Lighting device, panel lighting, and system ceiling

Abstract

This lighting device comprises a light source, a lens optical system, a first member, and a second member. The light source emits an illumination light. The lens optical system includes a first lens that is positioned in a first direction of the light source. Each of the first member and the second member surrounds the optical axis of the lens optical system and has a space penetrating in the first direction. The first member has a first opening and a second opening. The first opening is an opening on the light source side, and is positioned further to the first direction side than the lens optical system. The second opening is an opening on the opposite side from the light source, and surrounds the first opening when viewed in transparent plan view. The second member is positioned in the first direction with respect to the first member, and has a third opening. The third opening is surrounded by the second opening when viewed in transparent plan view.

Description

Lighting fixtures, panel lighting, and system ceilings Cross-reference of related applications

[0001] This application claims priority to Japanese Application No. 2024-232877 (filed December 27, 2024), and the entire disclosure of said Japanese Application is incorporated herein by reference.

[0002] This disclosure relates to lighting devices, panel lighting, and system ceilings.

[0003] Lighting devices include, for example, ceiling lighting devices widely known as so-called downlights (see, for example, the description in Patent Document 1).

[0004] There is a growing demand for reduced glare in lighting fixtures, panel lighting, and system ceilings.

[0005] Japanese Patent Publication No. 2019-121492

[0006] Lighting fixtures, panel lighting, and system ceilings are disclosed.

[0007] One embodiment of an illumination device comprises a light source, a lens optical system, a first member, and a second member. The light source emits illumination light. The lens optical system includes a first lens located in a first direction from the light source. Each of the first member and the second member surrounds the optical axis of the lens optical system and has a space penetrating in the first direction. The first member has a first aperture and a second aperture. The first aperture is the aperture on the light source side and is located on the first direction side of the lens optical system. The second aperture is the aperture on the opposite side from the light source and surrounds the first aperture when viewed from above. The second member is located in the first direction relative to the first member and has a third aperture. The third aperture is surrounded by the second aperture when viewed from above.

[0008] One embodiment of panel lighting comprises a panel body and a light-emitting unit fixed to the panel body. The panel lighting includes a lighting device according to the above embodiment. The light-emitting unit includes the light source, the lens optical system, and the first member. The panel body has an internal space in which the light-emitting unit is located and includes the second member. The second member is located on the first direction side of the panel body and covers the internal space from the first direction side around the third opening.

[0009] One embodiment of a system ceiling comprises a plurality of ceiling panels. The plurality of ceiling panels include one or more panel lights according to the above embodiment.

[0010] Figure 1 is a schematic cross-sectional view showing an example of the ceiling configuration. Figure 2 is a schematic bottom view showing an example of the ceiling configuration. Figure 3 is a schematic bottom view showing an example of the configuration of the first ceiling panel. Figure 4 is a schematic front view showing an example of the configuration of the first ceiling panel. Figure 5 is a schematic bottom view showing an example of the state in which two second members have been removed from the first ceiling panel. Figure 6 is a schematic front view showing an example of the state in which two second members have been removed from the first ceiling panel. Figure 7 is a schematic bottom view showing an example of the state in which two second members and two light-emitting units have been removed from the first ceiling panel. Figure 8 is a schematic front view showing an example of the state in which two second members and two light-emitting units have been removed from the first ceiling panel. Figure 9 is a schematic cross-sectional view showing an example of the configuration of the lighting device. Figure 10 is a schematic front view showing an example of the configuration of the first member of the lighting device. Figure 11 is a schematic bottom view showing an example of the configuration of the first member. Figure 12 is a schematic bottom view showing an example of the configuration of a lighting device. Figure 13 is a schematic cross-sectional view showing an example of the path of illumination light in a lighting device. Figure 14 is a schematic cross-sectional view showing another example of the path of illumination light in a lighting device. Figure 15 is a schematic cross-sectional view showing another first example of the configuration of a lighting device. Figure 16 is a schematic cross-sectional view showing another second example of the configuration of a lighting device. Figure 17 is a schematic cross-sectional view showing another third example of the configuration of a lighting device. Figure 18 is a schematic cross-sectional view showing another fourth example of the configuration of a lighting device. Figure 19 is a schematic cross-sectional view showing another fifth example of the configuration of a lighting device. Figure 20 is a schematic cross-sectional view showing another sixth example of the configuration of a lighting device. Figure 21 is a schematic bottom view showing another sixth example of the configuration of a lighting device. Figure 22 is a schematic cross-sectional view showing another seventh example of the configuration of a lighting device. Figure 23 is a schematic cross-sectional view showing another eighth example of the configuration of a lighting device. Figure 24 is an enlarged cross-sectional view schematicly showing a cross-section of a part of an example of an uneven shape.

[0011] Lighting devices include, for example, ceiling lighting devices widely known as so-called downlights. These downlights are also sometimes called recessed ceiling lighting devices.

[0012] This recessed ceiling lighting device has a structure comprising, for example, a light-emitting module, a lens, and a cylindrical frame. The light-emitting module can emit light. The lens can control the light emitted from the light-emitting module. The cylindrical frame is a cylindrical body positioned to surround the optical axis of the lens. In this recessed ceiling lighting device, the light emitted from the light-emitting module and transmitted through the lens passes through the inside of the cylindrical frame and is emitted into the illuminated space. The illuminated space is the space of the object to be illuminated by the lighting device.

[0013] One example of this type of recessed ceiling lighting is a ceiling panel (also called panel lighting) in which the lighting device is embedded in a plate-shaped ceiling material before the ceiling is installed. It is also conceivable that ceiling panels with pre-embedded lighting devices (panel lighting) may be applied to a portion of a ceiling, such as a system ceiling. A system ceiling is a suspended ceiling made up of multiple unit ceilings.

[0014] Incidentally, in lighting devices, the amount of light illuminating the surrounding space that primarily illuminates the object being lit by the device may increase due to reflection or diffuse reflection of light on the inner surface of the cylindrical frame. This can increase the glare (also known as brightness) of the lighting device that enters a person's field of vision.

[0015] Therefore, there is room for improvement in lighting fixtures, panel lighting, and system ceilings in terms of reducing glare from lighting fixtures.

[0016] Therefore, the inventors of this disclosure have created a technology that can reduce the glare of lighting devices, panel lighting, and system ceilings.

[0017] In relation to this, various embodiments and examples will be described below with reference to the drawings.

[0018] In the drawings, parts having the same or similar configurations and functions are denoted by the same reference numerals. For parts having the same or similar configurations and functions, redundant descriptions are omitted in the following explanations. The drawings are shown schematically. The ratios of the sizes and thicknesses of various components do not necessarily reflect the ratios of actual dimensions. For example, due to the illustrated relationships, there may be cases where the thickness of a plate-shaped ceiling panel is increased for convenience.

[0019] The drawings include diagrams to which a right-handed XYZ coordinate system is appropriately appended. In the following explanations, the direction in which light is emitted from the lighting device 300 into the indoor space Sp1 as an example of the lighting space S1 is taken as the -Z direction as the first direction. The direction opposite to the -Z direction as the first direction is taken as the +Z direction as the second direction. One direction orthogonal to the -Z direction as the first direction is taken as the +X direction as the third direction. The direction opposite to the +X direction as the third direction is taken as the -X direction as the fourth direction. One direction perpendicular to both the -Z direction as the first direction and the +X direction as the third direction is taken as the +Y direction as the fifth direction. The direction opposite to the +Y direction as the fifth direction is taken as the -Y direction as the sixth direction.

[0020] In the present disclosure, expressions indicating relative or absolute positional relationships, unless otherwise specified, not only precisely represent those positional relationships, but also represent states in which the positional relationships are displaced with respect to angles or distances within the range of tolerances or within the range where similar functions can be obtained. Expressions indicating relative or absolute positional relationships may include, for example, "in one direction", "along one direction", "parallel", "orthogonal", "center", "concentric", or "coaxial". In the present disclosure, expressions indicating equal states, unless otherwise specified, not only precisely represent quantitatively equal states, but also represent states in which there are differences within the range of tolerances or where similar functions can be obtained. Expressions indicating equal states may include, for example, "identical", "equal", or "homogeneous". In the present disclosure, expressions indicating shapes, unless otherwise specified, not only geometrically precisely represent those shapes, but also represent shapes that, for example, have either concavities and convexities or chamfers based on the shape within the range where similar effects can be obtained. Expressions indicating shapes may include, for example, "quadrilateral shape" or "cylindrical shape". In the present disclosure, expressions such as "comprising one or more components", "including one or more components", or "having one or more components" are not exclusive expressions that exclude the existence of other components different from the one or more components. In the present disclosure, the expression "at least one of A, B, and C" includes any case of only A, only B, only C, any two of A, B, and C, and all of A, B, and C.

[0021] <1. First Embodiment> <1-1. Structure of Ceiling> Regarding the structure of the ceiling 1 according to the first embodiment, the description will be given while referring to FIGS. 1 and 2.

[0022] FIG. 1 is a cross-sectional view schematically showing an example of the structure of the ceiling 1 according to the first embodiment. FIG. 2 is a bottom view schematically showing an example of the structure of the ceiling 1 according to the first embodiment. In the examples of FIGS. 1 and 2, the upward direction is the +Z direction, and the downward direction is the -Z direction.

[0023] Ceiling 1 is, for example, the part located between the interior space (also called the interior space) Sp1 and the space above the ceiling (also called the ceiling space) Sp2 in a building 2 such as a building. In other words, ceiling 1 is the part that divides space Sp0 within building 2 into interior space Sp1 and ceiling space Sp2. For this reason, ceiling 1 is located above interior space Sp1, and ceiling space Sp2 is located above ceiling 1. In other words, in space Sp0 within building 2, for example, from bottom to top, interior space Sp1, ceiling 1, and ceiling space Sp2 are located in this order. Figure 1 shows an example of a part that forms one of the spaces Sp0 in building 2. In the examples of Figures 1 and 2, when viewed in plan toward the upward direction (+Z), ceiling 1 has a rectangular shape.

[0024] For example, a system ceiling 1s is applied to ceiling 1. System ceiling 1s is a suspended ceiling made up of multiple unit ceilings. System ceiling 1s comprises multiple ceiling panels 10. Each of the multiple ceiling panels 10 has, for example, a plate-like outer shape. The plate-like outer shape may be, for example, a flat plate-like outer shape. Each of the multiple ceiling panels 10 may have, for example, a relatively thick plate-like outer shape. From another point of view, each of the multiple ceiling panels 10 may have, for example, a thin rectangular parallelepiped-like outer shape. Note that the plate-like outer shape is not limited to a flat plate-like outer shape, but may also be a curved plate-like outer shape, such as a slightly curved plate-like outer shape.

[0025] Each of the multiple ceiling panels 10 has, for example, a rectangular or square lower surface (also referred to as the panel bottom surface) 10bs. Each panel bottom surface 10bs of the multiple ceiling panels 10 constitutes, for example, the lower surface (also referred to as the ceiling surface) of the ceiling 1. The panel bottom surface 10bs may be, for example, a rectangular or square surface with sides of about 300 millimeters (mm) to 1200 mm. More specifically, the panel bottom surface 10bs may be, for example, a square surface with sides of about 600 mm. The panel bottom surface 10bs is, for example, located along a horizontal plane. In the examples of Figures 1 and 2, the panel bottom surface 10bs has two sides that are located along the +X direction as a third direction and are opposite each other in the +Y direction as a fifth direction, and two sides that are located along the +Y direction as a fifth direction and are opposite each other in the +X direction as a third direction.

[0026] Each of the multiple ceiling panels 10 has, for example, a rectangular or square upper surface (also referred to as the panel top surface) 10us. The panel top surface 10us may be, for example, a rectangular or square surface with sides of about 300 mm to 1200 mm. More specifically, the panel top surface 10us may be, for example, a square surface with sides of about 600 mm. The panel top surface 10us is positioned, for example, along a horizontal plane. In the examples of Figures 1 and 2, the panel top surface 10us has two sides that are positioned along the +X direction as a third direction and are opposite each other in the +Y direction as a fifth direction, and two sides that are positioned along the +Y direction as a fifth direction and are opposite each other in the +X direction as a third direction.

[0027] For example, as shown in Figures 1 and 2, the system ceiling 1s includes a base material 11. The base material 11 includes, for example, a plurality of first beam-like portions 11m, a plurality of second beam-like portions 11c, and a plurality of edge portions 11p.

[0028] The multiple edge portions 11p are located along the outer edge of the ceiling 1. In other words, the multiple edge portions 11p constitute the outer edge portion (also called the cornice) of the ceiling 1. In the examples of Figures 1 and 2, when viewed in plan toward the +Z direction (upward), the multiple edge portions 11p are located in a ring along the outer edge of the rectangular ceiling 1. Each of the multiple edge portions 11p is located along the inner surface of the wall 2w of the building 2 and is fixed to this wall 2w. Each of the multiple edge portions 11p is located, for example, along a horizontal plane. Each of the multiple edge portions 11p is fixed to the wall 2w, for example, by screwing it in. Each of the multiple edge portions 11p has, for example, an L-shaped imaginary cross-section perpendicular to the longitudinal direction. Each of the multiple edge portions 11p may be composed of one or more elongated members.

[0029] The multiple first beam-like sections 11m and the multiple second beam-like sections 11c are arranged in a grid pattern along a horizontal plane, for example. In the examples of Figures 1 and 2, each of the multiple first beam-like sections 11m is located along the +Y direction, which is the fifth direction. The multiple first beam-like sections 11m are arranged at predetermined intervals in the +X direction, which is the third direction. Each of the multiple second beam-like sections 11c is located along the +X direction, which is the third direction. The multiple second beam-like sections 11c are arranged at predetermined intervals in the +Y direction, which is the fifth direction. Each of the multiple first beam-like sections 11m and the multiple second beam-like sections 11c may be composed of, for example, one or more members called T-bars. More specifically, each of the multiple first beam-like sections 11m may be composed of one or more members called main T-bars. Each of the multiple second beam-like sections 11c may be composed of one or more members called cross T-bars.

[0030] Furthermore, the multiple edge portions 11p are positioned in a manner that surrounds, for example, the multiple first beam-like portions 11m and the multiple second beam-like portions 11c, which are arranged in a grid pattern. More specifically, the multiple edge portions 11p, the multiple first beam-like portions 11m, and the multiple second beam-like portions 11c are arranged in a grid pattern along a horizontal plane, for example. In other words, in the examples of Figures 1 and 2, when viewed in a plan view toward the +Z direction (upward), the base material 11 is positioned in a grid pattern.

[0031] The multiple first beam-like sections 11m and the multiple second beam-like sections 11c are fixed to each other, for example, at each of the multiple points where they intersect. The mutual fixing of the first beam-like sections 11m and the second beam-like sections 11c may be achieved, for example, by using predetermined parts. Furthermore, the multiple first beam-like sections 11m and the multiple second beam-like sections 11c, which are assembled in a grid pattern, and the multiple edge sections 11p are fixed to each other, for example, at each of the points where they intersect in a T-shape. The mutual fixing of the first beam-like sections 11m or the second beam-like sections 11c and the edge sections 11p may be achieved, for example, by using predetermined parts.

[0032] Multiple first beam-like sections 11m and multiple second beam-like sections 11c, arranged in a grid pattern, are held in place by multiple members fixed to, for example, the ceiling slab 2c of the building 2. These multiple members may include, for example, multiple suspension bolts 11hb embedded in the ceiling slab 2c of the building 2, and multiple suspension fittings (also called T-hangers) 11hh attached one to each of the multiple suspension bolts 11hb. In this case, the base material 11 includes, for example, multiple suspension bolts 11hb and multiple suspension fittings 11hh. For example, each of the multiple suspension fittings 11hh may clamp the upper part of one of the multiple first beam-like sections 11m by screw fastening or the like.

[0033] Multiple ceiling panels 10 are supported, for example, by a base material 11. In other words, the system ceiling 1s has a structure in which each of the multiple ceiling panels 10 rests on the base material 11. For example, when viewed in plan toward the upward direction (+Z), each of the multiple ceiling panels 10 is in a state where portions along the four sides of the ceiling panel 10 are resting on the base material 11. From another point of view, each of the multiple ceiling panels 10 is in a state where it rests on multiple edge portions 11p, multiple first beam-like portions 11m, and multiple second beam-like portions 11c of the base material 11, which are arranged in a grid pattern. In the examples of Figures 1 and 2, when viewed in plan toward the upward direction (+Z), the multiple ceiling panels 10 are arranged in a matrix.

[0034] Each of the multiple ceiling panels 10 may be a ceiling panel (also referred to as a first ceiling panel or panel lighting) 10a that includes a lighting device 300. In other words, in a system ceiling 1s, the multiple ceiling panels 10 may include one or more first ceiling panels (panel lighting) 10a. From another point of view, in a system ceiling 1s, each of the one or more first ceiling panels (panel lighting) 10a includes a lighting device 300. In other words, a first ceiling panel 10a includes a lighting device 300. From another point of view, the lighting device 300 may be a lighting device for the ceiling. This makes it easy to install a ceiling 1 that includes one or more lighting devices 300. Then, by the lighting device 300 of each of the one or more first ceiling panels (panel lighting) 10a, illumination light L1 can be irradiated onto an indoor space Sp1, which is an example of a space to be illuminated (also referred to as an illuminated space) S1. The illumination light L1 may be visible light. In Figure 1, a thin dashed line schematically represents an example of a hidden line depicting a portion of the lighting device 300 located inside the first ceiling panel 10a. Also in Figure 1, a thin dotted line schematically represents an example of the outer edge of the illumination light L1 irradiated from the lighting device 300 into an indoor space Sp1, which is an example of the lighting space S1.

[0035] The first ceiling panel 10a may include, for example, one or more sensors in addition to the lighting device 300, or one or more other pieces of equipment. One or more sensors could be, for example, smoke sensors. One or more other pieces of equipment could be, for example, speakers and sprinklers. This makes it easy to install a ceiling 1 that includes one or more sensors and / or one or more other pieces of equipment.

[0036] The multiple ceiling panels 10 may include, for example, one or more first ceiling panels 10a, as well as one or more ceiling panels (also referred to as second ceiling panels) 10b, each having a different configuration from the first ceiling panels 10a. The second ceiling panels 10b may include, for example, air conditioning outlets. This makes it possible to easily install a ceiling 1 that includes, for example, one or more air conditioning outlets.

[0037] In the examples shown in Figures 1 and 2, the base material 11 had three first beam-like sections 11m, three second beam-like sections 11c, and four edge sections 11p, but it is not limited to these. For example, the multiple first beam-like sections 11m could be two first beam-like sections 11m, or any number of four or more first beam-like sections 11m. For example, the multiple second beam-like sections 11c could be two second beam-like sections 11c, or any number of four or more second beam-like sections 11c.

[0038] <1-2. Configuration of the First Ceiling Panel> The configuration of the first ceiling panel (panel lighting) 10a according to the first embodiment will be described with reference to Figures 3 to 8.

[0039] Figure 3 is a schematic bottom view showing an example of the configuration of the first ceiling panel 10a. Figure 4 is a schematic front view showing an example of the configuration of the first ceiling panel 10a. Figure 5 is a schematic bottom view showing an example of the state in which two second members 340 have been removed from the first ceiling panel 10a. Figure 6 is a schematic front view showing an example of the state in which two second members 340 have been removed from the first ceiling panel 10a. Figure 7 is a schematic bottom view showing an example of the state in which two second members 340 and two light-emitting units 120 have been removed from the first ceiling panel 10a. Figure 8 is a schematic bottom view showing an example of the state in which two second members 340 and two light-emitting units 120 have been removed from the first ceiling panel 10a. In Figures 3, 4, and 6, hidden lines illustrating an example of the outer edge of some of the components are schematically shown by thin dashed lines.

[0040] For example, as shown in Figures 3 and 4, the first ceiling panel (panel lighting) 10a comprises a panel body 110 and a light-emitting unit 120.

[0041] The first ceiling panel 10a may be equipped with one or more light-emitting units 120. In the example shown in Figures 3 and 4, the first ceiling panel 10a is equipped with two light-emitting units 120, as one or more light-emitting units 120. In Figures 3, 4 and 6, hidden lines illustrating an example of the outer edges of the two light-emitting units 120 are schematically shown with thin dashed lines. The two light-emitting units 120 are the first light-emitting unit 120a and the second light-emitting unit 120b. The first light-emitting unit 120a is located on the side of the first ceiling panel 10a in the -X direction, which is the fourth direction, and the second light-emitting unit 120b is located on the side of the first ceiling panel 10a in the +X direction, which is the third direction. More specifically, the first ceiling panel 10a comprises a first region (also referred to as the first panel region), a second region (also referred to as the second panel region or central region), and a third region (also referred to as the third panel region), which are arranged in order in the +X direction as the third direction. The first light-emitting unit 120a is located in the first panel region. The second light-emitting unit 120b is located in the third panel region. The second panel region may contain, for example, one or more sensors, or one or more other pieces of equipment. The one or more sensors could be, for example, smoke sensors. The one or more other pieces of equipment could be, for example, speakers and sprinklers. Here, for example, it is assumed that the first ceiling panel 10a is divided into three equal regions in the +X direction as the third direction. In this case, the first panel region may be one region located on the side of the -X direction, which is the fourth direction among the three regions; the second region (central region) may be one region located in the center among the three regions; and the third panel region may be one region located on the side of the +X direction, which is the third direction among the three regions.

[0042] <1-2-1. Panel Body> The panel body 110 may be, for example, a part that constitutes the outer shape of the first ceiling panel 10a. More specifically, the panel body 110 may be, for example, a part that constitutes the plate-like outer shape of the first ceiling panel 10a. The panel body 110 may have, for example, a relatively thick plate-like outer shape. From another point of view, the panel body 110 may have, for example, a thin rectangular parallelepiped-shaped outer shape. The panel body 110 may have, for example, a rectangular or square lower surface (panel bottom surface) 10bs. The panel body 110 may also have, for example, a rectangular or square upper surface (panel top surface) 10us.

[0043] The panel body 110 has an internal space Is1 in which the light-emitting unit 120 is located. The panel body 110 may have, for example, one or more internal spaces Is1 in which the light-emitting units 120 are each located. In the example of Figures 3 and 4, the panel body 110 has two internal spaces Is1, which are one or more internal spaces Is1. These two internal spaces Is1 are the first internal space Is1a in which the first light-emitting unit 120a is located and the second internal space Is1b in which the second light-emitting unit 120b is located. For example, the first internal space Is1a may be located in the first panel region described above. For example, the second internal space Is1b may be located in the third panel region described above.

[0044] The panel body 110 includes a second member 340. This second member 340 is located on the side of the panel body 110 in the -Z direction, which is the first direction. The second member 340 may be, for example, a plate-shaped member (also referred to as a plate-shaped member). The panel body 110 may include, for example, one or more second members 340. In the example of Figures 3 and 4, the panel body 110 includes two second members 340 as one or more second members 340. These two second members 340 are the first second member (also referred to as the second A member) 340a and the second second member (also referred to as the second B member) 340b. Here, the second A member 340a may be, for example, the first plate-shaped member (also referred to as the first plate-shaped member). The second B member 340b may be the second plate-shaped member (also referred to as the second plate-shaped member). For example, the second A member 340a may be located on the side of the first panel region described above in the -Z direction, which is the first direction. For example, the second B member 340b may be located on the side of the third panel region described above in the -Z direction, which is the first direction.

[0045] The second member 340 includes a plate-like portion (also referred to as the first plate-like portion) 341. The first plate-like portion 341 has a plate-like shape. In the examples of Figures 3 and 4, the first plate-like portion 341 has a flat plate shape. Here, the flat plate shape may be, for example, a portion having the shape of a flat plate with a constant or substantially constant thickness. The shape of the flat plate may be, for example, a thin plate with a thickness of about 0.5 mm to several mm. The second member 340 may be, for example, mainly composed of the first plate-like portion 341. Note that the plate-like shape is not limited to a flat plate shape, and may be a curved plate shape, for example, a slightly curved plate shape.

[0046] The first plate-shaped portion 341 has an opening (also called an exit opening, third opening, or luminaire opening) 340o that allows light emitted from the light-emitting unit 120 to pass towards the indoor space Sp1, which is an example of the illuminated space S1. In Figures 4 and 6, a hidden line illustrating an example of the outer edge of the exit opening 340o is schematically shown by a thin dashed line. The exit opening 340o is a space that connects the internal space of the first ceiling panel 10a to the indoor space Sp1, which is an example of the illuminated space S1. This exit opening 340o functions as an exit for illumination light L1 from the internal space of the first ceiling panel 10a to the indoor space Sp1, which is an example of the illuminated space S1. In the example of Figures 3 and 4, the first plate-shaped portion 341 of the second A member 340a has an opening (exit opening) 340o that allows light emitted from the first light-emitting unit 120a to pass towards the indoor space Sp1, which is an example of the illuminated space S1. The first plate-shaped portion 341 of the second B member 340b has an opening (exit opening) 340o that allows light emitted by the second light-emitting unit 120b to pass towards the indoor space Sp1, which is an example of the illuminated space S1.

[0047] The second member 340 covers the internal space Is1 where the light-emitting unit 120 is located around the exit opening 340o from the side in the first direction, the -Z direction. For example, the first plate-like portion 341 may cover the internal space Is1 where the light-emitting unit 120 is located around the exit opening 340o from the side in the first direction, the -Z direction. In other words, the second member 340 has the function of a lid (also called a cover) that covers the light-emitting unit 120 from the side of the indoor space Sp1, which is an example of the lighting space S1, around the exit opening 340o. The presence of this second member 340 can, for example, improve the design of the first ceiling panel 10a and protect the light-emitting unit 120 from the side of the indoor space Sp1, which is an example of the lighting space S1.

[0048] In the examples shown in Figures 3 and 4, the second A member 340a covers the first internal space Is1a where the first light-emitting unit 120a is located, around the exit opening 340o of the second A member 340a, from the side in the -Z direction, which is the first direction. More specifically, the first plate-like portion 341 of the second A member 340a covers the first internal space Is1a where the first light-emitting unit 120a is located, around the exit opening 340o of the first plate-like portion 341 of the second A member 340a, from the side in the -Z direction, which is the first direction. The second B member 340b covers the second internal space Is1b where the second light-emitting unit 120b is located, around the exit opening 340o of the second B member 340b, from the side in the -Z direction, which is the first direction. More specifically, the first plate-like portion 341 of the second B member 340b covers the second internal space Is1b where the second light-emitting unit 120b is located, from the side in the -Z direction, which is the first direction, around the emission opening 340o of the first plate-like portion 341 of the second B member 340b. In other words, the second A member 340a has the function of a lid (also referred to as the first lid) that covers the first light-emitting unit 120a from the side of the indoor space Sp1, which is an example of the lighting space S1, around the emission opening 340o of the second A member 340a. The second B member 340b has the function of a lid (also referred to as the second lid) that covers the second light-emitting unit 120b from the side of the indoor space Sp1, which is an example of the lighting space S1, around the emission opening 340o of the second B member 340b.

[0049] The first plate-like portion 341 has, for example, a surface (also referred to as the second surface) Sf3 located on the side in the +Z direction as the second direction. The first plate-like portion 341 also has, for example, a surface (also referred to as the third surface) Sf4 located on the side in the -Z direction as the first direction. The third surface Sf4 may constitute a part of the lower surface 10bs of the panel body 110. Thus, the third surface Sf4 may constitute a part of the lower surface (ceiling surface) of the ceiling 1. In the examples of Figures 3 and 4, the third surface Sf4 of the first plate-like portion 341 of the second A member 340a may constitute a part of the lower surface 10bs of the panel body 110, and the third surface Sf4 of the first plate-like portion 341 of the second B member 340b may constitute a part of the lower surface 10bs of the panel body 110.

[0050] The second member 340 may be, for example, a simple sheet metal, or a sheet metal that has been processed by pressing or bending on a part of its peripheral edge. For the sheet metal, for example, a thin sheet of surface-treated steel (also called surface-treated steel sheet) may be used. For the surface-treated steel sheet, for example, a steel sheet that has been plated with zinc plating or other plating (also called plated steel sheet) or a steel sheet that has been plated with paint or other surface treatment (also called painted steel sheet) may be used. For the sheet metal, for example, a thin sheet of a non-ferrous metal such as stainless steel or aluminum, which is different from surface-treated steel sheet, may be used. The second member 340 may be, for example, a sheet metal member made of resin.

[0051] The panel body 110 includes, for example, a panel base 111. The panel base 111 may mainly consist of the remaining portion of the panel body 110, excluding one or more second members 340.

[0052] The panel base 111 includes, for example, an internal frame 111if. The panel base 111 may also include, for example, one or more plate-shaped members 111p and a frame (also referred to as an outer perimeter frame) 111pf. The panel base 111 may further include members having, for example, sound-absorbing and / or fire-resistant properties.

[0053] The internal frame 111if is, for example, the base portion of the panel foundation 111. The internal frame 111if may have a structure in which multiple members are connected. Each of the multiple members may be manufactured using, for example, surface-treated steel sheets such as plated steel sheets or painted steel sheets as described above, thin sheets of non-ferrous metals, or resin. The connection of the multiple members can be achieved by fastening with screws, crimping, joining, bonding, or fitting. In the examples of Figures 3, 5, and 7, the internal frame 111if includes four beam sections 111bm. The four beam sections 111bm are each located along the +Y direction as the fifth direction and are arranged apart from each other in the +X direction as the third direction.

[0054] One or more plate-shaped members 111p may constitute, for example, at least a portion of the upper panel surface 10us and the lower panel surface 10bs of the panel body 110. Each of the one or more plate-shaped members 111p may be fixed to, for example, an internal frame 111if. The fixing of the one or more plate members 111p to the internal frame 111if can be achieved, for example, by fastening with screws, crimping, joining, bonding, or fitting. Each of the one or more plate-shaped members 111p may be, for example, a simple plate, or a plate that has been processed by pressing or bending a portion of its peripheral edge. For the plate material, for example, a thin sheet of surface-treated steel such as plated steel or painted steel may be used, or a thin sheet of non-ferrous metal may be used. Each of the one or more plate-shaped members 111p may be, for example, a plate-shaped member made of resin.

[0055] The outer perimeter frame 111pf may, for example, define the outer shape of the outer perimeter of the panel body 110. The outer perimeter frame 111pf may, for example, include a portion that is located in an annular shape along the outer edge of the plate-shaped panel body 110. The outer perimeter frame 111pf may, for example, be composed of two or more connected members. The two or more members may include, for example, four members, one each located along each of the four sides of the panel base 111. The outer perimeter frame 111pf may, for example, be fixed to the inner frame 111if. The outer perimeter frame 111pf may, for example, be fixed to the inner frame 111if in a manner that surrounds the inner frame 111if from all sides. In the examples of Figures 3, 5, and 7, each of the four beam sections 111bm is located inside the outer perimeter frame 111pf and is installed between the outer perimeter frames 111pf.

[0056] <1-2-2. Light-emitting unit> The light-emitting unit 120 is fixed to the panel body 110. From another perspective, the light-emitting unit 120 may be built into the panel body 110. The light-emitting unit 120 includes the light source 310, the lens optical system 320, and the first member 330 of the lighting device 300. The light source 310, the lens optical system 320, and the first member 330 will be described later. The light-emitting unit 120 can emit light toward the exit aperture 340o of the first plate-shaped portion 341 of the second member 340. In the examples of Figures 3 and 4, the first light-emitting unit 120a can emit light toward the exit aperture 340o of the first plate-shaped portion 341 of the second A member 340a. The second light-emitting unit 120b can emit light toward the exit aperture 340o of the first plate-shaped portion 341 of the second B member 340b.

[0057] The light-emitting unit 120 may be attached, for example, to the panel base 111. In the examples shown in Figures 3 to 6, the first light-emitting unit 120a and the second light-emitting unit 120b, each consisting of two light-emitting units 120, are attached to the panel base 111. In Figures 3, 4, and 6, a thin dashed line schematically shows an example of the outer edge of each of the two light-emitting units 120.

[0058] The light-emitting unit 120 may be attached, for example, to the internal frame 111if of the panel base 111. In the examples shown in Figures 3 to 6, the first light-emitting unit 120a and the second light-emitting unit 120b, each of the two light-emitting units 120, are attached to the internal frame 111if. The attachment of the light-emitting unit 120 to the internal frame 111if can be achieved, for example, by fastening with screws, crimping, joining, bonding, or fitting. In the example shown in Figure 5, the light-emitting unit 120 is attached to the two beam sections 111bm by fastening with screws.

[0059] <1-2-3. Mounting configuration of plate-shaped member to panel base> Here, for example, as shown in Figures 3 to 6, in the first ceiling panel (panel lighting) 10a, the second member 340 may be attached to the panel base 111 in a manner that allows it to be removed to the room space Sp1 side, which is an example of the lighting space S1. This allows the second member 340 to be removed from the first ceiling panel 10a, which is in a state that constitutes the ceiling 1, to the room space Sp1 side, which is an example of the lighting space S1. As a result, the light-emitting unit 120 can be easily exposed to the room space Sp1 side, which is an example of the lighting space S1. Therefore, maintenance of the light-emitting unit 120 can be easily performed. Here, for example, the second member 340 may be removable from the panel base 111 to the room space Sp1 side, which is an example of the lighting space S1, and can be attached to the panel base 111 from the room space Sp1 side, which is an example of the lighting space S1. Maintenance of the light-emitting unit 120 may include, for example, inspection of the light-emitting unit 120 or replacement of parts.

[0060] Here, for example, in the first ceiling panel 10a, the second member 340 may be attached to the internal frame 111if of the panel base 111 in a manner that allows it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, for example, in the first ceiling panel 10a, the second member 340 may be attached to the two beam portions 111bm of the internal frame 111if in a manner that allows it to be removed to the interior space Sp1 side, which is an example of the lighting space S1.

[0061] In the examples shown in Figures 3 to 6, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is attached to the panel base 111 in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is attached to the internal frame 111if of the panel base 111 in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. Even more specifically, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is attached to the two beam portions 111bm of the internal frame 111if in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1.

[0062] Here, for example, as shown in Figures 3 to 6, in the first ceiling panel 10a, the second member 340 may be fixed to the panel base 111 by a plurality of fastening members (also referred to as first fastening members) Sw1 in a manner that allows it to be removed to the room space Sp1 side, which is an example of the lighting space S1. In other words, in the panel body 110, the second member 340 may be fixed to the panel base 111 by a plurality of first fastening members Sw1 in a manner that allows it to be removed to the room space Sp1 side, which is an example of the lighting space S1. This makes it easy to attach and detach the second member 340 from the panel base 111. As a result, maintenance of the light-emitting unit 120 can be easily performed.

[0063] Here, for example, in the first ceiling panel 10a, the second member 340 may be fixed to the internal frame 111if of the panel base 111 by a plurality of first fastening members Sw1 in a manner that allows it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, for example, in the first ceiling panel 10a, the second member 340 may be fixed to two beam portions 111bm of the internal frame 111if by a plurality of first fastening members Sw1 in a manner that allows it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. Each of the plurality of first fastening members Sw1 may be a male screw member such as a bolt. For example, each of the plurality of first fastening members Sw1 may be inserted through a through hole (also called a first through hole) Th1 of the second member 340 and screwed into a screw hole (also called a first screw hole) Sh1 of the panel base 111. As a result, the second member 340 may be fastened to the panel base 111 by multiple first fastening members Sw1. Here, for example, if the first screw hole Sh1 of the panel base 111 is provided in the internal frame 111if of the panel base 111, the second member 340 may be fastened to the internal frame 111if by the first fastening members Sw1. For example, if the first screw hole Sh1 of the panel base 111 is provided in the beam portion 111bm of the internal frame 111if, the second member 340 may be fastened to the beam portion 111bm by the first fastening members Sw1.

[0064] In the examples shown in Figures 3 to 6, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is fixed to the panel base 111 by a plurality of first fastening members Sw1 in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. In other words, in the panel body 110, each of the second A member 340a and the second B member 340b is fixed to the panel base 111 by a plurality of first fastening members Sw1 in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is fixed to the internal frame 111if of the panel base 111 by a plurality of first fastening members Sw1 in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. In other words, in the panel body 110, each of the second A member 340a and the second B member 340b is fixed to the internal frame 111if of the panel base 111 by a plurality of first fastening members Sw1, in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, each of the second A member 340a and the second B member 340b is fixed to the two beam portions 111bm of the internal frame 111if by a plurality of first fastening members Sw1, in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1. In other words, in the panel body 110, each of the second A member 340a and the second B member 340b is fixed to the two beam portions 111bm of the internal frame 111if by a plurality of first fastening members Sw1, in a manner that allows for removal to the interior space Sp1 side, which is an example of the lighting space S1.

[0065] In this example, the second member 340 was fixed to the panel base 111 by multiple first fastening members Sw1 in a manner that allowed it to be removed to the interior space Sp1, which is an example of the lighting space S1, but this is not limited to this. For example, the second member 340 may be attached to the panel base 111 in a manner that allows it to be removed to the interior space Sp1, which is an example of the lighting space S1, by other means. Other means may include, for example, a configuration in which multiple hooks provided on a part of the peripheral end of the second member 340 are hooked onto a part of the panel base 111.

[0066] <1-2-4. Mounting configuration of the light-emitting unit to the panel base> Here, for example, as shown in Figures 3 to 8, in the first ceiling panel (panel lighting) 10a, the light-emitting unit 120 may be mounted on the panel base 111 in such a manner that the second member 340 can be removed from the panel base 111, allowing it to be removed to the room space Sp1 side, which is an example of the lighting space S1. As a result, the second member 340 and the light-emitting unit 120 can be removed from the first ceiling panel 10a, which is in the state of constituting the ceiling 1, to the room space Sp1 side, which is an example of the lighting space S1, in the order described above. As a result, maintenance of the light-emitting unit 120 can be easily performed.

[0067] Here, for example, in the first ceiling panel 10a, the light-emitting unit 120 may be attached to the internal frame 111if of the panel base 111 in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, for example, in the first ceiling panel 10a, the light-emitting unit 120 may be attached to the two beam portions 111bm of the internal frame 111if in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1.

[0068] In the examples shown in Figures 3 to 8, in the first ceiling panel 10a, the first light-emitting unit 120a is attached to the panel base 111 in such a way that the second A member 340a can be removed from the panel base 111 to allow removal to the interior space Sp1 side as an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is attached to the panel base 111 in such a way that the second B member 340b can be removed from the panel base 111 to allow removal to the interior space Sp1 side as an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the first light-emitting unit 120a is attached to the internal frame 111if in such a way that the second A member 340a can be removed from the internal frame 111if of the panel base 111 to allow removal to the interior space Sp1 side as an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is attached to the internal frame 111if in such a way that the second B member 340b can be removed from the internal frame 111if of the panel base 111, allowing it to be removed to the interior space Sp1 side as an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the first light-emitting unit 120a is attached to the two beam portions 111bm of the internal frame 111if in such a way that the second A member 340a can be removed from the two beam portions 111bm of the internal frame 111if, allowing it to be removed to the interior space Sp1 side as an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is attached to the two beam portions 111bm of the internal frame 111if in such a way that the second B member 340b can be removed from the two beam portions 111bm of the internal frame 111if, allowing it to be removed to the interior space Sp1 side as an example of the lighting space S1.

[0069] Here, for example, as shown in Figures 3 to 8, in the first ceiling panel 10a, the light-emitting unit 120 may be fixed to the panel base 111 by a plurality of fastening members (also referred to as second fastening members) Sw2, such that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. This makes it easy to attach and detach the light-emitting unit 120 to and from the panel base 111. As a result, maintenance of the light-emitting unit 120 can be easily performed.

[0070] Here, for example, in the first ceiling panel 10a, the light-emitting unit 120 may be fixed to the internal frame 111if of the panel base 111 by a plurality of second fastening members Sw2, in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the light-emitting unit 120 may be fixed to the two beam portions 111bm of the internal frame 111if by a plurality of second fastening members Sw2, in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. Each of the plurality of second fastening members Sw2 may be a male screw member such as a bolt. For example, each of the multiple second fastening members Sw2 may be inserted through the through hole (also called the second through hole) Th2 of the light-emitting unit 120 and screwed into the screw hole (also called the second screw hole) Sh2 of the panel base 111. In this way, the light-emitting unit 120 may be fastened to the panel base 111 by multiple second fastening members Sw2. For example, if the second screw hole Sh2 of the panel base 111 is provided in the internal frame 111if of the panel base 111, the light-emitting unit 120 may be fastened to the internal frame 111if by the second fastening members Sw2. For example, if the second screw hole Sh2 of the panel base 111 is provided in the beam portion 111bm of the internal frame 111if, the light-emitting unit 120 may be fastened to the beam portion 111bm by the second fastening members Sw2.

[0071] Here, for example, the light-emitting unit 120 may include a plate (also referred to as the first plate or first mounting plate) 121 having a plurality of second through holes Th2. This first plate 121 may be made of resin or of metal such as aluminum alloy. The surface of part or all of this first plate 121 may have its visible light absorption rate increased by, for example, a blackening treatment. Blackening treatments may include, for example, chemical conversion treatment, plating, or painting. Blackening treatments may be matte or glossy. For example, the visible light absorption rate on part or all of the surface of the first plate 121 may be increased by having part or all of the surface of the first plate 121 composed of a black material. The black material may be, for example, one or more of the following materials: black metal, black metal oxide film, and black resin. The visible light absorption rate on part or all of the surface of the first plate 121 may be increased by having part or all of the surface of the first plate 121 composed of a dielectric multilayer film. A dielectric multilayer film has a structure in which multiple dielectric thin films are stacked, for example. Examples of dielectrics include silicon dioxide (SiO₂). ２ ), titanium oxide (TiO ２ ), niobium pentoxide (Nb ２ O ５ ), tantalum pentoxide (Ta ２ O ５ ) and magnesium fluoride (MgF ２ One or more of the following materials may be used. This dielectric multilayer film is also called a low-reflection film or anti-reflective film.

[0072] In the examples shown in Figures 3 to 8, in the first ceiling panel 10a, the first light-emitting unit 120a is fixed to the panel base 111 by a plurality of second fastening members Sw2 in such a way that the second A member 340a can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is fixed to the panel base 111 by a plurality of second fastening members Sw2 in such a way that the second B member 340b can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1.

[0073] More specifically, in the first ceiling panel 10a, the first light-emitting unit 120a is fixed to the internal frame 111if of the panel base 111 by a plurality of second fastening members Sw2, in such a way that the second A member 340a can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is fixed to the internal frame 111if of the panel base 111 by a plurality of second fastening members Sw2, in such a way that the second B member 340b can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1.

[0074] More specifically, in the first ceiling panel 10a, the first light-emitting unit 120a is fixed to two beam portions 111bm of the internal frame 111if by a plurality of second fastening members Sw2, in such a way that the second A member 340a can be removed from the panel base 111 to the interior space Sp1 side, which is an example of the lighting space S1. In the first ceiling panel 10a, the second light-emitting unit 120b is fixed to two beam portions 111bm of the internal frame 111if by a plurality of second fastening members Sw2, in such a way that the second B member 340b can be removed from the panel base 111 to the interior space Sp1 side, which is an example of the lighting space S1.

[0075] Here, the light-emitting unit 120 was fixed to the panel base 111 by a plurality of second fastening members Sw2 in such a way that the second member 340 could be removed from the panel base 111 to allow removal to the indoor space Sp1 side, which is an example of the illuminated space S1, but it is not limited to this. For example, the light-emitting unit 120 may be fixed to the panel base 111 in such a way that the second member 340 could be removed from the panel base 111 to allow removal to the indoor space Sp1 side, which is an example of the illuminated space S1, by allowing panel base 111. Other forms may include, for example, a configuration in which a plurality of hooks provided on a part of the first plate 121 of the light-emitting unit 120 are hooked onto a part of the panel base 111.

[0076] <1-2-5. Other Configurations of the First Ceiling Panel> Also, as shown in Figures 3, 5, and 7, for example, the first ceiling panel 10a may include a controller (also called a control unit) 150 in addition to the panel body 110 and the light-emitting unit 120. In Figure 3, a hidden line illustrating an example of the outer edge of the control unit 150 is schematically shown with a thin dashed line. The control unit 150 may control the operation of various components included in the first ceiling panel 10a, such as the light-emitting unit 120. The control unit 150 may include, for example, a CPU (Central Processing Unit) as a processor and a memory unit. The memory unit may include, for example, a non-temporary recording medium that the CPU can read, such as ROM (Read Only Memory) and RAM (Random Access Memory). The memory unit may store, for example, a program for controlling the operation of the light-emitting unit 120. Various functions in the control unit 150 are realized, for example, by the CPU executing a program in the memory unit. Here, the operation of the light-emitting unit 120 controlled by the control unit 150 may include, for example, starting light emission (also referred to as turning on), ending light emission (also referred to as turning off), and stepwise adjustment of the brightness of the emitted light (also referred to as dimming) in the light-emitting unit 120. Turning on and off can be achieved, for example, by controlling the presence or absence of current supplied to the light-emitting unit 120 for light emission. Dimming can be achieved, for example, by controlling the current supplied to the light-emitting unit 120 for light emission.

[0077] The control unit 150 may be located, for example, in the internal space Is1 of the panel body 110 where the light-emitting unit 120 is located. In the examples of Figures 3, 5, and 7, the control unit 150 is located in the first internal space Is1a of the panel body 110. The second member 340 may cover the internal space Is1 where the light-emitting unit 120 and the control unit 150 are located, around the emission opening 340o, from the side in the -Z direction, which is the first direction. In other words, the second member 340 may function as a lid (cover) that covers the control unit 150 from the side of the indoor space Sp1, which is an example of the lighting space S1. The presence of this second member 340 can, for example, improve the design of the first ceiling panel 10a and protect the control unit 150 from the side of the indoor space Sp1, which is an example of the lighting space S1. In the example shown in Figure 3, the second A member 340a covers the first internal space Is1a, where the first light-emitting unit 120a and the control unit 150 are located, from the side in the -Z direction, which is the first direction, around the emission opening 340o of the second A member 340a. In other words, the second A member 340a functions as a lid (first lid) that covers the first light-emitting unit 120a and the control unit 150 from the side of the indoor space Sp1, which is an example of the lighting space S1, around the emission opening 340o of the second A member 340a.

[0078] The control unit 150 may be attached, for example, to the panel base 111. The control unit 150 may be attached, for example, to the internal frame 111if. The attachment of the control unit 150 to the internal frame 111if can be achieved, for example, by fastening with screws, crimping, joining, bonding, or fitting. In the examples of Figures 5 and 7, the control unit 150 is attached to the two beam sections 111bm by fastening with screws.

[0079] Here, for example, as described above, in the first ceiling panel (panel lighting) 10a, the second member 340 may be attached to the panel base 111 in a manner that allows it to be removed to the room space Sp1 side, which is an example of the lighting space S1. This allows the second member 340 to be removed from the first ceiling panel 10a, which is in a state that constitutes the ceiling 1, to the room space Sp1 side, which is an example of the lighting space S1. As a result, the control unit 150 can be easily exposed to the room space Sp1 side, which is an example of the lighting space S1. Therefore, maintenance of the control unit 150 can be easily performed. Maintenance of the control unit 150 may include, for example, inspection of the control unit 150 or replacement of parts.

[0080] In the examples shown in Figures 3 to 6, as described above, the second A member 340a is attached to the panel base 111 of the first ceiling panel 10a in a manner that allows it to be removed to the room space Sp1 side, which is an example of the lighting space S1. This allows the second A member 340a to be removed from the first ceiling panel 10a, which is in a state that constitutes the ceiling 1, to the room space Sp1 side, which is an example of the lighting space S1. As a result, the control unit 150 can be easily exposed to the room space Sp1 side, which is an example of the lighting space S1. Therefore, maintenance of the control unit 150 can be easily performed. Here, for example, the second A member 340a may be removable from the panel base 111 to the room space Sp1 side, which is an example of the lighting space S1, and can be attached to the panel base 111 from the room space Sp1 side, which is an example of the lighting space S1.

[0081] Here, for example, in the first ceiling panel (panel lighting) 10a, the control unit 150 may be attached to the panel base 111 in such a way that the second member 340 can be removed from the panel base 111, allowing it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. As a result, the second member 340 and the control unit 150 can be removed from the first ceiling panel 10a, which is in the state of constituting the ceiling 1, to the interior space Sp1 side, which is an example of the lighting space S1, in the order described above. This makes maintenance of the control unit 150 easier.

[0082] Here, for example, in the first ceiling panel 10a, the control unit 150 may be attached to the internal frame 111if of the panel base 111 in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, for example, in the first ceiling panel 10a, the control unit 150 may be attached to the two beam portions 111bm of the internal frame 111if in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. In the examples of Figures 3, 5 and 7, the control unit 150 is attached to the panel base 111 in the first ceiling panel 10a in such a way that the second A member 340a can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the control unit 150 is attached to the internal frame 111if in such a way that the second A member 340a can be removed from the internal frame 111if of the panel base 111, allowing it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. Even more specifically, in the first ceiling panel 10a, the control unit 150 is attached to the two beam sections 111bm of the internal frame 111if in such a way that the second A member 340a can be removed from the two beam sections 111bm of the internal frame 111if, allowing it to be removed to the interior space Sp1 side, which is an example of the lighting space S1.

[0083] Here, for example, as shown in Figures 5 and 7, in the first ceiling panel 10a, the control unit 150 may be fixed to the panel base 111 by a plurality of fastening members (also referred to as third fastening members) Sw3, such that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. This makes it easy to attach and detach the control unit 150 from the panel base 111. As a result, maintenance of the control unit 150 can be easily performed.

[0084] Here, for example, in the first ceiling panel 10a, the control unit 150 may be fixed to the internal frame 111if of the panel base 111 by a plurality of third fastening members Sw3, in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the control unit 150 may be fixed to the two beam portions 111bm of the internal frame 111if by a plurality of third fastening members Sw3, in such a way that the second member 340 can be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1. Each of the plurality of third fastening members Sw3 may be a male screw member such as a bolt. For example, each of the multiple third fastening members Sw3 may be inserted through a through hole (also referred to as a third through hole) in the control unit 150 and screwed into a screw hole (also referred to as a third screw hole) in the panel base 111. In this way, the control unit 150 may be fastened to the panel base 111 by multiple third fastening members Sw3. For example, if the third screw hole of the panel base 111 is provided in the internal frame 111if of the panel base 111, the control unit 150 may be fastened to the internal frame 111if by the third fastening members Sw3. For example, if the third screw hole of the panel base 111 is provided in the beam portion 111bm of the internal frame 111if, the control unit 150 may be fastened to the beam portion 111bm by the third fastening members Sw3. Here, for example, the control unit 150 may include a plate 151 (also referred to as a second plate or second mounting plate) having a plurality of third through holes. This second plate 151 may be made of resin or of metal such as aluminum alloy.

[0085] In the examples shown in Figures 3 to 8, in the first ceiling panel 10a, the control unit 150 is fixed to the panel base 111 by a plurality of third fastening members Sw3 in such a way that the second A member 340a can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. More specifically, in the first ceiling panel 10a, the control unit 150 is fixed to the internal frame 111if of the panel base 111 by a plurality of third fastening members Sw3 in such a way that the second A member 340a can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1. Even more specifically, in the first ceiling panel 10a, the control unit 150 is fixed to the two beam portions 111bm of the internal frame 111if by a plurality of third fastening members Sw3 in such a way that the second A member 340a can be removed from the panel base 111 to allow it to be removed to the interior space Sp1 side, which is an example of the lighting space S1.

[0086] Here, the control unit 150 was fixed to the panel base 111 by a plurality of third fastening members Sw3 in such a way that the second member 340 could be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1, but it is not limited to this. For example, the control unit 150 may be fixed to the panel base 111 in such a way that the second member 340 could be removed from the panel base 111 to allow removal to the interior space Sp1 side, which is an example of the lighting space S1, by allowing removal to the interior space Sp1 side, which is an example of the lighting space S1, by allowing removal to the panel base 111. Other forms may include, for example, a configuration in which a plurality of hooks provided on a part of the second plate 151 of the control unit 150 are hooked onto a part of the panel base 111.

[0087] <1-3. Illumination Device> The illumination device 300 according to the first embodiment will be described with reference to Figures 9 to 13. Figure 9 is a schematic cross-sectional view showing an example of the configuration of the illumination device 300. Figure 10 is a schematic front view showing an example of the configuration of the first member 330 of the illumination device 300. Figure 11 is a schematic bottom view showing an example of the configuration of the first member 330. Figure 12 is a schematic bottom view showing an example of the configuration of the illumination device 300. Figure 13 is a schematic cross-sectional view showing an example of the path of illumination light L1 in the illumination device 300. The cross-section of the illumination device 300 in Figure 9 is a cross-section including the optical axis Ax1 of the lens optical system 320 of the illumination device 300. The lens optical system 320 will be described later. In Figures 9 to 13, hidden lines that depict an example of the outer edge of some of the components are schematically shown by thin dashed lines. In Figures 9, 10, and 13, the optical axis Ax1 of the lens optical system 320 is schematically shown by a thin dashed line. In Figures 11 and 12, the position of the optical axis Ax1 of the lens optical system 320 is schematically shown by small black circles. In Figure 13, an example of the outer edge of the path of the illumination light L1 emitted from the light source 310 is schematically shown by a thin double-dotted line.

[0088] For example, as shown in Figure 13, the lighting device 300 is a device that can emit illumination light L1 into an indoor space Sp1, which is an example of the illuminated space S1 outside the lighting device 300. The illumination light L1 emitted from the lighting device 300 can directly illuminate objects in the indoor space Sp1, which is an example of the illuminated space S1. Here, the expression "directly illuminates objects" means that the illumination light L1 emitted from the lighting device 300 irradiates objects without passing through optical components such as lenses and spatial light modulators. A person in the indoor space Sp1, which is an example of the illuminated space S1, can see the shape and color of the objects illuminated by the illumination light L1.

[0089] For example, as shown in Figure 9, the lighting device 300 includes a light source 310, a lens optical system 320, a first member 330, and a second member 340. In another example of the first embodiment, the lighting device 300 includes a first plate 121.

[0090] The light source 310 can emit illumination light L1. More specifically, the light source 310 can emit illumination light L1 in the -Z direction as a first direction. The lens optical system 320 is located in the -Z direction as a first direction of the light source 310. When we say that the first object is located in the -Z direction as a first direction of the second object, it means that the first object is located at a point in the -Z direction as a first direction from the second object. Each of the first member 330 and the second member 340 surrounds the optical axis Ax1 of the lens optical system 320. Each of the first member 330 and the second member 340 also has a space that penetrates in the -Z direction as a first direction. The first member 330 has a first aperture 331o and a second aperture (for example, a first end aperture 332o, which will be described later). The first aperture 331o is an aperture on the light source 310 side of the first member 330 and is located on the side of the lens optical system 320 in the -Z direction, which is the first direction. The second aperture (for example, the first end aperture 332o, which will be described later) is an aperture on the opposite side of the light source 310 of the first member 330 and surrounds the first aperture 331o when viewed from a plane (for example, when viewed from a plane in the +Z direction, which is the second direction). The second member 340 is located in the -Z direction, which is the first direction, relative to the first member 330 and has an exit aperture 340o as a third aperture. This exit aperture 340o as a third aperture is surrounded by the second aperture (for example, the first end aperture 332o, which will be described later) when viewed from a plane (for example, when viewed from a plane in the +Z direction, which is the second direction). More specifically, as described above, the second member 340 includes, for example, a plate-like portion (first plate-like portion) 341. The first plate-shaped portion 341 is located in the -Z direction, which is the first direction of the first member 330, and has an exit aperture 340o, which is the third aperture. In the lighting device 300, the illumination light L1 emitted from the light source 310 can be emitted into the illumination space S1 by sequentially passing through the lens optical system 320, the first aperture 331o of the first member 330, the second aperture of the first member 330 (for example, the first end aperture 332o, which will be described later), and the exit aperture 340o of the second member 340.More specifically, in the lighting device 300, the illumination light L1 emitted from the light source 310 passes in order through the lens optical system 320, the first aperture 331o of the first member 330, the space (also referred to as the first space) Sa1 enclosed by the second portion 332 of the first member 330, and the exit aperture 340o of the first plate-shaped portion 341, and can then be emitted into the illumination space S1. The first aperture 331o and the second portion 332 will be described later.

[0091] The exit aperture 340o may be a space connecting the first space Sa1 and the interior space Sp1, which is an example of the illumination space S1. This exit aperture 340o can function as an exit for illumination light L1 from the first space Sa1 to the interior space Sp1, which is an example of the illumination space S1. For example, as shown in Figure 9, a lens does not need to be located within the exit aperture 340o. Also, optical components such as lenses and spatial light modulation units do not need to be located on the side of the exit aperture 340o in the first direction, the -Z direction.

[0092] <1-3-1. Light Source> The light source 310 has, for example, an emission section (e.g., a light source emission surface) 311 that emits illumination light L1 in the -Z direction as a first direction. In other words, the light source 310 has, for example, an emission section (e.g., a light source emission surface) 311 that emits illumination light L1 toward the lens optical system 320. The light source 310 may include, for example, a semiconductor laser element such as a light-emitting diode (LED), a laser diode (LD), a light-emitting element such as a vertical cavity surface-emitting laser (VCSEL), or a superluminescent diode (SLD). The emission section 311 of the light source 310 may be, for example, the end of a light-emitting element that emits light.

[0093] The light source 310 may be attached to the first plate 121, for example. The light source 310 can be attached to the first plate 121 by means of, for example, adhesive, crimping, fitting, or fastening with screws.

[0094] Further, in addition to the light-emitting element, the light source 310 may further include a member for guiding light, such as a fiber and a rod lens (also referred to as a light guide member). The fiber includes a linear core and a cladding. The cladding has a refractive index lower than that of the core and covers the core. The illumination light L1 can pass through the core while undergoing total internal reflection at the interface between the core and the cladding. The rod lens has, for example, a columnar shape. The illumination light L1 can pass through the inside of the rod lens while undergoing total internal reflection at the side surface of the rod lens. The end portion (also referred to as the incident end) of the light guide member where light is incident corresponds to one end surface (also referred to as the first end surface) in the longitudinal direction of the fiber or the rod lens. The end portion (also referred to as the emission end) of the light guide member where light is emitted corresponds to the end surface on the opposite side of the first end surface in the longitudinal direction of the fiber or the rod lens (also referred to as the second end surface). The illumination light L1 from the light-emitting element is incident on the incident end of the light guide member, travels through the light guide member, and is emitted from the emission end of the light guide member toward the lens optical system 320. In this case, the emission portion 311 of the light source 310 corresponds to the emission end of the light guide member.

[0095] The emission portion 311 may include, for example, a wavelength conversion member 313. In this case, the light-emitting element emits excitation light. The wavelength conversion member 313 emits light having a wavelength different from that of the excitation light in response to the incidence of the excitation light from the light-emitting element. Here, the illumination light L1 may be fluorescence emitted from the wavelength conversion member 313. The light source 310 may be, for example, a light-emitting device including a substrate, a light-emitting element located on the substrate and emitting excitation light, and a wavelength conversion member 313 located on the substrate and sealing the light-emitting element. The wavelength conversion member 313 is, as a material for converting excitation light into blue light (also referred to as a blue phosphor), for example, BaMgAl １０ O １７ :Eu, (Sr, Ca, Ba) １０ (PO ４ ) ６ Cl ２ :Eu or (Sr, Ba) １０ (PO ４ ) ６ Cl ２: May contain Eu, etc. The wavelength conversion member 313 is a material (also called a blue-green phosphor) that converts excitation light into blue-green light, for example, (Sr, Ba, Ca) ５ (PO ４ ) ３ Cl:Eu or Sr ４ Al １４ O ２５ : May contain Eu, etc. The wavelength conversion member 313 is a material (also called a green phosphor) that converts excitation light into green light, for example, SrSi ２ (O, Cl) ２ N ２ :Eu, (Sr, Ba, Mg) ２ SiO ４ :Eu ２＋ ZnS: Cu, Al or Zn ２ SiO ４ : May contain Mn, etc. The wavelength conversion member 313 is a material (also called a red phosphor) that converts excitation light into red light, for example, Y ２ O ２ S: Eu, Y ２ O ３ :Eu, SrCaClAlSiN ３ :Eu ２＋ CaAlSiN ３ : Eu or CaAlSi(ON) ３ : May contain Eu, etc. The wavelength conversion member 313 is a material (also called a near-infrared phosphor) that converts excitation light into light having wavelengths in the near-infrared region, for example, 3Ga ５ O １２: May contain Cr or the like. The excitation light may be, for example, violet light with a peak near 405 nm or blue light with a peak near 450 nm. If the excitation light is light with a peak from 380 nm to 415 nm and the wavelength conversion member 313 has a red phosphor, a green phosphor and a blue phosphor, the color rendering of the illumination device 300 may be improved. Here, for example, a gallium nitride (GaN)-based semiconductor laser that emits violet laser light at 405 nm as excitation light may be applied to the light-emitting element. The light source 310 may also include, for example, a heat dissipation member (heat sink). The first plate 121 may be used as a heat sink. For example, the heat sink may be located in the part of the first plate 121 that overlaps with the light source 310.

[0096] As illustrated in Figure 13, the illumination light L1 from the emitter 311 of the light source 310 spreads as it travels. In other words, the size of the cross-section (also called the luminous beam cross-section) of the illumination light L1 perpendicular to the optical axis of the light source 310 increases as it moves away from the light source 310. In the examples of Figures 9 and 13, the optical axis of the light source 310 and the optical axis Ax1 of the lens optical system 320 coincide or approximately coincide. The size of the luminous beam cross-section of the illumination light L1 is equal to the peak value e in the light intensity distribution of the illumination light L1 in the cross-section perpendicular to the optical axis of the light source 310. ２ It may also be defined by contour lines having a light intensity of 1 / 1. Here, "e" is called Napier's number. In other words, the light rays on both sides of the illumination light L1 in Figure 13 are the peak value of the light intensity distribution in a cross section perpendicular to the optical axis Ax1 of the lens optical system 320, e. ２ The light rays may have 1 / 1 of the light intensity. Light in the region outside the area enclosed by the above contour lines (i.e., the outermost light rays) may be considered noise.

[0097] <1-3-2. Lens Optical System> For example, as shown in Figures 9 and 13, the lens optical system 320 is located on the path of illumination light L1 from the light source 310. The lens optical system 320 may be located, for example, between the light source 310 and the exit aperture 340o of the first plate-shaped portion 341. The lens optical system 320 may be attached to the first plate 121 via, for example, a lens holder (not shown). The lens holder can be attached to the first plate 121 by, for example, adhesive, crimping, fitting, or fastening with screws.

[0098] The lens optical system 320 includes one or more lenses 321, including a first lens 321a. In other words, the lens optical system 320 includes a first lens 321a. Each of the one or more lenses 321 of the lens optical system 320 is located on the optical axis of the light source 310. From another point of view, the lens optical system 320 includes one or more lenses 321, each located in the -Z direction as a first direction of the light source 310. In other words, the lens optical system 320 includes a first lens 321a located in the -Z direction as a first direction of the light source 310.

[0099] The lens optical system 320 focuses the illumination light L1 emitted from the light source 310 on the side of the lens optical system 320 in the first direction, the -Z direction. In other words, the lens optical system 320 focuses the illumination light L1 from the light source 310 on the side opposite to the light source 310. As a result, in the direction in which the optical axis Ax1 of the lens optical system 320 extends from the light source 310 toward the lens optical system 320 (also called the optical axis direction), the size of the cross-sectional area of ​​the illumination light L1 becomes smaller than at the lens optical system 320 before becoming larger as it travels along the optical axis Ax1 from the lens optical system 320. Therefore, for example, the proportion of illumination light L1 emitted by the light source 310 that reaches the inner surfaces of the first member 330 and the second member 340 of the illumination device 300 can be reduced. As a result, the reflection and scattering of light occurring on the inner surfaces of the illumination device 300 can be reduced. Thus, the glare of the illumination device 300 can be reduced. In other words, an indoor space Sp1 can be realized as an example of a more comfortable lighting space S1 in which glare from the lighting device 300 is reduced.

[0100] The lens optical system 320 emits illumination light L1 from the exit aperture 340o of the second member 340 into an indoor space Sp1, which is an example of an illuminated space S1. Here, if the lens optical system 320 focuses the illumination light L1 emitted by the light source 310 on the side of the exit aperture 340o of the second member 340 rather than the lens optical system 320, it becomes possible to reduce the size of the exit aperture 340o of the second member 340. This makes it possible to make the inner surfaces of the lens optical system 320 and the first member 330 less visible from outside the lighting device 300. As a result, the glare from the lighting device 300 can be reduced. Here, for example, if the exit aperture 340o is located at a position along the optical axis Ax1 of the lens optical system 320 toward the exit aperture 340o, where the size of the cross-sectional area of ​​the illumination light L1 is reduced due to the focusing of the illumination light L1 by the lens optical system 320, it may be possible to make the exit aperture 340o smaller.

[0101] From another perspective, the lens optical system 320 may, for example, focus the illumination light L1 from the light source 310 onto a virtual focusing surface FP1 on the opposite side of the light source 310 (more specifically, the output section 311). In other words, the magnitude of the illumination light L1 in a cross section perpendicular to the optical axis Ax1 of the lens optical system 320 may be smallest at the focusing surface FP1 on the side of the lens optical system 320 in the first direction (-Z direction). To put it another way, the focusing surface FP1 may be a virtual surface at the position where the magnitude of the illumination light L1 in a cross section perpendicular to the optical axis Ax1 of the lens optical system 320 is smallest on the side of the lens optical system 320 in the first direction (-Z direction). As illustrated in Figure 13, the lens optical system 320 may, for example, focus the illumination light L1 emitted by the light source 310 onto a virtual focusing surface FP1 located on the side of the lens optical system 320 in the first direction (-Z direction). In other words, the lens optical system 320 may focus the illumination light L1 from the light source 310 on a hypothetical focusing surface FP1 located on the opposite side of the light source 310. In Figure 13, the focusing surface FP1 is schematically shown by a thin dashed line.

[0102] Here, the lens optical system 320 may be, for example, an optical system (also called an imaging optical system) that forms an image of the light source 310 (also called a light source image) as a real image on the condensing surface FP1. This can reduce, for example, the proportion of illumination light L1 emitted by the light source 310 that reaches the inner surfaces of the first member 330 and the second member 340 of the illumination device 300. The emission section (light source emission surface) 311 may have a conjugate relationship with respect to the condensing surface FP1. Here, the condensing surface FP1 may also be called the image plane IS1. Note that the conjugate relationship here does not have to be in a strict sense. For example, the part on the emission aperture 340o side of the emission section 311 where the illumination light L1 is most focused may be considered as the image plane IS1. The part where the illumination light L1 is most focused is the part where the size of the illumination light L1 in a cross section perpendicular to the optical axis Ax1 of the lens optical system 320 is smallest.

[0103] Here, for example, as shown in Figure 13, the focusing surface FP1 may be located inside the exit aperture 340o. In other words, for example, the lens optical system 320 may focus the illumination light L1 emitted from the light source 310 inside the exit aperture 340o. In this case, the part of the illumination light L1 that is most focused may be located inside the exit aperture 340o. This makes it possible to make the inner surfaces of the lens optical system 320 and the first member 330 less visible from outside the lighting device 300 by reducing the size of the exit aperture 340o. As a result, the glare from the lighting device 300 can be reduced. As a result, an indoor space Sp1 as an example of a more comfortable illuminated space S1 can be realized with reduced glare from the lighting device 300.

[0104] Furthermore, the focusing surface FP1 does not necessarily have to be located inside the exit aperture 340o. The focusing surface FP1 may be located slightly offset from the exit aperture 340o in the direction of propagation of the illumination light L1 passing through the exit aperture 340o. More specifically, for example, as shown in Figure 14, the focusing surface FP1 may be located slightly closer to the lens optical system 320 than the exit aperture 340o. Figure 14 is a schematic cross-sectional view showing another example of the path of illumination light L1 in the illumination device 300. Figure 14 is based on Figure 13, with the path of illumination light L1 slightly modified. Also, for example, the focusing surface FP1 may be located slightly closer to the illumination space S1 than the exit aperture 340o.

[0105] The illumination light L1 spreads out as it travels in the direction in which the optical axis Ax1 of the lens optical system 320 extends from the light source 310 toward the lens optical system 320 (optical axis direction), in front of the point of greatest focus. Therefore, the illumination light L1 spreads out as it travels in the illumination space S1. In other words, the lens optical system 320 focuses the illumination light L1 on the side of the exit aperture 340o toward the lens optical system 320, and emits it from the exit aperture 340o at a predetermined beam angle θ1. The beam angle may be, for example, the beam angle at which the luminous intensity on a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320 (also called the illuminated surface) is 50 percent (%) or more of the luminous intensity on the optical axis Ax1 of the lens optical system 320 (also called the central luminous intensity). In other words, the beam angle may be, for example, the angle at which light with a luminous intensity of 50% or more of the luminous intensity (central luminous intensity) on the optical axis Ax1 of the lens optical system 320 spreads out in the illumination light L1 emitted from the illumination device 300 to the illumination space S1. The beam angle θ1 may also be called the half-power angle. The beam angle θ1 may be, for example, 60 degrees or less, 50 degrees or less, 40 degrees or less, 30 degrees or less, or 20 degrees or less.

[0106] For example, as shown in Figures 9 and 13, the lens optical system 320 may consist of a single lens 321 (more specifically, a first lens 321a). The lens 321 may be a biconvex lens or a plano-convex lens. The material of the lens 321 may be glass or resin. For example, optical glass may be used for the glass. For the resin, acrylic resin or polycarbonate resin may be used. For the acrylic resin, polymethyl methacrylate (PMMA) may be used.

[0107] Furthermore, for example, the lens optical system 320 may include a plurality of lenses 321. In this case, for example, the plurality of lenses 321 may be arranged at intervals along the path of illumination light L1 from the light source 310 to the exit aperture 340o. More specifically, for example, the plurality of lenses 321 may be arranged at intervals along the optical axis Ax1 of the lens optical system 320. The plurality of lenses 321 may be attached to the first plate 121 via, for example, a lens holder (not shown). For example, as shown in Figure 15, the plurality of lenses 321 may be two lenses 321. Figure 15 is a schematic cross-sectional view showing another example (also referred to as the first example) of the configuration of the illumination device 300. Figure 15 is based on Figure 13, in which one or more lenses 321 constituting the lens optical system 320 are changed from a single lens 321 to two lenses 321, and the path of illumination light L1 is slightly modified. In the example shown in Figure 15, the two lenses 321 are the first lens 321a and the second lens 321b. The number of lenses 321 may be, for example, three lenses 321, or four or more lenses 321.

[0108] For example, the focusing surface FP1 may be a planar surface or a curved surface (also referred to as a curved surface). This curved surface may be, for example, a surface that is convex toward the illumination space S1. For example, if the focusing surface FP1 is a curved surface, an inexpensive lens may be used as the lens 321 of the lens optical system 320. The lens 321 may be, for example, a spherical lens, an aspherical lens, or a free-form surface lens. The lens 321 may also have a continuous curved surface, or the surface on which the illumination light L1 is incident (also referred to as the incident surface) and the surface on which the illumination light L1 is emitted (also referred to as the emission surface) may each have curved surfaces without steps. The lens 321 may also be, for example, a lens having an arbitrary three-dimensional shape. Various shapes of lenses, such as Fresnel lenses, can be applied to the lens 321. The lens 321 may also be, for example, a lens that utilizes reflection due to the difference in refractive index.

[0109] For example, as shown in Figures 9 and 13, the light source 310, the lens optical system 320, and the exit aperture 340o may be aligned in a straight line. For example, the light source 310, the lens optical system 320, and the exit aperture 340o may be aligned in the vertical direction (direction of gravity). In the examples of Figures 9 and 13, the optical axis of the light source 310, the optical axis Ax1 of the lens optical system 320, and the central axis of the exit aperture 340o coincide or approximately coincide with each other.

[0110] <1-3-3. First Member> The first member 330 has, for example, an internal space that penetrates the first member 330 along the optical axis Ax1. From another point of view, the first member 330 has, for example, an opening located at the end on the side in the -Z direction as the first direction, and an opening located at the end on the side in the +Z direction as the second direction. In other words, the first member 330 has an opening on the side opposite to the light source 310 (also referred to as the second opening). In the example of Figures 9 to 13, the first member 330 has an opening 332o as the second opening (also referred to as the first end opening) located at the end on the side in the -Z direction as the first direction, and an opening 333o located at the end on the side in the +Z direction as the second direction (also referred to as the second end opening).

[0111] For example, the first member 330 surrounds at least the portion of the path of illumination light L1 from the light source 310 to the exit aperture 340o that is on the side of the second member 340. In the examples of Figures 9 and 13, the first member 330 surrounds the entire path of illumination light L1 from the light source 310 to the exit aperture 340o.

[0112] The first member 330 has the function of reducing leakage of illumination light L1 emitted from the light source 310 into the illumination space S1 from locations other than the emission opening 340o. Focusing on this function, the first member 330 may also be called, for example, a light-shielding member. From another perspective, the first member 330 has the function of protecting the lens optical system 320. For example, the first member 330 has the function of reducing contact between various members and the lens optical system 320. Focusing on this function, the first member 330 may also be called, for example, a lens cover.

[0113] The material of the first member 330 may be, for example, an aluminum alloy or a synthetic resin. The first member 330 may be composed of a single member, or it may have a structure in which multiple members are connected, bonded, or joined together to form an integrated structure.

[0114] The first member 330 may be attached to, for example, a lens holder (not shown). In other words, for example, the first member 330 may be attached to the lens optical system 320 via a lens holder (not shown). The attachment of the first member 330 to the lens holder can be achieved, for example, by bonding, crimping, fitting, or fastening with screws.

[0115] For example, as shown in Figures 9 to 13, the first member 330 includes a first portion 331 and a second portion 332. The first portion 331 and the second portion 332 may be connected. In one example of the first embodiment, the first member 330 includes a third portion 333. The third portion 333 may be connected to the first portion 331.

[0116] <<First part>> The first part 331 has a first aperture 331o and a first surface 331f. For example, as shown in Figures 9 to 13, the first part 331 surrounds the optical axis Ax1 of the lens optical system 320.

[0117] The first aperture 331o penetrates the first portion 331 in the -Z direction, which is the first direction. The first aperture 331o may be a space that penetrates the first portion 331 in the -Z direction, which is the first direction. This first aperture 331o is located, for example, in the -Z direction, which is the first direction of the lens optical system 320. From another point of view, for example, in the -Z direction, which is the first direction, the first aperture 331o is located between the lens optical system 320 and the exit aperture 340o. In other words, for example, the first aperture 331o is located in the middle of the path of illumination light L1 emitted from the light source 310 to the exit aperture 340o. From this point of view, the first aperture 331o is also called an intermediate aperture. Furthermore, the optical axis Ax1 of the lens optical system 320 passes through the inside of the first aperture 331o, for example. For example, when viewed from above in the second direction, the +Z direction, the optical axis Ax1 of the lens optical system 320 may pass through the center or approximate center of the first aperture 331o. In the examples of Figures 9 to 13, when viewed from above in the second direction, the +Z direction, the first aperture 331o has a circular or approximately circular shape with the optical axis Ax1 of the lens optical system 320 as its center or approximate center. Here, for example, when viewed from above in the second direction, the +Z direction, the first aperture 331o may surround the lens optical system 320.

[0118] The first surface 331f is the surface located on the side of the first portion 331 in the -Z direction, which is the first direction. Here, it is assumed that the first portion 331 is viewed from above in the +Z direction, which is the second direction opposite to the first direction. In this case, the first surface 331f surrounds the first opening 331o. In other words, when the first portion 331 is viewed from above in the +Z direction, which is the second direction, the first surface 331f is located extending away from the first opening 331o from its edge 331e. The edge 331e may be the inner edge of the first surface 331f along the first opening 331o.

[0119] The first surface 331f may be, for example, a plane or substantially plane perpendicular or substantially perpendicular to the optical axis Ax1 of the lens optical system 320. From another point of view, the first surface 331f may be, for example, a plane parallel or substantially parallel to the XY plane. For example, when viewed from a plane in the second direction, +Z, the first surface 331f may have a circular or substantially circular outer edge. More specifically, for example, when viewed from a plane in the second direction, +Z, the first surface 331f may have a circular or substantially circular outer edge centered or substantially centered on the optical axis Ax1 of the lens optical system 320. For example, when viewed from a plane in the second direction, +Z, the first surface 331f may have a circular or substantially circular inner edge. More specifically, for example, when viewed from a plane in the second direction, +Z, the first surface 331f may have a circular or substantially circular inner edge centered or substantially centered on the optical axis Ax1 of the lens optical system 320. In other words, for example, when viewed from above in the second direction, the +Z direction, the first aperture 331o may have a circular or substantially circular edge 331e. More specifically, for example, when viewed from above in the second direction, the +Z direction, the first aperture 331o may have a circular or substantially circular edge 331e centered or substantially centered on the optical axis Ax1 of the lens optical system 320. In further other words, the first surface 331f may have an annular shape. For example, when viewed from above in the second direction, the +Z direction, the first aperture 331o may be located in the center or substantially center of the first surface 331f.

[0120] The first portion 331 may be, for example, a plate-like portion (also referred to as the second plate-like portion). The second plate-like portion may have, for example, a plate-like shape. The second plate-like portion may have, for example, a flat plate-like shape. The flat plate-like shape may be, for example, a portion having the shape of a flat plate with a constant or substantially constant thickness. In the examples of Figures 9 to 13, the first portion 331 has a circular or substantially circular flat plate-like shape having a first surface 331f that is parallel or substantially parallel to the XY plane.

[0121] Furthermore, when viewed from above in the +Z direction as a second direction, the first aperture 331o is not limited to having a circular or substantially circular shape with the optical axis Ax1 of the lens optical system 320 as its center or substantially center. For example, when viewed from above in the +Z direction as a second direction, the first aperture 331o may have other shapes. Other shapes may include, for example, a polygon or substantially polygonal shape, or an ellipse or substantially ellipse shape. For example, when viewed from above in the +Z direction as a second direction, the first aperture 331o is not limited to having a circular or substantially circular edge 331e with the optical axis Ax1 of the lens optical system 320 as its center or substantially center. For example, when viewed from above in the +Z direction as a second direction, the first aperture 331o may have an edge 331e of other shapes. Other shapes may include, for example, a polygon or substantially polygonal shape, or an ellipse or substantially ellipse shape.

[0122] Furthermore, when viewed from above in the +Z direction as a second direction, the first surface 331f is not limited to a surface having a circular or approximately circular outer edge centered or approximately centered on the optical axis Ax1 of the lens optical system 320. For example, when viewed from above in the +Z direction as a second direction, the first surface 331f may have an outer edge of another shape. Other shapes may include, for example, a polygon or approximately polygonal shape, or an ellipse or approximately elliptical shape. For example, when viewed from above in the +Z direction as a second direction, the first surface 331f is not limited to a surface having a circular or approximately circular inner edge centered or approximately centered on the optical axis Ax1 of the lens optical system 320. For example, when viewed from above in the +Z direction as a second direction, the first surface 331f may have an inner edge of another shape. Other shapes may include, for example, a polygon or approximately polygonal shape, or an ellipse or approximately elliptical shape.

[0123] Furthermore, for example, the first surface 331f is not limited to a plane or substantially plane that is perpendicular or substantially perpendicular to the optical axis Ax1 of the lens optical system 320. In other words, for example, the first surface 331f is not limited to a plane that is parallel or substantially parallel to the XY plane. For example, as shown in Figure 16, the first surface 331f may be inclined with respect to a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320. In the example of Figure 16, the first surface 331f is inclined with respect to a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320 in a manner that it advances in the +Z direction as a second direction as it approaches the edge 331e of the first aperture 331o. Figure 16 is a schematic cross-sectional view showing another example (also referred to as the second example) of the configuration of the illumination device 300. Figure 16 is a diagram based on Figure 13, in which the first portion 331 is modified from a portion parallel or approximately parallel to the XY plane to a portion inclined with respect to a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320 (also referred to as a tapered portion), in which it advances in the +Z direction as a second direction as it approaches the edge 331e of the first aperture 331o. The angle at which the first surface 331f is inclined with respect to the virtual plane perpendicular to the optical axis Ax1 may be, for example, 45 degrees or more, 60 degrees or more, 70 degrees or more, or 80 degrees or more. Furthermore, the first surface 331f may have, for example, a curved portion or an uneven surface.

[0124] Furthermore, the shape of the first portion 331 is not limited to a flat plate shape. For example, the first portion 331 may have a constant or approximately constant thickness, but may be a tapered portion as described above, or a portion having a curved plate shape such as a curved plate shape. The first portion 331 may also be a portion whose thickness is neither constant nor approximately constant.

[0125] <<Second part>> For example, as shown in Figures 9 to 13, the second part 332 surrounds the optical axis Ax1 of the lens optical system 320. In other words, the second part 332 has an internal space that penetrates the second part 332 along the optical axis Ax1. More specifically, the second part 332 has an end located at the end on the side of the second direction, the +Z direction, and connected to the first part 331. The second part 332 also has a first end opening 332o located at the end on the side of the first direction, the -Z direction.

[0126] The second portion 332 is located in the -Z direction, which is the first direction of the first portion 331. Furthermore, when viewed through a plane in the +Z direction, which is the second direction, the second portion 332 surrounds the first aperture 331o. For this reason, the distance from the optical axis Ax1 of the lens optical system 320 to the second portion 332 is greater than the distance from the optical axis Ax1 of the lens optical system 320 to the inner surface of the first portion 331o along the first aperture 331o. In other words, the first space Sa1 surrounded by the second portion 332, which is located in the -Z direction, which is the first direction of the first aperture 331o, extends to a position relatively farther from the optical axis Ax1 of the lens optical system 320 than the first aperture 331o. To put it another way, the inner space (also called the third inner space) 330is of the first member 330 extends to a position further away from the optical axis Ax1 of the lens optical system 320 when moving in the -Z direction, which is the first direction, from the first aperture 331o toward the exit aperture 340o. Here, the distance from the optical axis Ax1 to the second portion 332 may be, for example, 1.5 times or more, 2 times or more, or 3 times or more, the distance from the optical axis Ax1 to the inner circumferential surface of the first portion 331 along the first aperture 331o. More specifically, the second portion 332 has, for example, a fourth surface 332f. The fourth surface 332f is the surface of the second portion 332 located on the side of the optical axis Ax1 of the lens optical system 320, and is the surface surrounding the optical axis Ax1 of the lens optical system 320. For example, the end portion of the fourth surface 332f in the -Z direction, which is the first direction, constitutes the first end aperture 332o. Here, we consider the case where the first portion 331 and the second portion 332 are viewed from above in the +Z direction, which is the second direction. In this case, for example, as shown in Figure 11, the fourth surface 332f surrounds the first aperture 331o. From another point of view, the distance from the optical axis Ax1 of the lens optical system 320 to the fourth surface 332f is greater than the distance from the optical axis Ax1 of the lens optical system 320 to the inner surface along the first aperture 331o of the first portion 331. In other words, the first space Sa1 surrounded by the fourth surface 332f, which is located in the -Z direction, which is the first direction of the first aperture 331o, extends to a position that is relatively farther from the optical axis Ax1 of the lens optical system 320 than the first aperture 331o.To put it another way, the inner space (third internal space) 330is of the first member 330 extends to a position further away from the optical axis Ax1 of the lens optical system 320 when moving in the -Z direction as the first direction from the first aperture 331o toward the exit aperture 340o. Here, the distance from the optical axis Ax1 to the fourth surface 332f may be, for example, 1.5 times or more, 2 times or more, or 3 times or more, the distance from the optical axis Ax1 to the inner circumferential surface of the first portion 331 along the first aperture 331o.

[0127] The fourth surface 332f may be, for example, a surface whose line of intersection with an arbitrary hypothetical plane along the optical axis Ax1 of the lens optical system 320 is located along the -Z direction as the first direction. From another point of view, the fourth surface 332f may be, for example, a surface parallel or substantially parallel to the optical axis Ax1 of the lens optical system 320. Here, the fourth surface 332f may be, for example, a surface whose line of intersection with a hypothetical plane perpendicular to the optical axis Ax1 of the lens optical system 320 is circular or substantially circular. The distance from the optical axis Ax1 of the lens optical system 320 to the fourth surface 332f may be, for example, constant or substantially constant.

[0128] The second part 332 may, for example, have a cylindrical shape. In other words, the second part 332 may include, for example, a cylindrical portion (also referred to as the first cylindrical portion). The second part 332 may, for example, have a cylindrical shape with a constant or substantially constant thickness. In the examples of Figures 9 to 13, the second part 332 is a cylindrical or cylindrical portion centered or substantially centered on the optical axis Ax1 of the lens optical system 320. In other words, in the examples of Figures 9 to 13, the second part 332 is a cylindrical or cylindrical portion having a central axis along the optical axis Ax1 of the lens optical system 320.

[0129] Furthermore, for example, the fourth surface 332f is not limited to a surface whose line of intersection with an arbitrary virtual plane along the optical axis Ax1 of the lens optical system 320 is located along the -Z direction as the first direction. From another point of view, for example, the fourth surface 332f is not limited to a surface parallel or substantially parallel to the optical axis Ax1 of the lens optical system 320. From yet another point of view, for example, the distance from the optical axis Ax1 of the lens optical system 320 to the fourth surface 332f is not limited to being constant or substantially constant. For example, as shown in Figure 17, the fourth surface 332f may be inclined with respect to the optical axis Ax1 of the lens optical system 320. In the example of Figure 17, the fourth surface 332f is inclined with respect to the optical axis Ax1 of the lens optical system 320 in such a way that it approaches the optical axis Ax1 of the lens optical system 320 as it moves toward the +Z direction as the second direction. Figure 17 is a schematic cross-sectional view showing another example (also referred to as the third example) of the configuration of the illumination device 300. Figure 17 is a diagram based on Figure 13, in which the fourth surface 332f is changed from a surface parallel or approximately parallel to the optical axis Ax1 of the lens optical system 320 to a surface inclined with respect to the optical axis Ax1 of the lens optical system 320 in a manner that it approaches the optical axis Ax1 as it moves in the second direction, +Z. The angle at which the fourth surface 332f is inclined with respect to the optical axis Ax1 may be, for example, 10 degrees or less, 20 degrees or less, 30 degrees or less, or 45 degrees or less. Also, for example, as shown in Figure 18, the fourth surface 332f may include a curved portion. In the example of Figure 18, the fourth surface 332f is curved in a manner that it approaches the optical axis Ax1 of the lens optical system 320 as it moves in the second direction, +Z. Figure 18 is a schematic cross-sectional view showing another example (also referred to as the fourth example) of the configuration of the illumination device 300. Figure 18 is based on Figure 13, but the fourth surface 332f is modified from a surface parallel or approximately parallel to the optical axis Ax1 of the lens optical system 320 to a curved surface that approaches the optical axis Ax1 of the lens optical system 320 as it moves in the second direction, the +Z direction. Furthermore, the fourth surface 332f may have, for example, irregularities.

[0130] Furthermore, the fourth surface 332f is not limited to a surface whose intersection line with a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320 is circular or approximately circular. For example, the fourth surface 332f may be a surface whose intersection line with a virtual plane perpendicular to the optical axis Ax1 has a different shape. Other shapes may include, for example, a polygon or approximately polygon, or an ellipse or approximately ellipse.

[0131] Furthermore, the shape of the second portion 332 is not limited to a cylindrical shape. The second portion 332 may be, for example, a portion with a constant or approximately constant thickness that is inclined with respect to the optical axis Ax1 of the lens optical system 320. The second portion 332 may also be a portion with a thickness that is neither constant nor approximately constant.

[0132] <<Third Part>> The third part 333 surrounds the optical axis Ax1 of the lens optical system 320 and also surrounds the lens optical system 320. In other words, the third part 333 has an internal space that penetrates the third part 333 along the optical axis Ax1. The presence of this third part 333 can reduce light leakage from the illumination device 300 to the sides of the lens optical system 320. This can reduce leakage of illumination light L1 emitted from the light source 310 into the illumination space S1 from locations other than the emission aperture 340o. As a result, the glare of the illumination device 300 can be reduced. Here, the sides of the lens optical system 320 may include, for example, a direction away from the optical axis Ax1 of the lens optical system 320 without going toward the first aperture 331o.

[0133] The third portion 333 has, for example, a second end opening 333o located at the end on the side in the second direction, the +Z direction. The third portion 333 also has, for example, an end located at the end on the side in the first direction, the -Z direction, and connected to the first portion 331. The end of the third portion 333 on the side in the first direction, the -Z direction, may be connected, for example, to an annular portion of the first portion 331 along the first opening 331o. In the examples of Figures 9 to 13, the third portion 333 is positioned in a form that extends in the second direction, the +Z direction, from the annular portion of the first portion 331 along the first opening 331o. The inner diameter of the third portion 333 and the diameter of the first opening 331o of the first portion 331 may be the same or substantially the same.

[0134] The third part 333 may, for example, have a cylindrical shape. In other words, the third part 333 may include, for example, a cylindrical portion (also referred to as the second cylindrical portion). The second cylindrical portion surrounds the optical axis Ax1 of the lens optical system 320 and also surrounds the lens optical system 320. This second cylindrical portion may, for example, have a cylindrical shape centered on the optical axis Ax1 of the lens optical system 320. The second cylindrical portion may, for example, have a cylindrical shape with a constant or substantially constant thickness. In the examples of Figures 9 to 13, the third part 333 is a cylinder or cylindrical portion centered on or substantially centered on the optical axis Ax1 of the lens optical system 320. In other words, in the examples of Figures 9 to 13, the third part 333 is a cylinder or cylindrical portion having a central axis along the optical axis Ax1 of the lens optical system 320. In the examples shown in Figures 9 to 13, the first member 330 has a configuration in which a cylindrical or cylindrical third portion 333 and a cylindrical or cylindrical second portion 332 having a larger inner diameter than the third portion 333 are connected via the first portion 331.

[0135] Furthermore, the shape of the third part 333 is not limited to a cylinder or cylindrical shape. The shape of the third part 333 may be, for example, another cylindrical shape. Other cylindrical shapes may include, for example, a polygonal cylinder or a polygonal cylindrical shape, or an elliptical cylinder or an elliptical cylindrical shape. Polygonal cylinders may include, for example, a square cylinder, a pentagonal cylinder, a hexagonal cylinder, or an octagonal cylinder. Polygonal cylindrical shapes may include a square cylinder, a pentagonal cylinder, a hexagonal cylinder, or an octagonal cylinder.

[0136] Furthermore, the shape of the third portion 333 is not limited to a cylindrical shape. The third portion 333 may be, for example, a portion with a constant or approximately constant thickness that is inclined with respect to the optical axis Ax1 of the lens optical system 320. The third portion 333 may also be a portion with a thickness that is neither constant nor approximately constant.

[0137] <1-3-4. Second Member> As described above, the second member 340 includes a plate-shaped portion (first plate-shaped portion) 341. This first plate-shaped portion 341 is located in the -Z direction, which is the first direction of the first member 330. Furthermore, this first plate-shaped portion 341 has an exit aperture 340o. For example, as shown in Figures 9, 12, and 13, the exit aperture 340o is located in the -Z direction, which is the first direction of the lens optical system 320. Also, for example, the optical axis Ax1 of the lens optical system 320 passes through the inside of the exit aperture 340o.

[0138] The first plate-like portion 341 may, for example, be in contact with the first member 330 or be in close proximity to the first member 330. The first plate-like portion 341 may be positioned along a virtual plane that is perpendicular or substantially perpendicular to the optical axis Ax1 of the lens optical system 320. In other words, the first plate-like portion 341 may be positioned along a virtual plane that is parallel or substantially parallel to the XY plane.

[0139] For example, when the second member 340 is viewed from above in the +Z direction as the second direction, the optical axis Ax1 of the lens optical system 320 may pass through the center or approximately the center of the exit aperture 340o. For example, when the second member 340 is viewed from above in the +Z direction as the second direction, the exit aperture 340o may have a circular or approximately circular shape with the optical axis Ax1 of the lens optical system 320 as its center or approximately the center. The exit aperture 340o may, for example, penetrate the first plate-like portion 341 in the -Z direction as the first direction.

[0140] Furthermore, when viewed from above in the second direction, the +Z direction, the exit aperture 340o is not limited to having a circular or substantially circular shape with the optical axis Ax1 of the lens optical system 320 as its center or substantially its center. For example, when viewed from above in the second direction, the +Z direction, the exit aperture 340o may have other shapes. Other shapes may include, for example, a polygon or substantially polygon, or an ellipse or substantially ellipse.

[0141] Here, we consider the case where the first member 330 and the second member 340 are viewed from above in the second direction, the +Z direction. In this case, for example, as shown in Figure 12, the second portion 332 surrounds the exit aperture 340o. In other words, when viewed from above in the second direction, the +Z direction, the fourth surface 332f surrounds the exit aperture 340o. From another point of view, the distance from the optical axis Ax1 of the lens optical system 320 to the second portion 332 (more specifically, the fourth surface 332f) is greater than the distance from the optical axis Ax1 of the lens optical system 320 to the inner surface of the second member 340 along the exit aperture 340o. From yet another perspective, the exit aperture 340o, located in the -Z direction as the first direction of the first space Sa1, extends only to a position relatively closer to the optical axis Ax1 of the lens optical system 320 than the first space Sa1 enclosed by the second part 332 (more specifically, the fourth surface 332f).

[0142] Therefore, in the lighting device 300, when viewed planar in the second direction, the +Z direction, the second portion 332 surrounds both the first aperture 331o and the exit aperture 340o. From another perspective, when viewed planar in the second direction, the +Z direction, the first end aperture 332o, which is the second aperture, surrounds both the first aperture 331o and the exit aperture 340o. In other words, the first space Sa1 surrounded by the second portion 332 extends to a position relatively farther from the optical axis Ax1 of the lens optical system 320 than the first aperture 331o. From another perspective, the space surrounded by the first member 330 extends to a position relatively farther from the optical axis Ax1 of the lens optical system 320 as it approaches the first end aperture 332o, which is the second aperture, than the first aperture 331o. From yet another perspective, in the illumination device 300, when viewed planar in the second direction, the +Z direction, the fourth surface 332f surrounds both the first aperture 331o and the exit aperture 340o. In other words, the first space Sa1 surrounded by the fourth surface 332f extends further from the optical axis Ax1 of the lens optical system 320 than the first aperture 331o. That is, in the illumination device 300, in the space between the lens optical system 320 and the third surface Sf4 of the first plate-like portion 341, when moving in the first direction, the -Z direction, the inner circumferential surface of the first member 330 extends further from the optical axis Ax1 of the lens optical system 320. Furthermore, the exit aperture 340o extends only to a position relatively closer to the optical axis Ax1 of the lens optical system 320 than the first space Sa1 surrounded by the second portion 332 (more specifically, the fourth surface 332f). In other words, the exit aperture 340o is narrower than the first space Sa1, reaching a position closer to the optical axis Ax1. From another perspective, the exit aperture 340o is narrower than the portion of the space enclosed by the first member 330 that is on the side of the first end aperture 332o, which is the second aperture, reaching a position closer to the optical axis Ax1.

[0143] As a result, the inner surface of the first member 330 may become less visible from outside the lighting device 300 through the emission opening 340o. Furthermore, by increasing the area of ​​the inner surface of the first member 330, even if some of the illumination light L1 emitted by the light source 310 reaches the inner surface of the first member 330, the amount of light per unit area reflected and scattered at the inner surface of the first member 330 may be reduced. In other words, the brightness of the inner surface of the first member 330 may be reduced. Therefore, the glare from the lighting device 300 may be reduced. In other words, an indoor space Sp1 as an example of a more comfortable lit space S1 with reduced glare from the lighting device 300 can be realized.

[0144] Here, as described above, the second member 340 may be, for example, a simple sheet metal, or a sheet metal that has been processed by pressing or bending on a part of its peripheral edge.

[0145] Here, for example, the first plate-like portion 341 may cover the first space Sa1 surrounded by the second portion 332 (more specifically, the fourth surface 332f) of the first member 330 around the ejection opening 340o from the side in the -Z direction, which is the first direction. In other words, for example, the second member 340 may cover the first space Sa1 surrounded by the second portion 332 (more specifically, the fourth surface 332f) of the first member 330 around the ejection opening 340o from the side in the -Z direction, which is the first direction. From another point of view, for example, the first plate-like portion 341 may cover the first end opening 332o of the second portion 332 of the first member 330 around the ejection opening 340o from the side in the -Z direction, which is the first direction. In other words, for example, the second member 340 may cover the first end opening 332o of the second portion 332 of the first member 330 from the side in the -Z direction, which is the first direction, around the exit opening 340o.

[0146] As a result, for example, the second member 340 may function as a lid (cover) that surrounds the first space Sa1 enclosed by the second portion 332 (more specifically, the fourth surface 332f) of the first member 330 around the exit opening 340o, from the side of the indoor space Sp1, which is an example of the lighting space S1. From another point of view, for example, the second member 340 may function as a lid (cover) that surrounds the first end opening 332o of the second portion 332 of the first member 330 around the exit opening 340o, from the side of the indoor space Sp1, which is an example of the lighting space S1. With the presence of this second member 340, for example, the aesthetic design of the lighting device 300 can be improved and leakage of illumination light L1 emitted from the light source 310 into the lighting space S1 from locations other than the exit opening 340o can be reduced.

[0147] Here, for example, the second surface Sf3 located on the side of the first plate-like portion 341 in the +Z direction as the second direction may be exposed to the first space Sa1 surrounded by the second portion 332 (more specifically, the fourth surface 332f) of the first member 330. For example, the third surface Sf4 located on the side of the first plate-like portion 341 in the -Z direction as the first direction may be exposed to the interior space Sp1 as an example of the lighting space S1.

[0148] Here, for example, the second surface Sf3 of the first plate-like portion 341 may be, for example, a surface aligned with the XY plane. From another point of view, the second surface Sf3 may be, for example, a surface located along a virtual plane that is perpendicular or approximately perpendicular to the optical axis Ax1 of the lens optical system 320. Also, for example, when viewed from a plane in the -Z direction as the first direction, the second surface Sf3 may have, for example, a circular or approximately circular inner edge.

[0149] In the examples of Figures 9, 12, and 13, the second surface Sf3 of the first plate-like portion 341 is a surface parallel or substantially parallel to the XY plane. From another point of view, the second surface Sf3 is a plane or substantially plane that is perpendicular or substantially perpendicular to the optical axis Ax1 of the lens optical system 320. More specifically, when viewed from above in the -Z direction as the first direction, the second surface Sf3 is a surface with a circular or substantially circular inner edge centered or substantially centered on the optical axis Ax1 of the lens optical system 320.

[0150] Furthermore, for example, the second surface Sf3 is not limited to a surface that is parallel or approximately parallel to the XY plane. In other words, for example, the second surface Sf3 is not limited to a plane or approximately plane that is perpendicular or approximately perpendicular to the optical axis Ax1 of the lens optical system 320. For example, the second surface Sf3 may have curved portions or irregularities.

[0151] Here, for example, the third surface Sf4 of the first plate-like portion 341 may be, for example, a surface aligned with the XY plane. From another point of view, the third surface Sf4 may be, for example, a surface located along a virtual plane that is perpendicular or approximately perpendicular to the optical axis Ax1 of the lens optical system 320. Also, for example, when viewed from above in the +Z direction as the second direction, the third surface Sf4 may have, for example, a circular or approximately circular inner edge.

[0152] In the examples of Figures 9, 12, and 13, the third surface Sf4 of the first plate-like portion 341 is a surface parallel or substantially parallel to the XY plane. From another point of view, the third surface Sf4 is a plane or substantially plane that is perpendicular or substantially perpendicular to the optical axis Ax1 of the lens optical system 320. More specifically, when viewed from a plane in the second direction, the +Z direction, the third surface Sf4 is a surface with a circular or substantially circular inner edge centered or substantially centered on the optical axis Ax1 of the lens optical system 320.

[0153] Furthermore, for example, the third surface Sf4 is not limited to a plane that is parallel or approximately parallel to the XY plane. In other words, for example, the third surface Sf4 is not limited to a plane or approximately plane that is perpendicular or approximately perpendicular to the optical axis Ax1 of the lens optical system 320. For example, the third surface Sf4 may have curved portions or irregularities.

[0154] Here, for example, the exit aperture 340o may have a smaller aperture area than the first aperture 331o. In other words, for example, the aperture area of ​​the exit aperture 340o may be smaller than the aperture area of ​​the first aperture 331o. To put it another way, for example, when viewed planar in the +Z direction as the second direction, the exit aperture 340o may be smaller than the first aperture 331o. From another point of view, the exit aperture 340o may be surrounded by the first aperture 331o when viewed planar (for example, when viewed planar in the +Z direction as the second direction). In this case, the inner surfaces of the lens optical system 320 and the first member 330 may be less visible from outside the illumination device 300. As a result, reflected and scattered light that may occur on the inner surfaces of the lens optical system 320 and the first member 330 may be less visible from outside the illumination device 300. As a result, the glare of the illumination device 300 may be reduced. In other words, an indoor space Sp1 can be realized as an example of a more comfortable lighting space S1 in which glare from the lighting device 300 is reduced.

[0155] Here, the aperture area of ​​the exit aperture 340o may be, for example, the area of ​​the exit aperture 340o as it appears when viewed in a direction along the optical axis Ax1 of the lens optical system 320. In other words, the aperture area of ​​the exit aperture 340o may be, for example, the area of ​​the cross-section of the exit aperture 340o along a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320. The aperture area of ​​the first aperture 331o may be, for example, the area of ​​the first aperture 331o as it appears when viewed in a direction along the optical axis Ax1 of the lens optical system 320. In other words, the aperture area of ​​the first aperture 331o may be, for example, the area of ​​the cross-section of the first aperture 331o along a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320.

[0156] Furthermore, the configuration is not limited to one in which the aperture area of ​​the exit aperture 340o is smaller than the aperture area of ​​the first aperture 331o. For example, the aperture area of ​​the exit aperture 340o may be the same as or approximately the same as the aperture area of ​​the first aperture 331o. In other words, for example, when viewed from a plane in the +Z direction as the second direction, the size of the exit aperture 340o may be the same as or approximately the same as the size of the first aperture 331o.

[0157] <1-4. Summary of the First Embodiment> In the illumination device 300 according to the first embodiment, illumination light L1 emitted from the light source 310 can be emitted into the illumination space S1 by sequentially passing through the lens optical system 320, the first aperture 331o of the first member 330, the first end aperture 332o as the second aperture of the first member 330, and the exit aperture 340o of the second member 340. More specifically, illumination light L1 emitted from the light source 310 can be emitted into the illumination space S1 by sequentially passing through the lens optical system 320, the first aperture 331o of the first member 330, the first space Sa1 surrounded by the second portion 332 of the first member 330, and the exit aperture 340o of the first plate-shaped portion 341. Here, when viewed from a plane in the +Z direction as the second direction, the second portion 332 surrounds both the first aperture 331o and the exit aperture 340o. From another perspective, when viewed through a plane in the second direction, the +Z direction, the first end aperture 332o, as the second aperture, surrounds both the first aperture 331o and the exit aperture 340o. In other words, the first space Sa1 surrounded by the second portion 332 extends further from the optical axis Ax1 of the lens optical system 320 than the first aperture 331o. From another perspective, the space surrounded by the first member 330 extends further from the optical axis Ax1 of the lens optical system 320 as it approaches the first end aperture 332o, as the second aperture, than the first aperture 331o. Furthermore, the exit aperture 340o extends only to a position relatively closer to the optical axis Ax1 of the lens optical system 320 than the first space Sa1 surrounded by the second portion 332. From another perspective, the exit aperture 340o is narrower, closer to the optical axis Ax1, than the portion of the space enclosed by the first member 330 that is on the side of the first end aperture 332o, which is the second aperture. As a result, the inner surface of the first member 330 may be less visible from outside the lighting device 300 through the exit aperture 340o. In addition, by increasing the area of ​​the inner surface of the first member 330, even if some of the illumination light L1 emitted by the light source 310 reaches the inner surface of the first member 330, the amount of light per unit area reflected and scattered at the inner surface of the first member 330 may be reduced. In other words, the brightness of the inner surface of the first member 330 may be reduced. Therefore, the glare of the lighting device 300 may be reduced.In other words, an indoor space Sp1 can be realized as an example of a more comfortable lighting space S1 in which glare from the lighting device 300 is reduced.

[0158] Furthermore, in the first ceiling panel (panel lighting) 10a including the lighting device 300, the inner surface of the first member 330 may be less visible from outside the first ceiling panel 10a through the emission opening 340o. Also, by increasing the area of ​​the inner surface of the first member 330, even if some of the illumination light L1 emitted by the light source 310 reaches the inner surface of the first member 330, the amount of light per unit area reflected and scattered at the inner surface of the first member 330 may be reduced. In other words, the brightness of the inner surface of the first member 330 may be reduced. Therefore, the glare from the lighting device 300 included in the first ceiling panel 10a may be reduced. In other words, an indoor space Sp1 as an example of a more comfortable lighting space S1 with reduced glare from the first ceiling panel 10a can be realized.

[0159] Furthermore, in a system ceiling 1s comprising multiple ceiling panels 10, including one or more first ceiling panels (panel lighting) 10a, the ceiling 1 including one or more lighting devices 300 can be easily installed. This makes it easy to reduce glare from the system ceiling 1s. In other words, an indoor space Sp1 can be realized as an example of a more comfortable lighting space S1 in which glare from the system ceiling 1s is reduced.

[0160] <2. Other Embodiments> This disclosure is not limited to the first embodiment described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0161] In the first embodiment described above, the first member 330 included a third portion 333, but is not limited thereto. For example, as shown in Figure 19, the third portion 333 is not included in the first member 330, and the lighting device 300 may include a third member 350 that includes the third portion 333. Figure 19 is a schematic cross-sectional view showing another example of the configuration of the lighting device 300 (also referred to as the fifth example). Figure 19 is based on Figure 13, in which a part of the first member 330 is changed to a third member 350. Here, the third member 350 may be attached to, for example, a lens holder (not shown). In other words, for example, the third member 350 may be attached to the lens optical system 320 via a lens holder (not shown) or the like. The attachment of the third member 350 to the lens holder can be achieved, for example, by bonding, crimping, fitting, or fastening with screws. Furthermore, the first member 330 may be attached to, for example, a lens holder (not shown), or to the third member 350. The first member 330 can be attached to the lens holder or the third member 350 by, for example, adhesive, crimping, fitting, or fastening with screws. Here, for example, the third member 350 may be a lens holder.

[0162] In the first embodiment described above, the lighting device 300 may further include a light-shielding portion 342, as shown in Figures 20 and 21, for example. This light-shielding portion 342 is located from a first region A1 along the second surface Sf3 to a second region A2 along a part of the exit aperture 340o. This light-shielding portion 342 has a fourth aperture 342o. This light-shielding portion 342 is a film-like, sheet-like, or thin plate-like portion having a thickness in the first direction, the -Z direction, which is smaller than that of the first plate-like portion 341. The optical axis Ax1 passes through the interior of the fourth aperture 342o. The fourth aperture 342o penetrates the light-shielding portion 342 in the first direction, the -Z direction. The aperture area of ​​the fourth aperture 342o is smaller than the aperture area of ​​the exit aperture 340o. In other words, the fourth aperture 342o has a smaller aperture area than the exit aperture 340o. To put it another way, for example, when viewed from a plane in the +Z direction as the second direction, the fourth aperture 342o is smaller than the exit aperture 340o.

[0163] The light-shielding portion 342 can block a portion of the light emitted from the light source 310, which passes through the lens optical system 320 and then heads toward the inner surface of the second member 340 along the exit aperture 340o. As a result, the amount of light emitted from the light source 310, which passes through the lens optical system 320 and then irradiates the inner surface of the second member 340 along the exit aperture 340o can be reduced. This can reduce the reflected and scattered light that may occur on the inner surface of the second member 340 along the exit aperture 340o. As a result, the glare from the lighting device 300 can be further reduced. In other words, an indoor space Sp1, as an example of a more comfortable lit space S1, can be realized with further reduced glare from the lighting device 300.

[0164] Figure 20 is a schematic cross-sectional view showing another example (also referred to as the sixth example) of the configuration of the lighting device 300. Figure 21 is a schematic bottom view showing the sixth example of the configuration of the lighting device 300. Figure 20 is a diagram in which the light-shielding portion 342 is added, based on Figure 13. Figure 21 is a diagram in which the light-shielding portion 342 is added, based on Figure 12. In Figure 21, a hidden line illustrating an example of the outer edge of the light-shielding portion 342 is schematically shown by a thin dashed line.

[0165] Here, the light-shielding portion 342 may be a portion that can block light. The material of the light-shielding portion 342 may be, for example, a metal such as stainless steel or aluminum. The material of the light-shielding portion 342 may also be, for example, another material capable of blocking visible light.

[0166] For example, in both cases where the plane is viewed in the +Z direction as the second direction, and in the -Z direction as the first direction, the first region A1 may be the region surrounding the exit aperture 340o. More specifically, for example, in both cases where the plane is viewed in the +Z direction as the second direction, and in the -Z direction as the first direction, the first region A1 may be an annular region surrounding the exit aperture 340o. In the example of Figure 21, when the plane is viewed in the +Z direction as the second direction, the first region A1 is an annular region surrounding the exit aperture 340o. Note that the first region A1 is not limited to an annular region, for example. The first region A1 may be an annular region having another shape, for example.

[0167] For example, the second region A2 may be a region located along a part of the end of the exit aperture 340o on the side in the second direction, the +Z direction. For example, in both cases where the view is plane-perspective in the second direction, the +Z direction, and in both cases where the view is plane-perspective in the first direction, the -Z direction, the second region A2 may be a region located along the edge of the exit aperture 340o. More specifically, for example, in both cases where the view is plane-perspective in the second direction, the +Z direction, and in both cases where the view is plane-perspective in the first direction, the -Z direction, the second region A2 may be an annular region located along the edge of the exit aperture 340o. In the example in Figure 21, when the view is plane-perspective in the second direction, the +Z direction, the second region A2 is an annular region located along the edge of the exit aperture 340o. Note that the second region A2 is not limited to an annular region, for example. The second region A2 may be an annular region having other shapes, for example.

[0168] From another perspective, for example, whether viewed planar in the +Z direction as the second direction, or in the -Z direction as the first direction, the annular portion of the light-shielding portion 342 along the fourth aperture 342o may protrude from the edge of the exit aperture 340o in a direction approaching the optical axis Ax1.

[0169] Here, the aperture area of ​​the fourth aperture 342o may be, for example, the area of ​​the fourth aperture 342o as it is viewed in a direction along the optical axis Ax1 of the lens optical system 320. In other words, the aperture area of ​​the fourth aperture 342o may be, for example, the area of ​​the cross-section of the fourth aperture 342o along a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320. The aperture area of ​​the exit aperture 340o may be, for example, the area of ​​the exit aperture 340o as it is viewed in a direction along the optical axis Ax1 of the lens optical system 320. In other words, the aperture area of ​​the exit aperture 340o may be, for example, the area of ​​the cross-section of the exit aperture 340o along a virtual plane perpendicular to the optical axis Ax1 of the lens optical system 320.

[0170] In the first embodiment described above, for example, a portion of the illumination light L1 may be reflected or scattered by the respective surfaces of one or more lenses 321 in the lens optical system 320. When such unwanted reflected and / or scattered light (also referred to as reflected and scattered light) is emitted through the exit aperture 340o into the indoor space Sp1, which is an example of the illumination space S1, glare from the illumination device 300 may occur in the indoor space Sp1, which is an example of the illumination space S1, and enters the field of view of a person. Here, the light of the illumination light L1 that is reflected and / or scattered inside the first member 330 is also referred to as reflected and scattered light L11. Reflected and scattered light L11 may be a portion of the illumination light L1 that deviates from the path of the illumination light L1 that is focused on the focusing surface FP1.

[0171] For example, the lighting device 300 may have a light reduction structure 360 ​​located inside the first member 330. The light reduction structure 360 ​​includes a structure that can reduce reflected and scattered light L11 emitted from the exit aperture 340o into an indoor space Sp1, which is an example of the lighting space S1. The light reduction structure 360 ​​may include, for example, a portion 361 that absorbs reflected and scattered light L11 (also called a reflection reduction portion), or it may include an uneven shape 362 that reflects or scatters the reflected and scattered light L11 to the side in the +Z direction, which is a second direction.

[0172] Figure 22 is a schematic cross-sectional view showing another example (also referred to as the seventh example) of the configuration of the lighting device 300. Figure 22 is based on Figure 13, with the addition of a light reduction structure 360. For example, as shown in Figure 22, the light reduction structure 360 ​​may be located along the inner surface of the first member 330. The inner surface of the first member 330 may be a surface exposed to the inner space of the first member 330. The light reduction structure 360 ​​may include a reflection reduction section 361. In the example of Figure 22, the reflection reduction section 361, which is the light reduction structure 360, is located along the inner surface of the first member 330. In other words, the portion of the first member 330 along the inner surface has the reflection reduction section 361, which is the light reduction structure 360.

[0173] The reflection reduction portion 361 may be positioned along the entire inner surface of the first member 330, as illustrated in Figure 22, or along only a portion of the inner surface of the first member 330. For example, the reflection reduction portion 361 may be positioned along all or only a portion of the inner circumferential surface of the first member 330 surrounding the optical axis Ax1. For example, the reflection reduction portion 361 may be positioned along the entire circumference around the optical axis Ax1 on the inner circumferential surface of the first member 330 surrounding the optical axis Ax1, or along only a portion of the circumferential direction around the optical axis Ax1.

[0174] The reflection reduction section 361 may include, for example, a film (also called an absorbing film) having a high absorption rate with respect to the illumination light L1. The absorption rate of the illumination light L1 in the absorbing film may be, for example, 60% or more, 80% or more, or 90% or more. The reflection reduction section 361 may have a high absorption rate over the entire wavelength range constituting the illumination light L1, or it may have a high absorption rate at the wavelength with the highest intensity in the illumination light L1 (also called a peak wavelength). Here, the absorption rate of the reflection reduction section 361 with respect to the illumination light L1 may be higher than the absorption rate of the main body of the first member 330 with respect to the illumination light L1. The main body of the first member 330 may be the part of the first member 330 other than the reflection reduction section 361.

[0175] The reflection reduction portion 361 can be formed, for example, by applying a blackening treatment to the inner surface of the first member 330. For example, the reflection reduction portion 361 may be formed on the inner surface of the first member 330 by a blackening treatment such as chemical conversion treatment, plating, or painting. A matte blackening treatment or a glossy blackening treatment may be used.

[0176] Here, for example, the reflection reduction section 361 is made of a black material. This black material may include, for example, at least one of a black metal, a black metal oxide film, and a black resin.

[0177] The reflection reduction section 361 may include a dielectric multilayer film. The dielectric multilayer film has, for example, a structure in which multiple dielectric thin films are stacked. Examples of dielectrics include titanium oxide (TiO2). ２ ), silicon oxide (SiO ２ ), niobium pentoxide (Nb ２ O ５ ), tantalum pentoxide (Ta ２ O ５ ) and magnesium fluoride (MgF ２ One or more of the following materials are used. Such dielectric multilayer films may also be called low-reflection films or anti-reflective films.

[0178] The reflection reduction portion 361 may be formed directly on the inner surface of the first member 330, or it may be formed indirectly on the inner surface of the first member 330 via another member. The other member may be, for example, a predetermined film-like substrate. In this case, for example, the substrate on which the reflection reduction portion 361 is formed may be attached to the inner surface of the first member 330, thereby forming the reflection reduction portion 361 along the inner surface of the first member 330. Attachment of the substrate to the inner surface of the first member 330 can be achieved, for example, by adhesive bonding of the substrate to the inner surface of the first member 330.

[0179] The reflection reduction section 361 may include flocked paper. For example, flocked paper may consist of a base material such as paper or cloth and chemical fibers attached to this base material in an upright position. If black flocked paper is used, the reflection of reflected scattered light L11 can be further reduced compared to flocked paper of other colors.

[0180] In such a lighting device 300, for example, reflected and / or scattered light L11 generated by reflection and / or scattering in the lens optical system 320 travels toward the inner surface of the first member 330 and is incident on the reflection reduction unit 361. Since the reflection reduction unit 361 reduces the reflection of reflected and scattered light L11, the amount of reflected and scattered light L11 emitted from the exit aperture 340o to the indoor space Sp1, which is an example of the lighting space S1, can be reduced. As a result, the glare of the lighting device 300 that enters a person's field of vision in the indoor space Sp1, which is an example of the lighting space S1, can be reduced.

[0181] Figure 23 is a schematic cross-sectional view showing another example (also referred to as the eighth example) of the configuration of the lighting device 300. Figure 23 is based on Figure 13, with the addition of a light reduction structure 360. For example, as shown in Figure 23, the light reduction structure 360 ​​may be located along the inner surface of the first member 330. The light reduction structure 360 ​​may include an uneven surface 362. In the example of Figure 23, the uneven surface 362 is the shape of the inner surface of the first member 330 surrounding the optical axis Ax1. In other words, the inner surface of the first member 330 surrounding the optical axis Ax1 has an uneven surface 362. The uneven surface 362 has a shape in which concave and convex portions are arranged alternately in a cross-section including the optical axis Ax1.

[0182] The uneven surface 362 may be located along the entire inner surface of the first member 330, or along only a portion of the inner surface of the first member 330. In other words, the uneven surface 362 may be located along at least the entire or a portion of the inner surface of the first member 330 surrounding the optical axis Ax1. For example, the uneven surface 362 may be located along the entire circumference of the inner surface of the first member 330 surrounding the optical axis Ax1, or along only a portion of the circumferential direction around the optical axis Ax1.

[0183] Figure 24 is an enlarged cross-sectional view schematically showing a part of the cross-section of an example of the uneven shape 362. In the examples of Figures 23 and 24, the uneven shape 362 has a sawtooth shape. Each tooth (i.e., convex part) of this sawtooth shape is composed of a surface F21 on the side in the second direction, the +Z direction (also referred to as the fifth surface) and a surface F22 on the side in the first direction, the -Z direction (also referred to as the sixth surface). In the uneven shape 362, the fifth surface F21 and the sixth surface F22 are arranged alternately in a continuous pattern. This uneven shape 362 may have the same helical shape as a female screw, or it may have a shape in which a plurality of ring shapes are arranged in a direction along the optical axis Ax1. The pitch between the multiple convex parts in the uneven shape 362 may be set to, for example, a few millimeters or less.

[0184] As shown in Figure 24, the length of the sixth surface F22 may be greater than the length of the fifth surface F21. Also, the angle that the sixth surface F22 makes with respect to the optical axis Ax1 may be smaller than the angle that the fifth surface F21 makes with respect to the optical axis Ax1. In the examples of Figures 23 and 24, the fifth surface F21 is approximately perpendicular to the optical axis Ax1.

[0185] Here, for example, as shown in Figure 24, reflected and scattered light L11 can be incident at an oblique angle from the light source 310 side toward the inner surface surrounding the optical axis Ax1 of the first member 330. This reflected and scattered light L11 is incident on the fifth surface F21 or the sixth surface F22.

[0186] Reflected scattered light L11 incident on the fifth surface F21 may be reflected by the fifth surface F21 and incident on the sixth surface F22, which is located on the side of the fifth surface F21 in the +Z direction, which is the second direction. Reflected scattered light L11 may be multiple reflected in the recess between the fifth surface F21 and the sixth surface F22, which is located on the side of the fifth surface F21 in the +Z direction, which is the second direction. Since the multiple reflected scattered light L11 is attenuated, the amount of reflected scattered light L11 can be reduced. Here, reflected scattered light L11 traveling toward the back of the recess (i.e., the boundary between the fifth surface F21 and the sixth surface F22, which is located on the side of the fifth surface F21 in the +Z direction, which is the second direction) may be reflected again toward the opposite side of the back of the recess. Since the distance between the fifth surface F21 and the sixth surface F22 in the recess widens toward the light source 310 side, reflected scattered light L11 may travel toward the light source 310 side. In other words, reflected and scattered light L11 that is incident on the fifth surface F21 from the light source 310 at an oblique angle can be reflected back towards the light source 310 at an oblique angle.

[0187] A portion of the reflected and scattered light L11 incident on the sixth surface F22 may be reflected by the sixth surface F22 and incident on the fifth surface F21, which is located on the side of the sixth surface F22 in the -Z direction, which is the first direction. The reflected and scattered light L11 incident on the fifth surface F21 may undergo multiple reflections in the recess between the fifth surface F21 and the sixth surface F22, which is located on the side of the fifth surface F21 in the +Z direction, which is the second direction, and travel towards the back of the press. Then, the reflected and scattered light L11 may travel again on the opposite side from the back of the recess due to reflection. Since the distance between the fifth surface F21 and the sixth surface F22 in the recess widens in the oblique direction toward the light source 310, the reflected and scattered light L11 may travel in the oblique direction toward the light source 310. In other words, the reflected and scattered light L11 incident on the sixth surface F22 in an oblique direction from the light source 310 may return in the oblique direction toward the light source 310 due to reflection.

[0188] As a result, the uneven shape 362 can attenuate the reflected and scattered light L11 within the first member 330. Therefore, the reflected and scattered light L11 emitted from the exit aperture 340o to the indoor space Sp1, which is an example of the illuminated space S1, can be reduced. Consequently, the glare of the lighting device 300 that enters a person's field of vision in the indoor space Sp1, which is an example of the illuminated space S1, can be reduced.

[0189] Furthermore, the light reduction structure 360 ​​located inside the first member 330 may be, for example, a surface with a rougher surface (also referred to as a rough surface) than the outer surface of the first member 330. In this case as well, the reflected and scattered light L11 directed from the inside of the first member 330 toward the exit aperture 340o can be reduced by the rough surface. Therefore, the reflected and scattered light L11 emitted from the exit aperture 340o toward the indoor space Sp1, which is an example of the illuminated space S1, can be reduced. As a result, the glare of the lighting device 300 that enters the field of view of a person in the indoor space Sp1, which is an example of the illuminated space S1, can be reduced.

[0190] In the first embodiment described above, for example, the light source 310 may have an output end 311 of a light guiding member such as a fiber or rod lens that guides light emitted from a light-emitting element located outside the lighting device 300. In other words, the light source 310 does not have to include a light-emitting element.

[0191] In the first embodiment described above, a filter (also called a light cut filter) that absorbs or reflects light of the wavelength of excitation light emitted by the light-emitting element may be located, for example, within the exit aperture 340o or in a region along the exit aperture 340o. In other words, the lighting device 300 may be equipped with a light cut filter. This light cut filter may have, for example, a transparent substrate made of glass or resin and a dielectric multilayer film formed on the surface of this substrate.

[0192] In the first embodiment described above, for example, the base material 11 of the system ceiling 1s does not necessarily have to include a plurality of second beam-like portions 11c.

[0193] In the first embodiment described above, for example, the illuminated space S1 was an indoor space Sp1, but it is not limited to this. The illuminated space S1 may be, for example, a space in which people can stay or pass through. The illuminated space S1 may be, for example, a passageway connecting two or more indoor spaces Sp1. Also, for example, the illuminated space S1 may be a space located outdoors below a roof.

[0194] In the first embodiment described above, for example, the first member 330 may be a member having a shape in which the diameter continuously widens from the first opening 331o toward the first end opening 332o as the second opening. In other words, the first member 330 may be a member having, for example, an integral tapered inner circumferential surface. In this case, for example, the portion of the first member 330 on the side of the first opening 331o may be considered as the first portion 331, and the portion of the first member 330 on the side of the first end opening 332o as the second opening may be considered as the second portion 332. Even if this configuration is adopted, when viewed from a plane in the +Z direction as the second direction, the first end opening 332o as the second opening surrounds the first opening 331o and also surrounds the exit opening 340o.

[0195] As described above, lighting devices, panel lighting, and system ceilings have been described in detail, but the above descriptions are illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various examples described above can be combined, as long as they do not contradict each other. And countless examples not illustrated can be conceived without falling outside the scope of this disclosure.

[0196] This disclosure includes the following:

[0197] In one embodiment, (1) the lighting device comprises a light source that emits illumination light, a lens optical system including a first lens located in a first direction from the light source, and a first member and a second member that each surround the optical axis of the lens optical system and each have a space penetrating in the first direction, wherein the first member has a first opening on the light source side and a second opening on the opposite side from the light source that surrounds the first opening when viewed through a plane, the first opening is located on the side of the lens optical system in the first direction, and the second member has a third opening located in the first direction relative to the first member and surrounded by the second opening when viewed through a plane.

[0198] (2) In the lighting device described in (1) above, the third opening may be surrounded by the first opening when viewed from above.

[0199] (3) In the lighting device of (1) or (2) above, the first member has a first part having a first surface and a second part, wherein the first surface is located on the side of the first part in the first direction and surrounds the first opening when viewed in plan in the second direction opposite to the first direction, and the second part is located in the first direction of the first part and surrounds the first opening when viewed in plan perspective in the second direction.

[0200] (4) In the illumination device described in (3) above, the second portion surrounds the third aperture when viewed planar in the second direction, and the illumination light emitted by the light source passes sequentially through the lens optical system, the first aperture, the first space surrounded by the second portion, and the third aperture, and exits into the illumination space, and the lens optical system may concentrate the illumination light emitted by the light source on the side of the lens optical system in the first direction.

[0201] (5) In any one of the lighting devices described in (1) to (4) above, the first member may include a third portion, the third portion may surround the optical axis and the lens optical system.

[0202] (6) In any one of the illumination devices described in (1) to (5) above, the lens optical system may concentrate the illumination light emitted by the light source inside the third aperture.

[0203] (7) In any one of the lighting devices described in (1) to (6) above, the second member has a first plate-like portion, the first plate-like portion has a second surface located on the side of a second direction opposite to the first direction, and the lighting device further comprises a film-like, sheet-like, or thin plate-like light-shielding portion that extends from a first region along the second surface to a second region along a part of the third opening and has a fourth opening, the light-shielding portion having a thickness in the first direction that is smaller than that of the first plate-like portion, the optical axis passes through the inside of the fourth opening, the fourth opening penetrates the light-shielding portion in the first direction and may be smaller than the third opening when viewed planar in the second direction.

[0204] In one embodiment, (8) the panel lighting comprises a panel body and a light-emitting unit fixed to the panel body, the panel lighting includes any one of the lighting devices described in (1) to (7) above, the light-emitting unit includes the light source, the lens optical system, and the first member, the panel body has an internal space in which the light-emitting unit is located and includes the second member, the second member is located on the first direction side of the panel body and covers the internal space from the first direction side around the third opening.

[0205] (9) In the panel lighting described in (8) above, the panel body includes a panel base, the light-emitting unit is attached to the panel base, and the second member may be attached to the panel base in a manner that allows it to be removed to the lighting space.

[0206] (10) In the panel lighting described in (9) above, the light-emitting unit may be attached to the panel base in such a manner that it can be removed to the lighting space side by removing the second member from the panel base.

[0207] In one embodiment, (11) the system ceiling comprises a plurality of ceiling panels, the plurality of ceiling panels including one or more panel lights from (8) to (10) above.

[0208] 1s System ceiling 10 Ceiling panel 10a First ceiling panel (panel lighting) 110 Panel body 111 Panel base 120 Light-emitting unit 300 Lighting device 310 Light source 320 Lens optical system 321a First lens 330 First component 331 First part 331e Edge 331f First surface 331o First opening 332 Second part 332o First end opening (second opening) 333 Third part 340 Second component 340o Outlet opening (third opening) 341 First plate-like part 342 Light-shielding part 342o Fourth opening A1 First region A2 Second region Ax1 Optical axis Is1 Internal space L1 Illumination light S1 Illumination space Sa1 First space Sf3 Second surface

Claims

1. An illumination device comprising: a light source that emits illumination light; a lens optical system including a first lens located in a first direction from the light source; a first member surrounding the optical axis of the lens optical system; and a second member surrounding the optical axis, wherein each of the first member and the second member has a space penetrating in the first direction; the first member has a first opening on the light source side and a second opening on the opposite side from the light source; the second opening surrounds the first opening when viewed through a plane; the first opening is located on the side of the lens optical system in the first direction; the second member is located in the first direction relative to the first member; and the second member has a third opening that is surrounded by the second opening when viewed through a plane.

2. The lighting device according to claim 1, wherein the third opening is surrounded by the first opening when viewed from above.

3. A lighting device according to claim 1 or claim 2, wherein the first member comprises a first portion having a first surface and a second portion, the first surface being located on the first direction side of the first portion and surrounding the first opening when viewed in a plan view in a second direction opposite to the first direction, and the second portion being located in the first direction of the first portion and surrounding the first opening when viewed in a plan view in the second direction.

4. An illumination device according to claim 3, wherein the second portion surrounds the third aperture when viewed planar in the second direction, the illumination light emitted from the light source passes sequentially through the lens optical system, the first aperture, the first space surrounded by the second portion, and the third aperture, and exits into the illumination space, and the lens optical system concentrates the illumination light emitted from the light source on the side of the lens optical system in the first direction.

5. An illumination device according to any one of claims 1 to 4, wherein the first member includes a third portion, the third portion surrounding the optical axis and surrounding the lens optical system.

6. An illumination device according to any one of claims 1 to 5, wherein the lens optical system concentrates the illumination light emitted by the light source inside the third aperture.

7. An illumination device according to any one of claims 1 to 6, wherein the second member has a first plate-like portion, the first plate-like portion has a second surface located on the side of a second direction opposite to the first direction, and the illumination device further comprises a film-like, sheet-like, or thin plate-like light-shielding portion that is located from a first region along the second surface to a second region along a part of the third opening and has a fourth opening, the light-shielding portion has a thickness in the first direction that is smaller than that of the first plate-like portion, the optical axis passes through the inside of the fourth opening, the fourth opening penetrates the light-shielding portion in the first direction and is smaller than the third opening when viewed planar in the second direction.

8. Panel lighting comprising a panel body and a light-emitting unit fixed to the panel body, wherein the panel lighting includes a lighting device according to any one of claims 1 to 7, the light-emitting unit includes the light source, the lens optical system, and the first member, the panel body has an internal space in which the light-emitting unit is located and includes the second member, the second member is located on the first direction side of the panel body and covers the internal space from the first direction side around the third opening.

9. Panel lighting according to claim 8, wherein the panel body includes a panel base, the light-emitting unit is attached to the panel base, and the second member is attached to the panel base in a manner that allows it to be removed to the side of the lighting space.

10. Panel lighting according to claim 9, wherein the light-emitting unit is attached to the panel base in such a manner that the second member can be removed from the panel base to be removed to the lighting space.

11. A system ceiling comprising a plurality of ceiling panels, wherein the plurality of ceiling panels include panel lighting according to one or more of claims 8 to 10.

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