs deflection scanning to change the irradiation direction of the electromagnetic wave that has passed through the lens group. As described above, the change unit includes at least the scanning unit 50, but may also include a wave guide unit 60, a mirror 61, and an emission unit 70, as in this embodiment.

[0035] The scanning unit 50 may be configured to include, for example, a reflective mirror that changes the irradiation direction of the incident electromagnetic wave. The reflective mirror of the scanning unit 50 may be, for example, a MEMS (Micro Electro Mechanical Systems) mirror, a polygon mirror, or a galvanometer mirror. In this embodiment, the scanning unit 50 is a MEMS mirror.

[0036] The scanning unit 50 has a rotation axis and rotates around the rotation axis. Here, the rotational motion does not necessarily have to be an orbital motion and may be, for example, a swinging motion. The scanning unit 50 changes the propagation direction of the first electromagnetic wave and the second electromagnetic wave. As described below, the scanning unit 50 changes the propagation direction of the second electromagnetic wave so that the irradiation position of the second electromagnetic wave can be changed between a first direction and a second direction on the detection surface of the detection unit 66 and on the substrate 65 on which the detection unit 66 is provided. Furthermore, as described below, the scanning unit 50 changes the irradiation direction of the second electromagnetic wave so that the irradiation position of the second electromagnetic wave can be changed between a third direction and a fourth direction on the detection surface of the detection unit 66 and on the substrate 65 on which the detection unit 66 is provided. The scanning unit 50 is positioned so that the first electromagnetic wave and the second electromagnetic wave, the irradiation direction of which has been changed, are not blocked by the first optical member (first anamorphic lens 42).

[0037] The waveguide 60 has a function of separating electromagnetic waves. The waveguide 60 may reflect visible light among the incident electromagnetic waves (electromagnetic waves combined by the combiner 40) and pass infrared light. That is, the waveguide 60 may pass the first electromagnetic wave (infrared light) irradiated by the first irradiator 31 and reflect the second electromagnetic wave (visible light) irradiated by the second irradiator 32. The waveguide 60 may include, for example, a cold mirror. However, the configuration of the waveguide 60 is not limited to including a cold mirror. In this embodiment, the waveguide 60 guides the first electromagnetic wave (infrared light) to the mirror 61. Furthermore, in this embodiment, the waveguide 60 guides at least a portion of the second electromagnetic wave (visible light) in a direction different from that of the first electromagnetic wave (infrared light).

[0038] The mirror 61 is a member that adjusts the optical path so that the first electromagnetic wave from the waveguide 60, which becomes the above-mentioned irradiating wave, heads toward the emitter 70. The changing unit may be configured without the mirror 61. In this case, the waveguide 60 is disposed relative to the emitter 70 so that the first electromagnetic wave from the waveguide 60 heads directly toward the emitter 70.

[0039] The emission unit 70 is scanned by the scanning unit 50 and emits electromagnetic waves that become the above-mentioned irradiation waves from the electromagnetic wave emission device. Specifically, the emission unit 70 may emit infrared rays whose irradiation direction is changed by the scanning unit 50. The emission unit 70 may be made of, for example, glass or acrylic so as to allow infrared rays to pass through.

[0040] 3 , the electromagnetic wave irradiation device has a second optical member including mirrors 62, 63, and a cylindrical lens 64, and a substrate 65 including a detection unit 66, arranged in the optical path of the second electromagnetic wave separated by the waveguide 60. The second optical member may have a configuration in which the mirrors 62 and 63 are omitted. In this case, the waveguide 60 is arranged with respect to the cylindrical lens 64 so that the second electromagnetic wave from the waveguide 60 is directed directly toward the cylindrical lens 64.

[0041] 4A to 4C are diagrams illustrating the trajectory of the irradiation position of the second electromagnetic wave, which changes on the detection surface of the detection unit 66 and on the substrate 65 due to the scanning unit 50. FIG. 4C corresponds to the electromagnetic wave irradiation device according to this embodiment. For example, the substrate 65 may be a printed circuit board (PCB), but is not limited to this. The detection unit 66 is provided on the surface of the substrate 65 that is irradiated with the second electromagnetic wave. The detection unit 66 is, for example, a photodiode that functions as a light detector, but is not limited to a photodiode as long as it is capable of detecting visible light.

[0042] As shown in FIGS. 4A to 4C , two detectors 66 are provided on the surface of the substrate 65 onto which the second electromagnetic waves are irradiated. Visible light reflected by the waveguide 60 can be detected by one detector 66 or the other detector 66 depending on the deflection direction of the rotating scanning unit 50, i.e., the change in the irradiation direction of the visible light. Therefore, the electromagnetic wave irradiation device can calculate the rotation angle (deflection angle) of the scanning unit 50 based on the detection information from the detector 66 and detect the irradiation direction of the infrared rays (irradiation waves) based on the calculated rotation angle. Accurate detection of the position of the second electromagnetic waves on the detection surface and the substrate 65 by the detector 66 leads to improved ranging accuracy in the LIDAR device. However, depending on the configuration of the optical components used in the electromagnetic wave irradiation device, the spot diameter of the second electromagnetic waves on the detection surface may not be shaped appropriately for accurately detecting the irradiation position of the second electromagnetic waves. Furthermore, depending on the configuration of the optical members used in the electromagnetic wave irradiation device, the movement range of the spot of the second electromagnetic wave in the third and fourth directions may exceed the detection ranges of the two detection units 66 capable of detecting the second electromagnetic wave. In other words, by selecting and arranging appropriate optical members, the shape of the spot diameter of the second electromagnetic wave on the detection surface and the substrate (spot shape) and the movement range of the spot of the second electromagnetic wave in the third and fourth directions can be adjusted to fall within the detection ranges of the two detection units 66 capable of detecting the second electromagnetic wave, thereby enabling accurate detection of the position of the second electromagnetic wave. The electromagnetic wave irradiation device according to this embodiment can adjust the shape of the spot diameter of the second electromagnetic wave and the movement range of the spot in the third and fourth directions as described below, and therefore can be used in a LIDAR device to improve ranging accuracy. The electromagnetic wave irradiation device of this embodiment can reduce the change in the irradiation position of the second electromagnetic wave, that is, narrow the movement range of the spot of the second electromagnetic wave, by using a first optical element (first anamorphic lens 42) placed in the optical path before the change unit and a second optical element (cylindrical lens 64) placed in the optical path after the change unit, thereby improving distance measurement accuracy.

[0043] 4A to 4C show a first direction (D1), a second direction (D2), a third direction (D3), and a fourth direction (D4). The first direction (D1) is one of the directions from one detection unit 66 to the other detection unit 66 on the detection surface and the substrate 65. The second direction (D2) is the direction opposite to the first direction (D1). The third direction (D3) is one of the directions perpendicular to the first direction (D1). The fourth direction is the direction opposite to the third direction (D3). The scanning unit 50 of the change unit changes the irradiation direction of the incident electromagnetic wave by rotational motion. By this rotational motion, the change unit can change the irradiation position of the second electromagnetic wave on the detection surface and the substrate 65 in the first direction and the second direction. Furthermore, the change unit can change the irradiation position of the second electromagnetic wave on the detection surface and the substrate 65 in the third direction and the fourth direction.

[0044] FIG. 4A shows the movement of the spot of the second electromagnetic wave on the detection surface and substrate 65 when the electromagnetic wave irradiation device does not include either the first optical element (first anamorphic lens 42) or the second optical element (cylindrical lens 64). The spot moves back and forth in the area between the two detectors 66 in the first and second directions. The spot also moves back and forth in the third and fourth directions intersecting the first and second directions, but moves beyond the detection range of the detector 66 as shown in FIG. 4A. This means that there are ranges in the third and fourth directions that cannot be detected by the detector 66. In contrast, if the device is configured to include the first optical element, the shape of the spot diameter in the third and fourth directions can be adjusted. The first optical element has a power greater in the third direction (or fourth direction) than in the first direction (or second direction). Therefore, it is possible to adjust the shape of the spot diameter in the third and fourth directions. On the other hand, the first optical member is disposed in the optical path between the second irradiation unit 32 and the scanning unit 50, and therefore does not affect the movement range of the spot in the third and fourth directions.

[0045] 4B shows the movement of the spot of the second electromagnetic wave on the detection surface and substrate 65 when the electromagnetic wave irradiation device includes the first optical element (first anamorphic lens 42) but does not include the second optical element (cylindrical lens 64). As shown in FIG. 4B, the spot diameter narrows in the third and fourth directions. In this case, the lens group includes the first optical element located in the optical path of the second electromagnetic wave from the combining unit 40 to the modifying unit.

[0046] 4C shows the movement of the spot of the second electromagnetic wave on the detection surface and substrate 65 when the electromagnetic wave irradiation device includes both the first optical member (first anamorphic lens 42) and the second optical member (cylindrical lens 64), i.e., in the configuration of the electromagnetic wave irradiation device according to this embodiment. As shown in FIG. 4C , the spot diameter becomes narrower in the third direction and the fourth direction. Furthermore, the movement range of the spot of the second electromagnetic wave in the third direction and the fourth direction becomes narrower, so that it falls within the detection range of the detection unit 66. The second optical member includes a cylindrical lens 64 whose power for narrowing the spot diameter of the second electromagnetic wave on the detection surface of the detection unit 66 and on the substrate 65 in the third direction (or the fourth direction) is greater than its power for narrowing in the first direction (or the second direction). Therefore, the second optical member narrows the shape of the spot diameter of the second electromagnetic wave in the third direction (or fourth direction) on the detection surface and on the substrate 65, and narrows the movement range of the spot in the third direction and the fourth direction so that it fits within the detection range of the detection unit 66 in the third direction (or fourth direction), thereby making it possible to adjust the shape of the spot and the movement range of the spot as shown in Figure 4C.

[0047] As described above, the electromagnetic wave irradiation device according to this embodiment can adjust the shape of the spot diameter of the second electromagnetic wave on the detection surface by using the configuration of the lens group described above, thereby improving distance measurement accuracy.

[0048] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure.

[0049] The electromagnetic wave irradiation device according to this embodiment may execute an electromagnetic wave irradiation method. The electromagnetic wave irradiation method first includes a step in which an irradiation unit irradiates second electromagnetic waves. The electromagnetic wave irradiation method also includes a step in which a change unit changes the traveling direction of the second electromagnetic waves so that the irradiation position when the second electromagnetic waves are irradiated on the detection surface of the detection unit 66 changes along the first direction and a third direction intersecting the first direction. The electromagnetic wave irradiation method also includes a step in which an optical system adjusts the traveling direction of the second electromagnetic waves so as to reduce the change in the irradiation position of the second electromagnetic waves in the third direction on the detection surface of the detection unit 66. The electromagnetic wave irradiation method also includes a step in which the detection unit 66 detects the second electromagnetic waves.

[0050] 15 Incident section 16 Separation section 17 Image sensor 18 Switching section 19 Post-stage optical system 20 Photodiode 31 First irradiation section 32 Second irradiation section 40 Combining section 41 Second anamorphic lens 42 First anamorphic lens (first optical member) 43 Collimator lens 50 Scanning section 60 Waveguide section 61 Mirror 62 Mirror 63 Mirror 64 Cylindrical lens (second optical member) 65 Substrate 66 Detection section 70 Emitter section

Claims

1. A second irradiation unit that irradiates a second electromagnetic wave, The detection unit for detecting the second electromagnetic wave, A modifying unit for changing the propagation direction of the second electromagnetic wave such that the irradiation position changes along the first direction and a third direction intersecting the first direction when the second electromagnetic wave is irradiated onto the detection surface of the detection unit, An electromagnetic wave irradiation device comprising: an optical system for reducing the change in the irradiation position of the second electromagnetic wave in the third direction on the detection surface of the detection unit.

2. The electromagnetic wave irradiation device according to claim 1, wherein the optical system reduces the spot diameter of the second electromagnetic wave on the detection surface of the detection unit in the third direction.

3. The electromagnetic wave irradiation device according to claim 1, wherein the optical system includes a second optical member having stronger power in the third direction than in the first direction, which is disposed in the optical path of the second electromagnetic wave from the modification unit to the detection unit.

4. The electromagnetic wave irradiation device according to claim 2, wherein the optical system is arranged in the optical path of the second electromagnetic wave from the second irradiation unit to the modification unit and includes a first optical member having a power greater in the third direction than in the power in the first direction for changing the spot shape of the second electromagnetic wave on the detection surface.

5. A first irradiation unit that irradiates a first electromagnetic wave for irradiating an object, The system comprises a combining unit that causes the first electromagnetic wave to propagate in the same direction as the second electromagnetic wave and to be incident on the modification unit, The electromagnetic wave irradiation device according to claim 4, wherein the modified part is positioned so that the first electromagnetic wave is not blocked by the first optical member due to a change in the propagation direction of the first electromagnetic wave.

6. The electromagnetic wave irradiation device according to claim 3, wherein the second optical member includes a cylindrical lens having a greater power to change the spot shape of the second electromagnetic wave on the detection surface in the third direction than the power to change it in the first direction.

7. The electromagnetic wave irradiation device according to claim 3, wherein the range in which the detection unit can detect the second electromagnetic wave in the third direction is greater than the range in which the irradiation position of the second electromagnetic wave changes in the third direction.

8. The electromagnetic wave irradiation device according to claim 5, further comprising a second anamorphic lens located between the first irradiation unit and the synthesis unit.

9. The electromagnetic wave irradiation device according to claim 8, wherein the second anamorphic lens has a power in the direction corresponding to the first direction on the detection surface that is greater than the power in the direction corresponding to the third direction on the detection surface.

10. The irradiation unit irradiates a second electromagnetic wave, The modification unit includes the step of changing the propagation direction of the second electromagnetic wave so that when the second electromagnetic wave is irradiated onto the detection surface of the detection unit, the irradiation position changes along the first direction and a third direction intersecting the first direction. The optical system adjusts the propagation direction of the second electromagnetic wave so as to reduce the change in the irradiation position of the second electromagnetic wave in the third direction on the detection surface of the detection unit, An electromagnetic wave irradiation method comprising the step of detecting the second electromagnetic wave using the detection unit.