Light projector, measurement device, and method for manufacturing projector

Abstract

To visualize invisible laser beams emitted from a laser source in a transfer process using a light transfer mechanism.SOLUTION: A light projector includes: a laser light source which emits an invisible laser beam; a light transfer mechanism for transferring the invisible laser beam emitted from the laser light source; and an output window for outputting the invisible laser beam transferred by the optical transfer mechanism to the outside. The light projector includes: a visible light source which emits visible light; and a meeting device which causes the visible light emitted from the visible light source to meet with the invisible laser beam in at least one of the entrance side and the middle of the optical transfer mechanism.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a light projector, a measuring device, and a method for manufacturing a light projector. [Background technology]

[0002] With the progress of AD (Autonomous Driving) and ADAS (Advanced Driver-Assistance Systems), research and development of LiDAR (Light Detection And Ranging) is being conducted as one of the measurement devices used for grasping the surrounding environment and estimating the vehicle's self-position while the vehicle is traveling. LiDAR includes a projector that projects (irradiates) laser light onto a measurement target, and a receiver that receives the reflected light of the laser light reflected off the measurement target. LiDAR outputs information about the measurement target by measuring the distance to the measurement target based on the difference between the timing when the projector emits the laser light and the timing when the receiver receives the reflected light. The projector includes a fiber laser (see, for example, Patent Document 1). The fiber laser includes a seed laser that emits infrared laser light, an optical fiber doped with a rare earth element and through which the infrared laser light passes, and an excitation laser that emits excitation light that excites the rare earth element of the optical fiber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 117912 Summary of the Invention [Problem to be solved by the invention]

[0004] In a floodlight equipped with a laser fiber, the infrared laser light emitted by the seed laser as a laser light source is invisible light. Therefore, the infrared laser light emitted by the seed laser cannot be visually recognized during the transmission process by a light transmission mechanism such as an optical fiber. As a result, problems occur such as being unable to determine whether the laser light source is on or off, or being unable to detect defective parts of the light transmission mechanism.

[0005] It should be noted that this problem is not limited to laser fibers, but is a common problem to any floodlight equipped with a laser light source that emits invisible laser light.

[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The technology disclosed in this specification can be realized, for example, in the following forms.

[0008] (1) The light projector disclosed in this specification includes a laser light source that emits invisible laser light, a light transmission mechanism that transmits the invisible laser light emitted by the laser light source, and an output window that outputs the invisible laser light transmitted by the light transmission mechanism to the outside, and further includes a visible light source that emits visible light, and a merger that merges the visible light emitted by the visible light source with the invisible laser light at least one of the entrance side and the middle of the light transmission mechanism. In this light projector, the visible light emitted by the visible light source merges with the invisible laser light at least one of the entrance side and the middle of the light transmission mechanism. Therefore, according to this light projector, the invisible laser light emitted by the laser light source can be visualized in the transmission process by the light transmission mechanism.

[0009] (2) In the above-described light projector, the confluence may be configured to converge the visible light into the invisible laser light at an entrance side of the light transmission mechanism. With this light projector, the invisible laser light can be made visible from the entrance side to the output side of the light transmission mechanism.

[0010] (3) In the above light projector, the laser light source may be a seed laser that emits invisible seed light, and the light transmission mechanism may include an optical fiber doped with a rare earth element and through which the invisible seed light passes, and an excitation laser that emits excitation light that excites the rare earth element in the optical fiber. According to this light projector, in a light projector equipped with an optical fiber laser, it is possible to visualize the invisible laser light propagating through the optical fiber.

[0011] (4) In the above-described light projector, the combiner may have a spatial multiplexing optical system and be configured to spatially multiplex the invisible laser light and the visible light. According to this light projector, the visible light can be combined with the invisible laser light by utilizing the spatial multiplexing optical system.

[0012] (5) In the above-described light projector, the combiner may have a wavelength multiplexing optical system and be configured to multiplex the invisible laser light and the visible light. According to this light projector, the visible light can be combined with the invisible laser light by utilizing the wavelength multiplexing optical system.

[0013] (6) The above floodlight may further include a limiting mechanism for prohibiting the visible light from being output to the outside through the output window or for reducing the amount of the visible light output to the outside through the output window. With this floodlight, it is possible to prevent inconveniences caused by the external output of visible light.

[0014] (7) A measuring device may be provided that includes the above-mentioned light projector and a light receiver that receives light output from the light projector and reflected by a measurement target. With this configuration, the invisible laser light can be made visible from the entrance side to the output side of the light transmission mechanism in the light projector or the measuring device.

[0015] (8) A method for manufacturing a floodlight disclosed in this specification is a method for manufacturing a floodlight including a laser light source that emits invisible laser light, a light transmission mechanism that transmits the invisible laser light emitted by the laser light source, and an output window that outputs the invisible laser light transmitted by the light transmission mechanism to the outside, and includes a step of merging visible light with the invisible laser light at least on either the entrance side or midway of the light transmission mechanism, and a step of confirming an optical path of the invisible laser light visualized by the visible light. According to this method for manufacturing a floodlight, in the manufacturing stage of the floodlight, the invisible laser light emitted by the laser light source can be visualized in the process of transmission by the light transmission mechanism.

[0016] The technology disclosed in this specification can be realized in various forms, for example, in the form of a light projector, a measuring device, a method for manufacturing a light projector, a method for inspecting a light projector, etc. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a measurement device 10 according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating a schematic configuration of a projector 20. [Diagram 3] FIG. 1 is an explanatory diagram illustrating a schematic configuration of an optical device 110. [Figure 4] FIG. 11 is a block diagram showing a schematic configuration of a measurement device 10a according to a second embodiment. [Diagram 5] FIG. 1 is an explanatory diagram illustrating a schematic configuration of an optical device 110a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A. First embodiment: A-1. Configuration of the measuring device 10: 1 is a block diagram showing a schematic configuration of a measuring device 10 according to the first embodiment. The measuring device 10 is a scanning type LiDAR. The measuring device 10 measures the difference between the timing when the projector 20 emits the output laser light Lout and the timing when the receiver 30 receives the input laser light Lin (the time of flight of the laser light, hereinafter referred to as "TOF" (Time of Flight)), and acquires information about the measuring object W.

[0019] The measuring device 10 is mounted on, for example, a vehicle (not shown) equipped with AD or ADAS. For example, while the vehicle is traveling, the measuring device 10 assists in the detection of objects such as people and other vehicles, and provides various types of information to other devices and users that are useful for ensuring the safety of the driver of the vehicle and those around the vehicle, and for reducing damage to surrounding objects while the vehicle is being driven.

[0020] The measuring device 10 includes a light projector 20, a light receiver 30, a scanner (beam deflector) 40, and a mirror 21.

[0021] The projector 20 includes a laser light source (a seed laser 112 described later) that outputs an output laser light Lout including at least invisible laser light, and a light projection control device 26 (see FIG. 2 described later). The invisible laser light is an electromagnetic wave (laser light) having a wavelength range that cannot be sensed as light by the human eye, such as an infrared laser light having an infrared wavelength range or an ultraviolet laser light having an ultraviolet wavelength range.

[0022] The light-projection control device 26 controls the emission of the seed laser 112, which will be described later. The light-projection control device 26 also inputs a signal indicating the timing of light projection at which the laser light source emits light to a TOF measurement device 36, which will be described later. The light-projection control device 26 periodically and repeatedly controls the on-off of a current flowing through the laser light source, for example, to cause the laser light source to emit light periodically and repeatedly. Other configurations of the light-projector 20 will be described later.

[0023] The scanner 40 has an optical scanning optical system that deflects the optical path (direction) of the output laser light Lout output by the projector 20, and scans the output laser light Lout in a predetermined direction. The scanner 40 has a polygon mirror 42 and a scanning mirror 46 as an optical scanning optical system. The polygon mirror 42 has a plurality of reflecting surfaces 44 (four in FIG. 1), and is a rotating body that is provided so as to be rotatable about a first rotation axis G1. The scanning mirror 46 is provided so as to be rotatable about a second axis G2. The output laser light Lout output by the projector 20 is reflected by a reflecting surface 48 of the scanning mirror 46, reflected by one reflecting surface 44 of the rotating polygon mirror 42, and emitted toward the measurement object W. The input laser light Lin reflected by the measurement object W is again reflected by one reflecting surface 44 of the rotating polygon mirror 42, and reflected by the reflecting surface 48 of the scanning mirror 46.

[0024] The mirror 21 reflects the input laser light Lin reflected by the reflecting surface 48 of the scanning mirror 46 and guides it to the photoreceiver 30. Specifically, the input laser light Lin reflected by the reflecting surface 48 of the scanning mirror 46 is reflected by the reflecting surface 22 of the mirror 21 and heads toward the photoreceiver 30.

[0025] The light receiver 30 includes a light receiving optical system 34, a light receiving section 32, and a TOF measurement device 36.

[0026] The light receiving optical system 34 collects the input laser light Lin to form a spot on the light receiving unit 32. The light receiving optical system 34 is configured using optical components such as various lenses such as a collecting lens, various filters such as a wavelength filter, and a reflecting mirror.

[0027] The light receiving unit 32 is a receiving light source having one or more light receiving elements (not shown), or one or more light receiving element arrays (for example, light receiving elements arranged linearly (one-dimensionally) or planarly (two-dimensionally)). The light receiving elements are, for example, photodiodes, SPADs (Single Photon Avalanche Diodes), balanced photodetectors, etc. The light receiving unit 32 photoelectrically converts the input laser light Lin incident from the light receiving optical system 34 to generate a current (hereinafter referred to as a "light receiving current") according to the intensity of the input laser light Lin. The light receiving unit 32 inputs a signal indicating the timing (hereinafter referred to as a "light receiving timing") at which the light receiving element constituting the light receiving unit 32 receives the input laser light Lin, and the light receiving current generated by the light receiving element to the TOF measurement device 36.

[0028] The TOF measurement device 36 obtains the TOF based on a signal indicating the light projection timing input from the light projection control device 26 and a signal indicating the light reception timing input from the light receiving unit 32. The TOF measurement device 36 has, for example, a time measurement IC (Integrated Circuit) equipped with a TDC (Time to Digital Converter) circuit. The TOF measurement device 36 inputs the obtained TOF and the light reception current input from the light receiving unit 32 to the controller 49.

[0029] With the above configuration, the irradiation position of the output laser light Lout on the measurement object W can be moved in a first scanning direction (e.g., vertical direction on the paper in FIG. 1) according to a change in the rotation angle (θx) accompanying the rotation of the polygon mirror 42, thereby obtaining image information of the measurement object W in the first scanning direction. Also, the irradiation position of the output laser light Lout on the measurement object W can be moved in a second scanning direction (e.g., a direction perpendicular to the first scanning direction, the depth direction on the paper in FIG. 1) according to a change in the rotation angle (θy) accompanying the rotation of the scanning mirror 46, thereby obtaining information of the measurement object W in the second scanning direction.

[0030] The measuring device 10 further includes a controller 49 and a communication I / F (Interface) 50.

[0031] The controller 49 has a processor (such as a central processing unit (CPU), a micro processing unit (MPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and a digital signal processor (DSP)). The controller 49 generates information used for various measurements such as detection and distance measurement of the measurement target W based on the light receiving current and TOF input from the TOF measurement device 36. The information is, for example, a histogram used in time correlated single photon counting, a distance to each point of the measurement target W, a point cloud (point cloud information), and the like. The controller 49 also controls the light projection control device 26 and the light receiving unit 32. The controller 49 controls the light projection timing and the light receiving timing described above, for example, by controlling the light projection control device 26 and the light receiving unit 32, so that the process for generating the histogram is accelerated or optimized. The information generated by the controller 49 is provided (transmitted) via the communication I / F 50 to a device that uses the information (hereinafter, referred to as "various use devices 60").

[0032] The various utilization devices 60 perform, for example, creating an environmental map using a point cloud, self-position estimation (SLAM (Simultaneous Localization and Mapping)) using a scan matching algorithm (NDT (Normal Distributions Transform), ICP (Iterative Closest Point), etc.), and the like.

[0033] A-2. Configuration of projector 20: Fig. 2 is an explanatory diagram that shows a schematic configuration of the floodlight 20. As shown in Fig. 2, the floodlight 20 includes a fiber laser, a light-projecting optical system 24, and the above-mentioned light-projection control device 26. The light-projecting optical system 24 is an example of an output window.

[0034] The projection optical system 24 adjusts the light distribution of the output laser light Lout by, for example, applying an optical effect (such as refraction, scattering, or diffraction) to the light emitted by the fiber laser. The projection optical system 24 is configured using optical components such as various lenses, such as a collimator lens, and a reflector (mirror).

[0035] The fiber laser includes a seed laser 112, a pump laser 120, a first optical fiber F1, and a second optical fiber F2. The seed laser 112 is an example of a laser light source.

[0036] The seed laser 112 emits seed light La (see FIG. 3) whose peak wavelength is included in the near-infrared range. The seed light La is an example of invisible laser light. In this embodiment, the wavelength of the seed light La is 1550 nm, but is not limited to this and may be, for example, 900 nm.

[0037] The first optical fiber F1 and the second optical fiber F2 are doped with a rare earth element, and the seed light La passes through them. The first optical fiber F1 and the second optical fiber F2 are arranged in series. The optical fibers F1 and F2 are doped with at least one of ytterbium (Yb) and erbium (Er) as a rare earth element. The length of each of the optical fibers F1 and F2 is, for example, about 5 m.

[0038] The pump laser 120 emits pump light (for example, 940 nm) that excites the rare earth elements contained in the optical fibers F1 and F2.

[0039] More specifically, the fiber laser includes a first isolator (ISO) 130, a first multiplexer (WDM) 140, a splitter (TAP) 150, a second isolator 160, and a second multiplexer 170.

[0040] The seed laser 112 is coupled to a normal optical fiber F3 (see FIG. 3) that is not doped with rare earth elements, and is optically coupled to a first multiplexer 140 via a first isolator 130. The first multiplexer 140 is coupled to one end of a first optical fiber F1. The other end of the first optical fiber F1 is optically coupled to a second multiplexer 170 via a second isolator 160. The second multiplexer 170 is coupled to one end of a second optical fiber F2. The other end of the second optical fiber F2 is directed toward the light projection optical system 24.

[0041] The pumping laser 120 is coupled to a normal optical fiber that is not doped with rare earth elements, and is optically coupled to a splitter 150. The splitter 150 splits the pumping light emitted by the pumping laser 120 into multiple lights. The splitter 150 is optically coupled to a first multiplexer 140 and a second multiplexer 170. The first multiplexer 140 combines the seed light La emitted by the seed laser 112 and the pumping light from the splitter 150. The second multiplexer 170 combines the seed light La amplified by the first optical fiber F1 and the pumping light from the splitter 150.

[0042] With this configuration, in the fiber laser, the pumping light emitted from the pumping laser 120 is incident on the first optical fiber F1 and the second optical fiber F2 via the first multiplexer 140 and the second multiplexer 170, respectively, to photo-excite the rare earth element from the ground state to the excited state (to create a population inversion carrier). In this state, the seed light La of the seed laser 112 passes through the first isolator 130 and the second isolator 160 and is then incident on the first optical fiber F1 and the second optical fiber F2, causing stimulated emission of the excited rare earth element, thereby amplifying the seed light La in two stages. As a result, a high-power output laser light Lout is output via the projection optical system 24.

[0043] A-3. Configuration for visualizing the seed light La emitted by the seed laser 112: As described above, the seed light La emitted by the seed laser 112 is invisible laser light. The projector 20 has a configuration for making the seed light La visible during the transmission process by the optical transmission mechanism. In this embodiment, the above-mentioned first isolator 130, first multiplexer 140, first optical fiber F1, second isolator 160, second multiplexer 170, and second optical fiber F2 are an example of the optical transmission mechanism.

[0044] Specifically, the projector 20 has a visible light source 200 and a combiner 210. The visible light source 200 emits visible light Lb (see FIG. 3). The visible light Lb is an electromagnetic wave (laser light) having a wavelength range that can be sensed as light by the human eye, and is preferably light of a chromatic color (such as red). The visible light source 200 is, for example, a light-emitting diode or a laser diode. The combiner 210 combines the visible light Lb emitted by the visible light source 200 with the seed light La emitted by the seed laser 112 at the entrance side of the light transmission mechanism.

[0045] In this embodiment, the multiplexer 210 has a spatial multiplexing optical system 212, and is configured to spatially multiplex the seed light La and the visible light Lb.

[0046] Fig. 3 is an explanatory diagram that shows a schematic configuration of the optical device 110. As shown in Fig. 3, the optical device 110 has a seed laser 112, a visible light source 200, and a combiner 210. In the optical device 110, the seed laser 112, the visible light source 200, and the combiner 210 are accommodated in the same package.

[0047] In the optical device 110, a seed laser 112 and a visible light source 200 are arranged in parallel. The multiplexer 210 has a spatial multiplexing optical system 212. The seed light La emitted by the seed laser 112 is incident on the spatial multiplexing optical system 212 via a lens 202. The visible light Lb emitted by the visible light source 200 is incident on the spatial multiplexing optical system 212 via a lens 204. The spatial multiplexing optical system 212 spatially multiplexes the seed light La and the visible light Lb, and outputs a combined light Lc in which the seed light La and the visible light Lb are combined. The combined light Lc is incident on an optical fiber F3 coupled to the first isolator 130. The optical fiber F3 is, for example, a multimode optical fiber.

[0048] The projector 20 further includes an optical filter 300 (see FIG. 2). The optical filter 300 is an example of a limiting mechanism. The optical filter 300 prohibits the visible light Lb from being output to the outside of the projector 20 via the projecting optical system 24. Specifically, the optical filter 300 is a band-pass filter that passes the seed light La and does not pass the visible light Lb. The optical filter 300 is disposed between the other end of the second optical fiber F2 and the projecting optical system 24 in the projector 20. For this reason, in this embodiment, the output laser light Lout output by the projector 20 via the projecting optical system 24 includes the seed light La and does not include the visible light Lb.

[0049] A-4. Advantages of this embodiment: As described above, the light projector 20 of this embodiment includes the visible light source 200 that emits visible light Lb (see FIG. 3) and the combiner 210. The combiner 210 combines the visible light Lb emitted by the visible light source 200 with the seed light La emitted by the seed laser 112 at the entrance side of the light transmission mechanism. Therefore, according to this embodiment, the invisible laser light (seed light La) emitted by the seed laser 112 can be visualized in the transmission process by the optical fibers F1 and F2. As a result, the presence or absence of light emission by the seed laser 112 can be confirmed based on the presence or absence of the visible light Lb. In addition, for example, defects (damaged parts, connection failures, etc.) of the optical fibers F1 and F2 can be detected based on the optical path of the visible light Lb.

[0050] Moreover, the above-mentioned technique of visualizing the seed light La by using the visible light Lb can be used in the manufacturing process of the projector 20 and the measurement device 10. For example, at the stage of inspection after the manufacture of the projector 20, the above-mentioned defects in the projector 20 can be confirmed by merging the visible light Lb into the optical path of the seed light La. In this case, after the inspection of the projector 20, the visible light source 200 may be removed and the projector 20 may be shipped.

[0051] In this embodiment, the projector 20 includes an optical filter 300 that prohibits the visible light Lb from being output to the outside of the projector 20 via the projecting optical system 24. Therefore, according to this embodiment, it is possible to suppress the occurrence of inconveniences caused by the external output of the visible light Lb (for example, an effect on the measurement accuracy of the measurement device 10 caused by the seed light La including the visible light Lb).

[0052] B. Second embodiment: B-1. Configuration of the measuring device 10a: 4 is a block diagram showing a schematic configuration of a measurement device 10a according to the second embodiment. In the following, the description of the configuration of the measurement device 10a according to the second embodiment that is the same as that of the measurement device 10 according to the first embodiment will be omitted as appropriate.

[0053] 4, the measuring device 10a is a flash-type LiDAR. The measuring device 10a includes a light projector 20a and a light receiver 30a.

[0054] The light projector 20a includes a light emitting section 22a, a light projecting optical system 24, a light projecting control device 26a, and a current source 28a.

[0055] The light-emitting unit 22a includes a light-emitting source having one or a plurality of light-emitting elements, or one or a plurality of light-emitting element arrays (e.g., light-emitting elements arranged linearly (one-dimensionally) or planarly (two-dimensionally)). The light-emitting element is, for example, a laser diode, a surface-emitting type laser light-emitting element (e.g., VCSEL (Vertical Cavity Surface Emitting Laser), hereinafter referred to as a "surface-emitting element"), a surface-emitting element array (e.g., a VCSEL array) in which a plurality of surface-emitting elements are arranged one-dimensionally or two-dimensionally on a substrate (semiconductor substrate, ceramic substrate, etc.). The light-emitting element 21a of the light-emitting unit 22a emits infrared laser light Ld (see FIG. 5). The light-emitting element 21a is an example of a laser light source. The configuration of the light-emitting unit 22a will be described later.

[0056] The current source 28a supplies a current corresponding to a control signal input from the light-projection control device 26a to the light-emitting element constituting the light-emitting unit 22a. The current source 28a supplies, for example, a periodic square wave current to the light-emitting element for turning on and off the current flowing through the light-emitting element.

[0057] The light-projection control device 26a generates a control signal for the current source 28a and inputs it to the current source 28a, thereby controlling the current (drive current) supplied from the current source 28a to the light-emitting element 21a. The light-projection control device 26a inputs a signal indicating the light-projection timing at which the light-emitting element 21a emits light to the TOF measurement device 36a. The light-projection control device 26a periodically and repeatedly controls the on-off of the current flowing through the light-emitting element 21a, for example, to cause the light-emitting element 21a to emit light periodically and repeatedly.

[0058] The light receiver 30a has a light receiving section 32 and a light receiving optical system 34. The light receiving optical system 34 collects on the light receiving section 32 the input laser light Lin that is returned after being reflected by a measurement target W or the like as an output laser light Lout from the light projector 20.

[0059] The measurement apparatus 10 a further includes a TOF measurement device 36 , a controller 49 , and a communication I / F 50 .

[0060] B-2. Configuration for visualizing the infrared laser light Ld emitted by the light emitting element 21a: As described above, the infrared laser light Ld emitted by the light emitting element 21a is invisible laser light. The projector 20a has a configuration for making the infrared laser light Ld visible during the transmission process by the optical transmission mechanism. In this embodiment, the condenser lens 209a described later is an example of the optical transmission mechanism.

[0061] The projector 20a (light emitting section 22a) has a visible light source 200 and a multiplexer 210a. In this embodiment, the multiplexer 210a has a wavelength multiplexing optical system 212a and is configured to multiplex the infrared laser light Ld and the visible light Lb.

[0062] Fig. 5 is an explanatory diagram showing a schematic configuration of light-emitting unit 22a. As shown in Fig. 5, light-emitting unit 22a has light-emitting element 21a, visible light source 200, and junction 210a. In light-emitting unit 22a, light-emitting element 21a, visible light source 200, and junction 210a are accommodated in the same package.

[0063] In the light-emitting unit 22a, the light-emitting element 21a and the visible light source 200 are arranged in parallel. The junction 210a has a wavelength multiplexing optical system 212a. The infrared laser light Ld emitted by the light-emitting element 21a is incident on the half mirror 206a via the lens 202a (collimation lens). The half mirror 206a reflects the infrared laser light Ld and transmits the visible light Lb. The visible light Lb emitted by the visible light source 200 is incident on the reflection mirror 208a via the lens 204a (collimation lens). The reflection mirror 208a reflects the visible light Lb toward the half mirror 206a. The visible light Lb reflected by the reflection mirror 208a is transmitted through the half mirror 206a. The condenser lens 209a condenses the infrared laser light Ld reflected by the half mirror 206a and the visible light Lb transmitted through the half mirror 206a, and outputs a composite light Le in which the infrared laser light Ld and the visible light Lb are combined. As a result, the output laser light Lout containing the infrared laser light Ld and the visible light Lb is output to the outside of the projector 20 via the projection optical system 24.

[0064] In this embodiment, the controller 49 controls the light projection control device 26a to execute a first mode in which both the light emitting element 21a and the visible light source 200 emit light, and a second mode in which the light emitting element 21a emits light and the visible light source 200 does not emit light. In this way, by executing the first mode, the optical path of the infrared laser light Ld can be visualized. Also, by executing the second mode, it is possible to suppress the occurrence of inconveniences caused by the external output of the visible light Lb.

[0065] C. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0066] The configuration of the measuring device 10, 10a in the above embodiment is merely an example, and various modifications are possible. For example, in the above first embodiment, the light projecting optical system 24 is exemplified as the output window of the light projector 20, but the output window may be, for example, a transparent member that passes the output laser light Lout reflected and output by the polygon mirror 42 of the scanner 40. In this case, the scanner 40 is also an example of the light transmission mechanism. Also, in the above embodiment, the optical fibers F1, F2, etc. are exemplified as the transmission mechanism, but a reflecting mirror, etc. may also be used.

[0067] In the above first embodiment, the fiber laser has a first optical fiber F1 and a second optical fiber F2, and is configured to amplify the seed light La in two stages, but this is not limited to this, and the fiber laser may be configured to amplify the seed light La in only one stage, or may be configured to amplify the seed light La in three or more stages.

[0068] In the first embodiment, the visible light Lb may be merged in the middle of the optical transmission path by the optical fibers F1 and F2 (for example, the multiplexers 140 and 170). In the first embodiment, for example, a wavelength multiplexing optical system or a multiplexer may be used as the multiplexer. In the first embodiment, the optical filter 300 that does not pass the visible light Lb is exemplified as the limiting mechanism, but an optical filter that passes a part of the visible light Lb and reduces the amount of visible light Lb output from the light projecting optical system 24 may also be used. In the first embodiment, the optical filter 300 may not be provided. For example, if the measuring device 10 that does not include the optical filter 300 is mounted on a lamp system of a vehicle, it becomes easier to visually recognize the position and width of the vehicle from the outside based on the visible light Lb, or to recognize an image of the vehicle.

[0069] In the second embodiment, the optical transmission mechanism may include, for example, a beam deflector. In the second embodiment, the multiplexer may include, for example, a spatial multiplexing optical system or a multiplexer. In the second embodiment, the restriction mechanism may include an optical filter that does not transmit visible light Lb and is disposed between the light emitter 22a and the light projecting optical system 24.

[0070] In the second embodiment, the infrared laser light Ld emitted by the light emitting element 21a is reflected by the half mirror 206a located on the most output side. However, the infrared laser light Ld emitted by the light emitting element 21a may be reflected by, for example, the reflection mirror 208a. However, with the configuration of the second embodiment, it is possible to suppress a reduction in the light intensity of the infrared laser light Ld caused by the transmission of the infrared laser light Ld through a transparent member.

[0071] In the above embodiment, the materials used to form the components are merely examples, and the components may be formed from other materials. [Explanation of symbols]

[0072] 10, 10a: Measuring device 20, 20a: Light projector 21: Mirror 21a: Light emitting element 22a: Light emitting section 24: Light projecting optical system 26, 26a: Light projecting control device 28a: Current source 30, 30a: Light receiver 32: Light receiving section 34: Light receiving optical system 36, 36a: TOF measuring device 40: Scanner 42: Polygon mirror 46: Scanning mirror 49: Controller 50: Communication I / F 60: Utilization device 110, 110a: Optical device 112: Seed laser 120: Excitation laser 130: First isolator 140: First multiplexer 150: Demultiplexer 160: Second isolator 170: Second multiplexer 200: Visible light source 206a: Half mirror 208a: Reflecting mirror 209a: Condenser lens 210, 210a: junction 212: spatial multiplexing optical system 212a: wavelength multiplexing optical system 300: optical filter F1: first optical fiber F2: second optical fiber F3: optical fiber La: seed light Lb: visible light Lc: composite light Ld: infrared laser light Le: composite light Lin: input laser light Lout: output laser light W: measurement object

Claims

1. a laser light source that emits invisible laser light; a light transmission mechanism that transmits the invisible laser light emitted by the laser light source; an output window that outputs the invisible laser light transmitted by the optical transmission mechanism to the outside; A floodlight comprising: Further, a visible light source that emits visible light; a confluence device that confluences the visible light emitted from the visible light source with the invisible laser light at least either at an entrance side or midway through the light transmission mechanism.

2. 2. The floodlight according to claim 1, The confluencer is configured to converge the visible light into the invisible laser light at an entrance side of the light transmission mechanism.

3. 3. The floodlight according to claim 1 or 2, the laser light source is a seed laser that emits invisible seed light, The light transmission mechanism includes: an optical fiber doped with a rare earth element and through which the invisible seed light passes; and an excitation laser that emits excitation light for exciting the rare earth element in the optical fiber.

4. 3. The floodlight according to claim 1 or 2, The combiner has a spatial multiplexing optical system and is configured to spatially multiplex the invisible laser light and the visible light.

5. 3. The floodlight according to claim 1 or 2, The multiplexer has a wavelength multiplexing optical system and is configured to multiplex the invisible laser light and the visible light.

6. 3. The floodlight according to claim 1 or 2, The floodlight further comprises a limiting mechanism that prohibits the visible light from being output to the outside through the output window, or that reduces the amount of the visible light output to the outside through the output window.

7. A floodlight according to claim 1 or 2; a light receiver that receives light output from the light projector and reflected by a measurement target; A measuring device comprising:

8. A manufacturing method for a floodlight including a laser light source that emits invisible laser light, a light transmission mechanism that transmits the invisible laser light emitted by the laser light source, and an output window that outputs the invisible laser light transmitted by the light transmission mechanism to an outside, the method comprising the steps of: a step of merging visible light with the invisible laser light at at least one of an entrance side and an intermediate portion of the light transmission mechanism; and confirming the optical path of the invisible laser light visualized by the visible light.

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