Lighting device

Abstract

An illumination device (10) is provided with: a light source (11) that emits illumination light; an optical system (12); a branching unit (13) that branches the illumination light emitted from the light source (11); a plurality of detection units (15, 16) that detect the amount of light arriving through the branch unit (13); a holding unit (180) that holds each of the plurality of detection units (15, 16); and a lens barrel (30) that houses the branch section (13), the plurality of detection sections (15, 16), and the holding section (180). The lens barrel (30) has a mounting plane that intersects a first direction from which a holding section (180) for holding the plurality of detection sections (15, 16) is mounted, and the mounting plane intersects the optical axis of the optical system (12). In the lens barrel (30), the optical system (12) and the light source (11) are mounted in a second direction along the optical axis.

Description

Technical Field

[0001] The invention relates to a lighting device. Background Art

[0002] In the past, there are known moving bodies such as cars that are equipped with lighting devices and project light through the lighting devices to perform various displays. The moving body of Patent Document 1 is equipped with a lighting device that illuminates the illuminated area with coherent light emitted from a light source via a diffractive optical element. The direction in which the moving body moves according to the pattern formed on the diffractive optical element is projected onto the illuminated area. That is, the lighting device functions as a direction display device. The coherent light emitted from the light source is high-intensity, but it is attenuated to an intensity that does not cause adverse effects even if it enters the human eye due to passing through the diffractive optical element.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-27014 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When light whose intensity is not attenuated due to damage or the like is incident on a person's eyes, there is a risk of causing obstruction to the person's eyes, so in order to ensure safety, it is required to detect abnormalities in the device. In Patent Document 1, for the installation state between the diffractive optical element and the housing, two terminals are electrically connected, and the detachment of the diffractive optical element is detected when the connection between the terminals is interrupted. However, damage that is different from detachment, such as a hole in a part of the diffractive optical element, cannot be detected in the device of Patent Document 1. In order to detect such damage to the diffractive optical element, a detection unit needs to be provided. However, since a detector is provided in the lighting device, the outer diameter of the lighting device increases, and there is a problem of large-scale lighting device. In addition, when multiple detectors are installed, there is a problem that assembly becomes complicated.

[0008] Means for solving problems

[0009] An illumination device according to one embodiment includes: a light source that emits illumination light; an optical system; a branching portion that branches the illumination light emitted from the light source; a plurality of detection portions that detect the amount of light that arrives via the branching portion; a holding portion that holds the plurality of detection portions, respectively; and a storage portion that stores the branching portion, the plurality of detection portions, and the holding portion. The storage portion has an installation plane that is a plane that intersects a first direction, and the holding portion that holds the plurality of detection portions is installed from the first direction, and the first direction intersects the optical axis of the optical system. In the storage portion, the optical system and the light source are installed along a second direction, and the second direction is along the optical axis.

[0010] Effects of the Invention

[0011] According to the present invention, an increase in the outer diameter of the lighting device is suppressed, thereby contributing to miniaturization of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view of the appearance of the lighting device according to the embodiment.

[0013] Figure 2 is a cross-sectional view of the lighting device.

[0014] Figure 3A This is a stereoscopic view of the lens barrel.

[0015] Figure 3B It is a side view of the lens barrel.

[0016] Figure 3C This is the appearance of the rear of the lens barrel.

[0017] Figure 4 Yes Figure 2 A portion of the cross-sectional view shown is an enlarged view of the partial cross-sectional view shown.

[0018] Figure 5A It is a perspective view of the appearance of the first holding portion, the second holding portion, the first detection portion, and the second detection portion.

[0019] Figure 5B yes Figure 5A Cross-sectional view at line BB.

[0020] Figure 6 It is a block diagram showing the main structure of the lighting device.

[0021] Figure 7 This is a flowchart illustrating the operation of the lighting device.

[0022] Figure 8 This is a flowchart illustrating the operation of the lighting device.

[0023] Fig. 9 This is a flowchart illustrating the operation of the lighting device according to the first modification. DETAILED DESCRIPTION

[0024] Hereinafter, a lighting device according to an embodiment will be described in detail with reference to the drawings.

[0025] <Lighting device>

[0026] The lighting device is provided on a mobile body such as a railway vehicle, automobile, trolley, ship, airplane, helicopter, drone, robot, etc., which is a movable device. The lighting device emits lighting light in the direction of travel of the mobile body, for example, to project information related to the travel of the mobile body onto the road surface. The lighting device projects, for example, an arrow indicating the direction of travel, and text such as "go straight", "turn right", "slow down", and "accelerate" as information related to the travel. In addition, the lighting device is not limited to projecting the above-mentioned arrows and texts, and may also project patterns, signs, marks, illustrations, characters, pictograms, etc. In addition, there is no limit to the number of lighting devices mounted on the mobile body, and it may be one or more than two.

[0027] Figure 1 is a perspective view of the appearance of the lighting device 10 according to the embodiment. Figure 2 yes Figure 1 . The illuminating device 10 is a cross-sectional view of the illuminating device 10 at the AA line in FIG. The illuminating device 10 includes a lens barrel 30, an inner barrel 40, an outer barrel 50, and an outer peripheral barrel 60. The lens barrel 30 is a cylindrical member, and is a housing portion that houses the light source 11, the branching portion 13, the first detection portion 15, the second detection portion 16, a holding portion 180 that holds the first detection portion 15 and the second detection portion 16, and a portion of the optical system 12. In addition, as described in detail later, the holding portion 180 includes a first holding portion 18 that holds the first detection portion 15 and the branching portion 13, and a second holding portion 19 that holds the second detection portion 16.

[0028] In addition, for the sake of convenience, it is assumed that the x-axis is parallel to the optical axis Ax of the optical system 12, and the x-axis is perpendicular to the x-axis and along the Figure 1 An orthogonal coordinate system consisting of the y-axis in the vertical direction of the paper and the z-axis perpendicular to the x-axis and the y-axis. In addition, in the following description, the x-axis + side is sometimes referred to as the front, the x-axis - side is sometimes referred to as the back, the y-axis + side is sometimes referred to as the top, and the y-axis - side is sometimes referred to as the bottom.

[0029] The inner tube 40 is a cylindrical component that accommodates the remaining part of the optical system 12 inside, and is accommodated in the lens barrel 30 at the end on one side (x-axis + side) of the lens barrel 30. The outer tube 50 is a cylindrical component that accommodates the control substrate 17 and the end on the other side (x-axis - side) of the lens barrel 30. The outer tube 60 is a cylindrical component that accommodates the end on one side (x-axis + side) of the lens barrel 30.

[0030] <Lens barrel 30>

[0031] Figure 3A is a perspective view of the appearance of the lens barrel 30, Figure 3B is a side view of the lens barrel 30, Figure 3C 1 is an appearance view of the x-axis side (rear) of the lens barrel 30. The lens barrel 30 is composed of a first barrel 31 and a second barrel 32 having different outer diameters and being concentric with the optical axis Ax of the optical system 12. The light source 11, the branching section 13, the first detection section 15, and the second detection section 16 are assembled in the first barrel 31.

[0032] <First lens barrel 31>

[0033] The first lens barrel 31 is formed with a mounting plane 330 for mounting the holding portion 18. Specifically, the mounting plane 330 includes a first mounting plane 311 formed on the y-axis + side (upper side) of the first lens barrel 31 and a second mounting plane 312 formed on the y-axis - side (lower side) of the first lens barrel 31. The first mounting plane 311 is a surface parallel to the zx plane formed on the y-axis at a position where the distance from the optical axis Ax is shorter than the outer diameter of the first lens barrel 31. The first holding portion 18 (see FIG. 1 ) for holding the first detection portion 15 and the branch portion 13 is mounted on the first mounting plane 311. Figure 2 ). The first holding portion 18 holding the first detection portion 15 is arranged on the first mounting plane 311 from the upper side (y-axis + side) and is mounted by screw fastening or the like. That is, the mounting direction of the first holding portion 18 is from the upper side (y-axis + side) along the y-axis toward the optical axis Ax.

[0034] The second mounting plane 312 is a plane parallel to the zx plane and formed on the y-axis at a position where the distance from the optical axis Ax is shorter than the outer diameter of the first lens barrel 31. The second holding portion 19 (see FIG. 1 ) for holding the second detection portion 16 is mounted on the second mounting plane 312. Figure 2 ). The second holding portion 19 holding the second detection portion 16 is arranged on the second mounting plane 312 from the lower side (y-axis side) and is mounted by screw fastening or the like. That is, the mounting direction of the second holding portion 19 is from the lower side (y-axis side) along the y-axis toward the optical axis Ax. In addition, details of the first holding portion 18 and the second holding portion 19 will be described later.

[0035] In addition, the first mounting plane 311 and the second mounting plane 312 may not be parallel to the zx plane. That is, the first mounting plane 311 and the second mounting plane 312 only need to be planes intersecting the direction (first direction) intersecting the optical axis Ax. In this case, the mounting direction of the first holding portion 18 is the direction from the upper side toward the optical axis Ax along the first direction. The mounting direction of the second holding portion 19 is the direction from the lower side toward the optical axis Ax along the first direction.

[0036] A third mounting surface 313 parallel to the yz plane is formed at the ends of the first mounting plane 311 and the second mounting plane 312 on the x-axis side. In other words, the third mounting surface 313 is the end surface on the x-axis side (the other side of the second direction) of the lens barrel 30. A light source holder 111 (see FIG. 1 ) for holding the light source 11, which will be described in detail later, is mounted on the third mounting surface 313 from the x-axis side (rear) by screw fastening or the like. Figure 2 ). In other words, the light source 11 is mounted on the x-axis side of the lens barrel 30 with reference to the first detection unit 15 and the second detection unit 16. The control board 17 is mounted on the x-axis side (rear) of the light source holder 111 by screwing or the like.

[0037] A through hole 314 having a shape extending in the vertical direction centered around the vicinity of the optical axis Ax is formed on the third mounting surface 313. The through hole 314 is an opening through which the wiring 153 connecting the first detection unit 15 and the control substrate 17 and the wiring 163 connecting the second detection unit 16 and the control substrate 17, which will be described in detail later, pass.

[0038] The first lens 121 and the second lens 122 constituting the optical system 12 are mounted on the x-axis + side (front) of the first lens barrel 31. In other words, in the lens barrel 30, the optical system 12 is mounted on the x-axis + side with reference to the first detection unit 15 and the second detection unit 16. That is, in the lighting device 10, the lens barrel 30, the optical system 12 disposed on the x-axis + side (one side of the second direction) with respect to the first detection unit 15 and the second detection unit 16, and the light source 11 disposed on the x-axis - side (the other side of the second direction) are assembled into one body.

[0039] A recess 310 is formed along the outer circumference of the outer wall of the first lens barrel 31. A sealing member 315 such as an O-ring is provided in the recess 310. A threaded hole 316 for inserting a mounting screw 90 is formed on the x-axis + side of the outer wall of the first lens barrel 31 relative to the recess 310. Through the mounting screw 90, the lens barrel 30 is connected to the outer cylinder 50 described in detail later.

[0040] <Second lens barrel 32>

[0041] The second lens barrel 32 is formed in front of the first lens barrel 31. The outer diameter of the second lens barrel 32 is larger than the outer diameter of the first lens barrel 31. The third lens 123 of the optical system 12 mounted on the inner barrel 40, which will be described in detail later, is accommodated in the second lens barrel 32. A fitting portion 320 is formed on the inner peripheral surface near the end portion on the front side of the second lens barrel 32. The fitting portion 320 is a threaded groove that is formed with a threaded portion 403 (see FIG. 1 ) formed on the inner barrel 40, which will be described later. Figure 4 ) are integrated.

[0042] A recess 321 is formed along the periphery in the outer wall of the second lens barrel 32. A sealing member 322 such as an O-ring is provided in the recess 321. A threaded hole 323 for inserting a mounting screw 91 is formed on the x-axis-side of the outer wall of the second lens barrel 32 relative to the recess 321. Through the mounting screw 91, the lens barrel 30 is connected to the peripheral cylinder 60 described in detail later. A threaded hole 324 for inserting the mounting screw 92 is formed on the x-axis+side of the outer wall of the second lens barrel 32 relative to the recess 321. Through the mounting screw 92, the inner cylinder 40 described in detail later is fixed to the lens barrel 30.

[0043] <Inner tube 40>

[0044] Figure 4 Yes Figure 2 The partial cross-sectional view shown in an enlarged manner near the end portion on the x-axis + side of the cross-sectional view shown in FIG. The inner cylinder 40 is a cylindrical component, and the third lens 123 is installed inside. The inner cylinder 40 is housed in the second barrel 32 of the lens barrel 30. On the outer wall of the inner cylinder 40, a first diameter fitting portion 401, a second diameter fitting portion 402, and a threaded portion 403 are formed in sequence along the outer peripheral surface from the x-axis - side. The first diameter fitting portion 401 and the second diameter fitting portion 402 are protrusions that protrude outward (in the direction away from the optical axis Ax) relative to the outer peripheral surface 404 of the inner cylinder 40. When the inner cylinder 40 is housed in the lens barrel 30, the first diameter fitting portion 401 and the second diameter fitting portion 402 are in contact with the inner wall of the second barrel 32 of the lens barrel 30.

[0045] The threaded portion 403 is formed near the end portion of the inner cylinder 40 on the + side of the x-axis, and when the inner cylinder 40 is accommodated in the interior of the second lens barrel 32, it is engaged with the engaging portion 320 formed in the second lens barrel 32. Thus, the inner cylinder 40 is mounted on the lens barrel 30 in a manner that allows it to rotate around the optical axis Ax. As the inner cylinder 40 rotates in the lens barrel 30, the inner cylinder 40 moves in the front-to-back direction along the optical axis Ax relative to the lens barrel 30. As a result, when the inner cylinder 40 is mounted to the lens barrel 30, the position of the inner cylinder 40 along the optical axis Ax (i.e., the position of the third lens 123) can be adjusted. That is, the position of the inner cylinder 40 in the direction of the optical axis Ax can be adjusted with a simple structure.

[0046] The outer peripheral surface 404 between the first diameter fitting part 401 and the second diameter fitting part 402 in the outer wall of the inner cylinder 40 is a contact surface for the lower end of the mounting screw 92 inserted into the threaded hole 324 of the lens barrel 30 to abut. In other words, the diameter of the abutting surface abutting the mounting screw 92, i.e., the outer peripheral surface 404, is smaller than the diameter of the first diameter fitting part 401 and the second diameter fitting part 402 that are diameter-fitted with the outer peripheral cylinder 60. The inner cylinder 40 that has been position-adjusted is fixed relative to the lens barrel 30 by the mounting screw 92 abutting against the outer peripheral surface 404. In other words, the inner cylinder 40 can be moved between the first diameter fitting part 401 and the second diameter fitting part 402 along the x-axis direction when the position is adjusted. Therefore, the third lens 123 of the optical system 12 can be moved and adjusted in the direction of the optical axis Ax, and the spread angle of the illumination light emitted from the light source 11 outside the illumination device 10 can be adjusted.

[0047] In addition, since the inner cylinder 40 after the movement adjustment is fixed by the mounting screws 92, the position of the third lens 123 in the direction of the optical axis Ax can be easily fixed with high reliability. In addition, it is also considered that the outer peripheral surface 404 is uneven due to curling, depression, etc. due to the force applied when fixing with the mounting screws 92. However, since the diameter of the outer peripheral surface 404 is smaller than the diameters of the first diameter fitting portion 401 and the second diameter fitting portion 402, it is possible to prevent the uneven portion from protruding to the radial side (outside) of the inner cylinder 40 away from the optical axis Ax from the first diameter fitting portion 401 and the second diameter fitting portion 402. As a result, when the inner cylinder 40 is removed from the lens barrel 30 when repairing the lighting device 10, it is possible to prevent the uneven portion on the outer peripheral surface 404 from contacting the inner wall of the lens barrel 30 and causing damage.

[0048] When the inner cylinder 40 is accommodated in the lens barrel 30, the first diameter fitting portion 401 and the second diameter fitting portion 402 are in contact with the inner wall of the second barrel 32 of the lens barrel 30. That is, by the inner cylinder 40 and the lens barrel 30 being in contact at two or more locations, the inner cylinder 40 is suppressed from tilting relative to the optical axis Ax in the lens barrel 30. In addition, the outer peripheral surface 404, which is the abutment surface of the mounting screw 92, is located between the first diameter fitting portion 401 and the second diameter fitting portion 402 along the x-axis, thereby suppressing the force that tilts the inner cylinder 40 relative to the optical axis Ax due to the force applied by the mounting screw 92 during fixing.

[0049] <Outer tube 60>

[0050] The outer peripheral tube 60 has a cylindrical shape extending toward the x-axis-side with the end wall surface 61 on the x-axis + side as the bottom. An opening 610 is formed in the central portion of the end wall surface 61. Through the opening 610, a portion of the illumination light emitted from the light source 11, which will be described in detail later, is emitted to the outside of the lighting device 10. On the x-axis-side of the end wall surface 61, a diffraction portion 14, which will be described in detail later, is installed via a sealing member 601 such as a waterproof tape. In addition, the area of ​​the surface of the diffraction portion 14 parallel to the yz plane is larger than the area of ​​the opening 610. The sealing member 601 prevents water that enters from the mounting portion of the diffraction portion 14 and the opening 610 through the immersion path R1 from reaching the inside of the outer peripheral tube 60.

[0051] The inner diameter of the outer tube 60 is larger than the outer diameter of the second barrel 32 of the lens barrel 30. The lens barrel 30 is inserted into the outer tube 60 from the x-axis side. As a result, the second barrel 32 of the lens barrel 30, the inner tube 40 mounted on the second barrel 32, and the third lens 123 are accommodated in the outer tube 60.

[0052] A threaded hole 602 is formed near the end portion on the x-axis side of the outer peripheral tube 60. The threaded hole 602 is formed at a position overlapping with the threaded hole 323 formed in the second lens barrel 32 of the lens barrel 30 accommodated in the outer peripheral tube 60 in the x-axis direction. By inserting the mounting screw 91 into the threaded hole 602 and the threaded hole 323 formed in the second lens barrel 32, the outer peripheral tube 60 is connected to the lens barrel 30 by threaded fastening.

[0053] As described above, in the second lens barrel 32, a sealing member 322 is provided in front of the threaded hole 323 (x-axis + side). By means of the sealing member 322, water entering through the threaded hole 323, 602 through the immersion path R2 and water entering through the immersion path R3 from the end of the rear side (x-axis - side) of the outer peripheral tube 60 is prevented from reaching the inside of the outer peripheral tube 60. The sealing member 322 is provided in the recessed portion 321 formed on the outer peripheral surface of the second lens barrel 32, so that compared with the case of a structure in which the sealing member is provided from the outside of the second lens barrel 32, it is possible to prevent the lighting device 10 from being enlarged in the radial direction.

[0054] <Outer cylinder 50>

[0055] like Figure 2 As shown, the outer cylinder 50 has a cylindrical shape extending toward the x-axis + side with the end wall surface 51 on the x-axis - side (rear) as the bottom. The inner diameter of the outer cylinder 50 is larger than the outer diameter of the first barrel 31 of the lens barrel 30. The outer cylinder 50 accommodates the first barrel 31 of the lens barrel 30 in the vicinity of the end on the x-axis + side (front). In addition, the control substrate 17 of the light source holder 111 mounted on the rear of the third mounting surface 313 of the first barrel 31 is accommodated in the outer cylinder 50.

[0056] The outer tube 50 is mounted on the outer side of the first lens barrel 31 from the x-axis-side (rear) of the lens barrel 30. A threaded hole 511 is formed at the end of the x-axis+side of the outer tube 50. The threaded hole 511 is formed at a position overlapping with the threaded hole 316 formed in the first lens barrel 31 in the x-axis direction. By inserting the mounting screw 90 into the threaded hole 511 and the threaded hole 316 formed in the first lens barrel 31, the outer tube 50 is connected to the lens barrel 30 by threaded fastening.

[0057] As described above, in the first lens barrel 31, the sealing member 315 is provided behind the screw hole 316 (on the x-axis side). The sealing member 315 prevents the water from passing through the screw hole 316 and the water immersion path R4 (see Figure 2 ) and the water entering from the front end (x-axis + side) of the outer cylinder 50 through the immersion path R5 (refer to Figure 2 ) and enters the outer tube 50. The sealing member 315 is provided in the recessed portion 310 formed on the outer peripheral surface of the first lens barrel 31, so that compared with the case where the sealing member is provided from the outside of the first lens barrel 31, the radial enlargement of the lighting device 10 can be suppressed.

[0058] The end wall surface 51 is provided with a connector 70 used when connecting to an external device of the lighting device 10. A through hole 501 is formed near the center (optical axis Ax) of the end wall surface 51, through which wiring etc. connecting the control substrate 17 and the connector 70 pass. In addition, the surface of the connector 70 parallel to the yz plane is larger than the through hole 501, and the connector 70 is mounted on the end wall surface 51 via a sealing member 502 such as an O-ring. The sealing member 502 is used to prevent the connector 70 from passing through the water immersion path R6 (see FIG. 6 ) from being mounted on the end wall surface 51. Figure 2 ) and the water entering reaches the interior of the outer cylinder 50.

[0059] <Light source 11>

[0060] The light source 11 is, for example, a laser diode (semiconductor laser), which receives power supply and emits illumination light as laser (coherent light) toward the x-axis + direction. The light source 11 is mounted from the x-axis - side of the third mounting surface 313 of the lens barrel 30 via the light source holder 111. The light source holder 111 is a disc-shaped component having a diameter smaller than the inner diameter of the first barrel 31 of the lens barrel 30. The light source holder 111 is formed with an opening 111a near the central portion (optical axis Ax). By inserting the light source 11 into the opening 111a from the x-axis - side, the light source 11 is held in the light source holder 111. By mounting the light source holder 111 on the third mounting surface 313, the light source 11 is arranged on the optical axis Ax. A threaded hole for threaded fastening with the third mounting surface 313 and a threaded hole for threaded fastening with the control substrate 17 are formed in the light source holder 111. The light source 11 is controlled by a control unit 170 (see Figure 6 ) is controlled to change the amount of illumination light. In addition, it is not limited to that the light source 11 is mounted on the light source holder 111, and the lighting device 10 may not have the light source holder 111, and the light source 11 is mounted on the third mounting surface 313 of the first lens barrel 31.

[0061] <Optical system 12>

[0062] The optical system 12 is arranged on the + side of the x-axis relative to the light source 11, and is a collimating lens that shapes the illumination light emitted from the light source 11 into parallel light. As described above, the optical system 12 includes a first lens 121, a second lens 122, and a third lens 123. The first lens 121 and the second lens 122 are mounted in the first barrel 31 of the lens barrel 30. As described above, the third lens 123 is mounted in the inner barrel 40 and is stored in the second barrel 32 of the lens barrel 30 via the inner barrel 40. In addition, the optical system 12 is not limited to having the above-mentioned three lenses, and can be less than two or more than four.

[0063] <Branch 13>

[0064] The branching portion 13 is an optical component such as a beam splitter or a half mirror, and branches the traveling direction of the incident illumination light into the x-axis + side and the y-axis + side. That is, the branching portion 13 transmits a part of the illumination light emitted from the light source 11, and reflects the other part (the remaining part) toward the y-axis + side. The branching portion 13 is held in the first holding portion 18, the details of which will be described later, and is housed in the first barrel 31 of the lens barrel 30. The branching portion 13 is arranged on the optical axis Ax of the optical system 12. In addition, in the lighting device 10 of the present embodiment, the branching portion 13 is arranged on the x-axis - side relative to the optical system 12, but the branching portion 13 may also be arranged on the x-axis + side relative to the optical system 12.

[0065] <First Detection Unit 15>

[0066] Figure 5A 1 is a perspective view of the appearance of the first holding portion 18, the second holding portion 19, the first detection portion 15, and the second detection portion 16. Figure 5B yes Figure 5A Cross-sectional view at line BB.

[0067] The first detection unit 15 has a substrate 151 and a light receiving unit 152 composed of a photoelectric conversion element such as a photodiode. The first detection unit 15 is arranged on the + side of the y-axis relative to the branch portion 13. That is, the first detection unit 15 is housed on the + side of the y-axis relative to the optical axis Ax in the lens barrel 30. The first detection unit 15 is held by the first holding portion 18, the details of which will be described later, and is mounted on the first mounting plane 311 formed on the first barrel 31 of the lens barrel 30 from the + side of the y-axis together with the branch portion 13. The first detection unit 15 is electrically connected to the control substrate 17 through the wiring 153. As described above, the wiring 153 passes through the through hole 314 formed on the third mounting surface 313.

[0068] <Second Detection Unit 16>

[0069] The second detection unit 16 has a substrate 161 and a light receiving unit 162 composed of a photoelectric conversion element such as a photodiode. The second detection unit 16 is arranged on the y-axis side relative to the branch portion 13. That is, the second detection unit 16 is housed on the y-axis side relative to the optical axis Ax in the lens barrel 30. Thus, the first detection unit 15 and the second detection unit 16 are housed in the lens barrel 30 in a manner opposite to each other across the optical axis Ax. The second detection unit 16 is held by the second holding portion 19, the details of which will be described later, and is mounted on the second mounting plane 312 formed on the first barrel 31 of the lens barrel 30 from the y-axis side. The second detection unit 16 is electrically connected to the control substrate 17 through the wiring 163. As described above, the wiring 163 passes through the through hole 314 formed on the third mounting surface 313.

[0070] <First holding portion 18>

[0071] As described above, the first holding portion 18 holds the branch portion 13 and the first detection portion 15. The first holding portion 18 includes the first mounting portion 181 that holds the first detection portion 15 and the second mounting portion 182 that holds the branch portion 13.

[0072] <First mounting portion 181>

[0073] The first mounting portion 181 is a member having a protrusion 184 protruding toward the y-axis + side along the edge of a plate-shaped surface member 183, and the surface member 183 is along the zx plane. An opening 185 is formed near the center of the surface member 183. The substrate 151 of the first detection unit 15 is arranged at the upper end (y-axis + side) of the protrusion 184 of the first mounting portion 181. The light receiving unit 152 is mounted on the surface of the substrate 151 on the y-axis - side. Therefore, the first detection unit 15 receives light that passes through the opening 185 and travels toward the y-axis + side.

[0074] The protrusion 184a on the + side of the x-axis in the protrusion 184 protrudes toward the + side of the y-axis more than the protrusion 184b on the - side of the x-axis. Therefore, the substrate 151 mounted on the protrusion 184 is inclined relative to the zx plane. That is, the light receiving portion 152 of the first detection portion 15 is inclined relative to the direction perpendicular to the optical axis Ax (y-axis direction). Therefore, as described later, the light in the illumination light that is reflected by the branch portion 13 and reaches the light receiving portion 152 of the first detection portion 15 and is reflected by the light receiving surface of the light receiving portion 152 is suppressed from traveling in the opposite direction on the same optical path as when it is incident on the light receiving portion 152. That is, the light reflected by the light receiving surface of the light receiving portion 152 is suppressed from being incident on the branch portion 13 again and being reflected and traveling toward the - side of the x-axis to be incident on the light source 11.

[0075] In addition, the protrusion 184b on the x-axis-side of the protrusion 184 may protrude toward the y-axis+ side more than the protrusion 184a on the x-axis+ side. That is, the height of the protrusion 184 (the amount of protrusion toward the y-axis+ side) may be different in the front-back direction. Alternatively, the height of the protrusion 184 (the amount of protrusion toward the y-axis+ side) may be different in the left-right direction (z-axis direction).

[0076] <Second mounting portion 182>

[0077] The second mounting portion 182 is formed on the y-axis-side of the first mounting portion 181, and is a square cylindrical component extending from the bottom 190 disposed on the y-axis + side to the y-axis-side. An opening 190a is formed in the bottom 190. The second mounting portion 182 holds the branch portion 13 by accommodating the branch portion 13 from the y-axis-side inside. An opening 188 and an opening 189 are formed near the center of each on the surface 186 on the x-axis-side and the surface 187 on the x-axis + side in the second mounting portion 182. When the first holding portion 18 is mounted on the lens barrel 30, the openings 188 and 189 are arranged on the optical axis Ax. As a result, the illumination light emitted from the light source 11 is incident on the branch portion 13 via the opening 188, and the light passing through the branch portion 13 travels toward the x-axis + side via the opening 189. In addition, the light of the illumination light that enters the branching portion 13 via the opening 188 and is reflected by the branching portion 13 travels toward the first mounting portion 181 on the + side of the y-axis via the opening 190 a .

[0078] <Second holding portion 19>

[0079] As described above, the second holding portion 19 holds the second detection portion 16. The second holding portion 19 is a component having a protrusion 192 protruding toward the y-axis-side along the edge of a plate-shaped surface component 191, and the surface component 191 is along the zx plane. An opening 193 is formed near the center of the component 192. The substrate 161 is arranged at the lower end (y-axis-side) of the protrusion 192 of the second holding portion 19. The light receiving portion 162 is mounted on the surface of the substrate 161 on the y-axis+ side. Therefore, the second detection portion 16 receives light that passes through the opening 193 and travels toward the y-axis-side.

[0080] The protrusion 192a on the x-axis + side of the protrusion 192 protrudes toward the y-axis - side more than the protrusion 192b on the x-axis - side. Therefore, the substrate 161 mounted on the protrusion 192 is inclined relative to the zx plane. That is, the light receiving portion 162 of the second detection portion 16 is inclined relative to the direction perpendicular to the optical axis Ax (y-axis direction). Therefore, as described later, the light that travels from the x-axis + side via the diffraction portion 14 and is reflected by the branch portion 13 and reaches the light receiving portion 162 of the second detection portion 16, and the light reflected by the light receiving surface of the light receiving portion 162 is suppressed from traveling in the opposite direction on the same optical path as when it is incident on the light receiving portion 162. That is, the light reflected by the light receiving surface of the light receiving portion 162 is suppressed from being incident on the branch portion 13 again and being reflected and traveling toward the diffraction portion 14 on the x-axis + side.

[0081] In addition, the protrusion 192b on the x-axis-side of the protrusion 192 may protrude toward the y-axis-side more than the protrusion 192a on the x-axis+side. That is, the height of the protrusion 192 (the amount of protrusion toward the y-axis-side) may be different in the front-back direction. Alternatively, the height of the protrusion 192 (the amount of protrusion toward the y-axis-side) may be different in the left-right direction (z-axis direction).

[0082] A protrusion 194 is formed on the surface of the surface member 191 on the y-axis + side (upper side) near the end on the x-axis - side, and protrudes toward the y-axis + side. The protrusion 194 is formed on the surface member 191 along the z-axis. That is, the end 194 is a part of the end on the x-axis - side (the other side in the second direction) of the surface member 191 of the second holding portion 19. When the first holding portion 18 and the second holding portion 19 are mounted on the lens barrel 30, as shown in FIG. Figure 5BAs shown, the protrusion 194 is located at a position on the light source 11 side that is rearward (x-axis-side) of the end of the second mounting portion 182 of the first holding portion 18 on the x-axis-side. The top of the protrusion 194 (the front end on the y-axis+side) is located above (y-axis+side) the lower end (the front end on the y-axis-side) of the second mounting portion 182 of the first holding portion 18. That is, a portion of the end of the x-axis-side (the other side of the second direction) of the second holding portion 19, i.e., the protrusion 194, overlaps with a portion of the end of the second mounting portion 182 of the first holding portion 18 on the other side of the second direction in the direction along the optical axis Ax. As a result, a portion of the illumination light emitted from the light source 11 is suppressed from passing between the first holding portion 18 and the second holding portion 19 and becoming stray light.

[0083] In addition, the top of the protrusion 194 can be located below (on the y-axis side) the lower end of the opening 188 formed on the x-axis side of the second mounting portion 182. Thus, the illumination light emitted from the light source 11 is not blocked by the protrusion 194 and can pass through the opening 188 and enter the branch portion 13.

[0084] <Diffraction portion 14>

[0085] The diffraction portion 14 is arranged on the x-axis + side relative to the x-axis + side end portion in the outer peripheral tube 60, that is, the branch portion 13, and is illuminated by the light in the illumination light that passes through the branch portion 13. The diffraction portion 14 is, for example, a diffraction grating such as a hologram element. As a hologram element, various holograms such as the well-known Fourier transform type, Fresnel type, computer synthesis type, analog recording type, relief type, etc. can be used. Information related to the movement of the above-mentioned moving body is recorded in the hologram element. A part of the light that passes through the branch portion 13 passes through the diffraction portion 14 and is emitted to the outside of the lighting device 10. As a result, the information recorded in the diffraction portion 14 is projected to the outside of the lighting device 10 (that is, in front of the moving direction of the moving body).

[0086] <Action>

[0087] Next, the operation of the lighting device 10 having the above-described structure will be described. Figure 6 1 is a block diagram showing the main structure of the lighting device 10. As described above, the branching portion 13 transmits a part of the illumination light L emitted from the light source 11, and reflects the other part (the remaining part) toward the + side of the y-axis. The light reflected by the branching portion 13 in the illumination light L is referred to as the first illumination light L1, and the light transmitted through the branching portion 13 is referred to as the second illumination light L2. In the following description, the branching portion 13 transmits 50% of the illumination light L, and reflects the remaining 50%.

[0088] The first illumination light L1 reflected by the branching portion 13 is incident on the first detection portion 15 disposed on the + side of the y-axis relative to the branching portion 13. In the first detection portion 15, the incident first illumination light L1 is converted into an electrical signal by the light receiving portion 152 and output as a first detection signal. The electrical signal (i.e., the first detection signal) has a value (signal intensity) corresponding to the light amount of the light incident on the first detection portion 15. Therefore, the first detection portion 15 detects the light amount of the first illumination light L1.

[0089] The second illumination light L2 transmitted through the branching portion 13 illuminates the diffraction portion 14. A portion of the second illumination light L2 is transmitted through the diffraction portion 14 and emitted to the outside of the illumination device 10, and the remaining portion is reflected by the diffraction portion 14. As described above, the diffraction portion 14 is illuminated by a portion of the second illumination light L2, and thus the information recorded in the diffraction portion 14 is projected to the outside of the illumination device 10 (i.e., in front of the moving direction of the moving body). The light (reflected light) reflected by the diffraction portion 14 in the second illumination light L2 travels toward the x-axis side and enters the branching portion 13. The reflected light is reflected by the branching portion 13 toward the y-axis side and enters the second detection portion 16.

[0090] In addition, the light of the second illumination light L2 that is reflected by the branching portion 13 after being reflected by the diffraction portion 14 (i.e., the reflected light after being reflected by the diffraction portion 14) and the light (i.e., the external light) L3 that is reflected by the branching portion 13 after passing through the diffraction portion 14 from the outside of the illumination device 10 enters the second detection portion 16. That is, the second detection portion 16 detects the amount of light that enters through the diffraction portion 14. In the second detection portion 16, the incident light is converted into an electrical signal by the light receiving portion 162 and output as a second detection signal. The electrical signal (i.e., the second detection signal) has a value (signal intensity) corresponding to the amount of light of the reflected light and the external light L3 that enters the second detection portion 16. However, when the external light L3 does not pass through the diffraction portion 14, the second detection portion 16 detects the amount of light of the reflected light, i.e., the amount of light of the second illumination light L2. In this case, the second detection signal has a signal intensity corresponding to the amount of light of the reflected light.

[0091] The control unit 170 is composed of a CPU, a memory, etc., and is mounted on the control substrate 17 described above. The control unit 170 is, for example, a processor that controls each unit of the lighting device 10 by reading and executing a control program pre-recorded in a storage medium such as a flash memory. The control unit 170 performs a light quantity control process for controlling the light quantity of the illumination light L emitted by the light source 11 based on the first light quantity of the first illumination light L1 detected by the first detection unit 15. The control unit 170 performs a light source control process for stopping the emission of the illumination light L by the light source 11 based on the second light quantity of the light detected by the second detection unit 16. However, when the external light L3 is incident, the control unit 170 continues to emit the illumination light L using the light source 11.

[0092] <Light intensity control processing>

[0093] The control unit 170 supplies a predetermined electric power (current) from the power supply unit 20 to the light source 11, and the illumination light L is emitted from the light source 11. The control unit 170 detects the light amount of the first illumination light L1, that is, the first light amount, that is, the light amount of the illumination light L emitted from the light source 11, based on the first detection signal output by the first detection unit 15. As described above, the first illumination light L1 is the light in the illumination light L that is reflected by the branching portion 13 toward the + side of the y-axis. In addition, as described above, the reflectivity of the branching portion 13 is 50%, which is a known value, so the first light amount of the first illumination light L1 reflected by the branching portion 13 is proportional to the light amount of the illumination light L emitted from the light source 11. Therefore, the control unit 170 can process (detect) the first light amount of the first illumination light L1 detected by the first detection unit 15 as the light amount of the illumination light L.

[0094] The control unit 170 compares the detected first light amount of the illumination light L with the preset lower limit specified value Th1 and upper limit specified value Th2. The lower limit specified value Th1 is a value obtained by multiplying the lower limit value of the light amount of the illumination light L by the reflectivity of the branching portion 13, that is, 50%. The lower limit value of the light amount of the illumination light L refers to the value of the light amount required to visually confirm the projection pattern formed externally by the light emitted from the lighting device 10. The value of the lower limit specified value Th1 is determined based on the results of simulation, etc., and the threshold voltage (current) corresponding to the lower limit specified value Th1 is preset in the control unit 170. The comparator of the control unit 170 compares the threshold voltage (current) with the voltage (current) of the first detection signal of the first light amount of the first illumination light L1, and outputs a signal corresponding to the comparison result. The control unit 170 performs processing corresponding to the comparison result based on the signal.

[0095] In addition, the upper limit value Th2 is a value obtained by multiplying the upper limit value of the light amount of the illumination light L by the reflectivity of the branching portion 13, that is, 50%. The upper limit value of the light amount of the illumination light L is a value of the light amount that will not cause adverse effects even if the light emitted from the illumination device 10 enters the eyes of an outside person. The value of the upper limit value Th2 is determined based on the results of simulation, etc., and the threshold voltage (current) corresponding to the upper limit value Th2 is pre-set in the control unit 170. The comparator of the control unit 170 compares the threshold voltage (current) with the voltage (current) of the first detection signal of the first light amount of the first illumination light L1, and outputs a signal corresponding to the comparison result. The control unit 170 performs processing corresponding to the comparison result based on the signal.

[0096] The control unit 170 compares the calculated value of the amount of light of the illumination light L with the lower limit specified value Th1, and when the value of the amount of light of the illumination light L is less than the lower limit specified value Th1, increases the amount of light of the illumination light L emitted from the light source 11. Specifically, the control unit 170 increases the power (current) supplied from the power supply unit 20 to the light source 11. In this case, the control unit 170 increases the amount of power supplied by a predetermined value. Alternatively, the control unit 170 increases the amount of power supplied according to the difference between the calculated value of the amount of light of the illumination light L and the lower limit specified value Th1. As a result, the amount of light of the illumination light L emitted from the light source 11 increases, and a projection pattern formed externally by the light emitted from the lighting device 10 can be visually confirmed.

[0097] The control unit 170 compares the calculated value of the amount of light of the illumination light L with the upper limit value Th2, and when the value of the amount of light of the illumination light L is greater than the upper limit value Th2, the control unit 170 reduces the amount of light of the illumination light L emitted from the light source 11. Specifically, the control unit 170 reduces the power (current) supplied from the power supply unit 20 to the light source 11. In this case, the control unit 170 reduces the amount of power supplied by a predetermined value. Alternatively, the control unit 170 reduces the amount of power supplied according to the difference between the calculated value of the amount of light of the illumination light L and the upper limit value Th2. Thus, even when the light emitted from the lighting device 10 enters the eyes of an outside person, it is possible to suppress the adverse effects.

[0098] In addition, the control unit 170 may detect (calculate) the light amount of the illumination light L emitted from the light source 11 by doubling the first light amount of the first illumination light L1 instead of processing the first light amount of the first illumination light L1 detected by the first detection unit 15 as the light amount of the illumination light L. In this case, the lower limit specified value Th1 is the lower limit value of the light amount of the illumination light L, and the upper limit specified value Th2 is the upper limit value of the light amount of the illumination light L.

[0099] Note that the above-described light amount control process is executed by the control unit 170 at every predetermined time interval.

[0100] Reference Figure 7 The flowchart of the light amount control process shown in FIG. 1 illustrates the process performed by the control unit 170. Each process shown in the flowchart is performed by the control unit 170 reading a program stored in a storage medium and executing the program.

[0101] In step S10, the control unit 170 detects the value of the first light amount of the first illumination light L1 using the first detection signal output from the first detection unit 15. Thereafter, the process proceeds to step S11. In step S11, the control unit 170 determines whether the value of the first light amount of the first illumination light L1 is less than the lower limit specified value Th1. When the value of the first light amount of the first illumination light L1 is less than the lower limit specified value Th1, the control unit 170 makes an affirmative determination, and the process proceeds to step S12. In step S12, the control unit 170 increases the power supplied from the power supply unit 20 to the light source 11, thereby increasing the light amount of the illumination light L emitted by the light source 11. Thereafter, the process returns to step S10.

[0102] In step S11, when the value of the first light amount of the first illumination light L1 is greater than the lower limit prescribed value Th1, the control unit 170 makes a negative determination, and the process proceeds to step S13. In step S13, the control unit 170 determines whether the value of the light amount of the first illumination light L1 is greater than the upper limit prescribed value Th2. In the case where the value of the first light amount of the first illumination light L1 is greater than the upper limit prescribed value Th2, the control unit 170 makes an affirmative determination, and the process proceeds to step S14. In step S14, the control unit 170 reduces the power supplied from the power supply unit 20 to the light source 11, thereby reducing the light amount of the illumination light L emitted by the light source 11. Thereafter, the process returns to step S10. In addition, in step S13, when the value of the first light amount of the first illumination light L1 is less than the upper limit prescribed value Th2, the control unit 170 makes a negative determination, and the process returns to step S10.

[0103] By performing the above-described light quantity control process, it is suppressed that the illumination light L emitted from the light source 11 becomes insufficient in light quantity or excessive in light quantity.

[0104] <Light source control processing>

[0105] The control unit 170 detects the light amount of the light (hereinafter referred to as the arrival light) L4 reaching the second detection unit 16 via the diffraction unit 14, i.e., the second light amount, based on the second detection signal output by the second detection unit 16. However, as described above, sometimes the external light L3 also enters the second detection unit 16 through the diffraction unit 14. Therefore, the control unit 170 determines whether the arrival light L4 includes the external light L3 based on the second detection signal, and controls the emission of the illumination light L of the light source 11 differently depending on whether the arrival light L4 includes the external light L3 and whether the arrival light L4 does not include the external light L3.

[0106] When the arriving light L4 does not include the external light L3, as described above, a part of the arriving second illumination light L2 is reflected in the diffracting section 14, and the reflected light enters the second detection section 16. The reflectivity of the diffracting section 14 is a known value determined by the material of the diffracting section 14, and therefore, when the arriving light L4 does not include the external light L3, the amount of the reflected light after being reflected by the diffracting section 14 (i.e., the amount of light based on the second detection signal) is proportional to the amount of the second illumination light L2 arriving at the diffracting section 14. Thus, when the arriving light L4 does not include the external light L3, the control section 170 can process (detect) the second light amount of the arriving light L4 detected by the second detection section 16 as the light amount of the second illumination light L2. The following is a specific description of the processing of the control section 170.

[0107] The control unit 170 compares the detected second light amount of the arrival light L4 with the preset upper limit value Th3 and lower limit value Th4. The upper limit value Th3 is, for example, a value obtained by multiplying the upper limit value of the light amount of the second illumination light L2 by the reflectivity of the diffraction unit 14. The upper limit value of the light amount of the second illumination light L2 is a value of the light amount that will not cause adverse effects even if the light emitted from the illumination device 10 enters the eyes of an outside person.

[0108] The value of the upper limit value Th3 is determined based on the result of simulation, etc., and the threshold voltage (current) corresponding to the upper limit value Th3 is pre-set in the control unit 170. The comparator of the control unit 170 compares the threshold voltage (current) with the second light amount reaching the light L4, that is, the voltage (current) of the second detection signal output by the second detection unit 16, and outputs a signal corresponding to the comparison result. The control unit 170 performs processing corresponding to the comparison result based on the signal.

[0109] In addition, the lower limit specified value Th4 is, for example, a value obtained by multiplying the lower limit value of the light amount of the second illumination light L2 by the reflectivity of the diffraction portion 14. The lower limit value of the light amount of the second illumination light L2 refers to a value of the light amount required to visually confirm a projection pattern formed externally by the light emitted from the illumination device 10 when the diffraction portion 14 is not damaged.

[0110] The value of the lower limit value Th4 is determined based on the result of simulation or the like, and the threshold voltage (current) corresponding to the lower limit value Th4 is preset in the control unit 170. The control unit 170 includes, for example, a comparator, which compares the threshold voltage (current) with the voltage (current) of the second detection signal output by the second detection unit 16, which is the second light amount reaching the light L4, and outputs a signal corresponding to the comparison result. The control unit 170 performs processing corresponding to the comparison result based on the signal.

[0111] When the second light amount of the arrival light L4 is below the lower limit specified value Th4, it is considered that damage (abnormality) such as an opening is generated in the diffraction part 14, and the reflectivity of the diffraction part 14 is reduced. That is, it is considered that the light amount of the second illumination light L2 that is not reflected by the diffraction part 14 but transmitted is increased. In this case, since the light amount of the light emitted to the outside of the lighting device 10 is too much, if the light enters the eyes of the outside person, it may cause adverse effects. Therefore, when the second light amount of the arrival light L4 detected is below the lower limit specified value Th4, the control unit 170 stops the current supply from the power supply unit 20 to the light source 11, so that the emission of the illumination light L from the light source 11 is stopped.

[0112] When the second light amount of the arrival light L4 is greater than the upper limit specified value Th3, the following two main reasons are considered. As the first main reason, the diffraction unit 14 does not have an abnormality, but when, for example, the first detection unit 15 fails, the light amount of the second illumination light L2 transmitted through the diffraction unit 14 increases. As the second main reason, neither the first detection unit 15 nor the diffraction unit 14 has an abnormality, but since the external light L3 is incident from the outside of the lighting device 10 via the diffraction unit 14, the second light amount of the arrival light L4 incident on the second detection unit 16 increases.

[0113] In the case of the first main cause, the amount of light emitted to the outside of the lighting device 10 is too much, so if the light enters the eyes of people outside, it may cause adverse effects. Therefore, when the second light amount of the detected arrival light L4 is greater than the upper limit specified value Th3, the control unit 170 stops the current supply from the power supply unit 20 to the light source 11, and stops the emission of the illumination light L from the light source 11. In the case of the second main cause, the amount of light emitted to the outside of the lighting device 10 is appropriate, so the control unit 170 continues to emit the illumination light L from the light source 11.

[0114] Specifically, when the second light amount of the arriving light L4 is greater than the upper limit prescribed value Th3, the control unit 170 determines whether the state in which the second light amount is greater than the upper limit prescribed value Th3 has continued for more than a predetermined time (predetermined time). In this case, the control unit 170 starts timing when the second light amount of the arriving light L4 becomes greater than the upper limit prescribed value Th3. When the state in which the second light amount of the arriving light L4 is greater than the upper limit prescribed value Th3 has continued for a time longer than the prescribed time, it is considered that the first detection unit 15 has failed, the light amount of the illumination light L has increased, and the state in which the light amount of the light emitted to the outside of the illumination device 10 is excessive continues. That is, the second light amount of the arriving light L4 has increased due to the first main reason mentioned above, and therefore the control unit 170 determines that the arriving light L4 does not include the external light L3, and stops the emission of the illumination light L from the light source 11.

[0115] When the state in which the second light amount of the reaching light L4 is equal to or greater than the upper limit predetermined value Th3 is shorter than a predetermined time, it is considered that the external light L3 is incident for a short time via the diffracting portion 14. That is, the second light amount of the reaching light L4 increases due to the second main reason described above, and therefore the control portion 170 determines that the reaching light L4 includes the external light L3, and the illumination light L continues to be emitted from the light source 11.

[0116] The predetermined time is set to a time that can be regarded as a time that allows the external light L3 to enter the lighting device 10 in a short time as the moving object on which the lighting device 10 is mounted moves, based on the results of simulations or the like.

[0117] Note that the above-described light source control process is executed by the control unit 170 at predetermined time intervals.

[0118] Reference Figure 8 The flowchart of the light amount control process shown in FIG. 1 illustrates the process performed by the control unit 170. Each process shown in the flowchart is performed by the control unit 170 reading a program stored in a storage medium and executing the program.

[0119] In step S20, the control unit 170 supplies a predetermined power (current) from the power supply unit 20 to the light source 11, and the illumination light L is emitted from the light source 11. Then, the process proceeds to step S21. In step S21, the control unit 170 detects the value of the second light amount of the reaching light L4 using the second detection signal output from the second detection unit 16. Then, the process proceeds to step S22.

[0120] In step S22, the control unit 170 compares the detected value of the second light amount of the reaching light L4 with the lower limit value Th4. When the value of the second light amount of the reaching light L4 is greater than the lower limit value Th4, the control unit 170 makes an affirmative determination, and the process proceeds to step S23. When the value of the second light amount of the reaching light L4 is less than the lower limit value Th4, the control unit 170 makes a negative determination, and the process proceeds to step S25 described later.

[0121] In step S23, it is determined whether the value of the second light amount of the light reaching the light L4 is less than the upper limit value Th3. If the value of the second light amount of the light reaching the light L4 is less than the upper limit value Th3, the control unit 170 makes an affirmative determination, and the process returns to step S21. If the value of the second light amount of the light reaching the light L4 is greater than the upper limit value Th3, the control unit 170 makes a negative determination, and the process proceeds to step S24.

[0122] In step S24, the control unit 170 determines whether the state of being above the upper limit prescribed value Th3 in the value of the second light amount of the reaching light L4 is shorter than the prescribed time. If it is shorter than the prescribed time, the control unit 170 makes a positive determination, and the process returns to step S21. If it is longer than the prescribed time, the control unit 170 makes a negative determination, and the process proceeds to step S25. In step S25, the control unit 170 stops the power supply to the light source 11, stops the illumination light L emitted from the light source 11, and ends the process.

[0123] According to the above-described embodiment, the following effects can be obtained.

[0124] (1) The lens barrel 30 of the lighting device 10 has a mounting plane 330 (a first mounting plane 311 and a second mounting plane 312), which is a plane intersecting with a first direction intersecting with the optical axis Ax of the optical system 12, and on which the holding portion 180 (a first holding portion 18 and a second holding portion 19) holding the first detection portion 15 and the second detection portion 16 is mounted. In the lens barrel 30, the optical system 12 and the light source 11 are mounted along a second direction along the optical axis Ax. Thus, even when the lighting device 10 has a plurality of detection portions (a first detection portion 15 and a second detection portion 16), an increase in the outer diameter of the lens barrel 30 can be suppressed, which contributes to miniaturization of the lighting device 10.

[0125] In addition, the first holding portion 18 and the second holding portion 19 holding the first detection portion 15 and the second detection portion 16 are respectively mounted on the first mounting plane 311 and the second mounting plane 312 from the y-axis + side and the y-axis - side. Thus, it is easy to mount the first detection portion 15 and the second detection portion 18 to the lens barrel 30 when manufacturing the lighting device 10, and the efficiency of the assembly operation is improved.

[0126] Furthermore, the mounting position of the optical system 12 for parallelizing the illumination light L output from the light source 11 can be determined based on the inner diameter of the lens barrel 30 as a single component, so the mounting accuracy of the optical system 12 can be improved.

[0127] (2) In the lens barrel 30, the optical system 12 is installed on one side (x-axis + side) in the second direction relative to the first detection unit 15 and the second detection unit 16, and the light source 11 is installed on the other side (x-axis - side) in the second direction. As a result, the diameter of the illumination light L passing through the x-axis - side of the lens barrel 30 is smaller than the diameter of the first illumination light L1 passing through the x-axis + side of the lens barrel 30, so that the branching unit 13 can be miniaturized.

[0128] (3) The first detection unit 15 and the second detection unit 16 are housed in the housing portion 180 so as to face each other across the optical axis Ax. This allows the first detection unit 15 and the second detection unit 16 to be separated in the mounting direction of the lens barrel 30, thereby preventing the outer diameter of the lens barrel 30 from increasing.

[0129] (4) A portion of the end portion on the other side (x-axis side) in the second direction of the first holding portion 18 mounted on the first mounting plane 311 overlaps a portion of the end portion on the other side (x-axis side) in the second direction of the second holding portion 19 mounted on the second mounting plane 312 in the direction along the optical axis Ax of the optical system 12. Thus, a portion of the illumination light L emitted from the light source 11 is prevented from passing between the first holding portion 18 and the second holding portion 19 and reaching the optical system 12 as stray light.

[0130] (5) The light receiving surface of the light receiving section 152 of the first detection section 15 and the light receiving surface of the light receiving section 162 of the second detection section 16 are housed in the lens barrel 30 so as to be inclined with respect to the direction (y-axis direction) perpendicular to the optical axis Ax of the optical system 12. Thus, it is possible to suppress the light reflected by the light receiving surfaces of the light receiving sections 152 and 162 from traveling in the opposite direction on the same optical path as when the light was incident and becoming stray light.

[0131] (6) The control substrate 17 is disposed on the other side (x-axis side) in the second direction relative to the light source 11. A through hole 314 is provided on the end surface on the x-axis side of the lens barrel 30, i.e., the third mounting surface 313, through which the wirings 153 and 163 for connecting the control substrate 17 to the first detection unit 15 and the second detection unit 16 pass. Thus, when the lens barrel 30 and the outer tube 50 are mounted, the wirings 153 and 163 are prevented from being caught between the lens barrel 30 and the outer tube 50.

[0132] <First Modification>

[0133] The light receiving section 162 of the second detection section 16 of the lighting device 10 of the first modified example may also be composed of an image sensor (imaging element) in which a plurality of imaging pixels (photoelectric conversion elements) are arranged two-dimensionally in the row direction and the column direction. The second detection section 16 detects the second light quantity of the arrival light L4 incident via the diffraction section 14 and the distribution area of ​​the arrival light L4 distributed on the light receiving surface of the light receiving section 162 of the second detection section 16. The control section 170 of the first modified example performs light source control processing based on the detected second light quantity and the distribution area of ​​the arrival light L4.

[0134] In this case, the control unit 170 uses the distribution area of ​​the arrival light L4 when the diffraction unit 14 does not have an abnormality, the first detection unit 15 does not have a malfunction, and the arrival light L4 does not include the external light L3 as the reference area. That is, the reference area refers to the area where the arrival light L4 is distributed on the light receiving surface of the light receiving unit 162 of the second detection unit 16 when the arrival light L4 is the reflected light of the second illumination light L2 reflected by the diffraction unit 14. For example, the reference area may be the distribution area where the second illumination light L2 is distributed on the light receiving surface of the light receiving unit 162 of the second detection unit 16 when the light amount of the second illumination light L2 is the upper limit value mentioned above. The reference area is data represented by the position (coordinates) of the imaging pixels constituting the second detection unit 16, and is preset in the control unit 170.

[0135] The control unit 170 compares the distribution area of ​​the arrival light L4 detected by the second detection unit 16 with the reference area to determine whether the arrival light L4 includes the external light L3. Specifically, the control unit 170 calculates the difference between the position (coordinates of the imaging pixel) of the arrival light L4 distributed on the light receiving surface of the light receiving unit 162 based on the second detection signal and the position (coordinates) of the imaging pixel of the reference area. Then, the control unit 170 determines whether the calculated difference value exceeds a preset reference value. The reference value is a value that specifies a shape that can be regarded as a shape of the distribution area of ​​the arrival light L4 that is similar to the shape of the reference area. In the case where the reference area is set to the distribution area when the light amount of the second illumination light L2 is the upper limit value as described above, the reference value can be set to, for example, the difference between the shape of the distribution area when the light amount of the second illumination light L2 is the above-mentioned lower limit value and the shape of the reference area.

[0136] When the difference between the shape of the distribution area of ​​the arriving light L4 and the shape of the reference area exceeds the above-mentioned reference value, that is, when the shape of the distribution area of ​​the arriving light L4 is not similar to the shape of the reference area, the control unit 170 determines that the arriving light L4 contains the external light L3. In other words, when the shape of the distribution area of ​​the arriving light L4 exceeds the reference value and is different from the shape of the reference area, the control unit 170 determines that the arriving light L4 contains the external light L3.

[0137] When the difference value exceeds the reference value, that is, when the arrival light L4 includes the external light L3, the control unit 170 excludes the area where the external light L3 is distributed from the distribution area of ​​the arrival light L4 based on the second detection signal. In this case, the control unit 170 generates a correction signal by excluding the signals from the imaging pixels corresponding to the coordinates outside the reference area from the signals from each imaging pixel included in the second detection signal. Therefore, the correction signal represents the amount of light in the area overlapping with the reference area in the distribution area of ​​the arrival light L4. In other words, the control unit 170 extracts the amount of light in the area overlapping with the reference area in the distribution area of ​​the arrival light L4.

[0138] As in the embodiment, the control unit 170 compares the value of the second light quantity of the reaching light L4 based on the correction signal with the lower limit value Th4 and the upper limit value Th3. Then, as in the embodiment, the control unit 170 stops or continues the illumination light L from the light source 11 according to the comparison result.

[0139] When the difference between the shape of the distribution area of ​​the arriving light L4 and the shape of the reference area is less than the reference value, that is, when the shape of the distribution area of ​​the arriving light L4 does not differ from the shape of the reference area by more than the reference value, the shape of the distribution area of ​​the arriving light L4 is similar to the shape of the reference area. Therefore, when the difference is less than the reference value, the control unit 170 determines that the arriving light L4 does not include the external light L3. Then, similarly to the embodiment, the control unit 17 compares the value of the second light amount of the arriving light L4 based on the second detection signal with the lower limit specified value Th4 and the upper limit specified value Th3, and stops or continues the illumination light L of the light source 11 according to the comparison result.

[0140] Fig. 9 1 is a flowchart showing the light source control process in the first modification. Each process shown in the flowchart is performed by the control unit 170 reading a program stored in a storage medium and executing the program.

[0141] In step S30, the control unit 170 causes the light source 11 to emit the illumination light L. Then, the process proceeds to step S31. In step S31, the control unit 170 detects the distribution area and the second light amount of the arrival light L4 using the second detection signal output from the second detection unit 16. Then, the process proceeds to step S32.

[0142] In step S32, the control unit 170 determines whether the shape of the distribution area of ​​the detected arrival light L4 is different from the shape of the reference area by more than the reference value. When the difference between the shape of the distribution area of ​​the arrival light L4 (the coordinates of the imaging pixels) and the shape (coordinates) of the reference area is less than the reference value, the control unit 170 makes a negative determination, and the process proceeds to step S34 described later. When the difference between the shape of the distribution area of ​​the arrival light L4 (the coordinates of the imaging pixels) and the shape (coordinates) of the reference area exceeds the reference value, the control unit 170 makes an affirmative determination, and the process proceeds to step S33.

[0143] In step S33, the control unit 170 excludes the area where the external light L3 is distributed from the distribution area of ​​the arrival light L4 based on the second detection signal, and generates a correction signal. Thereafter, the process proceeds to step S34. In step S34, the control unit 170 compares the value of the second light amount of the arrival light L4 with the lower limit prescribed value Th4 and the upper limit prescribed value Th3. In addition, in the case of proceeding from step S32 to step S34, the control unit 170 compares the value of the second light amount with the lower limit prescribed value Th4 and the upper limit prescribed value Th3 using the second detection signal. In the case of proceeding from step S33 to step S34, the control unit 170 compares the value of the second light amount with the lower limit prescribed value Th4 and the upper limit prescribed value Th3 using the correction signal generated in step S33. In the case where the value of the second light amount of the arrival light L4 is greater than the lower limit prescribed value Th4 and less than the upper limit prescribed value Th3, the control unit 170 makes an affirmative determination, and the process returns to step S31. When the value of the second light amount of the reaching light L4 is less than the lower limit value Th4 or greater than the upper limit value Th3, the control unit 170 makes a negative determination and the process proceeds to step S35. In step S35, the control unit 170 stops the power supply to the light source 11, stops the emission of the illumination light L from the light source 11, and ends the process.

[0144] <Second Modification>

[0145] In the light source control process, it is not limited to stopping the emission of the illumination light L from the light source 11 when the second light amount detected by the second detection unit 16 is less than the lower limit prescribed value Th4 or more than the upper limit prescribed value Th3. For example, the control unit 170 may reduce the light amount of the illumination light L emitted from the light source 11. In this case, the control unit 170 can reduce the power supplied to the light source 11 to reduce the light amount of the illumination light L. At this time, the light amount of the illumination light L may be reduced according to the difference between the second light amount detected by the second detection unit 16 and the upper limit prescribed value Th3 or the lower limit prescribed value Th4, or may be reduced according to a predetermined ratio.

[0146] In the above, various embodiments and modifications are described, but the present invention is not limited to these contents. Other methods considered within the scope of the technical idea of ​​the present invention are also included in the scope of the present invention. For example, the control unit 170 may only perform light source control processing. In this case, the control unit 170 may also use the second detection signal output from the second detection unit 16 to determine whether the arriving light L4 includes the external light L3, and use the determination result and the second light amount of the arriving light L4 that has reached the second detection unit 16 to control the illumination light L emitted from the light source 11. In other words, the control unit 170 can control the illumination light L emitted by the light source 11 based on at least the determination result of whether the arriving light L4 includes the external light L3, the second light amount of the arriving light L4, and the first light amount of the first illumination light L1, and the second light amount of the arriving light L4.

[0147] In addition, the present technology can adopt the following structures.

[0148] (1) The lighting device comprises: a light source that emits illumination light; an optical system; a branching portion that branches the illumination light emitted from the light source; a plurality of detection portions that detect the amount of light arriving via the branching portion; a holding portion that holds the plurality of detection portions, respectively; and a storage portion that stores the branching portion, the plurality of detection portions, and the holding portion. The storage portion has an installation plane that is a plane intersecting with a first direction, and the holding portion that holds the plurality of detection portions is installed from the first direction, and the first direction intersects with the optical axis of the optical system. In the storage portion, the optical system and the light source are installed along a second direction, and the second direction is along the optical axis.

[0149] (2) The lighting device according to (1), wherein, in the housing portion, the optical system is mounted on one side in the second direction relative to the detection portion, and the light source is mounted on the other side in the second direction.

[0150] (3) The lighting device according to (1) or (2), wherein the plurality of detection units include a first detection unit and a second detection unit, and the first detection unit and the second detection unit are housed in the housing unit so as to face each other with the optical axis interposed therebetween.

[0151] (4) A lighting device according to (3), wherein the holding portion includes a first holding portion for holding the first detection portion and a second holding portion for holding the second detection portion, the mounting plane includes a first mounting plane for mounting the first holding portion and a second mounting plane for mounting the second holding portion, and a portion of an end portion on the other side of the second direction of the first holding portion mounted on the first mounting plane overlaps with a portion of an end portion on the other side of the second direction of the second holding portion mounted on the second mounting plane in a direction along the optical axis.

[0152] (5) The lighting device according to (3) or (4), wherein the light receiving surface of the first detection unit and the light receiving surface of the second detection unit are housed in the housing portion in a manner inclined relative to a direction perpendicular to the optical axis of the optical system.

[0153] (6) A lighting device according to any one of (1) to (5), wherein the lighting device comprises: a control substrate, which is arranged on the other side of the second direction relative to the light source; and wiring, which connects the control substrate and the detection unit, and a through hole for the wiring to pass through is provided on the end face of the storage unit on the other side of the second direction.

[0154] Description of symbols

[0155] 10: lighting device; 11: light source; 12: optical system; 13: branching unit; 14: diffraction unit; 15: first detection unit; 16: second detection unit; 17: control substrate; 18: first holding unit; 19: second holding unit; 30: lens barrel; 31: first lens barrel; 32: second lens barrel; 40: inner barrel; 50: outer barrel; 60: outer barrel; 121: first lens; 122: second lens; 123: third lens; 152: light receiving unit; 153: wiring; 162: light receiving unit; 163: wiring line; 170: control part; 180: holding part; 181: first mounting part; 182: second mounting part; 194: protrusion; 310: recess; 311: first mounting plane; 312: second mounting plane; 312: mounting plane; 313: third mounting surface; 314: through hole; 315: sealing part; 320: fitting part; 321: recess; 322: sealing part; 323: hole; 324: hole; 330: mounting plane; 401: first diameter fitting part; 402: second diameter fitting part.

Claims

1. A lighting device, comprising: a light source that emits illuminating light; Optical system; a branching portion that branches the illumination light emitted from the light source; a plurality of detection units that detect the amount of light arriving via the branching unit; a holding unit that holds the plurality of detection units respectively; as well as a storage unit that stores the branch unit, the plurality of detection units, and the holding unit, The storage portion has an installation plane, which is a plane intersecting with a first direction, and the holding portion holding the plurality of detection portions is installed from the first direction, and the first direction intersects with the optical axis of the optical system. In the housing portion, the optical system and the light source are installed along a second direction, and the second direction is along the optical axis.

2. The lighting device according to claim 1, wherein: In the housing portion, the optical system is mounted on one side of the detection portion in the second direction, and the light source is mounted on the other side of the detection portion in the second direction.

3. The lighting device according to claim 1, wherein: The plurality of detection units include a first detection unit and a second detection unit, The first detection unit and the second detection unit are housed in the housing portion so as to face each other across the optical axis.

4. The lighting device according to claim 3, wherein: The holding portion includes a first holding portion that holds the first detection portion and a second holding portion that holds the second detection portion. The mounting plane includes a first mounting plane for mounting the first holding portion and a second mounting plane for mounting the second holding portion. A portion of the end portion on the other side in the second direction of the first holding portion mounted on the first mounting plane overlaps a portion of the end portion on the other side in the second direction of the second holding portion mounted on the second mounting plane in a direction along the optical axis.

5. The lighting device according to claim 3, wherein: The light receiving surface of the first detection unit and the light receiving surface of the second detection unit are housed in the housing portion so as to be inclined with respect to a direction perpendicular to the optical axis of the optical system.

6. The lighting device according to any one of claims 1 to 5, wherein: The lighting device has: a control substrate disposed on the other side of the second direction relative to the light source; and wiring connecting the control substrate and the detection unit, A through hole through which the wiring passes is provided on the end surface of the housing portion on the other side in the second direction.

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