Lighting system

Abstract

To reduce conspicuousness of a lighting system when emitting light.SOLUTION: A lighting system includes: a casing; a light source; a wavelength conversion section; a first optical system; and a first light shielding section. The casing has a first opening. The light source emits excitation light. The wavelength conversion section emits fluorescence having a wavelength spectrum different from that of excitation light to an internal space of the casing according to irradiation of the excitation light. The first optical system is positioned in the internal space. The first optical system includes at least one optical component positioned between the wavelength conversion section and the first opening in an optical path of fluorescence, forms an image of fluorescence emitted from the wavelength conversion section on a virtual image surface on a side of the first opening, and emits fluorescence from the first opening. The wavelength conversion section has a first surface positioned on a side of the first optical system. The first surface includes a first area, and a second area surrounding the first area. The first light shielding section has a first through hole positioned between the first area and the first optical system, and covers the second area.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a lighting device. [Background technology]

[0002] 2. Description of the Related Art There are light-emitting devices in which a phosphor emits fluorescent light in response to incidence of excitation light from a light source (see, for example, the description in Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-203852 A Summary of the Invention [Problem to be solved by the invention]

[0004] Regarding the lighting device, there is room for improvement in terms of reducing the conspicuousness of the lighting device when illuminated. [Means for solving the problem]

[0005] SUMMARY OF THE DISCLOSURE An illumination device is disclosed.

[0006] One aspect of the lighting device includes a housing, a light source, a wavelength conversion unit, a first optical system, and a first light shielding unit. The housing has a first opening. The light source emits excitation light. The wavelength conversion unit emits fluorescence having a wavelength spectrum different from that of the excitation light in response to irradiation of the excitation light into the internal space of the housing. The first optical system is located in the internal space. The first optical system includes one or more optical components located between the wavelength conversion unit and the first opening in the optical path of the fluorescence, and forms an image of the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side, and emits the fluorescence from the first opening. The wavelength conversion unit has a first surface located on the side of the first optical system. The first surface includes a first region and a second region surrounding the first region. The first light shielding unit has a first through hole located between the first region and the first optical system, and covers the second region.

[0007] One aspect of the lighting device includes a housing, a light source, a wavelength conversion unit, a first optical system, and a second optical system. and a second light-shielding unit. The housing has a first opening. The light source emits excitation light. The wavelength conversion unit emits fluorescence having a wavelength spectrum different from the excitation light in response to irradiation of the excitation light into the internal space of the housing. The first optical system is located in the internal space. The second optical system is located between the light source and the wavelength conversion unit in the optical path of the excitation light from the light source to the wavelength conversion unit. The first optical system includes one or more optical components located between the wavelength conversion unit and the first opening in the optical path of the fluorescence, and forms an image of the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side, and emits the fluorescence from the first opening. The wavelength conversion unit has a first surface located on the side of the first optical system and a fourth surface on the opposite side to the first surface. The fourth surface is irradiated with the excitation light from the light source. The fourth surface includes a third region and a fourth region surrounding the third region. The second light-shielding portion has a second through-hole located between the third area and the second optical system, and covers the fourth area. Effect of the Invention

[0008] This makes it possible to reduce the visibility of the lighting device when it emits light. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view that illustrates an example of the configuration of the lighting device according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view that illustrates an example of a light path in the lighting device according to the first embodiment. [Diagram 3] FIG. 3 is an enlarged cross-sectional view that illustrates a schematic enlargement of a portion of the lighting device of FIG. [Figure 4] FIG. 4 is a front view illustrating an example of a configuration of a first member of the lighting device of FIG. [Diagram 5] 5 is an enlarged front view showing a V portion surrounded by a two-dot chain line as a part of the first member in FIG. [Figure 6] FIG. 6 is a front view illustrating an example of the configuration of the first light-shielding portion and the second mounting member. [Figure 7] FIG. 7 is a rear view that illustrates an example of the configuration of the first light-shielding portion and the second attachment member. [Figure 8] FIG. 8 is a cross-sectional view that illustrates an example of a path of light in the wavelength conversion member, the first light blocking portion, and the 1A lens in the lighting device according to the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view that illustrates an example of a path of light in a wavelength conversion member and a 1A lens in an illumination device according to a reference example. [Figure 10] FIG. 10 is a graph showing a schematic example of the relationship between the wavelength of light and the transmittance of light in the wavelength separation filter according to the first embodiment. [Figure 11] FIG. 11 is a cross-sectional view that illustrates a first example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view that illustrates a second example of the configuration of the wavelength conversion member and the first light blocking portion according to the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view that illustrates a schematic state during the formation of a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by the first method. [Figure 14] FIG. 14 is a cross-sectional view that illustrates a schematic state during the formation of a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by the first method. [Figure 15] FIG. 15 is a cross-sectional view illustrating a schematic state during the formation of a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by the first method. [Figure 16] FIG. 16 is a cross-sectional view that illustrates a state in the middle of forming a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by a second method. [Figure 17] FIG. 17 is a cross-sectional view that illustrates a schematic state during the formation of a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by a second method. [Figure 18] FIG. 18 is a cross-sectional view that illustrates a state in the middle of forming a second example of the configuration of a wavelength conversion member and a first light blocking portion according to the second embodiment by a second method. [Figure 19] FIG. 19 is a cross-sectional view illustrating an example of the configuration of an illumination device according to the third embodiment. [Figure 20] FIG. 20 is a diagram illustrating an example of a manner in which the first region is changed in response to rotation of the wavelength conversion member in the illumination device according to the third embodiment. [Figure 21] FIG. 21 is a cross-sectional view that illustrates an example of the configuration of an illumination device according to a fourth embodiment. [Figure 22] FIG. 22 is a graph showing a schematic example of the relationship between the wavelength of light and the light transmittance in the wavelength separation filter according to the fourth embodiment. [Diagram 23] FIG. 23 is an enlarged bottom view that diagrammatically illustrates a portion of the first member according to the fourth embodiment. [Figure 24] FIG. 24 is a cross-sectional view illustrating an example of the configuration of an illumination device according to a fifth embodiment. [Diagram 25]FIG. 25 is a plan view illustrating an example of the configuration of a wavelength converting unit and a first light shielding unit according to the fifth embodiment. As shown in FIG. [Figure 26] FIG. 26 is a cross-sectional view illustrating an example of the configuration of an illumination device according to a sixth embodiment. [Figure 27] FIG. 27 is an enlarged cross-sectional view that illustrates a schematic enlargement of a portion of the lighting device of FIG. [Figure 28] FIG. 28 is a bottom view illustrating an example of the configuration of a wavelength converting unit and a first light blocking unit according to the sixth embodiment. As shown in FIG. [Figure 29] FIG. 29 is a cross-sectional view that illustrates a schematic view of a portion of another example of the configuration of the illumination device according to the sixth embodiment. [Diagram 30] FIG. 30 is a plan view illustrating an example of the configuration of a wavelength converting unit and a second light shielding unit according to the sixth embodiment. As shown in FIG. [Diagram 31] FIG. 31 is a cross-sectional view that illustrates a schematic view of a portion of another example of the configuration of the illumination device according to the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] There is a light-emitting device that includes a light source that emits excitation light and a wavelength conversion unit that includes a phosphor. The phosphor emits fluorescent light in response to the incidence of the excitation light from the light source.

[0011] The light-emitting device may be applied to, for example, a lighting device in which the fluorescent light emitted from the wavelength conversion unit is projected as illumination light into a target space.

[0012] Here, for example, a form is conceivable in which the illumination device includes a housing having an opening for emitting illumination light, and a light-emitting device and an optical system disposed within the housing. In this illumination device, the optical system reduces the spread of the optical path of the fluorescence emitted from the wavelength conversion unit, thereby making it possible to effectively utilize the fluorescence while reducing the target space onto which the fluorescence is projected as illumination light. In other words, the illumination light can be efficiently irradiated onto the target space onto which it is desired to project the illumination light.

[0013] In addition, for example, it is possible to reduce the amount of fluorescence emitted from the wavelength conversion unit that is irradiated onto the inner surface of the housing using an optical system, thereby reducing unnecessary light (also known as stray light) that may be generated by reflection of fluorescence on the inner surface of the housing.

[0014] Incidentally, for example, a part of the excitation light (also referred to as the second excitation light) irradiated from the light source to the wavelength conversion unit (also referred to as the first excitation light) may be emitted toward the outside of the wavelength conversion unit by reflection and scattering in the wavelength conversion unit without being converted to fluorescence in the wavelength conversion unit. Then, this second excitation light may be reflected by the surface of the optical system or the like and be irradiated again to the wavelength conversion unit. In this case, for example, the second excitation light may be irradiated to an area around the area of ​​the wavelength conversion unit where the first excitation light is irradiated. As a result, for example, fluorescence may be emitted from an unexpected area of ​​the wavelength conversion unit, and stray light that may be generated by reflection of the fluorescence on the inner surface of the housing may increase. As a result, stray light from the illumination device may be irradiated in a space different from the intended target space where the illumination device is intended to project the illumination light, making the presence of the illumination device more noticeable. In other words, the illumination device may be more noticeable when emitting illumination light (also referred to as emitting light).

[0015] For this reason, there is room for improvement in terms of reducing the conspicuousness of the lighting device when it emits light.

[0016] Therefore, the inventors of the present disclosure have created a technology for reducing the conspicuousness of an illumination device when it emits light.

[0017] In this regard, various embodiments and examples will be described below with reference to the drawings. In the drawings, parts having the same or similar configurations and functions are given the same reference numerals. In the following description, duplicated descriptions are omitted. The drawings are shown diagrammatically. A right-handed XYZ coordinate system is attached to Figs. 1 to 9, 11, 12, 19 to 21, and 23 to 31. In this XYZ coordinate system, the direction in which light is emitted from the lighting device 1 is the -Z direction, one direction perpendicular to the -Z direction is the +X direction, and one direction perpendicular to both the -Z direction and the +X direction is the +Y direction.

[0018] In this disclosure, when an expression indicating a relative or absolute positional relationship (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) is used, this expression not only strictly indicates the positional relationship, but also indicates a state in which the angle or distance is relatively displaced within a range in which a tolerance or similar function is obtained, unless otherwise specified. When an expression indicating an equal state (e.g., "same," "equal," "homogeneous," etc.) is used, this expression not only indicates a quantitatively strictly equal state, but also indicates a state in which a difference exists in which a tolerance or similar function is obtained, unless otherwise specified. When an expression indicating a shape (e.g., "square shape" or "cylindrical shape," etc.) is used, this expression not only strictly indicates the shape geometrically, but also indicates a shape having, for example, any of unevenness and chamfering, within a range in which a similar effect is obtained, unless otherwise specified. When an expression "comprises," "includes," "has," "includes," "includes," or "has" one component is used, this expression is not an exclusive expression that excludes the presence of other components. When the expression "at least one of A, B, and C" is used, this expression includes any of the following cases: A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0019] <1. First embodiment> An illumination device 1 according to a first embodiment will be described with reference to FIGS.

[0020] <1-1. Overview of lighting equipment> Fig. 1 is a cross-sectional view that shows an example of the configuration of the illumination device 1 according to the first embodiment. Fig. 2 is a cross-sectional view that shows an example of the path of light in the illumination device 1 according to the first embodiment. Fig. 3 is an enlarged cross-sectional view that shows an enlarged part of the illumination device 1 in Fig. 1. The examples of Figs. 1 to 3 show an example of the configuration of the illumination device 1 in a cross section that includes a first optical axis Ax1, a second optical axis Ax2, and a third optical axis Ax3, which will be described later.

[0021] As shown in Fig. 2, the lighting device 1 is a device capable of emitting fluorescence L1 as illumination light into a lighting space S1. In the examples of Figs. 2 and 3, an example of an outer edge of a path of the fluorescence L1 is shown typically by a thin two-dot chain line. The lighting space S1 is, for example, an indoor space of a building. The lighting device 1 is disposed, for example, on a ceiling portion located above the lighting space S1.

[0022] Here, first, an example of the configuration of the lighting device 1 will be outlined, and then the example of the configuration of the lighting device 1 will be described in more detail.

[0023] The lighting device 1 includes a housing 10, a light source 20, a wavelength conversion section 32, a first optical system 40, and a first light blocking section 50.

[0024] The housing 10 has an internal space 10is. The internal space 10is is a space surrounded by the inner surface of the housing 10. The housing 10 accommodates a first optical system 40 in the internal space 10is. The housing 10 has a first opening (also referred to as an irradiation opening) 10a. Fluorescence L1 as illumination light is emitted from the irradiation opening 10a to an illumination space S1.

[0025] The light source 20 can emit the excitation light L0. In the example of FIG. 2, an example of the outer edge of the path of the excitation light L0 is shown by a thin dashed line. In FIGS. 1 and 2, an example of the optical axis (also called the first optical axis) Ax1 of the light source 20 is shown by a thin dashed line. A direction Dp1 along the first optical axis Ax1 (also called the first optical axis direction) may be a first direction in which the light source 20 emits the excitation light L0. In the example of FIGS. 1 and 2, the first direction and the first optical axis direction Dp1 are the -X direction. The direction in which the fluorescence L1 is emitted from the irradiation opening 10a to the illumination space S1 may be the second direction. The light source 20 has an emission part (for example, an emission surface) 20e that emits the excitation light L0. For example, light having a peak of light intensity within a wavelength range from 380 nm to 415 nm is adopted as the excitation light L0. Here, the wavelength at which the light intensity of the excitation light L0 is maximum is defined as the first peak wavelength. As a specific example of the excitation light L0, purple light having a first peak wavelength in the vicinity of 405 nm is adopted. The excitation light L0 is not necessarily limited to purple light, and may be, for example, blue light having a first peak wavelength in the vicinity of 450 nm. The excitation light L0 emitted from the light source 20 may be irradiated to the wavelength conversion unit 32 via, for example, the first optical system 40.

[0026] FIG. 4 is a front view that shows a schematic example of the configuration of the first member 100 of the lighting device 1 of FIG. 1. The first member 100 may be a member in which the wavelength conversion member 30 including the wavelength conversion unit 32 and the first light-shielding unit 50 are attached to the cover unit 12 as a part of the housing 10 by the second mounting member 70. FIG. 5 is an enlarged front view that shows an enlarged V portion surrounded by a two-dot chain line as a part of the first member 100 of FIG. 4. In FIG. 4 and FIG. 5, an example of the outer edge of the wavelength conversion member 30 and the wavelength conversion unit 32 hidden behind the first light-shielding unit 50 is typically shown by a thin dashed line. FIG. 6 is a front view that shows a schematic example of the configuration of the first light-shielding unit 50 and the second mounting member 70. In FIG. 6, an example of the outer edge of the first light-shielding unit 50 hidden behind the second mounting member 70 is shown by a thin dashed line. FIG. 7 is a rear view that shows a schematic example of the configuration of the first light-shielding unit 50 and the second mounting member 70. In FIG. 7, an example of the outer edge of the through hole 70h of the second mounting member 70 hidden behind the first light-shielding portion 50 is indicated by a thin dashed line.

[0027] The wavelength conversion unit 32 can emit the fluorescence L1 into the internal space 10is of the housing 10 in response to irradiation with the excitation light L0. The fluorescence L1 has a wavelength spectrum different from that of the excitation light L0. The wavelength conversion unit 32 has a first surface 32a that is a surface located on the side of the first optical system 40. The first surface 32a may be, for example, a substantially flat surface. In the example of FIG. 1 to FIG. 3, the first surface 32a is a flat surface along the YZ plane. The first surface 32a includes a first region 32a1 and a second region 32a2. The second region 32a2 is a region surrounding the first region 32a1. The first region 32a1 is, for example, a region facing the first optical system 40. The first region 32a1 is, for example, a region not covered by the first light shielding unit 50. The second region 32a2 is a region covered by the first light shielding unit 50. The second region 32a2 may be, for example, the remaining region of the first surface 32a excluding the first region 32a1.

[0028] The first optical system 40 is located in the internal space 10is of the housing 10. The first optical system 40 includes one or more optical components 41. The one or more optical components 41 are located between the wavelength conversion unit 32 and the irradiation opening 10a in the optical path of the fluorescence L1 emitted from the wavelength conversion unit 32. The one or more optical components 41 may include, for example, one or more optical lenses (also simply referred to as lenses) 412. In the example of FIG. 1 and FIG. 2, the first optical system 40 can guide the excitation light L0 from the light source 20 to the wavelength conversion unit 32 and guide the fluorescence L1 emitted from the wavelength conversion unit 32 to the irradiation opening 10a.

[0029] In addition, the first optical system 40 focuses the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side, and emits the fluorescence L1 from the irradiation opening 10a. Here, the first optical system 40 focuses the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side located on the opposite side to the first surface 32a of the wavelength conversion unit 32 in the path of the fluorescence L1. In other words, the first optical system 40 focuses the image of the wavelength conversion unit 32 as a real image on the image plane Is1. This can reduce the amount of light of the fluorescence L1 irradiated to the inner surface of the housing 10, for example. The first surface 32a of the wavelength conversion unit 32 has a conjugate relationship with the image plane Is1. Note that the conjugate relationship referred to in this disclosure does not have a strict meaning, and the portion on the irradiation opening 10a side relative to the first surface 32a where the fluorescence L1 is most concentrated (the portion in the fluorescence L1 where the cross-sectional size perpendicular to the third optical axis Ax3 described later is the smallest) can be regarded as the image plane Is1.

[0030] The first light-shielding part 50 covers a part of the first surface 32a of the wavelength conversion part 32. The first light-shielding part 50 may be a part capable of blocking light rays. The light rays blocked by the first light-shielding part 50 include, for example, the excitation light L0. The light rays blocked by the first light-shielding part 50 may include, for example, the excitation light L0 and the fluorescence L1. The first light-shielding part 50 may have, for example, a plate-like, film-like, or foil-like shape. In the examples of FIG. 6 and FIG. 7, the outer edge of the first light-shielding part 50 has a circular shape, but is not limited thereto. The outer edge of the first light-shielding part 50 may have other shapes, such as an elliptical shape or a polygonal shape. The first light-shielding part 50 has a through hole (also referred to as a first through hole) 50h. The first through hole 50h is located between the first area 32a1 of the first surface 32a of the wavelength conversion part 32 and the first optical system 40. The first light-shielding portion 50 covers the second region 32a2 of the first surface 32a of the wavelength converting portion 32.

[0031] The first light-shielding portion 50 may be located along the first surface 32a of the wavelength conversion portion 32. More specifically, the first light-shielding portion 50 may be located along the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. The first light-shielding portion 50 may be located, for example, in a state of contact with the first surface 32a of the wavelength conversion portion 32, or in a state of being close to the first surface 32a of the wavelength conversion portion 32. In the first embodiment, the excitation light L0 from the light source 20 passes through the first through-hole 50h and is irradiated onto the first region 32a1 of the first surface 32a of the wavelength conversion portion 32. Of the excitation light L0 from the light source 20, the light portion directed toward the second region 32a2 of the first surface 32a of the wavelength conversion portion 32 is blocked by the first light-shielding portion 50.

[0032] FIG. 8 is a cross-sectional view that shows an example of a path of light in the wavelength conversion member 30, the first light shielding portion 50, and the 1A lens 4121A described later as an example of the lens 412 in the illumination device 1 according to the first embodiment. FIG. 9 is a cross-sectional view that shows an example of a path of light in the wavelength conversion member 30 and the 1A lens 4121A described later in the illumination device according to a reference example. The illumination device according to the reference example has a configuration in which the first light shielding portion 50 is removed from the illumination device 1 according to the first embodiment. In FIG. 8, the configuration of the illumination device 1 other than the wavelength conversion member 30, the first light shielding portion 50, and the 1A lens 4121A is omitted. In FIG. 9, the configuration of the illumination device according to the reference example other than the wavelength conversion member 30 and the 1A lens 4121A is omitted. In both FIG. 8 and FIG. 9, the outer edge of the path of the excitation light L0 is shown typically by a thin dashed line, and the outer edge of the path of the fluorescence L1 is shown typically by a thin two-dot chain line.

[0033] In both of FIG. 8 and FIG. 9, it is assumed that a part of the excitation light L0 irradiated from the light source 20 to the wavelength conversion unit 32 (also referred to as partial excitation light) is not converted to fluorescence L1 in the wavelength conversion unit 32, but is emitted toward the 1A lens 4121A by reflection and scattering in the wavelength conversion unit 32. In both of FIG. 8 and FIG. 9, an example of a path of a part of the partial excitation light reflected by the surface (also referred to as the first lens surface) 412a of the 1A lens 4121A on the wavelength conversion unit 32 side is shown by a thin solid arrow. Here, the partial excitation light emitted toward the 1A lens 4121A by reflection and scattering in the wavelength conversion unit 32 may have a luminous intensity distribution similar to that of perfect diffuse reflection (also referred to as Lambertian reflection). For this reason, a part of the partial excitation light may be reflected in a direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 by the first lens surface 412a of the 1A lens 4121A.

[0034] For example, in an illumination device according to a reference example, as shown in FIG. 9, the first light-shielding portion 50 does not exist. Therefore, a part of the partial excitation light reflected in a direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 by the first lens surface 412a of the 1A lens 4121A of the first optical system 40 may be irradiated to the second region 32a2. Here, for example, in the case where the first region 32a1 is a circular region having a diameter M1 (unit: millimeter (mm)), when the excitation light L0 from the light source 20 is irradiated to the first region 32a1, a part of the partial excitation light may be irradiated to a circular region having a diameter M1A (unit: mm) larger than M1 of the first surface 32a of the wavelength conversion unit 32. This may expand the region of the first surface 32a of the wavelength conversion unit 32 where the excitation light L0 including the partial excitation light is irradiated. As a result, the region of the first surface 32a of the wavelength conversion unit 32 that emits the fluorescence L1 toward the first optical system 40 may be expanded. In this case, the path of the fluorescence L1 along a direction perpendicular to the traveling direction of the fluorescence L1 may be expanded in the internal space 10is of the housing 10. Then, the amount of the fluorescence L1 irradiated to the inner surface of the housing 10 may increase. This may increase unnecessary light (also called stray light) that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10. Therefore, according to the lighting device of one reference example, in a space different from the original target space to which the illumination light is intended to be projected, the stray light from the lighting device may be irradiated, making the presence of the lighting device more noticeable. In other words, the lighting device of one reference example may be more noticeable when emitting the illumination light.

[0035] In contrast, in the lighting device 1 according to the first embodiment, for example, as shown in FIG. 8, the first light-shielding portion 50 is present. Therefore, a part of the partial excitation light reflected in the direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 at the first lens surface 412a of the 1A lens 4121A can be blocked by the first light-shielding portion 50. This can reduce the irradiation of the excitation light L0 to the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. From another perspective, the expansion of the region of the first surface 32a of the wavelength conversion unit 32 where the excitation light L0 including the partial excitation light is irradiated can be reduced. In this case, the emission of the fluorescence L1 from the second region 32a2 can be reduced. Therefore, the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32 can be reduced. This can reduce the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, according to the lighting device 1 of the first embodiment, in a space different from the original target space to which the illumination light is to be projected, the amount of stray light irradiated from the lighting device 1 is reduced, and the conspicuousness of the lighting device 1 can be reduced. In other words, according to the lighting device 1 of the first embodiment, the conspicuousness of the lighting device 1 when emitting the illumination light (when emitting light) can be reduced.

[0036] A more specific example of each component of the lighting device 1 will now be described.

[0037] <1-2.Light source> The light source 20 may include a light emitting element such as a semiconductor laser element such as a laser diode (LD), a vertical cavity surface emitting laser (VCSEL), a light emitting diode (LED) or a super luminescent diode (SLD). For example, an emission end of a light emitting element is applied to the emission unit 20e. For example, a gallium nitride (GaN)-based semiconductor laser that emits a 405 nm purple laser light as the excitation light L0 may be applied to this light emitting element.

[0038] If a laser is applied to the light source 20, the excitation light L0 from the light source 20 can be condensed by an optical system such as the first optical system 40 to reduce the diameter of the spot of the excitation light L0 irradiated to the wavelength conversion unit 32. This can reduce the emission of the fluorescence L1 from an unexpectedly wide area of ​​the first surface 32a of the wavelength conversion unit 32. This can reduce the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. This can reduce the conspicuousness of the lighting device 1 when emitting illumination light (when emitting light).

[0039] The light source 20 may further include a light-guiding member such as a fiber and a rod lens in addition to the light-emitting element. The fiber includes a linear core and a clad. The clad has a lower refractive index than the core and covers the core. The excitation light L0 can be transmitted through the core while being totally reflected at the boundary surface between the core and the clad. The rod lens has, for example, a columnar shape. The excitation light L0 can be transmitted through the inside of the rod lens while being totally reflected at the side of the rod lens. The incident end of the light-guiding member corresponds to a first end face located at the end of the longitudinal direction of the fiber, or a first end face located at the end of the rod lens. The exit end of the light-guiding member corresponds to a second end face on the opposite side to the first end face of the fiber, or a second end face on the opposite side to the first end face of the rod lens. The excitation light L0 from the light-emitting element is incident on the incident end of the light-guiding member, travels through the light-guiding member, and is emitted from the exit end of the light-guiding member. In this case, the exit section 20e of the light source 20 corresponds to the exit end of the light-guiding member.

[0040] The light source 20 may be attached to the housing 10 by, for example, a first attachment member 21. The first attachment member 21 may be, for example, a cylindrical member having a through hole along the first optical axis Ax1.

[0041] The illumination device 1 may include, for example, a second optical system 60. The second optical system 60 may be located between the light source 20 and the first optical system 40. In other words, the second optical system 60 may be capable of guiding the excitation light L0 from the light source 20 to the first optical system 40. The second optical system 60 includes, for example, one or more lenses 61. In the example of FIG. 1 and FIG. 2, the one or more lenses 61 include a third lens 61a and a fourth lens 61b each located on the first optical axis Ax1. The third lens 61a and the fourth lens 61b are arranged in the order described above in the −X direction as the first optical axis direction Dp1 along the first optical axis Ax1.

[0042] <1-3. 1st optical system> In the first embodiment, the one or more optical components 41 in the first optical system 40 include, for example, a wavelength separation filter 411 and one or more lenses 412.

[0043] <1-3-1. Wavelength separation filter> The excitation light L0 from the light source 20 is incident on the wavelength separation filter 411. The wavelength separation filter 411 guides the excitation light L0 from the light source 20 to the wavelength conversion unit 32. In addition, the wavelength separation filter 411 guides the fluorescence L1 emitted from the wavelength conversion unit 32 to the irradiation opening 10a.

[0044] In the example of FIG. 1 and FIG. 2, the light source 20, the wavelength separation filter 411, the first light shielding unit 50, and the wavelength conversion unit 32 are aligned along the −X direction as the first optical axis direction Dp1. In other words, the light source 20, the wavelength separation filter 411, the first light shielding unit 50, and the wavelength conversion unit 32 may be aligned along the −X direction as the first direction. The wavelength separation filter 411 and the irradiation opening 10a are aligned along the −Z direction as the second direction intersecting with the first direction. In this case, the wavelength separation filter 411 transmits the excitation light L0 from the light source 20 toward the wavelength conversion unit 32, and reflects the fluorescence L1 from the wavelength conversion unit 32 toward the irradiation opening 10a. According to this configuration, the size of the illumination device 1 in the −Z direction as the second direction can be reduced.

[0045] For example, a dichroic mirror (also called a dichroic film) is applied to the wavelength separation filter 411. As shown in FIG. 1, the wavelength separation filter 411 includes, for example, a base material 411b and a dielectric multilayer film 411f. For example, a transparent member containing one or more materials of glass and resin is applied to the base material 411b. For example, a flat shape is applied to the shape of the base material 411b. In the example of FIG. 1, the base material 411b has a first plate surface 4a and a second plate surface 4b. The first plate surface 4a is a surface of the base material 411b located on the light source 20 side. The second plate surface 4b is a surface of the base material 411b located on the opposite side to the first plate surface 4a. More specifically, the second plate surface 4b is a surface of the base material 411b located on the wavelength conversion unit 32 and the irradiation opening 10a side. The dielectric multilayer film 411f may be located on, for example, the second plate surface 4b. The dielectric multilayer film 411f may be located, for example, on the first surface 4a of the substrate 411b.

[0046] The dielectric multilayer film 411f has a structure in which, for example, thin dielectric films are repeatedly laminated. As the dielectric, for example, one or more materials selected from silicon oxide (SiO2), titanium oxide (TiO2), aluminum oxide (Al2O3), zirconium oxide (ZrO2), tantalum oxide (Ta2O5), and niobium oxide (Nb2O3) are adopted.

[0047] For example, by appropriately setting the thicknesses of the thin dielectric films constituting the dielectric multilayer film 411f, a spectral transmittance that transmits the excitation light L0 and reflects the fluorescence L1 in the dielectric multilayer film 411f can be realized. The transmittance of the wavelength separation filter 411 for the excitation light L0 may be, for example, 80% or more, 90% or more, or 95% or more. The reflectance of the wavelength separation filter 411 for the fluorescence L1 may be, for example, 80% or more, 90% or more, or 95% or more. When the wavelength at which the intensity of the fluorescence L1 is maximum (also referred to as the second peak wavelength) is greater than the wavelength at which the intensity of the excitation light L0 is maximum (the first peak wavelength), a short pass filter (SPF) may be applied to the wavelength separation filter 411. FIG. 10 is a graph that illustrates an example of the relationship between the wavelength of light and the transmittance of light in the wavelength separation filter 411 according to the first embodiment.

[0048] The angle α1 between the wavelength separation filter 411 and the first optical axis Ax1 is the angle between the second plate surface 4b of the base material 411b and a second optical axis Ax2 described later. In FIG. 1, an example of the angle α1 is shown by a thin arc-shaped arrow. In the example of FIG. 1, the angle α1 is set to about 45 degrees. Here, for example, when the second optical axis Ax2 described later and the third optical axis Ax3 described later are not perpendicular but intersect with each other, the angle α1 may be an angle other than 45 degrees.

[0049] <1-3-2. Imaging optical system consisting of one or more lenses> The one or more lenses 412 are located on the optical path of the fluorescence L1 from the wavelength conversion unit 32 to the irradiation opening 10a in the internal space 10is of the housing 10. The one or more lenses 412 may include, for example, one or more first lenses 4121 as one or more first optical components 41 located between the wavelength separation filter 411 and the wavelength conversion unit 32. The one or more lenses 412 may also include, for example, one or more second lenses 4122 as one or more second optical components 41 located between the wavelength separation filter 411 and the irradiation opening 10a. Each of the one or more lenses 412 may be made of, for example, one or more materials selected from glass and resin such as acrylic resin.

[0050] 1 and 2, the one or more first lenses 4121 located between the wavelength separation filter 411 and the wavelength conversion unit 32 include a 1A lens 4121A and a 1B lens 4121B. The 1A lens 4121A is located on the wavelength conversion unit 32 side with respect to the 1B lens 4121B. In FIGS. 1 to 3, an example of an optical axis (also referred to as a second optical axis) Ax2 of the 1A lens 4121A is typically shown by a thin dashed line.

[0051] 1 and 2, the one or more second lenses 4122 located between the wavelength separation filter 411 and the irradiation opening 10a include one second lens 4122. In FIG. 1 and FIG. 2, an example of an optical axis (also called a third optical axis) Ax3 of the second lens 4122 is shown typically by a thin dashed line. Here, a direction (also called a third optical axis direction) Dp3 along the third optical axis Ax3 may be a second direction in which the irradiation opening 10a emits the fluorescence L1. In the example of FIG. 1 and FIG. 2, the second direction and the third optical axis direction Dp3 are the -Z direction.

[0052] For example, the excitation light L0 from the light source 20 passes through the wavelength separation filter 411, then passes through the 1B lens 4121B and the 1A lens 4121A in this order, and enters the wavelength conversion unit 32. The 1B lens 4121B and the 1A lens 4121A focus the excitation light L0 that has passed through the wavelength separation filter 411 on the wavelength conversion unit 32. More specifically, for example, the 1B lens 4121B and the 1A lens 4121A focus the excitation light L0 that has passed through the wavelength separation filter 411 on the first region 32a1 of the first surface 32a of the wavelength conversion unit 32. Here, the 1B lens 4121B and the 1A lens 4121A may cause the excitation light L0 to be incident on the entire first region 32a1, or may cause the excitation light L0 to be incident on a part of the first region 32a1. For example, a convex lens is applied to each of the one or more first lenses 4121 such as the 1A lens 4121A and the 1B lens 4121B. The convex lens may be, for example, a biconvex lens or a plano-convex lens. In the example of FIG. 2, the excitation light L0 is transmitted through the 1B lens 4121B and the 1A lens 4121A in order, so that the degree of spread of the excitation light L0 is gradually reduced. In other words, the size of the cross section perpendicular to the second optical axis Ax2 of the excitation light L0 traveling from the wavelength separation filter 411 to the wavelength conversion unit 32 is gradually reduced.

[0053] The wavelength conversion unit 32 emits fluorescence L1 in response to the incident excitation light L0. More specifically, the first region 32a1 of the first surface 32a of the wavelength conversion unit 32 emits fluorescence L1 in response to the incident excitation light L0. This fluorescence L1 travels from the wavelength conversion unit 32 at a large spread angle, passes through the 1A lens 4121A and the 1B lens 4121B, and enters the wavelength separation filter 411. The 1A lens 4121A and the 1B lens 4121B transmit the fluorescence L1 toward the effective surface of the wavelength separation filter 411. The effective surface here refers to the range in which the filter function of the wavelength separation filter 411 can be realized.

[0054] In the example of FIG. 2, the fluorescence L1 is transmitted through the 1A lens 4121A and the 1B lens 4121B in order, so that the degree of spread of the fluorescence L1 is gradually reduced. In other words, the fluorescence L1 traveling from the wavelength conversion unit 32 to the wavelength separation filter 411 is gradually reduced in size of the cross section perpendicular to the second optical axis Ax2. For this reason, the spread angle of the fluorescence L1 from the wavelength conversion unit 32 is reduced by the 1A lens 4121A and the 1B lens 4121B. This allows more fluorescence L1 to be guided to the wavelength separation filter 411 without increasing the size of the wavelength separation filter 411. In other words, for example, by applying one or more first lenses 4121 as one or more lenses 412 to one or more optical components 41, the size of the cross section perpendicular to the second optical axis Ax2 of the fluorescence L1 can be easily reduced. This allows the size of the cross section of the housing 10 perpendicular to the traveling direction of the fluorescence L1 to be reduced. Therefore, the housing 10 and the lighting device 1 can be easily reduced in size.

[0055] Here, for example, the number of the one or more first lenses 4121 located between the wavelength separation filter 411 and the wavelength conversion unit 32 is not limited to two, and may be one, or three or more. In this case, each of the one or more first lenses 4121 may be, for example, a convex lens such as a biconvex lens or a plano-convex lens.

[0056] 2, the wavelength separation filter 411 reflects the fluorescence L1 toward the irradiation opening 10a. The fluorescence L1 from the wavelength separation filter 411 transmits through the second lens 4122, passes through the irradiation opening 10a, and is emitted into the illumination space S1.

[0057] The second lens 4122 may be, for example, a convex lens. This convex lens may be, for example, a biconvex lens or a plano-convex lens. The second lens 4122 collects the fluorescence L1 from the wavelength separation filter 411 on the side of the irradiation opening 10a. The number of the second lenses 4122 located between the wavelength separation filter 411 and the irradiation opening 10a is not limited to one, and may be two or more. In this case, each of the two or more second lenses 4122 may be, for example, a convex lens such as a biconvex lens or a plano-convex lens. In this case, for example, the second lens 4122 may not be located between the wavelength separation filter 411 and the irradiation opening 10a. In this case, for example, the third optical axis Ax3 may be located along a path along which a central ray of the optical path of the fluorescence L1 traveling from the first optical system 40 (specifically, the wavelength separation filter 411) to the irradiation opening 10a passes.

[0058] One or more lenses 412 in the first optical system 40 may be an imaging optical system that forms an image of the wavelength conversion unit 32 on a virtual image plane Is1. In the example of Fig. 1 and Fig. 2, this imaging optical system is configured by the 1A lens 4121A, the 1B lens 4121B, and the second lens 4122. The first surface 32a of the wavelength conversion unit 32 may have a conjugate relationship with the image plane Is1.

[0059] The image surface Is1 may be located at the irradiation opening 10a, for example. The image surface Is1 may be a flat surface or a curved surface. The fluorescence L1 is emitted to the illumination space S1 through the irradiation opening 10a while being collected at the image surface Is1. Here, for example, the image surface Is1 may not be located inside the irradiation opening 10a. The image surface Is1 may be located at the boundary between the internal space of the irradiation opening 10a and the internal space 10is of the housing 10, as shown in FIG. 2. Alternatively, the image surface Is1 may be located at a position slightly shifted from this boundary toward the internal space 10is of the housing 10. Alternatively, the image surface Is1 may be located at the boundary between the internal space of the irradiation opening 10a and the illumination space S1, or may be located at a position slightly shifted from this boundary toward the illumination space S1.

[0060] Here, for example, the size of the fluorescence L1 on the first surface 32a of the wavelength conversion unit 32 is the first size M1, the size of the fluorescence L1 on the image surface Is1 is the second size M2, and the size of the irradiation opening 10a is the third size M3. Each of the first size M1, the second size M2, and the third size M3 may be, for example, an area. In this illumination device 1, the imaging magnification of the imaging optical system formed by one or more lenses 412 may be set to be equal to or less than the value obtained by dividing the third size M3 by the first size M1. The first size M1 may be, for example, the size of a region of the first surface 32a of the wavelength conversion unit 32 that is irradiated with the excitation light L0. More specifically, for example, the first size M1 may be the size of a first region 32a1 of the first surface 32a of the wavelength conversion unit 32 that is irradiated with the excitation light L0. The third size M3 may be the minimum value of the area (also referred to as the aperture area) of the irradiation opening 10a when the irradiation opening 10a is viewed in a plan view in a direction (third optical axis direction) Dp3 along the third optical axis Ax3. The imaging magnification may be a value obtained by dividing the second size M2 by the first size M1. The aperture area of ​​the irradiation opening 10a may be the area of ​​the irradiation opening 10a along a virtual plane perpendicular to the third optical axis Ax3.

[0061] The magnitude of the fluorescence L1 is the peak value e in the light intensity distribution of the fluorescence L1 in a cross section perpendicular to the second optical axis Ax2 or the third optical axis Ax3. 2 The light rays at both outer edges of the fluorescence L1 shown in FIG. 2 and FIG. 3 may be defined by a contour line having a light amount equal to or smaller than the peak value e of the light amount distribution in a cross section perpendicular to the second optical axis Ax2 or the third optical axis Ax3. Here, "e" is called the Napier's number. In other words, the light rays at both outer edges of the fluorescence L1 shown in FIG. 2 and FIG. 3 may be defined by a contour line having a light amount equal to or smaller than the peak value e of the light amount distribution in a cross section perpendicular to the second optical axis Ax2 or the third optical axis Ax3. 2 The light in the area outside the area surrounded by the above contour lines (i.e., the light rays on both outer edges) may be regarded as noise light.

[0062] If the imaging magnification is equal to or less than the value obtained by dividing the third size M3 by the first size M1, the size (second size M2) of the fluorescence L1 on the image plane Is1 can be made equal to or less than the size (third size M3) of the irradiation opening 10a. This makes it possible to reduce the possibility that the fluorescence L1 enters the peripheral portion of the irradiation opening 10a of the housing 10. This makes it possible to reduce stray light, which is unnecessary reflected and scattered light that is generated by reflection of the fluorescence L1 on the inner surface of the housing 10 and leaks out from the irradiation opening 10a.

[0063] Furthermore, the imaging magnification of the imaging optical system formed by one or more lenses 412 may be set to a value such that the size of the fluorescence L1 passing through the irradiation opening 10a is smaller than the irradiation opening 10a. This makes it possible to further reduce stray light, which is unnecessary reflected and scattered light that is generated by reflection of the fluorescence L1 on the inner surface of the housing 10 and leaks out from the irradiation opening 10a.

[0064] In addition, here, for example, the spread angle of the fluorescence L1 from the wavelength conversion unit 32 toward the 1A lens 4121A is defined as the first spread angle θ1, and the spread angle of the fluorescence L1 in the illumination space S1 is defined as the second spread angle θ2. In FIG. 3, an example of the first spread angle θ1 is shown by a thin arc-shaped arrow. In FIG. 2, an example of the second spread angle θ2 is shown by a thin arc-shaped arrow. The first spread angle θ1 can be regarded as the spread angle of the fluorescence L1 immediately before the imaging optical system formed by one or more lenses 412, and the second spread angle θ2 can be regarded as the spread angle of the fluorescence L1 immediately after the image plane Is1. The imaging optical system formed by one or more lenses 412 may be designed under the condition that the second spread angle θ2 is smaller than the first spread angle θ1. As a specific example of the second spread angle θ2, the orientation angle (for example, half-value angle) of the fluorescence L1 in the illumination space S1 is about 60 degrees or less. The orientation angle of the lighting device 1 may be, for example, less than 45 degrees, less than 30 degrees, or less than 15 degrees. This reduces the glare of the lighting devices 1 in the field of view in the lighting space S1, for example, when multiple lighting devices 1 are positioned at regular intervals in the lighting space S1. As a result, the comfort of the lighting space S1 can be increased.

[0065] <1-3-3. Further details on the imaging optical system consisting of one or more lenses> Next, examples of the 1A lens 4121A and the 1B lens 4121B will be described in more detail. As shown in FIG. 1 and FIG. 2, the refractive power of the 1A lens 4121A, which is located closest to the wavelength conversion unit 32 among the one or more lenses 412, may be greater than the refractive power of the 1B lens 4121B and the refractive power of the second lens 4122. This allows the 1A lens 4121A to significantly reduce the degree of spread of the fluorescence L1 at the position closest to the wavelength conversion unit 32. In the example of FIG. 2 and FIG. 3, although the fluorescence L1 immediately after the 1A lens 4121A spreads as it advances toward the 1B lens 4121B, the spread angle is significantly smaller than the spread angle θ1 of the fluorescence L1 incident on the 1A lens 4121A. For this reason, the size of the 1B lens 4121B in the direction perpendicular to the second optical axis Ax2 (also referred to as the first width direction) can be reduced. In other words, even if the size of the 1B lens 4121B is reduced, the fluorescence L1 from the 1A lens 4121A can be made to be appropriately incident on the 1B lens 4121B. As a result, the size of the illumination device 1 in the first width direction can be reduced. In other words, the size of the illumination device 1 in the -Z direction as the second direction can be reduced.

[0066] As shown in FIG. 1 and FIG. 2, the 1A lens 4121A has a first lens surface 412a and a second lens surface 412b. The 1B lens 4121B has a third lens surface 412c and a fourth lens surface 412d. The first lens surface 412a is a surface of the 1A lens 4121A on the wavelength conversion unit 32 side. The second lens surface 412b is a surface of the 1A lens 4121A on the wavelength separation filter 411 side. The third lens surface 412c is a surface of the 1B lens 4121B on the wavelength conversion unit 32 side. The fourth lens surface 412d is a surface of the 1B lens 4121B on the wavelength separation filter 411 side.

[0067] As shown in FIG. 1 and FIG. 2, in the 1A lens 4121A, the first lens surface 412a may be curved in a form convex toward the wavelength conversion unit 32 side, and the second lens surface 412b may be curved in a form convex toward the wavelength separation filter 411 side. Each of the first lens surface 412a and the second lens surface 412b of the 1A lens 4121A may be a curved surface without a step. In other words, the 1A lens 4121A may not be a Fresnel lens. This can reduce scattering or reflection of light in the 1A lens 4121A. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, according to the lighting device 1, the conspicuousness of the lighting device 1 when emitting illumination light (when emitting light) can be reduced.

[0068] Also, as shown in FIG. 1 and FIG. 2, the curvature of the first lens surface 412a of the 1A lens 4121A may be smaller than the curvature of the second lens surface 412b. In other words, the first lens surface 412a may be flatter than the second lens surface 412b. This allows a wider range of the fluorescence L1 from the wavelength conversion unit 32 to be incident on the first lens surface 412a of the 1A lens 4121A. In other words, the proportion of the fluorescence L1 incident on the first lens surface 412a of the 1A lens 4121A out of the entire fluorescence L1 emitted by the wavelength conversion unit 32 can be increased, and thus the proportion of the fluorescence L1 emitted from the irradiation opening 10a can be increased. Therefore, the illumination device 1 can emit the fluorescence L1 to the illumination space S1 with higher efficiency.

[0069] Conversely, the curvature of second lens surface 412b of 1A lens 4121A may be larger than the curvature of first lens surface 412a. If the curvature of second lens surface 412b is larger, the refractive power of 1A lens 4121A can be improved. Therefore, 1A lens 4121A can significantly reduce the spread angle of fluorescence L1. As a result, the size of illumination device 1 in the first width direction can be reduced.

[0070] As shown in FIG. 1 and FIG. 2, in the 1B lens 4121B, the third lens surface 412c may be curved in a form convex toward the wavelength conversion unit 32 side, and the fourth lens surface 412d may be curved in a form convex toward the wavelength separation filter 411 side. Each of the third lens surface 412c and the fourth lens surface 412d of the 1B lens 4121B may be a curved surface without a step. In other words, the 1B lens 4121B may not be a Fresnel lens. This can reduce scattering or reflection of light in the 1B lens 4121B. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, according to the lighting device 1, the conspicuousness of the lighting device 1 when emitting illumination light (when emitting light) can be reduced.

[0071] Also, the curvature of the first lens surface 412a of the 1A lens 4121A may be smaller than the curvatures of both the third lens surface 412c and the fourth lens surface 412d of the 1B lens 4121B. Also, the curvature of the second lens surface 412b of the 1A lens 4121A may be larger than the curvatures of both the third lens surface 412c and the fourth lens surface 412d of the 1B lens 4121B.

[0072] When three or more first lenses 4121 are arranged, the refractive power of the first lens 4121 closest to the wavelength conversion section 32 may be the largest. This allows the first lens 4121 closest to the wavelength conversion section 32 to significantly reduce the spread angle of the fluorescence L1. As a result, the size of the illumination device 1 in the first width direction can be effectively reduced.

[0073] 1 and 2, when the refractive power of the first-A lens 4121A is large, for example, the curvature of the second lens surface 412b of the first-A lens 4121A is very large. If the size of the first-A lens 4121A having the second lens surface 412b with such a large curvature in the first width direction is increased, it becomes difficult to manufacture the first-A lens 4121A. In addition, the size of the first-A lens 4121A along the second optical axis Ax2 also increases, leading to an increase in the size of the lighting device 1.

[0074] 1 and 2, the size of the 1A lens 4121A may be smaller than that of the 1B lens 4121B. In other words, when viewed in a planar perspective view in a direction (also referred to as the second optical axis direction) Dp2 along the second optical axis Ax2, the area of ​​the 1A lens 4121A may be smaller than that of the 1B lens 4121B. This can facilitate the manufacture of the 1A lens 4121A and reduce the size of the illumination device 1 in the second optical axis direction Dp2. In the example of FIG. 1 and FIG. 2, the second optical axis direction Dp2 is the +X direction.

[0075] 1 and 2, the second lens 4122 has a fifth lens surface 412e and a sixth lens surface 412f. The fifth lens surface 412e is a surface of the second lens 4122 on the wavelength separation filter 411 side. The sixth lens surface 412f is a surface of the second lens 4122 on the irradiation opening 10a side. The fifth lens surface 412e may be curved in a form that is convex toward the wavelength separation filter 411 side. The sixth lens surface 412f may be curved in a form that is convex toward the irradiation opening 10a side. Each of the fifth lens surface 412e and the sixth lens surface 412f of the second lens 4122 may be a curved surface that does not have a step. In other words, the second lens 4122 may not be a Fresnel lens. This can reduce scattering or reflection of light in the second lens 4122. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, the lighting device 1 can reduce the conspicuousness of the lighting device 1 when emitting illumination light (during light emission). In the second lens 4122, the curvature of the fifth lens surface 412e may be smaller than the curvature of the sixth lens surface 412f.

[0076] <1-4. Wavelength conversion section> The wavelength converter 32 may be exposed to the internal space 10is of the housing 10 at least in the first region 32a1 of the first surface 32a. Here, the state of being exposed to the internal space 10is includes a state in which light from the internal space 10is can be irradiated.

[0077] The wavelength conversion unit 32 includes a phosphor. For example, a wavelength at which the intensity of the fluorescence L1 is maximized is greater than a first peak wavelength of the excitation light L0. The fluorescence L1 may be visible light. The wavelength conversion unit 32 has, for example, a plate-like or film-like shape. The thickness direction of the wavelength conversion unit 32 may be set in, for example, a second optical axis direction Dp2 along the second optical axis Ax2. The wavelength conversion unit 32 may be located in, for example, the internal space 10is of the housing 10.

[0078] The wavelength conversion unit 32 is made of a wavelength conversion material (also called a fluorescent material) that converts the excitation light L0 into blue light. For example, BaMgAl 10 O 17 :Eu, (Sr,Ca,Ba) 10 (PO4)6Cl2:Eu or (Sr,Ba) 10 The wavelength conversion unit 32 may contain, for example, (Sr,Ba,Ca)5(PO4)3Cl:Eu or Sr4Al as a wavelength conversion material that converts the excitation light L0 into blue-green light. 14 O 25 The wavelength conversion unit 32 may contain, for example, SrSi2(O,Cl)2N2:Eu, (Sr,Ba,Mg)2SiO4:Eu, etc. as a wavelength conversion material that converts the excitation light L0 into green light. 2+ , ZnS:Cu,Al, or Zn2SiO4:Mn. The wavelength conversion unit 32 may include, as a wavelength conversion material for converting the excitation light L0 into red light, for example, Y2O2S:Eu, Y2O3:Eu, SrCaClAlSiN3:Eu. 2+ , CaAlSiN3:Eu, CaAlSi(ON)3:Eu, or the like. The wavelength conversion unit 32 may contain 3Ga5O 12:Cr, etc. If the wavelength conversion section 32 contains multiple types of wavelength conversion materials corresponding to multiple colors of light, the wavelength conversion section 32 can emit fluorescence L1 with high color rendering. Specifically, if the excitation light L0 is light having a first peak wavelength in the range of 380 nm to 415 nm and the wavelength conversion section 32 has phosphors corresponding to the three colors of light, red, green, and blue, the color rendering of the fluorescence L1 can be improved.

[0079] Furthermore, the wavelength conversion section 32 may include, for example, a binder that bonds the multiple phosphor particles together. The binder material may be, for example, a resin or a glass such as a low-melting point glass. The low-melting point glass may be, for example, an oxide glass having a melting point (Tm) of 200 degrees Celsius (200°C) to 700°C. This oxide glass has, for example, a glass transition point (Tg) in the range of 100°C to 600°C and a crystallization temperature (Tc) in the range of 150°C to 650°C. As the oxide glass, for example, a glass containing two or more oxides selected from silicon dioxide (SiO2), aluminum oxide (Al2O3), boron oxide (B2O3), sodium oxide (Na2O3), potassium oxide (K2O), lithium oxide (Li2O), calcium oxide (CaO), barium oxide (BaO), zinc oxide (ZnO), lead monoxide (PbO), and diphosphorus pentoxide (P2O5) as a main component may be used. In other words, the oxide glass may contain an oxide of a metal element or an oxide of a metalloid element.

[0080] The fluorescence L1 from the wavelength conversion unit 32 advances toward the first lens 4121 while spreading. For this reason, when the 1A lens 4121A and the wavelength conversion unit 32 are seen through in a plan view in the second optical axis direction Dp2 along the second optical axis Ax2, the size of the first region 32a1 of the wavelength conversion unit 32 may be set to be smaller than the size of the 1A lens 4121A. In other words, when the 1A lens 4121A and the wavelength conversion unit 32 are seen through in a plan view in the second optical axis direction Dp2 along the second optical axis Ax2, the size of the 1A lens 4121A may be set to be larger than the size of the first region 32a1 of the wavelength conversion unit 32. When the first region 32a1 of the wavelength conversion unit 32 has a circular shape centered on the second optical axis Ax2, the diameter of the first region 32a1 of the wavelength conversion unit 32 may be smaller than the diameter of the 1A lens 4121A. For example, the diameter of the first region 32a1 of the wavelength converting unit 32 may be set to, for example, about 1 mm to 4 mm. When the first region 32a1 of the wavelength converting unit 32 has a rectangular shape, the length of the diagonal line of the first region 32a1 of the wavelength converting unit 32 may be set to, for example, about 1 mm to 4 mm. The diameter of the 1A lens 4121A may be set to, for example, about 4 mm to 15 mm.

[0081] According to this structure, a wider range of the fluorescence L1 from the wavelength conversion unit 32 can be made incident on the 1A lens 4121A. As shown in FIG. 1 and FIG. 2, the distance between the wavelength conversion unit 32 and the 1A lens 4121A may be smaller than the distance between the 1A lens 4121A and the 1B lens 4121B. For example, the distance between the wavelength conversion unit 32 and the 1A lens 4121A may be set to about 1 mm or less, and the distance between the 1A lens 4121A and the 1B lens 4121B may be set to about 2 mm or more. By reducing the distance between the wavelength conversion unit 32 and the 1A lens 4121A, a larger portion of the fluorescence L1 emitted by the wavelength conversion unit 32 can be made incident on the 1A lens 4121A.

[0082] The wavelength conversion unit 32 may be, for example, a film-like or plate-like portion located on one surface of the substrate 31. In this case, the substrate 31 has a function as a holder that holds the wavelength conversion unit 32. The substrate 31 may hold the wavelength conversion unit 32 from the opposite side of the first optical system 40. For example, a plate-like member is applied to the substrate 31. The thickness direction of the substrate 31 may be located along the second optical axis direction Dp2. The substrate 31 and the wavelength conversion unit 32 may, for example, constitute an integrated member (also called a wavelength conversion member) 30. In other words, the illumination device 1 may include, for example, the wavelength conversion member 30. In the example of FIG. 1 to FIG. 3, the substrate 31 has a plate surface on which the wavelength conversion unit 32 is attached.

[0083] The material of the substrate 31 may be, for example, a metal material or other inorganic material such as ceramics. The wavelength conversion member 30 may be formed by adhering the wavelength conversion section 32 onto the substrate 31. The wavelength conversion section 32 may be produced, for example, by disposing a mixture (also called mixed powder) obtained by mixing a powder of fine particles of a phosphor (also called phosphor powder) and a powder of low-melting point glass (also called low-melting point glass powder) on the substrate 31, and applying pressure and heat to the mixed powder to sinter the low-melting point glass powder. Alternatively, for example, a slurry as a liquid mixture obtained by mixing a phosphor powder, a low-melting point glass powder, and a liquid such as water or an organic solvent may be applied onto the substrate 31, and the slurry may be applied with pressure and heat to produce the wavelength conversion section 32. The wavelength conversion section 32 has a structure having a spread on the plate surface of the substrate 31 on the first optical system 40 side. The wavelength converting sections 32 may be located over almost the entire surface of the substrate 31 facing the first optical system 40, or may be located only in a portion of the surface. A layer including portions corresponding to the wavelength converting sections 32 may be formed on a substrate made of an inorganic material, and then the substrate made of an inorganic material may be divided into small pieces to produce a plurality of wavelength converting members 30. The substrate 31 may have, for example, a recess filled with the wavelength converting sections 32.

[0084] Here, for example, if the material of the substrate 31 has a higher thermal conductivity than the wavelength conversion unit 32, the substrate 31 can increase the rate at which heat dissipates from the wavelength conversion unit 32. This can reduce quenching (also called thermal quenching) in which the intensity of the fluorescence L1 emitted from the wavelength conversion unit 32 decreases as the temperature of the wavelength conversion unit 32 increases. In addition, the degree to which the wavelength conversion unit 32 deteriorates due to heat can be reduced. For example, a metal material with high thermal conductivity is used as the material of the substrate 31. For example, copper (Cu), aluminum (Al), magnesium (Mg), gold (Au), silver (Ag), iron (Fe), chromium (Cr), cobalt (Co), beryllium (Be), molybdenum (Mo), tungsten (W), or an alloy is used as the metal material.

[0085] Furthermore, the surface of the substrate 31 may have a characteristic of reflecting the excitation light L0 (also referred to as reflectivity). For example, the reflectance of the excitation light L0 on the surface of the substrate 31 may be 60% or more, 80% or more, or 90% or more. In this case, the excitation light L0 transmitted through the wavelength conversion unit 32 is reflected by the surface of the substrate 31 and enters the wavelength conversion unit 32 again. This may increase the amount of fluorescence L1 emitted by the wavelength conversion unit 32. Here, for example, if the metal material of the substrate 31 is Al, Mg, Ag, Fe, Cr, or Co, the reflectance of visible light on the surface of the substrate 31 increases, and the amount of fluorescence L1 emitted by the wavelength conversion unit 32 in response to the excitation light L0 may increase.

[0086] As shown in FIGS. 1 to 4, for example, the wavelength conversion member 30 may be attached to the housing 10 by a second attachment member 70 or the like.

[0087] <1-5. First light-shielding part> In the first embodiment, the first light-shielding unit 50 is located on the optical path of the excitation light L0 traveling from the light source 20 to the wavelength conversion unit 32. Here, for example, it is assumed that the excitation light L0 is a Gaussian beam having a Gaussian distribution of light intensity in a direction perpendicular to the light traveling direction (also referred to as the radial direction). In this case, for example, the first light-shielding unit 50 can reduce irradiation of the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 with a weak light intensity portion in the radial outer periphery of the excitation light L0. Therefore, the emission of the fluorescence L1 from the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 toward the first optical system 40 can be reduced. In other words, the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32 can be reduced. This can reduce the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, according to the lighting device 1 of the first embodiment, in a space different from the original target space to which the illumination light is to be projected, the amount of stray light irradiated from the lighting device 1 is reduced, and the conspicuousness of the lighting device 1 can be reduced. In other words, according to the lighting device 1 of the first embodiment, the conspicuousness of the lighting device 1 when emitting the illumination light (when emitting light) can be reduced.

[0088] The first light-shielding part 50 may have, for example, a plate-like, film-like, or foil-like form. The first light-shielding part 50 has, for example, a surface (also referred to as a front surface or a second surface) 50f located on the first optical system 40 side, and a surface (also referred to as a back surface or a third surface) 50b located on the second region 32a2 side of the wavelength conversion part 32.

[0089] The first light-shielding portion 50 may be located in a state of contact with the first surface 32a of the wavelength conversion portion 32, or in a state of being close to the first surface 32a of the wavelength conversion portion 32. More specifically, for example, the third surface 50b of the first light-shielding portion 50 may be in contact with the second region 32a2 of the first surface 32a of the wavelength conversion portion 32, or in a state of being close to the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. Here, the state in which the third surface 50b and the second region 32a2 are close to each other includes, for example, a state in which the distance between the third surface 50b and the second region 32a2 is several hundred μm or less. The first light-shielding portion 50 may be located in the internal space 10is of the housing 10, for example.

[0090] When the first surface 32a and the first light-shielding portion 50 are viewed in a plane along a direction perpendicular to the first surface 32a, the shape of the first through hole 50h may be, for example, circular, elliptical, or another shape such as a shape including a notch.

[0091] The first light-shielding part 50 may have a film-like or foil-like form having a thickness of, for example, 50 micrometers (μm) to several hundred μm. In this case, the first light-shielding part 50 can reduce a decrease in the magnitude of the spread angle (first spread angle θ1) of the fluorescence L1 traveling from the wavelength converting part 32 toward the 1A lens 4121A.

[0092] The first light-shielding part 50 may include, for example, a metal film, a metal foil, or a metal plate-shaped member. In this case, the thermal conductivity of the first light-shielding part 50 is high, and the speed at which heat dissipates from the wavelength conversion part 32 can be increased. This can reduce thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion part 32 decreases as the temperature of the wavelength conversion part 32 increases. In addition, the degree to which the wavelength conversion part 32 deteriorates due to heat can be reduced. For example, metals such as stainless steel and aluminum can be used as the material of the first light-shielding part 50.

[0093] Here, for example, the first light-shielding unit 50 may have metal exposed on the third surface 50b. In this case, for example, the rate at which heat dissipates from the wavelength conversion unit 32 to the first light-shielding unit 50 can be increased. This can reduce thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion unit 32 decreases as the temperature of the wavelength conversion unit 32 increases. In addition, the degree to which the wavelength conversion unit 32 deteriorates due to heat can be reduced. Furthermore, for example, when the excitation light L0 from the light source 20 is incident on the wavelength conversion unit 32, the excitation light L0 traveling from the wavelength conversion unit 32 toward the first light-shielding unit 50 can be reflected toward the inside of the wavelength conversion unit 32 by the third surface 50b of the first light-shielding unit 50. This can increase the ratio of the excitation light L0 converted into the fluorescence L1 among the excitation light L0 irradiated to the wavelength conversion unit 32. As a result, the luminous efficiency of the lighting device 1 can be increased.

[0094] Furthermore, the second surface 50f of the first light-shielding portion 50 may be, for example, a black surface. In this case, reflection of the fluorescence L1 reflected by the first lens surface 412a of the 1A lens 4121A as one or more optical components 41, by the surface of the first light-shielding portion 50 is reduced. This can reduce the generation of stray light that may be caused by reflection of the fluorescence L1 by the inner surface of the housing 10.

[0095] The second surface 50f can be made black by, for example, blackening treatment. The blackening treatment may be performed on the surface of a metal foil or a metal plate-like member serving as the film-like or plate-like substrate of the first light-shielding unit 50. The blackening treatment may be a chemical conversion treatment, a plating treatment, a coating treatment, or a painting treatment. The blackening treatment may be a matte blackening treatment or a glossy blackening treatment. More specifically, the blackening treatment may be, for example, a black chromate treatment, a black electroless nickel plating treatment, a treatment for forming a black oxide film, or a black anodizing treatment.

[0096] The black chromate treatment is, for example, a chemical conversion treatment performed as a post-treatment on zinc plating. The black chromate treatment includes a chromate treatment using hexavalent chromium (also called hexavalent black chromate treatment) and a chromate treatment using trivalent chromium (also called trivalent black chromate treatment). The hexavalent black chromate treatment may be, for example, a treatment that creates a black appearance by including silver ions in the components of the chromium chemical conversion coating (chromate). The trivalent black chromate treatment may be, for example, a treatment that creates a black appearance by including cobalt or sulfur in the components other than the trivalent chromium in the chromium chemical conversion coating (chromate).

[0097] The black electroless nickel plating treatment may be, for example, a treatment in which an electroless nickel plating film is formed and then this film is roughened with a blackening treatment solution.

[0098] The treatment for forming a black iron oxide film may be, for example, a treatment for forming a black coating of black iron oxide (Fe3O4) on the surface of steel.

[0099] Black anodizing can be used when the material of the film-like or plate-like base material of the first light-shielding portion 50 is aluminum. Black anodizing may be, for example, a process in which a black dye or pigment is adsorbed into holes formed on the surface of the oxide film after anodizing, which is a process in which oxygen is bonded to the aluminum surface by performing an electrolytic process using aluminum as the anode, to create a highly durable oxide film.

[0100] The blackening treatment using painting may be, for example, a treatment of painting a paint having heat resistance against heat generated when the wavelength conversion unit 32 emits light. For example, a paint having heat resistance may be applied in which graphite fine powder is mixed into a silicone resin paint having a heat resistance temperature of about 400°C. Silicone resin has a three-dimensionally cross-linked siloxane skeleton. Among silicone resins, silicones with relatively low molecular weights are called silicone oligomers. Here, silicone oligomers having alkoxysilyl groups as reactive functional groups may be used as the base material for silicone resin paint. The silicone resin coating film may be hardened by a dealcoholization condensation reaction caused by the humidity in the air using a catalyst.

[0101] The first light-shielding portion 50 may be in contact with, for example, the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. In this case, the excitation light L0 irradiated to the second region 32a2 of the first surface 32a of the wavelength conversion portion 32 through the gap between the first surface 32a of the wavelength conversion portion 32 and the first light-shielding portion 50 may be reduced. Then, the emission of the fluorescence L1 from the second region 32a2 may be reduced. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 may be reduced. Therefore, the conspicuousness of the lighting device 1 during emission may be reduced.

[0102] The first light-shielding portion 50 may be attached to the wavelength conversion member 30 and the housing 10 by, for example, the second mounting member 70. For example, the first light-shielding portion 50 may be sandwiched between the wavelength conversion member 30 and the second mounting member 70. For example, the wavelength conversion member 30 and the first light-shielding portion 50 may be attached to a lid portion 12 (described later) as a part of the housing 10 by the second mounting member 70 to form the first member 100. In the example of FIG. 1 to FIG. 5, the first light-shielding portion 50 is sandwiched between the first surface 32a of the wavelength conversion portion 32 of the wavelength conversion member 30 and the second mounting member 70. According to this configuration, the heat resistance of the first light-shielding portion 50 can be improved compared to a configuration in which the first light-shielding portion 50 is fixed to the wavelength conversion member 30 using an adhesive.

[0103] <1-6. Cabinet> Next, a specific example of the housing 10 will be described. As shown in Fig. 1 and Fig. 2, the housing 10 may include, for example, a main body 11, a cover 12, and a frame 13. In the example of Fig. 1 and Fig. 2, the main body 11 houses the first optical system 40. If, for example, an aluminum alloy is used as the material of the main body 11, the weight of the lighting device 1 can be reduced and the rigidity can be improved. The material of the main body 11 is not limited to an aluminum alloy, and may be, for example, another material such as a synthetic resin.

[0104] As shown in FIGS. 1 and 2, the body portion 11 may include a sidewall portion 111 and an opening portion 112 .

[0105] In the example of FIG. 1 and FIG. 2, the side wall portion 111 has, for example, a cylindrical shape. The side wall portion 111 has, for example, a cylindrical shape bent into an L-shape. More specifically, the side wall portion 111 has a shape in which a portion having a hollow space (also referred to as a first hollow space) 1sp penetrating along the -X direction as the first optical axis direction Dp1 and the +X direction as the second optical axis direction Dp2, and a portion having a hollow space (also referred to as a second hollow space) 2sp penetrating along the -Z direction as the third optical axis direction Dp3 are connected. In other words, the side wall portion 111 has a longitudinal direction bent into an L-shape. The side wall portion 111 has a first end E1 and a second end E2 at both ends of the longitudinal direction. More specifically, the first end E1 is located at the end of the side wall portion 111 on the -Z direction side as the third optical axis direction Dp3. The second end E2 is located at the end of the side wall portion 111 on the -X direction side as the first optical axis direction. The side wall portion 111 may be a single piece, or may be a composite member in which a plurality of members are combined.

[0106] Inside the side wall portion 111, the 1A lens 4121A, the 1B lens 4121B, and the wavelength separation filter 411 are positioned in this order in the +X direction as the second optical axis direction Dp2. Also, inside the side wall portion 111, the wavelength separation filter 411 and the second lens 4122 are positioned in this order in the -Z direction as the third optical axis direction Dp3.

[0107] The opening portion 112 has, for example, a plate-like shape. The thickness direction of the opening portion 112 may be along the second optical axis direction Dp2. The periphery of the opening portion 112 may be connected to the edge of the side wall portion 111 on the second end E2 side. The opening portion 112 has a second opening 11b. The second opening 11b may penetrate the opening portion 112 along the second optical axis direction Dp2. For example, the second optical axis Ax2 may be inserted through the second opening 11b. The second opening 11b may be located, for example, in approximately the center of the opening portion 112.

[0108] The lid portion 12 may be attached to the opening portion 112 in a state where the second opening 11b of the opening portion 112 is closed. The lid portion 12 has, for example, a plate-like shape. The thickness direction of the lid portion 12 may be a direction along the second optical axis direction Dp2. As shown in FIG. 1 and FIG. 2, the lid portion 12 may be attached to a surface 112a of the opening portion 112 on the opposite side to the first optical system 40. The lid portion 12 may be attached to the opening portion 112 by, for example, any attachment method. For example, the lid portion 12 may be attached to the opening portion 112 by fixing with a fixing agent such as an adhesive or by screwing at multiple points. The multiple points may be any number of points, for example, three or more points. Since the lid portion 12 is attached to the opening portion 112, it can also be said to be an attachment member.

[0109] As shown in Fig. 3, the lid portion 12 may have a first surface 12a, a second surface 12b, and a side surface 12c. The second surface 12b is a surface of the lid portion 12 on the opening portion 112 side. A part of the outer circumferential side of the second surface 12b of the lid portion 12 may be in contact with the surface 112a of the opening portion 112 while facing the surface 112a in the second optical axis direction Dp2. The first surface 12a is a surface of the lid portion 12 on the opposite side to the second surface 12b. The side surface 12c is a side surface that connects the periphery of the first surface 12a and the periphery of the second surface 12b of the lid portion 12.

[0110] As shown in FIG. 1 to FIG. 3, the wavelength conversion member 30 may be located on the second surface 12b of the lid portion 12. Here, for example, if the material of the lid portion 12 is a material having a higher thermal conductivity than the wavelength conversion portion 32, the speed at which heat dissipates from the wavelength conversion portion 32 by the lid portion 12 can be increased. In other words, the lid portion 12 can function as a so-called heat sink. This can reduce thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion portion 32 decreases as the temperature of the wavelength conversion portion 32 increases. In addition, the degree to which the wavelength conversion portion 32 deteriorates due to heat can be reduced. For example, a metal material having a high thermal conductivity is applied to the material of the lid portion 12. For example, Cu, Al, Mg, Au, Ag, Fe, Cr, Co, Be, Mo, W, or an alloy is applied to this metal material. Here, for example, the material of the lid portion 12 and the material of the substrate 31 may be the same or different.

[0111] The wavelength conversion member 30 may be located, for example, on a region of the second surface 12b of the lid portion 12 that faces the second opening 11b of the opening portion 112 in the second optical axis direction Dp2. As shown in FIG. 1 to FIG. 3, the second surface 12b of the lid portion 12 may have a first recess 12d1 in which the wavelength conversion member 30 is located. The first recess 12d1 may have, for example, a shape in which the wavelength conversion member 30 fits. When the wavelength conversion portion 32 and the opening portion 112 are seen through in a plan view in a direction along the second optical axis Ax2, the area of ​​the wavelength conversion portion 32 may be smaller or larger than the minimum value of the area of ​​the second opening 11b of the opening portion 112 (also referred to as the opening area). The opening area of ​​the second opening 11b may be the area of ​​the second opening 11b along a virtual plane perpendicular to the second optical axis Ax2.

[0112] The wavelength conversion member 30 may be attached to the lid portion 12 by, for example, a second attachment member 70. The lid portion 12 can function as a support that supports the wavelength conversion member 30.

[0113] In the example of FIG. 1 to FIG. 5, the wavelength conversion member 30 is located in the first recess 12d1 of the lid portion 12. The first light-shielding portion 50 and the second mounting member 70 are located on the first surface 32a of the wavelength conversion portion 32 of the wavelength conversion member 30 in a state where they are stacked in the described order in the +X direction as the second optical axis direction Dp2. The second mounting member 70 may be, for example, a plate-shaped member having a through hole 70h penetrating in the second optical axis direction Dp2. The thickness direction of the second mounting member 70 may be set, for example, in the second optical axis direction Dp2 along the second optical axis Ax2. The material of the second mounting member 70 may be, for example, a metal such as stainless steel. The second mounting member 70 may have, for example, a rigidity capable of fixing the wavelength conversion member 30 and the first light-shielding portion 50 to the lid portion 12. The thickness of the second mounting member 70 may be, for example, about 0.5 mm to 2 mm.

[0114] The surface of the second mounting member 70 may be subjected to a blackening treatment. The second mounting member 70 may have a circular outer shape when viewed in a plane in a direction along the second optical axis Ax2, as shown in FIG. 5, for example. This outer shape is not limited to a circular shape, and may be any shape such as an elliptical shape, a rectangular shape, or a polygonal shape. The through-hole 70h may have a circular shape when viewed in a plane in a direction along the second optical axis Ax2, or may have any shape such as an elliptical shape, a rectangular shape, or a polygonal shape.

[0115] As shown in FIG. 5, when the through hole 70h and the first light-shielding part 50 are viewed in a plane in a direction along the second optical axis Ax2, the first through hole 50h of the first light-shielding part 50 may be located within the through hole 70h. The second optical axis Ax2 may pass through the through hole 70h, or may pass through the center of the through hole 70h. The center of the through hole 70h may be, for example, the center of gravity of a cross section of the through hole 70h perpendicular to the second optical axis Ax2. The second optical axis Ax2 may pass through the first through hole 50h, or may pass through the center of the first through hole 50h. The center of the first through hole 50h may be, for example, the center of gravity of a cross section of the first through hole 50h perpendicular to the second optical axis Ax2. When the through hole 70h and the first light-shielding part 50 are viewed in a plane in a direction along the second optical axis Ax2, the area of ​​the first through hole 50h is smaller than the area of ​​the through hole 70h. Here, the area of ​​the through hole 70h may be, for example, several times to several tens of times the area of ​​the first through hole 50h.

[0116] The second mounting member 70 may be attached to the second surface 12b of the lid portion 12 by, for example, any mounting method. For example, the second mounting member 70 may be attached to the second surface 12b of the lid portion 12 by screw fastening or the like at multiple locations. The multiple locations may be any number of locations, for example, three or more locations.

[0117] As shown in FIG. 1 to FIG. 3, the second surface 12b of the lid portion 12 may have a second recess 12d2 in which the second mounting member 70 is located. Here, the first recess 12d1 may be located in the second recess 12d2. The second recess 12d2 may have a shape in which the second mounting member 70 fits, for example. The second mounting member 70 may sandwich the wavelength conversion member 30 and the first light shielding portion 50 with the lid portion 12. More specifically, the second mounting member 70 and the lid portion 12 may sandwich a portion of the wavelength conversion member 30 along the outer periphery and a portion of the first light shielding portion 50 along the outer periphery. The outer periphery of the wavelength conversion member 30 may be a portion of the outer periphery of the wavelength conversion member 30 centered on the second optical axis Ax2. The outer periphery of the first light shielding portion 50 may be a portion of the outer periphery of the first light shielding portion 50 centered on the second optical axis Ax2. Here, for example, when viewed in a planar view along the second optical axis Ax2, if the shape of the outer edge of the first shading portion 50 is approximately the same as the shape of the outer edge of the second mounting member 70, it may be easier to align the first shading portion 50 with the second mounting member 70.

[0118] When the second opening 11b of the opening portion 112 and the first surface 32a of the wavelength conversion portion 32 are viewed in a plane along the second optical axis Ax2, the first region 32a1 of the first surface 32a may be located within the second opening 11b. The first region 32a1 may be located on the second optical axis Ax2. The second optical axis Ax2 may pass through the center of the first region 32a1. The center of the first region 32a1 may be, for example, the center of gravity of the first region 32a1. Here, for example, when the second opening 11b of the opening portion 112 and the first surface 32a of the wavelength conversion portion 32 are viewed in a plane along the second optical axis Ax2, the area of ​​the first region 32a1 may be smaller than the minimum value of the area (opening area) of the second opening 11b of the opening portion 112.

[0119] From another perspective, when the second opening 11b of the opening portion 112 and the first light-shielding portion 50 are viewed in a plane in a direction along the second optical axis Ax2, the first through hole 50h of the first light-shielding portion 50 may be located within the second opening 11b. Here, for example, when the second opening 11b of the opening portion 112 and the first light-shielding portion 50 are viewed in a plane in a direction along the second optical axis Ax2, the area of ​​the first through hole 50h may be smaller than the minimum value of the area (opening area) of the second opening 11b of the opening portion 112.

[0120] According to this configuration, a larger portion of the fluorescence L1 that spreads and travels from the first region 32a1 of the wavelength converting unit 32 can pass through the second opening 11b. The first surface 32a of the wavelength converting unit 32 may be located outside the second opening 11b of the opening portion 112, may be located inside the second opening 11b of the opening portion 112, or may be located in a form in which it is flush with the surface 112a of the opening portion 112.

[0121] As shown in FIG. 1 to FIG. 3, the 1A lens 4121A may be located at the second opening 11b of the opening portion 112. More specifically, as shown in FIG. 3, the second opening 11b of the opening portion 112 may be composed of an aperture opening (also referred to as a 2A opening) 11ba and a storage opening (also referred to as a 2B opening) 11bb. The storage opening 11bb is a space in which the 1A lens 4121A is stored. The storage opening 11bb is located on the 1B lens 4121B side with respect to the aperture opening 11ba. The aperture opening 11ba is connected to the storage opening 11bb in the second optical axis direction Dp2. When viewed in a plan view in a direction along the second optical axis Ax2, the area (opening area) of the aperture opening 11ba is smaller than the area (opening area) of the storage opening 11bb. In other words, the inner peripheral surface forming the second opening 11b in the opening portion 112 has a step. More specifically, the inner circumferential surface of the opening portion 112 has a first inner circumferential surface 1121a forming the diaphragm opening 11ba, a second inner circumferential surface 112b forming the storage opening 11bb, and a connection surface 1121b connecting the first inner circumferential surface 1121a and the second inner circumferential surface 112b. The first inner circumferential surface 1121a is closer to the second optical axis Ax2 than the second inner circumferential surface 112b. Therefore, when viewed in a plan view in a direction along the second optical axis Ax2, the area (opening area) of the diaphragm opening 11ba is smaller than the area (opening area) of the storage opening 11bb.

[0122] The opening portion 112 includes, for example, an inner peripheral protrusion 1121. The inner peripheral protrusion 1121 has a shape protruding from the second inner peripheral surface 112b toward the second optical axis Ax2 and surrounds the second optical axis Ax2. The inner peripheral surface of this inner peripheral protrusion 1121 is a first inner peripheral surface 1121a, and the surface of the inner peripheral protrusion 1121 on the 1A lens 4121A side is a connecting surface 1121b. The second inner peripheral surface 112b of the opening portion 112 may be in contact with the outer peripheral surface of the 1A lens 4121A. The outer peripheral surface of the 1A lens 4121A is an annular side surface that connects the periphery of the first lens surface 412a and the periphery of the second lens surface 412b. The 1A lens 4121A may be fitted into the storage opening 11bb of the opening portion 112.

[0123] Here, for example, light of the fluorescence L1 from the wavelength conversion unit 32 having a spread angle of the predetermined spread angle θ1 or less passes through the aperture 11ba and enters the first optical system 40. More specifically, for example, light of the fluorescence L1 from the wavelength conversion unit 32 having a spread angle of the predetermined spread angle θ1 or less passes through the aperture 11ba and enters the 1A lens 4121A. In other words, for example, the second aperture 11b of the opening portion 112 (specifically, the aperture 11ba) passes the fluorescence L1 from the wavelength conversion unit 32 having a spread angle of the predetermined spread angle θ1 or less to the first optical system 40 side. Conversely, for example, light (hereinafter referred to as blocked light) traveling at a spread angle larger than the predetermined spread angle θ1 of the fluorescence L1 from the wavelength conversion unit 32 is blocked by the opening portion 112 (specifically, the inner peripheral protrusion 1121).

[0124] In the example of FIG. 3, the first inner peripheral surface 1121a of the aperture 11ba is inclined with respect to the second optical axis Ax2. More specifically, the first inner peripheral surface 1121a is inclined in such a manner that the aperture area of ​​the aperture 11ba increases toward the wavelength conversion section 32 side. In other words, the first inner peripheral surface 1121a of the aperture 11ba is inclined in such a manner that it moves away from the central axis (here, the second optical axis Ax2) of the second aperture 11b toward the wavelength conversion section 32 side. Since the wavelength conversion section 32 is located in the vicinity of the aperture 11ba, most of the blocked light from the wavelength conversion section 32 is incident on the first inner peripheral surface 1121a of the aperture 11ba. The blocked light is, for example, reflected or scattered by the first inner peripheral surface 1121a of the aperture 11ba and travels in the opposite direction to the 1A lens 4121A, or a part of it is absorbed by the opening portion 112.

[0125] Here, of the fluorescence L1 output from the wavelength conversion unit 32, the fluorescence L1 having a divergence angle equal to or smaller than a predetermined divergence angle θ1 passes through the aperture 11ba, and the shielded light outside the fluorescence L1 passing through the aperture 11ba is shielded by the opening portion 112. This can reduce a portion of the fluorescence L1 emitted from the wavelength conversion unit 32 that travels toward the inner surface of the housing 10. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. This can reduce the conspicuousness of the lighting device 1 when emitting light.

[0126] The opening 112 may be a light-absorbing member. The light-absorbing member may be a member having an absorptivity of 60% or more in the visible light range. The opening 112 may have a first inner circumferential surface 1121a that is a surface of a light-absorbing member. The absorptivity of the fluorescence L1 in the first inner circumferential surface 1121a may be high. The absorptivity of the fluorescence L1 in the first inner circumferential surface 1121a may be, for example, 60% or more, 80% or more, or 90% or more. The first inner circumferential surface 1121a may have a high absorptivity of light in the entire wavelength range of the fluorescence L1, or may have a high absorptivity of light in the peak wavelength of the fluorescence L1. For example, the first inner circumferential surface 1121a is formed by, for example, performing a blackening process. As the blackening process, a blackening process using chemical conversion treatment, plating, formation of a coating, painting, or the like may be adopted. As the blackening process, a matte blackening process may be adopted, or a glossy blackening process may be adopted. The first inner circumferential surface 1121a may be made of a black material. This material may include, for example, one or more of a black metal, a black metal oxide film, and a black resin. For the blackening treatment, for example, a black chromate treatment, a black electroless nickel plating treatment, a treatment for forming a black oxide film, a black anodizing treatment, or the like may be applied.

[0127] The first inner circumferential surface 1121a may be formed of, for example, a dielectric multilayer film. The dielectric multilayer film has, for example, a structure in which a plurality of dielectric thin films are laminated. As the dielectric material, for example, one or more materials selected from TiO2, SiO2, Nb2O3, Ta2O5, and magnesium fluoride (MgF2) are used. Such a dielectric multilayer film may also be called a low reflection film or an anti-reflection film.

[0128] In the above example, the 1A lens 4121A is located at the second opening 11b of the opening portion 112 close to the wavelength conversion unit 32. More specifically, the 1A lens 4121A is located in the storage opening 11bb located immediately on the first optical system 40 side of the diaphragm opening 11ba. This makes it possible to narrow the distance between the wavelength conversion unit 32 and the 1A lens 4121A. This allows most of the fluorescence L1 from the wavelength conversion unit 32 to be incident on the 1A lens 4121A.

[0129] Next, a mechanism for holding the first optical system 40 will be described. As shown in FIG. 1 and FIG. 2, the housing 10 may further include, for example, a plurality of inner housings 14 located inside the main body 11. The plurality of inner housings 14 have a function of holding the first optical system 40 inside the housing 10. In the example of FIG. 1 and FIG. 2, the plurality of inner housings 14 include a first inner housing 14a, a second inner housing 14b, a third inner housing 14c, a fourth inner housing 14d, and a fifth inner housing 14e. The material of the plurality of inner housings 14 may be the same as that of the main body 11 of the housing 10, or may be a material different from that of the main body 11 of the housing 10. The material of the plurality of inner housings 14 may be, for example, an aluminum alloy, or may be another material such as a synthetic resin.

[0130] The first inner housing 14a may function as a lens holder that holds the 1A lens 4121A together with the opening portion 112 of the housing 10. As shown in FIG. 1 to FIG. 3, the first inner housing 14a is located between the 1A lens 4121A and the 1B lens 4121B. The first inner housing 14a may have, for example, a cylindrical shape that surrounds the second optical axis Ax2. The outer periphery of the 1A lens 4121A may be in a state of being sandwiched between the inner peripheral protrusion 1121 of the opening portion 112 and the first inner housing 14a in the second optical axis direction Dp2. The outer periphery of the 1A lens 4121A may be a part of the outer periphery of the 1A lens 4121A centered on the second optical axis Ax2. More specifically, the inner peripheral protrusion 1121 of the opening portion 112 may be in contact with the outer periphery of the first lens surface 412a of the 1A lens 4121A, and the first inner housing 14a may be in contact with the outer periphery of the second lens surface 412b of the 1A lens 4121A. The outer periphery of the first lens surface 412a may be a part of the outer periphery centered on the second optical axis Ax2 of the first lens surface 412a. The outer periphery of the second lens surface 412b may be a part of the outer periphery centered on the second optical axis Ax2 of the second lens surface 412b.

[0131] The inner peripheral surface of the first inner housing 14a is located closer to the second optical axis Ax2 than the outer peripheral surface of the 1B lens 4121B. The inner peripheral surface of the first inner housing 14a may be an inner peripheral surface located closer to the second optical axis Ax2 of the first inner housing 14a. The outer peripheral surface of the 1B lens 4121B may be an outer peripheral surface centered on the second optical axis Ax2 of the 1B lens 4121B. In the example of FIG. 1 and FIG. 2, the outer peripheral surface of the 1B lens 4121B may be an annular side surface connecting the periphery of the third lens surface 412c and the periphery of the fourth lens surface 412d.

[0132] The outer peripheral surface of the first inner housing 14a may be in contact with the inner peripheral surface of the side wall portion 111. The outer peripheral surface of the first inner housing 14a may be a surface of the outer periphery centered on the second optical axis Ax2 of the first inner housing 14a. The outer peripheral surface of the first inner housing 14a may be fitted into the inner peripheral surface of the side wall portion 111. For example, if a structure is adopted in which the male thread portion of the outer peripheral surface of the first inner housing 14a is fitted into the female thread portion of the inner peripheral surface of the side wall portion 111, the occurrence of a positional shift (also referred to as a positional deviation) of the first inner housing 14a during transportation and use of the lighting device 1 can be reduced. The outer peripheral surface of the first inner housing 14a may be fixed to the inner peripheral surface of the side wall portion 111 by adhesion or the like. The outer peripheral surface of the 1B lens 4121B may be in contact with the inner peripheral surface of the side wall portion 111. The 1B lens 4121B may be fitted into the inner peripheral surface of the side wall portion 111.

[0133] Here, for example, if the first inner housing 14a is in contact with the outer periphery of the 1B lens 4121B, the first inner housing 14a can function as a spacer that determines the distance between the 1A lens 4121A and the 1B lens 4121B. In other words, if the first optical system 40 includes the 1A lens 4121A and the 1B lens 4121B, and the lighting device 1 includes the first inner housing 14a as a spacer that is sandwiched between the 1A lens 4121A and the 1B lens 4121B, the distance between the 1A lens 4121A and the 1B lens 4121B can be easily set. The outer periphery of the 1B lens 4121B may be a portion of the outer periphery of the 1B lens 4121B centered on the second optical axis Ax2.

[0134] The second inner housing 14b may function as a lens holder for holding the 1B lens 4121B together with the first inner housing 14a. As shown in FIG. 1 and FIG. 2, the second inner housing 14b is located between the 1B lens 4121B and the third inner housing 14c. The second inner housing 14b may have, for example, a cylindrical shape surrounding the second optical axis Ax2. The inner peripheral surface of the second inner housing 14b is located closer to the second optical axis Ax2 than the outer peripheral surface of the 1B lens 4121B. The inner peripheral surface of the second inner housing 14b may be an inner peripheral surface located closer to the second optical axis Ax2 of the second inner housing 14b.

[0135] The outer periphery of the 1B lens 4121B may be in a state of being sandwiched between the first inner housing 14a and the second inner housing 14b in the second optical axis direction Dp2. In this case, the edge portion of the first inner housing 14a on the 1B lens 4121B side may be in contact with the outer periphery of the third lens surface 412c of the 1B lens 4121B. The edge portion of the second inner housing 14b on the 1B lens 4121B side may be in contact with the outer periphery of the fourth lens surface 412d of the 1B lens 4121B. The outer periphery of the third lens surface 412c may be a part of the outer periphery centered on the second optical axis Ax2 of the third lens surface 412c. The outer periphery of the fourth lens surface 412d may be a part of the outer periphery centered on the second optical axis Ax2 of the fourth lens surface 412d.

[0136] The outer peripheral surface of the second inner housing 14b may be in contact with the inner peripheral surface of the side wall portion 111. The outer peripheral surface of the second inner housing 14b may be an outer peripheral surface centered on the second optical axis Ax2 of the second inner housing 14b. The outer peripheral surface of the second inner housing 14b may be fitted into the inner peripheral surface of the side wall portion 111. For example, if a structure is adopted in which the male thread portion of the outer peripheral surface of the second inner housing 14b is fitted into the female thread portion of the inner peripheral surface of the side wall portion 111, the occurrence of positional deviation (displacement) of the second inner housing 14b during transportation and use of the lighting device 1 can be reduced. The outer peripheral surface of the second inner housing 14b may be fixed to the inner peripheral surface of the side wall portion 111 by adhesion or the like.

[0137] An edge portion of the second inner housing 14b on the wavelength separation filter 411 side may be in contact with, for example, an edge portion of the third inner housing 14c on the wavelength conversion unit 32 side. In this case, the second inner housing 14b can function as a spacer that determines the distance between the 1B lens 4121B and the third inner housing 14c.

[0138] As shown in FIG. 1 and FIG. 2, the third inner housing 14c may have a portion located between the second inner housing 14b and the wavelength separation filter 411. The third inner housing 14c may have a shape in which, for example, a cylindrical portion surrounding the second optical axis Ax2 and a cylindrical portion surrounding the third optical axis Ax3 are connected. The outer peripheral surface of the third inner housing 14c may be in contact with the inner peripheral surface of the side wall portion 111. The outer peripheral surface of the third inner housing 14c may be, for example, an outer peripheral surface centered on the second optical axis Ax2 of the third inner housing 14c and an outer peripheral surface centered on the third optical axis Ax3 of the third inner housing 14c.

[0139] The edge portion of the third inner housing 14c on the wavelength separation filter 411 side may be in contact with, for example, the outer periphery of the wavelength separation filter 411. In this case, the second inner housing 14b and the third inner housing 14c may function as a spacer that determines the distance between the 1B lens 4121B and the wavelength separation filter 411. The outer periphery of the wavelength separation filter 411 may be a part of the outer periphery of the wavelength separation filter 411 centered on the second optical axis Ax2 and a part of the outer periphery of the wavelength separation filter 411 centered on the third optical axis Ax3. The end face of the third inner housing 14c facing the wavelength separation filter 411 may have a shape that follows the second plate surface 4b facing the wavelength conversion unit 32 side of the wavelength separation filter 411, and may be inclined to the same or approximately the same degree as the second plate surface 4b of the wavelength separation filter 411 with respect to the second optical axis Ax2.

[0140] 1 and 2, the third inner housing 14c may also have a portion located between the wavelength separation filter 411 and the second lens 4122. Here, for example, if an edge portion of the third inner housing 14c on the second lens 4122 side is in contact with an outer periphery of the second lens 4122, the third inner housing 14c can function as a spacer that determines the distance between the wavelength separation filter 411 and the second lens 4122. The outer periphery of the second lens 4122 may be a portion of the outer periphery of the second lens 4122 centered on the third optical axis Ax3.

[0141] The fourth inner housing 14d can function as a filter holder 14h that holds the wavelength separation filter 411 together with the third inner housing 14c. As shown in FIG. 1 and FIG. 2, the fourth inner housing 14d may be located between the wavelength separation filter 411 and the side wall portion 111. The fourth inner housing 14d has, for example, a cylindrical shape that surrounds the first optical axis Ax1. The outer peripheral surface of the fourth inner housing 14d may be in contact with the inner peripheral surface of the side wall portion 111. The outer peripheral surface of the fourth inner housing 14d may be a surface of the outer periphery centered on the first optical axis Ax1 of the fourth inner housing 14d. The edge portion of the fourth inner housing 14d on the wavelength separation filter 411 side may be in contact with, for example, the outer peripheral portion of the wavelength separation filter 411.

[0142] In the example of FIG. 1 and FIG. 2, the edge portion of the fourth inner housing 14d on the wavelength separation filter 411 side is in contact with the outer periphery of the first plate surface 4a of the wavelength separation filter 411. The end surface of the fourth inner housing 14d facing the wavelength separation filter 411 may have a shape along the first plate surface 4a facing the side opposite to the wavelength conversion unit 32 of the wavelength separation filter 411, and may be inclined to the same or approximately the same degree as the first plate surface 4a of the wavelength separation filter 411 with respect to the first optical axis Ax1. The outer periphery of the wavelength separation filter 411 may be in a state of being sandwiched between the third inner housing 14c and the fourth inner housing 14d in the second optical axis direction Dp2 and the third optical axis direction Dp3. In this case, the edge portion of the third inner housing 14c on the wavelength separation filter 411 side is in contact with the outer periphery of the surface of the wavelength separation filter 411 located on the wavelength conversion unit 32 side. An edge portion of the fourth inner housing 14d on the wavelength separation filter 411 side is in contact with an outer periphery of the surface of the wavelength separation filter 411 located on the opposite side to the wavelength conversion unit 32. The outer periphery of the surface of the wavelength separation filter 411 located on the wavelength conversion unit 32 side may be an outer periphery portion centered on the second optical axis Ax2 and an outer periphery portion centered on the third optical axis Ax3 in the surface of the wavelength separation filter 411 located on the wavelength conversion unit 32 side. The outer periphery of the surface of the wavelength separation filter 411 located on the opposite side to the wavelength conversion unit 32 may be an outer periphery portion centered on the second optical axis Ax2 and an outer periphery portion centered on the third optical axis Ax3 in the surface of the wavelength separation filter 411 located on the opposite side to the wavelength conversion unit 32.

[0143] An adhesive may be located between the wavelength separation filter 411 and the third inner housing 14c. An adhesive may be located between the wavelength separation filter 411 and the fourth inner housing 14d. An adhesive may be located between the wavelength separation filter 411 and the inner circumferential surface of the side wall portion 111. An adhesive may be located between the third inner housing 14c and the inner circumferential surface of the side wall portion 111. An adhesive may be located between the fourth inner housing 14d and the inner circumferential surface of the side wall portion 111.

[0144] 1 and 2, the side wall portion 111 of the main body portion 11 of the housing 10 and the fourth inner housing 14d may have an introduction opening 11c as a third opening. The introduction opening 11c is an opening that passes the excitation light L0 from the light source 20 located outside the main body portion 11 of the housing 10 and guides the excitation light L0 to the first optical system 40 in the housing 10. In the example of FIG. 1 and FIG. 2, the introduction opening 11c penetrates the side wall portion 111 and the fourth inner housing 14d along the −X direction as the first optical axis direction Dp1.

[0145] The fifth inner housing 14e can function as a lens holder that holds the second lens 4122 together with the third inner housing 14c. The fifth inner housing 14e is located between the second lens 4122 and the frame portion 13. The fifth inner housing 14e has, for example, a cylindrical shape that surrounds the third optical axis Ax3. The inner peripheral surface of the fifth inner housing 14e is located closer to the third optical axis Ax3 than the outer peripheral surface of the second lens 4122. The inner peripheral surface of the fifth inner housing 14e may be an inner peripheral surface that is located closer to the third optical axis Ax3 of the fifth inner housing 14e. The outer peripheral surface of the second lens 4122 may be an outer peripheral surface centered on the third optical axis Ax3 of the second lens 4122. In the example of FIG. 1 and FIG. 2, the outer peripheral surface of the second lens 4122 is an annular side surface that connects the fifth lens surface 412e of the second lens 4122 and the sixth lens surface 412f.

[0146] The outer periphery of the second lens 4122 may be sandwiched between the third inner housing 14c and the fifth inner housing 14e in the third optical axis direction Dp3. In this case, the edge of the third inner housing 14c on the second lens 4122 side is in contact with the outer periphery of the surface of the second lens 4122 on the wavelength separation filter 411 side. The edge of the fifth inner housing 14e on the second lens 4122 side is in contact with the outer periphery of the surface of the second lens 4122 on the irradiation opening 10a side.

[0147] The outer peripheral surface of the fifth inner housing 14e may be in contact with the inner peripheral surface of the side wall portion 111. The outer peripheral surface of the fifth inner housing 14e may be a surface of the outer periphery centered on the third optical axis Ax3 of the fifth inner housing 14e. For example, if a structure is adopted in which the male thread portion of the outer peripheral surface of the fifth inner housing 14e is fitted into the female thread portion of the inner peripheral surface of the side wall portion 111, the occurrence of positional deviation of the second lens 4122 during transportation and use of the lighting device 1 can be reduced. The outer peripheral surface of the fifth inner housing 14e may be fixed to the inner peripheral surface of the side wall portion 111 by adhesion or the like. The outer peripheral surface of the second lens 4122 may be in contact with the inner peripheral surface of the side wall portion 111. The second lens 4122 may be fitted into the inner peripheral surface of the side wall portion 111.

[0148] In the above example, the multiple inner housings 14 include the first inner housing 14a, the second inner housing 14b, the third inner housing 14c, the fourth inner housing 14d, and the fifth inner housing 14e as five inner housings 14, but are not limited to this. For example, as long as the first optical system 40 can be held within the housing 10, the multiple inner housings 14 may include any number of inner housings 14 that is two or more.

[0149] For example, the third inner housing 14c and the fourth inner housing 14d may be an integral filter holder 14h that is connected to each other. In this case, the filter holder 14h may have, for example, a concave groove for holding the outer periphery of the wavelength separation filter 411 on the inner circumferential surface of the filter holder 14h, and a slit connected to the concave groove on the side wall of the filter holder 14h. In this configuration, for example, the wavelength separation filter 411 may be inserted into the concave groove through the slit, thereby realizing a configuration in which the wavelength separation filter 411 is held by the filter holder 14h.

[0150] Furthermore, each of the multiple inner housings 14 may be configured, for example, from one member, or may have a configuration in which two or more members are connected together.

[0151] The frame 13 is located in a state where it is fixed to a first end E1 of the sidewall 111 on the opposite side to the opening 112. As shown in FIG. 1 and FIG. 2, the frame 13 may include a plate-like portion 131 and a cylindrical portion 132. The plate-like portion 131 has a plate-like shape. The thickness direction of the plate-like portion 131 may be located along the third optical axis direction Dp3. The cylindrical portion 132 has a cylindrical shape extending from the periphery of the plate-like portion 131 toward the first optical system 40 along the opposite direction of the third optical axis direction Dp3. The cylindrical portion 132 is connected to, for example, an end of the sidewall 111. The plate-like portion 131 has an irradiation opening 10a. This irradiation opening 10a penetrates the plate-like portion 131 in the third optical axis direction Dp3. The irradiation opening 10a may be located, for example, in the approximate center of the plate-like portion 131. The diameter of the irradiation opening 10a is, for example, smaller than the inner diameter of the fourth inner housing 14d. Note that the structure including the main body 11 and the frame 13 may be appropriately configured by a plurality of components. For example, this structure may be formed by connecting a plurality of components in the second optical axis direction Dp2 and / or the third optical axis direction Dp3. Here, the structure including the main body 11 and the frame 13 may be assembled by attaching a plurality of components to each other.

[0152] 1 and 2, the inner circumferential surface 131a of the frame 13 that forms the irradiation opening 10a may be inclined in a manner that the opening area increases as the inner circumferential surface 131a approaches the illumination space S1 in the direction along the third optical axis Ax3. In other words, the inner circumferential surface 131a may be inclined in a manner that the inner circumferential surface 131a moves away from the central axis of the irradiation opening 10a as the inner circumferential surface 131a approaches the illumination space S1. The central axis of the irradiation opening 10a may be located along the third optical axis Ax3, for example.

[0153] Aluminum alloys or various synthetic resins may be used as the material of the frame 13. The frame 13 may have a structure in which a plurality of components are connected by adhesion, bonding, fitting, fastening, or the like.

[0154] <1-7. Numerical aperture of an imaging optical system composed of one or more lenses> As shown in FIG. 3, in the illumination device 1, an angle φ1 that defines the numerical aperture of an imaging optical system composed of one or more lenses 412 may be equal to or greater than a spread angle θ1 of the fluorescence L1 passing through the diaphragm aperture 11ba. The numerical aperture is the product of the sine of the half-value of the angle φ1 and the refractive index. The angle φ1 is, for example, an angle formed by both outer rays of virtual light that can pass through an effective area of ​​an imaging optical system composed of one or more lenses 412. The effective area here corresponds to a light passing area that can exhibit the optical performance of the imaging optical system. For example, the effective area of ​​the 1A lens 4121A may be an area excluding a peripheral portion of a predetermined width of the 1A lens 4121A. As a more specific example, the effective area of ​​the 1A lens 4121A may be an area surrounded by the inner peripheral edge of a portion of the housing 10 that holds the peripheral edge of the 1A lens 4121A (here, the opening portion 112 and the first inner housing 14a). In the example of FIG. 3, the spread angle θ1 and the angle φ1 are equal to each other.

[0155] If the spread angle θ1 is equal to or smaller than the angle φ1, the fluorescence L1 passing through the aperture 11ba can pass within the effective area of ​​the imaging optical system composed of one or more lenses 412. Therefore, the fluorescence L1 is hardly incident on the edges of the first lens 4121 and the second lens 4122 in the imaging optical system composed of one or more lenses 412, and unnecessary reflection and scattering of the fluorescence L1 caused by these edges can be reduced.

[0156] <2. Other embodiments> The present disclosure is not limited to the first embodiment described above, and various modifications and improvements are possible without departing from the gist of the present disclosure.

[0157] <2-1. Second embodiment> In the first embodiment, for example, as shown in Fig. 11 and Fig. 12, the first light-shielding unit 50 may be configured integrally with the wavelength conversion unit 32. If this configuration is adopted, it may be easy to align the wavelength conversion unit 32 and the first light-shielding unit 50 when manufacturing the lighting device 1. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 may be easily reduced.

[0158] Fig. 11 is a cross-sectional view that illustrates a first example of the configuration of the wavelength conversion member 30 and the first light shielding portion 50 according to the second embodiment. Fig. 12 is a cross-sectional view that illustrates a second example of the configuration of the wavelength conversion member 30 and the first light shielding portion 50 according to the second embodiment.

[0159] As shown in FIG. 11, for example, the first light-shielding portion 50 may be a film (also referred to as a first film or a first coating film) 50A located on the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. In this case, the first light-shielding portion 50 may be configured integrally with the wavelength conversion portion 32. With this configuration, the gap between the second region 32a2 of the first surface 32a of the wavelength conversion portion 32 and the first light-shielding portion 50 can be easily reduced. This can reduce the amount of excitation light L0 irradiated to the second region 32a2 of the first surface 32a through the gap between the first surface 32a of the wavelength conversion portion 32 and the first light-shielding portion 50. Then, the emission of the fluorescence L1 from the second region 32a2 can be reduced. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, the visibility of the lighting device 1 during emission can be reduced.

[0160] The first coating film 50A may be formed, for example, by performing a blackening treatment using a coating on the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. In this case, the second surface 50f of the first light-shielding unit 50 may be a black surface. The blackening treatment using a coating may be, for example, a treatment of applying a paint having heat resistance against heat generated when the wavelength conversion unit 32 emits light. For example, a paint having heat resistance of about 400°C may be applied as the heat-resistant paint, and a paint in which graphite fine powder is mixed with the paint. The silicone resin has a three-dimensionally cross-linked siloxane skeleton. Here, a silicone oligomer having an alkoxysilyl group as a reactive functional group may be used as a base material for the silicone resin paint. The silicone resin coating film may be hardened by a dealcoholization condensation reaction caused by the humidity in the air using a catalyst.

[0161] Also, as shown in FIG. 12, for example, the first light-shielding portion 50 may be integrated with the wavelength conversion portion 32 when the wavelength conversion portion 32 is produced by sintering. In this case, the first light-shielding portion 50 may be configured integrally with the wavelength conversion portion 32. Even if this configuration is adopted, the gap between the second region 32a2 of the first surface 32a of the wavelength conversion portion 32 and the first light-shielding portion 50 can be easily reduced. This can reduce the excitation light L0 irradiated to the second region 32a2 through the gap between the first surface 32a of the wavelength conversion portion 32 and the first light-shielding portion 50. Then, the emission of the fluorescence L1 from the second region 32a2 can be reduced. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, the conspicuousness of the lighting device 1 during emission can be reduced.

[0162] When producing the wavelength conversion section 32 by sintering, the first light-shielding section 50 can be integrated with the wavelength conversion section 32 by various methods, for example.

[0163] 13 to 15 are cross-sectional views each showing a schematic state in the middle of forming a second example of the configuration of the wavelength conversion member 30 and the first light-shielding portion 50 according to the second embodiment by the first method. First, for example, as shown in FIG. 13, a mixed powder 32p obtained by mixing a phosphor powder and a low-melting point glass powder is arranged on a substrate 31. Next, for example, as shown in FIG. 14, a first light-shielding portion 50 is arranged on the mixed powder 32p arranged on the substrate 31. Next, for example, by press molding using a pressing jig J1, the mixed powder 32p and the first light-shielding portion 50 are molded into a flat plate shape as shown in FIG. 15, so that the first light-shielding portion 50 is embedded in the mixed powder 32p. Thereafter, for example, the mixed powder 32p is heated, and the wavelength conversion portion 32 and the first light-shielding portion 50 can be integrated on the substrate 31 by sintering the low-melting point glass powder. As a result, as shown in Figure 12, a configuration can be formed in which the wavelength converting section 32 is fixed onto the substrate 31, and the wavelength converting section 32 and the first light-shielding section 50 are integrated with each other, with the first light-shielding section 50 embedded on top of the wavelength converting section 32.

[0164] 16 to 18 are cross-sectional views each showing a schematic state in the middle of forming a second example of the configuration of the wavelength conversion member 30 and the first light-shielding portion 50 according to the second embodiment by the second method. First, as shown in FIG. 16, for example, a slurry 32s as a liquid mixture obtained by mixing a phosphor powder, a low-melting-point glass powder, and a liquid such as water or an organic solvent is applied on a substrate 31 by a screen printing method or the like, and then the slurry 32s is dried. Next, as shown in FIG. 17, for example, the first light-shielding portion 50 is disposed on a slurry (also called a dried slurry) 32sd dried on the substrate 31. Next, for example, the dried slurry 32sd and the first light-shielding portion 50 are molded into a flat plate shape by press molding using a pressing jig J1, as shown in FIG. 18, so that the first light-shielding portion 50 is embedded in the dried slurry 32sd. Thereafter, for example, the dried slurry 32sd is heated to sinter the low-melting point glass powder, thereby integrating the wavelength conversion section 32 and the first light shielding section 50 on the substrate 31. As a result, as shown in Fig. 12, a configuration can be formed in which the wavelength conversion section 32 is fixed onto the substrate 31, and the wavelength conversion section 32 and the first light shielding section 50 are integrated together in a state in which the first light shielding section 50 is embedded above the wavelength conversion section 32.

[0165] <2-2. Third embodiment> In the first embodiment, for example, as shown in Fig. 19 and Fig. 20, the lighting device 1 may include a mechanism (also referred to as a first rotation mechanism) 90 that can change the position of the first region 32a1 on the first surface 32a by rotating the wavelength conversion unit 32 about a virtual first rotation axis Ax4. Here, the first rotation axis Ax4 may be positioned offset from the first through hole 50h in a direction (also referred to as a first orthogonal direction) perpendicular to a normal line (also referred to as a first normal line) Ln1 perpendicular to the first region 32a1, and may be positioned along a direction (also referred to as a first normal direction) along the first normal line Ln1. The first light-shielding unit 50 may be positioned in a fixed state relative to the housing 10.

[0166] If this configuration is adopted, the region of the wavelength conversion unit 32 that is irradiated with the excitation light L0 can be changed over time by rotating the wavelength conversion unit 32 about the first rotation axis Ax4. This allows the locations where heat is generated in the wavelength conversion unit 32 to be dispersed. As a result, thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion unit 32 decreases as the temperature of the wavelength conversion unit 32 increases, can be reduced. In addition, the degree to which the wavelength conversion unit 32 is deteriorated by heat can be reduced.

[0167] Fig. 19 is a cross-sectional view illustrating an example of the configuration of the lighting device 1 according to the third embodiment. Fig. 20 is a diagram illustrating an example of how the first region 32a1 is changed in response to rotation of the wavelength conversion member 30 in the lighting device 1 according to the third embodiment.

[0168] An example of the lighting device 1 according to the third embodiment shown in Fig. 19 is based on the example of the lighting device 1 according to the first embodiment. This example of the lighting device 1 according to the third embodiment includes a first rotation mechanism 90 that rotates the wavelength conversion member 30 and a support unit 15 that supports the first rotation mechanism 90, instead of the lid unit 12. Furthermore, this example of the lighting device 1 according to the third embodiment has a configuration in which the first light blocking unit 50 is fixed to the surface 112a of the opening portion 112, instead of being attached to the wavelength conversion member 30 by the second attachment member 70, and has a configuration in which the shape of the wavelength conversion member 30 is changed.

[0169] 1 and 2, in Fig. 19, an example of a first optical axis Ax1, an example of a second optical axis Ax2, and an example of a third optical axis Ax3 are each shown typically by a thin dashed line. An example of an outer edge of the path of the excitation light L0 is shown typically by a thin broken line. An example of an outer edge of the path of the fluorescence L1 is shown typically by a thin two-dot chain line.

[0170] As shown in Fig. 19, the first light-shielding part 50 may be fixed directly to the housing 10, for example. In the example of Fig. 19, the outer periphery of the first light-shielding part 50 is fixed to the surface 112a of the opening part 112. The outer periphery of the first light-shielding part 50 may be attached to the surface 112a of the opening part 112 by a fixing agent such as an adhesive, for example.

[0171] The support portion 15 has a form that protrudes from the surface 112a of the opening portion 112, for example. The support portion 15 may form a member integral with the opening portion 112, or may be a part of a member attached to the opening portion 112. The support portion 15 may be attached to the opening portion 112 by, for example, fixing with a fixing agent such as an adhesive, or by screwing or fitting at one or more points. The support portion 15 may have, for example, a portion having an L-shaped bent shape that extends from the surface 112a in the -X direction and then in the +Z direction.

[0172] The first rotation mechanism 90 may be attached to, for example, a tip portion of the support portion 15. The first rotation mechanism 90 may be attached to the support portion 15 by, for example, fixing with a fixing agent such as an adhesive, screwing or fitting at one or more points, or the like. The first rotation mechanism 90 may have a shaft portion 90p that supports the wavelength conversion member 30 rotatably around a first rotation axis Ax4. A normal line (first normal line) Ln1 of the first region 32a1 in the first surface 32a may be parallel to the second optical axis Ax2, or may be located along the second optical axis direction Dp2. The first rotation axis Ax4 may be positioned offset from the first through hole 50h in a first orthogonal direction perpendicular to the first normal line Ln1. In the example of FIG. 19, the first orthogonal direction is the +Z direction. The first rotation axis Ax4 is positioned along the first normal direction along the first normal line Ln1. In other words, the first rotation axis Ax4 may be, for example, parallel to the second optical axis Ax2, or may be located along the second optical axis direction Dp2. The plate surface of the wavelength conversion member 30 on the opposite side to the first optical system 40 may be attached to the shaft portion 90p by, for example, fixing with a fixing agent such as an adhesive, screwing, or fitting. For example, a motor may be applied to the first rotation mechanism 90. The lighting device 1 may have a power supply circuit that supplies power to the first rotation mechanism 90, and a control circuit that controls the operation of the first rotation mechanism 90.

[0173] In the wavelength conversion member 30, for example, as shown in FIG. 19 and FIG. 20, the wavelength conversion unit 32 may have an annular shape centered on the first rotation axis Ax4. The shape of the wavelength conversion unit 32 is not limited to an annular shape centered on the first rotation axis Ax4. The wavelength conversion unit 32 may be located, for example, over almost the entire plate surface of the substrate 31 on the first optical system 40 side. There may be a slight gap between the first surface 32a of the wavelength conversion unit 32 and the third surface 50b of the first light shielding unit 50. The distance between the first surface 32a of the wavelength conversion unit 32 and the third surface 50b of the first light shielding unit 50 may be set to, for example, 50 μm to 500 μm.

[0174] In Fig. 20, the rotation of the wavelength conversion member 30 around the first rotation axis Ax4 is depicted by thin arrows. In addition, in Fig. 20, the outer edge and inner edge of the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 are respectively indicated by thin two-dot chain lines. In other words, the outer edge of the first region 32a1 of the first surface 32a of the wavelength conversion unit 32 is indicated by a thin two-dot chain line.

[0175] For example, as shown in FIG. 20, the first rotation mechanism 90 can rotate the wavelength conversion member 30 including the wavelength conversion unit 32 around the first rotation axis Ax4. For example, the operation of the first rotation mechanism 90 can be controlled by a control circuit to appropriately control the timing and speed of rotating the wavelength conversion member 30 around the first rotation axis Ax4. With this configuration, the area on the first surface 32a of the wavelength conversion unit 32 irradiated with the excitation light L0 from the light source 20 can be changed over time in the circumferential direction around the first rotation axis Ax4. This allows the locations where heat is generated in the wavelength conversion unit 32 to be dispersed in the circumferential direction around the first rotation axis Ax4. As a result, thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion unit 32 decreases as the temperature of the wavelength conversion unit 32 increases, can be reduced. In addition, the degree to which the wavelength conversion unit 32 is deteriorated by heat can be reduced.

[0176] <2-3. Fourth embodiment> In each of the above embodiments, for example, as shown in Fig. 21, the light source 20 and the wavelength separation filter 411 may be arranged in the first direction in the order described above, and the wavelength conversion unit 32, the first light blocking unit 50, the wavelength separation filter 411, and the irradiation opening 10a may be arranged along a second direction intersecting the first direction. The wavelength separation filter 411 may reflect the excitation light L0 from the light source 20 toward the wavelength conversion unit 32, and transmit the fluorescence L1 from the wavelength conversion unit 32 toward the irradiation opening 10a. If this configuration is adopted, the size of the illumination device 1 in the first direction can be reduced.

[0177] Fig. 21 is a cross-sectional view showing an example of the configuration of the illumination device 1 according to the fourth embodiment. The example of the illumination device 1 according to the fourth embodiment shown in Fig. 21 is based on the illumination device 1 according to the first embodiment shown in Figs. 1 and 2. This example of the illumination device 1 according to the fourth embodiment has a configuration in which the shape of the housing 10 is changed from an L-shape to an I-shape, and the arrangement of the wavelength conversion member 30, the first light blocking portion 50, the second mounting member 70, the wavelength separation filter 411 and one or more lenses 412 in the first optical system 40, and the multiple inner housings 14 are changed in the internal space 10is of the housing 10.

[0178] In FIG. 21, as in FIG. 1 and FIG. 2, an example of the first optical axis Ax1, an example of the second optical axis Ax2, and an example of the third optical axis Ax3 are each shown by a thin dashed line. An example of the outer edge of the path of the excitation light L0 is shown by a thin broken line. An example of the outer edge of the path of the fluorescence L1 is shown by a thin two-dot chain line. The first optical axis direction Dp1 may be, for example, the -X direction as the first direction. The second optical axis Ax2 and the third optical axis Ax3 may be the same or substantially the same. Each of the second optical axis direction Dp2 and the third optical axis direction Dp3 may be, for example, the -Z direction as the second direction. In other words, the first optical axis direction Dp1 may be perpendicular to the second optical axis direction Dp2 and the third optical axis direction Dp3.

[0179] Also in this fourth embodiment, the first light-shielding portion 50 has a first through-hole 50h located between the first region 32a1 of the first surface 32a of the wavelength conversion portion 32 and the first optical system 40, and covers the second region 32a2 surrounding the first region 32a1 of the first surface 32a.

[0180] Here, for example, a case is assumed in which a part (partial excitation light) of the excitation light L0 irradiated from the light source 20 to the wavelength conversion unit 32 is not converted into the fluorescence L1 in the wavelength conversion unit 32, but is emitted toward the 1A lens 4121A, which is the first optical component 41, by reflection and scattering in the wavelength conversion unit 32. In this case, a part of the partial excitation light reflected in a direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 at the surface (first lens surface) 412a of the 1A lens 4121A, which is the first optical component 41, may be blocked by the first light blocking unit 50. This may reduce the irradiation of the excitation light L0 to the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. This may reduce the emission of the fluorescence L1 from the second region 32a2. This may reduce the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32. As a result, the amount of fluorescence L1 irradiated to the inner surface of the housing 10 can be reduced. Thus, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, in a space different from the original target space to which the illumination light is intended to be projected, the amount of stray light irradiated from the illumination device 1 is reduced, and the conspicuousness of the presence of the illumination device 1 can be reduced. In other words, the conspicuousness of the illumination device 1 when emitting illumination light (when emitting light) can be reduced.

[0181] In the fourth embodiment, for example, as shown in FIG. 21, the wavelength separation filter 411 may be located between the wavelength conversion unit 32 and the irradiation opening 10a. In the −Z direction as the second direction, the wavelength conversion unit 32, the wavelength separation filter 411, and the irradiation opening 10a may be arranged in the order described above. In the wavelength separation filter 411, the first plate surface 4a may be located on the side of the light source 20 and the wavelength conversion unit 32 of the base material 411b. The second plate surface 4b may be the surface of the base material 411b located on the side of the irradiation opening 10a. The dielectric multilayer film 411f may be located on, for example, the first plate surface 4a. The dielectric multilayer film 411f may be located on, for example, the second plate surface 4b of the base material 411b. For example, by appropriately setting the thicknesses of the multiple dielectric thin films constituting the dielectric multilayer film 411f, a spectral transmittance that reflects the excitation light L0 and transmits the fluorescence L1 in the dielectric multilayer film 411f can be realized. The transmittance of the wavelength separation filter 411 for the fluorescence L1 may be, for example, 80% or more, 90% or more, or 95% or more. The reflectance of the wavelength separation filter 411 for the excitation light L0 may be, for example, 80% or more, 90% or more, or 95% or more. When the wavelength (second peak wavelength) at which the intensity of the fluorescence L1 is maximum is greater than the wavelength (first peak wavelength) at which the intensity of the excitation light L0 is maximum, a long pass filter (LPF) may be applied to the wavelength separation filter 411. FIG. 22 is a graph showing an example of a relationship between the wavelength of light and the transmittance of light in the wavelength separation filter 411 according to the fourth embodiment.

[0182] The angle α1 between the wavelength separation filter 411 and the second optical axis Ax2 may be the angle between the first plate surface 4a of the base material 411b and the second optical axis Ax2. In FIG. 21, an example of the angle α1 is shown by a thin arc-shaped arrow. In the example of FIG. 21, the angle α1 is set to about 45 degrees. Here, for example, when the first optical axis Ax1 and the second optical axis Ax2 are not perpendicular but intersect with each other, the angle α1 may be an angle other than 45 degrees.

[0183] As shown in Fig. 21, in the -Z direction as the second direction, the wavelength conversion unit 32, the first light blocking unit 50, the first optical system 40, and the irradiation opening 10a may be arranged in this order. In the example of Fig. 21, in the -Z direction as the second direction, the wavelength conversion unit 32, the first light blocking unit 50, the 1A lens 4121A, the 1B lens 4121B, the wavelength separation filter 411, the second lens 4122, and the irradiation opening 10a are arranged in this order.

[0184] Here, as shown in FIG. 21, an object having an unbent I-shaped cylindrical shape (also called an I-shaped cylindrical body) is applied to the side wall portion 111 of the housing 10, for example.

[0185] As shown in FIG. 21, the sidewall portion 111 may have a hollow space (also referred to as a third hollow space) 3sp penetrating along the -Z direction as the second optical axis direction Dp2 along the optical axis (second optical axis) Ax2 of the 1A lens 4121A. In other words, the sidewall portion 111 may have a linear longitudinal direction. The sidewall portion 111 has, for example, a first end E1 and a second end E2 at both ends in the longitudinal direction. In the example of FIG. 21, the first end E1 is located at the end of the sidewall portion 111 on the -Z direction side as the third optical axis direction Dp3, and the second end E2 is located at the end of the sidewall portion 111 on the +Z direction side as the direction opposite to the second optical axis direction Dp2. Inside the side wall portion 111, one or more first lenses 4121, wavelength separation filter 411, and one or more second lenses 4122 may be positioned in this order in the -Z direction as the second optical axis direction Dp2. In the example of Fig. 21, inside the side wall portion 111, the 1A lens 4121A, the 1B lens 4121B, the wavelength separation filter 411, and the second lens 4122 are positioned in this order in the -Z direction as the second optical axis direction Dp2.

[0186] 21, the thickness direction of the opening portion 112 may be a direction along the -Z direction as the second optical axis direction Dp2. The second opening 11b of the opening portion 112 may penetrate the opening portion 112 along the -Z direction as the second optical axis direction Dp2. The second optical axis Ax2 may pass through the second opening 11b. The second opening 11b may be located, for example, in approximately the center of the opening portion 112.

[0187] As shown in FIG. 21, the thickness direction of the lid 12 may be a direction along the -Z direction as the second optical axis direction Dp2. The lid 12 may be attached to the surface 112a of the opening 112 on the +Z direction side as the opposite side to the first optical system 40. The wavelength conversion member 30 is located in the first recess 12d1 of the lid 12, and the first light-shielding portion 50 and the second mounting member 70 may be located on the first surface 32a of the wavelength conversion portion 32 in the -Z direction as the second optical axis direction Dp2 in a state of being stacked in this order. The first surface 32a may be, for example, a substantially flat surface along the XY plane. The second mounting member 70 may be a plate-shaped member having a through hole 70h penetrating in the -Z direction as the second optical axis direction Dp2. The thickness direction of the second mounting member 70 may be set to the -Z direction as the second optical axis direction Dp2 along the second optical axis Ax2.

[0188] Fig. 23 is an enlarged bottom view showing a part of the first member 100 according to the fourth embodiment. Fig. 23 shows a part corresponding to the V part surrounded by the two-dot chain line in Fig. 4 as a part of the first member 100 of the first embodiment. In Fig. 23, as in Fig. 5, an example of the outer edge of the wavelength converting member 30 and the wavelength converting portion 32 hidden behind the first light shielding portion 50 is typically shown by a thin dashed line.

[0189] As shown in FIG. 23, when the through hole 70h and the first light-shielding part 50 are viewed in a plan view in the +Z direction along the second optical axis Ax2, the first through hole 50h of the first light-shielding part 50 may be located within the through hole 70h. The second optical axis Ax2 may pass through the first through hole 50h. The second optical axis Ax2 may pass through the center of the first through hole 50h. When the through hole 70h and the first light-shielding part 50 are viewed in a plan view in the +Z direction along the second optical axis Ax2, the area of ​​the first through hole 50h may be smaller than the area (opening area) of the through hole 70h. When the second opening 11b of the opening part 112 and the first surface 32a of the wavelength converting part 32 are viewed in a plan view in the +Z direction along the second optical axis Ax2, the first region 32a1 of the first surface 32a may be located within the second opening 11b. The first region 32a1 may be located on the second optical axis Ax2. The second optical axis Ax2 may pass through the center of the first region 32a1. Here, for example, when the second opening 11b of the opening portion 112 and the first surface 32a of the wavelength conversion portion 32 are viewed in a plan view in the +Z direction along the second optical axis Ax2, the area of ​​the first region 32a1 may be smaller than the minimum value of the area (opening area) of the second opening 11b of the opening portion 112.

[0190] In the example of FIG. 21, the multiple inner housings 14 include the first inner housing 14a, the third inner housing 14c, the fourth inner housing 14d, and the fifth inner housing 14e, but do not include the second inner housing 14b. Here, the outer periphery of the 1A lens 4121A is sandwiched between the inner peripheral protrusion 1121 of the opening portion 112 and the first inner housing 14a in the -Z direction as the second optical axis direction Dp2. The outer periphery of the 1B lens 4121B is sandwiched between the first inner housing 14a and the third inner housing 14c in the -Z direction as the second optical axis direction Dp2. The third inner housing 14c is located between the 1B lens 4121B and the wavelength separation filter 411. The fourth inner housing 14d functions as a filter holder 14h that holds the wavelength separation filter 411 together with the third inner housing 14c. The outer periphery of the second lens 4122 is sandwiched between the fourth inner housing 14d and the fifth inner housing 14e in the -Z direction as the second optical axis direction Dp2. The side wall portion 111 of the main body 11 of the housing 10 and the third inner housing 14c have an introduction opening 11c. The introduction opening 11c penetrates the side wall portion 111 and the third inner housing 14c along the -X direction as the first optical axis direction Dp1.

[0191] <2-4. Fifth embodiment> In each of the above embodiments, for example, as shown in FIG. 24, one or more optical components 41 in the first optical system 40 may include a reflecting member 413. The reflecting member 413 may have a concave, curved reflecting surface 413m. If this configuration is adopted, for example, it is easy to reduce an error in the reflecting surface 413m, and therefore an error in the spread angle (second spread angle) θ2 of the fluorescence L1 in the illumination space S1 can be reduced. In addition, for example, the first optical system 40 can be easily simplified. In addition, for example, the occurrence of chromatic aberration in the illumination light can be reduced.

[0192] Fig. 24 is a cross-sectional view that shows a schematic example of the configuration of the illumination device 1 according to the fifth embodiment. The illumination device 1 according to the fifth embodiment shown in Fig. 24 is based on the illumination device 1 according to the first embodiment shown in Fig. 1 and Fig. 2. This illumination device 1 according to the fifth embodiment has a configuration in which the shape of the housing 10 is changed, and the arrangement of the light source 20, the second optical system 60, the wavelength conversion member 30, and the first light blocking unit 50, as well as one or more optical components 41 that constitute the first optical system 40, are changed.

[0193] In FIG. 24, as in FIG. 1 and FIG. 2, an example of the optical axis (first optical axis) Ax1 of the light source 20 is shown typically by a thin dashed line. An example of the optical axis (second optical axis) Ax2 of the reflecting member 413 as the first optical component 41 is shown typically by a thin dashed line. An example of the third optical axis Ax3 along a path through which the center of the optical path of the fluorescence L1 from the first optical system 40 to the irradiation opening 10a passes is shown typically by a thin dashed line. The first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be the same or approximately the same. In this case, the first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be collectively referred to simply as the optical axis Ax0. The first optical axis direction Dp1 along the first optical axis Ax1, the second optical axis direction Dp2 along the second optical axis Ax2, and the third optical axis direction Dp3 along the third optical axis Ax3 may be the -Z direction as the first direction and the second direction, respectively. In this case, the first optical axis direction Dp1, the second optical axis direction Dp2, and the third optical axis direction Dp3 may be collectively referred to simply as the optical axis direction and Dp0.

[0194] In addition, in FIG. 24, a plurality of members constituting the housing 10 are shown as being integrally formed members for convenience. The housing 10 may be a composite body in which a plurality of members are combined. An example of a first spread angle θ1, which is a spread angle of the fluorescence L1 from the wavelength conversion unit 32 toward the reflecting member 413, is shown by a thin arc-shaped arrow. An example of a second spread angle θ2, which is a spread angle of the fluorescence L1 in the illumination space S1, is shown by a thin arc-shaped arrow. Here, the first spread angle θ1 is a spread angle of the fluorescence L1 immediately before the imaging optical system constituted by the reflecting member 413, which is one or more optical components 41. The second spread angle θ2 is a spread angle of the fluorescence L1 immediately after the image plane Is1.

[0195] In the fifth embodiment, as in the above-described embodiments, the illumination device 1 includes, for example, a housing 10, a light source 20, a wavelength conversion section 32, a first optical system 40, and a first light blocking section 50.

[0196] As shown in Fig. 24, like the above-described embodiments, the housing 10 has an irradiation opening 10a. The housing 10 may include, for example, a main body portion 11 and a frame portion 13. In the example of Fig. 24, the main body portion 11 houses the second optical system 60, the wavelength conversion member 30, the first optical system 40, and the first light-shielding portion 50. The main body portion 11 includes, for example, a first side wall portion 111a, a second side wall portion 111b, a connecting portion 113, and a holding portion 114.

[0197] The first side wall portion 111a and the second side wall portion 111b may each have a cylindrical shape. The first side wall portion 111a has, for example, a hollow space (also referred to as a fourth hollow space) 4sp penetrating along the second optical axis direction Dp2. The second side wall portion 111b has, for example, a hollow space (also referred to as a fifth hollow space) 5sp penetrating along the first optical axis direction Dp1. In other words, the first side wall portion 111a and the second side wall portion 111b may each have a linear longitudinal direction. An edge of the fifth hollow space 5sp in the -Z direction as the first optical axis direction Dp1 may be connected to the fourth hollow space 4sp. In this case, the fourth hollow space 4sp and the fifth hollow space 5sp may form the internal space 10is of the housing 10. For example, the second optical axis Ax2 may pass through the fourth hollow space 4sp of the first sidewall portion 111a, and the first optical axis Ax1 may pass through the fifth hollow space 5sp of the second sidewall portion 111b. In the example of FIG. 24, the optical axis Ax0 passes through each of the fourth hollow space 4sp of the first sidewall portion 111a and the fifth hollow space 5sp of the second sidewall portion 111b. The cross section perpendicular to the second optical axis Ax2 in the fourth hollow space 4sp of the first sidewall portion 111a may be larger than the cross section perpendicular to the first optical axis Ax1 in the fifth hollow space 5sp of the second sidewall portion 111b. In the example of FIG. 24, the cross section perpendicular to the optical axis Ax0 in the fourth hollow space 4sp of the first sidewall portion 111a is larger than the cross section perpendicular to the optical axis Ax0 in the fifth hollow space 5sp of the second sidewall portion 111b.

[0198] The connecting portion 113 is a portion that connects the first side wall portion 111a and the second side wall portion 111b. The connecting portion 113 may connect an end edge of the second side wall portion 111b in the -Z direction as the first optical axis direction Dp1 to an end edge of the first side wall portion 111a in the +Z direction as the opposite direction to the second optical axis direction Dp2.

[0199] The holding portion 114 is a portion that holds the wavelength conversion member 30. The holding portion 114 may be, for example, a portion that protrudes from the inner circumferential surface of the first side wall portion 111a toward the inside of the fourth hollow space 4sp of the first side wall portion 111a. The holding portion 114 includes, for example, a first portion 114a that holds the wavelength conversion member 30, and a second portion 114b that connects the first portion 114a and the first side wall portion 111a. For example, a disk-shaped member having a thickness direction along the second optical axis direction Dp2 may be applied to the first portion 114a. For example, a rod-shaped member having a longitudinal direction along a direction intersecting the second optical axis Ax2 may be applied to the second portion 114b. In the example of FIG. 24, a rod-shaped member having a longitudinal direction along a direction perpendicular to the optical axis Ax0 is applied to the second portion 114b. The second portion 114b may include, for example, a plurality of rod-shaped members each connecting the first side wall portion 111a and the first portion 114a.

[0200] The frame portion 13 is located in a fixed state at the end of the first side wall portion 111a opposite to the connecting portion 113. As in each of the above embodiments, the housing 10 has an irradiation opening 10a in the frame portion 13.

[0201] For example, as shown in Fig. 24, the light source 20, the second optical system 60, the first optical system 40, and the wavelength conversion member 30 including the wavelength conversion section 32 may be arranged in this order in the -Z direction as the first optical axis direction Dp1. In the example of Fig. 24, the light source 20, the second optical system 60, and the wavelength conversion member 30 are located on the first optical axis Ax1. The first optical system 40 includes a reflecting member 413. The reflecting member 413 may have a through hole 413h penetrating along the first optical axis Ax1.

[0202] The light source 20 can emit the excitation light L0 in the same manner as in each of the above-described embodiments. In the example of Fig. 24, the light source 20 can emit the excitation light L0 toward the -Z direction as the first optical axis direction Dp1. The light source 20 may be attached to, for example, an edge of the second side wall portion 111b in the +Z direction as the opposite direction to the first optical axis direction Dp1.

[0203] The second optical system 60 may be held, for example, inside the second sidewall portion 111b. In other words, the second optical system 60 may be located in the fifth hollow space 5sp of the second sidewall portion 111b. The second optical system 60 may be capable of guiding, for example, the excitation light L0 from the light source 20 to the wavelength conversion unit 32 through the through hole 413h. The second optical system 60 may include, for example, one lens 61, or may include two or more lenses 61 arranged in the -Z direction as the first optical axis direction Dp1. The second optical system 60 may be capable of condensing, for example, the excitation light L0 from the light source 20 on the first region 32a1 of the first surface 32a of the wavelength conversion unit 32.

[0204] The wavelength conversion member 30 may be attached to, for example, the first portion 114a of the holding portion 114 on the +Z direction side as the opposite direction to the first optical axis direction Dp1. The wavelength conversion member 30 may be attached to the first portion 114a in a state in which the substrate 31 is located on the first portion 114a side of the holding portion 114. The wavelength conversion member 30 may be attached to the first portion 114a of the holding portion 114 by, for example, fixing with a fixing agent such as an adhesive, joining by soldering, or by screwing at one or more points. In the wavelength conversion member 30, the substrate 31 may hold the wavelength conversion section 32 from the opposite side to the second optical system 60. The thickness directions of the substrate 31 and the wavelength conversion section 32 may be set to, for example, the first optical axis direction Dp1 along the first optical axis Ax1.

[0205] Fig. 25 is a plan view illustrating an example of the configuration of the wavelength conversion unit 32 and the first light shielding unit 50 according to the fifth embodiment. Fig. 25 illustrates a plan view of the wavelength conversion unit 32 and the first light shielding unit 50 viewed along the -Z direction as the first optical axis direction Dp1. In Fig. 25, an example of the outer edge of the wavelength conversion unit 32 hidden behind the first light shielding unit 50 is illustrated by a thin dashed line.

[0206] The wavelength conversion unit 32 can emit the fluorescence L1 into the internal space 10is of the housing 10 in response to irradiation with the excitation light L0 from the light source 20, as in the above-mentioned embodiments. The wavelength conversion unit 32 also has a first surface 32a located on the side of the first optical system 40, as in the above-mentioned embodiments. In the example of FIG. 24, in the wavelength conversion unit 32, the first surface 32a is located on the side of the reflecting member 413. The first surface 32a may face the +Z direction, which is the opposite direction to the first optical axis direction Dp1. The first surface 32a may be, for example, a substantially flat surface. In the examples of FIG. 24 and FIG. 25, the first surface 32a is a flat surface along the XY plane. As in the above-mentioned embodiments, the first surface 32a includes a first region 32a1 and a second region 32a2. The first region 32a1 is, for example, a region facing the reflecting member 413. Strictly speaking, the first region 32a1 may be a region facing the through-hole 413h of the reflecting member 413. The first region 32a1 may be located on the first optical axis Ax1. The first optical axis Ax1 may pass through the center of the first region 32a1. The second region 32a2 is a region surrounding the first region 32a1. The second region 32a2 is covered by the first light-shielding portion 50. In other words, the first region 32a1 is a region not covered by the first light-shielding portion 50. The second region 32a2 may be, for example, a remaining region of the first surface 32a excluding the first region 32a1.

[0207] In the example of FIG. 24 and FIG. 25, the wavelength conversion section 32 emits fluorescence L1 toward the reflecting member 413 in response to irradiation with the excitation light L0 from the light source 20.

[0208] As shown in FIG. 24, for example, the first optical system 40 is located in the internal space 10is of the housing 10, as in each of the above-mentioned embodiments. In the example of FIG. 24, the first optical system 40 includes a reflecting member 413 as one or more optical components 41. As in each of the above-mentioned embodiments, the first optical system 40 is located between the wavelength conversion unit 32 and the irradiation opening 10a in the optical path of the fluorescence L1 emitted from the wavelength conversion unit 32. The reflecting member 413 may have a reflecting surface 413m positioned toward the wavelength conversion unit 32. As in each of the above-mentioned embodiments, the first optical system 40 forms an image of the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side, and emits the fluorescence L1 from the irradiation opening 10a. In the example of FIG. 24, the first optical system 40 uses the reflecting member 413 as one or more optical components 41 to focus the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side, and emits the fluorescence L1 from the irradiation opening 10a. Here, the reflecting member 413 may focus the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side located on the opposite side to the first surface 32a of the wavelength conversion unit 32 in the path of the fluorescence L1. In other words, the reflecting member 413 may focus the image of the wavelength conversion unit 32 as a real image on the image plane Is1. This may reduce the amount of light of the fluorescence L1 irradiated to the inner surface of the housing 10, for example. The first surface 32a of the wavelength conversion unit 32 may have a conjugate relationship with the image plane Is1. The reflecting member 413 in the first optical system 40 may be an imaging optical system that forms an image of the wavelength conversion section 32 on a virtual image plane Is1, like the one or more lenses 412 in the first optical system 40 in the first embodiment. The reflecting member 413 may be, for example, a member whose entirety is made of metal and whose mirror-finished surface serves as the reflecting surface 413m, or a member whose reflecting surface 413m is formed by forming a metal film on a metal or nonmetallic base material.

[0209] 24, the first light-shielding portion 50 has a first through-hole 50h located between the first region 32a1 of the first surface 32a of the wavelength converting portion 32 and the reflecting member 413. The first light-shielding portion 50 covers the second region 32a2 of the first surface 32a of the wavelength converting portion 32. The first optical axis Ax1 or the second optical axis Ax2 may pass through the first through-hole 50h. Here, the second optical axis Ax2 may pass through the center of the first through-hole 50h.

[0210] In this fifth embodiment, as in the above-mentioned embodiments, the first light-shielding portion 50 has a first through-hole 50h located between the first region 32a1 of the first surface 32a of the wavelength conversion portion 32 and the first optical system 40, and covers the second region 32a2 surrounding the first region 32a1 of the first surface 32a.

[0211] Here, for example, a case is assumed in which a part (partial excitation light) of the excitation light L0 irradiated from the light source 20 to the wavelength conversion unit 32 is not converted to the fluorescence L1 in the wavelength conversion unit 32, but is emitted toward the reflection member 413, which is the first optical component 41, by reflection and scattering in the wavelength conversion unit 32. In this case, a part of the partial excitation light reflected in a direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 by the surface (for example, the reflection surface 413m, etc.) of the reflection member 413, which is the first optical component 41, may be blocked by the first light shielding unit 50. This may reduce the irradiation of the excitation light L0 to the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. Therefore, the emission of the fluorescence L1 from the second region 32a2 may be reduced. This may reduce the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32. As a result, the amount of the fluorescence L1 irradiated to the inner surface of the housing 10 may be reduced. This can reduce stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10. As a result, the amount of stray light irradiated from the lighting device 1 in a space different from the intended target space to which the illumination light is to be projected is reduced, and the visibility of the lighting device 1 can be reduced. In other words, the visibility of the lighting device 1 when it is emitting illumination light (when emitting light) can be reduced.

[0212] Furthermore, according to the illumination device 1 according to the fifth embodiment, for example, the traveling direction of the fluorescence L1 can be changed by reflection of the fluorescence L1 by the reflecting member 413. This eliminates the need to include the wavelength separation filter 411 in one or more optical components 41 of the first optical system 40. Furthermore, it is possible to simplify the configuration of the imaging optical system constituted by one or more optical components 41. As a result, it is possible to simplify the configuration of the illumination device 1.

[0213] Here, for example, in an imaging optical system constituted by one or more optical components 41, by using a reflecting member 413 instead of the lens 412, the occurrence of chromatic aberration in the illumination light can be reduced.

[0214] Here, for example, it is assumed that the excitation light L0 is a Gaussian beam having a Gaussian distribution of light intensity in a direction (radial direction) perpendicular to the light traveling direction. In this case, if the first light-shielding unit 50 is located on the optical path of the excitation light L0 traveling from the light source 20 to the wavelength conversion unit 32, the first light-shielding unit 50 can reduce the irradiation of the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 with the weak light intensity part in the radial outer periphery of the excitation light L0. Therefore, the emission of the fluorescence L1 from the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 toward the first optical system 40 (for example, the reflecting member 413) can be reduced. In other words, the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32 can be reduced. This can reduce the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, in a space other than the original target space to which the illumination light is to be projected, the amount of stray light irradiated from the illumination device 1 is reduced, and the conspicuousness of the presence of the illumination device 1 can be reduced. Therefore, the conspicuousness of the illumination device 1 when emitting the illumination light (when emitting light) can be reduced.

[0215] Here, for example, as shown in FIG. 24, the illumination device 1 may include an aperture portion 112 having a second aperture 11b. Here, the second aperture 11b of the aperture portion 112 passes the fluorescence L1 having a predetermined spread angle θ1 or less of the fluorescence L1 from the wavelength conversion unit 32 to the first optical system 40 side. In other words, the light (blocked light) traveling at a spread angle larger than the predetermined spread angle θ1 of the fluorescence L1 from the wavelength conversion unit 32 is blocked by the aperture portion 112. The aperture portion 112 may be located on the reflection member 413 side of the first light shielding unit 50. The aperture portion 112 may be, for example, a plate-shaped member having a thickness direction along the second optical axis direction Dp2. The second aperture 11b may be a through hole penetrating along the thickness direction of the aperture portion 112. The aperture portion 112 may be in contact with the first light shielding unit 50 or may not be in contact with the first light shielding unit 50. The opening portion 112 may be, for example, a part of the housing 10 that is connected to the holding portion 114. The opening portion 112 may have a first inner circumferential surface 1121a that surrounds the second optical axis Ax2.

[0216] The second opening 11b may have a shape corresponding to the diaphragm opening 11ba of the first embodiment. Specifically, the first inner circumferential surface 1121a of the second opening 11b may be inclined with respect to the second optical axis Ax2. More specifically, the first inner circumferential surface 1121a may be inclined in such a manner that the area (opening area) of the second opening 11b increases toward the wavelength conversion section 32 side. The area (opening area) of the second opening 11b may be the area of ​​a cross section perpendicular to the second optical axis Ax2 in the second opening 11b. In other words, the first inner circumferential surface 1121a of the second opening 11b may be inclined in such a manner that it moves away from the central axis (e.g., the second optical axis Ax2) of the second opening 11b toward the wavelength conversion section 32 side. Since the wavelength conversion section 32 is located near the second opening 11b, most of the shielded light from the wavelength conversion section 32 may be incident on the first inner peripheral surface 1121a of the second opening 11b. The shielded light may be reflected or scattered by the first inner peripheral surface 1121a of the second opening 11b and travel in the opposite direction to the reflecting member 413, or a part of the shielded light may be absorbed by the opening portion 112, for example.

[0217] Here, of the fluorescence L1 output from the wavelength conversion unit 32, the fluorescence L1 having a divergence angle equal to or smaller than a predetermined divergence angle θ1 passes through the second opening 11b, and the shielded light outside the fluorescence L1 passing through the second opening 11b is shielded by the opening portion 112. This can reduce a portion of the fluorescence L1 emitted from the wavelength conversion unit 32 that travels toward the inner surface of the housing 10. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, the conspicuousness of the lighting device 1 during emission can be reduced.

[0218] Also, here, for example, as in each of the above-mentioned embodiments, the imaging optical system constituted by one or more reflecting members 413 as the optical components 41 may be designed under the condition that the second spread angle θ2 is smaller than the first spread angle θ1. As a specific example of the second spread angle θ2, the orientation angle (e.g., half-value angle) of the fluorescence L1 in the illumination space S1 may be about 60 degrees or less, or may be less than 45 degrees, less than 30 degrees, or less than 15 degrees. As a result, for example, when a plurality of illumination devices 1 are positioned at regular intervals with respect to the illumination space S1, the glare of the illumination devices 1 entering the field of view in the illumination space S1 is reduced. As a result, the comfort of the illumination space S1 may be increased.

[0219] Also, here, for example, as in each of the above-mentioned embodiments, the imaging magnification of the imaging optical system constituted by one or more reflecting members 413 as the optical components 41 may be set to be equal to or less than the value obtained by dividing the size (third size) M3 of the irradiation opening 10a by the size (first size) M1 of the fluorescence L1 on the first surface 32a of the wavelength conversion unit 32. This can reduce the possibility that the fluorescence L1 will be incident on the peripheral portion of the irradiation opening 10a in the housing 10. As a result, it is possible to reduce stray light, which is unnecessary reflected and scattered light that is generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 and leaks out from the irradiation opening 10a. The imaging magnification may be a value obtained by dividing the size (second size) M2 of the fluorescence L1 on the image plane Is1 by the first size M1.

[0220] <2-5. Sixth embodiment> In each of the above-described embodiments, for example, as shown in FIG. 26, the wavelength conversion unit 32 may have a surface (also referred to as a fourth surface) 32b on the opposite side to the first surface 32a, and the fourth surface 32b may be a surface onto which the excitation light L0 from the light source 20 is irradiated. If this configuration is adopted, the wavelength conversion unit 32 can emit the fluorescence L1 from the first surface 32a on the opposite side to the fourth surface 32b toward the first optical system 40 in response to irradiation of the excitation light L0 onto the fourth surface 32b. In this case, it is not necessary to include the wavelength separation filter 411 in one or more optical components 41 of the first optical system 40. As a result, the configuration of the illumination device 1 can be simplified. In addition, the design of the optical path of the fluorescence L1 from the wavelength conversion unit 32 to the irradiation opening 10a can be made simpler.

[0221] Fig. 26 is a cross-sectional view showing a schematic example of the configuration of the illumination device 1 according to the sixth embodiment. Fig. 27 is an enlarged cross-sectional view showing a part of the illumination device 1 in Fig. 26. The illumination device 1 according to the sixth embodiment shown in Figs. 26 and 27 is based on the illumination device 1 according to the fourth embodiment shown in Fig. 21. This illumination device 1 according to the sixth embodiment has a configuration in which the shapes of the housing 10 and the wavelength conversion member 30, the arrangement of the light source 20, the second optical system 60, the wavelength conversion member 30, one or more optical components 41 constituting the first optical system 40, and the first light blocking unit 50 are changed.

[0222] 26 and 27, as in FIG. 21, an example of the optical axis (first optical axis) Ax1 of the light source 20, an example of the optical axis (second optical axis) Ax2 of the 1A lens 4121A as the first optical component 41, and an example of the third optical axis Ax3 along the path through which the center of the optical path of the fluorescence L1 from the first optical system 40 to the irradiation opening 10a passes are each shown typically by a thin dashed line. An example of the outer edge of the path of the excitation light L0 is shown typically by a thin broken line. An example of the outer edge of the path of the fluorescence L1 is shown typically by a thin two-dot chain line. The first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be the same or approximately the same. In this case, the first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be collectively simply referred to as the optical axis Ax0. The first optical axis direction Dp1 along the first optical axis Ax1, the second optical axis direction Dp2 along the second optical axis Ax2, and the third optical axis direction Dp3 along the third optical axis Ax3 may be the -Z direction as the first direction and the second direction, respectively. In this case, the first optical axis direction Dp1, the second optical axis direction Dp2, and the third optical axis direction Dp3 may be collectively referred to simply as the optical axis direction and Dp0.

[0223] 26 and 27, the plurality of members constituting the housing 10 are shown as being integrally formed members for convenience. The housing 10 may be a composite body in which a plurality of members are combined. In FIG. 27, an example of a first spread angle θ1, which is a spread angle of the fluorescence L1 from the wavelength conversion unit 32 toward the 1A lens 4121A, is shown by a thin arc-shaped arrow. In FIG. 26, an example of a second spread angle θ2, which is a spread angle of the fluorescence L1 in the illumination space S1, is shown by a thin arc-shaped arrow. Here, the first spread angle θ1 is a spread angle of the fluorescence L1 immediately before an imaging optical system constituted by one or more lenses 412 as one or more optical components 41. The second spread angle θ2 is a spread angle of the fluorescence L1 immediately after the image plane Is1.

[0224] In the sixth embodiment, as in the above-described embodiments, the illumination device 1 includes, for example, a housing 10, a light source 20, a wavelength conversion section 32, a first optical system 40, and a first light blocking section 50.

[0225] 26 and 27, like the above-described embodiments, the housing 10 has an irradiation opening 10a. The housing 10 may include, for example, a main body 11 and a frame 13. In the example of FIG. 26 and FIG. 27, the main body 11 houses the second optical system 60, the wavelength conversion member 30, the first optical system 40, and the first light-shielding part 50. The main body 11 includes, for example, a third side wall portion 111c and a fourth side wall portion 111d.

[0226] The third side wall portion 111c and the fourth side wall portion 111d may each have a cylindrical shape. The third side wall portion 111c may have a hollow space (also referred to as a sixth hollow space) 6sp penetrating along the second optical axis direction Dp2. The fourth side wall portion 111d may have a hollow space (also referred to as a seventh hollow space) 7sp penetrating along the first optical axis direction Dp1. In other words, the third side wall portion 111c and the fourth side wall portion 111d may each have a linear longitudinal direction. An edge of the seventh hollow space 7sp in the -Z direction as the first optical axis direction Dp1 may be connected to the sixth hollow space 6sp. The sixth hollow space 6sp and the seventh hollow space 7sp may form an internal space 10is of the housing 10. The second optical axis Ax2 may pass through the sixth hollow space 6sp of the third side wall portion 111c. The first optical axis Ax1 may pass through the seventh hollow space 7sp of the fourth side wall portion 111d. In the example of Fig. 26 and Fig. 27, the optical axis Ax0 passes through each of the sixth hollow space 6sp of the third side wall portion 111c and the seventh hollow space 7sp of the fourth side wall portion 111d. The cross section perpendicular to the second optical axis Ax2 in the sixth hollow space 6sp of the third side wall portion 111c may be larger than the cross section perpendicular to the first optical axis Ax1 in the seventh hollow space 7sp of the fourth side wall portion 111d. In the example of Fig. 26 and Fig. 27, the cross section perpendicular to the optical axis Ax0 in the sixth hollow space 6sp is larger than the cross section perpendicular to the optical axis Ax0 in the seventh hollow space 7sp.

[0227] The frame portion 13 may be located in a fixed state at an end portion of the third side wall portion 111c opposite to the fourth side wall portion 111d. As in each of the above embodiments, the housing 10 may have an irradiation opening 10a in the frame portion 13.

[0228] The light source 20, the second optical system 60, the wavelength conversion member 30 including the wavelength conversion portion 32, and the first optical system 40 may be arranged in this order in the first optical axis direction Dp1. More specifically, the light source 20, the second optical system 60, the wavelength conversion member 30, and the first optical system 40 may be located on the first optical axis Ax1. In the example of FIG. 26 and FIG. 27, the light source 20, the second optical system 60, the wavelength conversion member 30, and the first optical system 40 are arranged in this order in the -Z direction as the optical axis direction Dp0. The light source 20, the second optical system 60, the wavelength conversion member 30, and the first optical system 40 are located on the optical axis Ax0. The first optical system 40 includes, as one or more optical components 41, a 1A lens 4121A and a 1B lens 4121B which are one or more lenses 412.

[0229] The light source 20 can emit the excitation light L0 in the same manner as in each of the above-described embodiments. In the example of Fig. 26 and Fig. 27, the light source 20 can emit the excitation light L0 toward the -Z direction as the first optical axis direction Dp1. The light source 20 may be attached to an edge of the fourth side wall portion 111d in the +Z direction as the opposite direction to the first optical axis direction Dp1.

[0230] The second optical system 60 is located between the light source 20 and the wavelength conversion unit 32 in the optical path of the excitation light L0 from the light source 20 to the fourth surface 32b of the wavelength conversion unit 32. The second optical system 60 may be held, for example, inside the fourth side wall portion 111d. In other words, the second optical system 60 may be located, for example, in the seventh hollow space 7sp of the fourth side wall portion 111d. The second optical system 60 may be able to guide the excitation light L0 from the light source 20 to the wavelength conversion unit 32. The second optical system 60 may include, for example, one lens 61, or may include two or more lenses 61 arranged in the first optical axis direction Dp1. The second optical system 60, for example, focuses the excitation light L0 from the light source 20 on the fourth surface 32b of the wavelength conversion unit 32. More specifically, the second optical system 60 may focus the excitation light L0 from the light source 20 on a region of the fourth surface 32b of the wavelength conversion section 32 that is located on the opposite side of the first region 32a1 of the first surface 32a in the direction along the first optical axis Ax1.

[0231] 26 and 27, the wavelength conversion member 30 includes a holding portion 33 and a wavelength conversion portion 32. In other words, in the examples of Fig. 26 and Fig. 27, the wavelength conversion member 30 includes a holding portion 33 instead of the substrate 31 in each of the above embodiments.

[0232] The holding portion 33 may be, for example, a member having a through hole 33h penetrating along the first optical axis Ax1. The holding portion 33 may be, for example, a plate-shaped member having a through hole 33h. In this case, the thickness direction of the holding portion 33 may be set, for example, in the first optical axis direction Dp1. The wavelength conversion portion 32 may be, for example, located in the through hole 33h of the holding portion 33. Here, the wavelength conversion portion 32 may be, for example, located in a state filled in the through hole 33h of the holding portion 33. The material of the holding portion 33 may be, for example, a metal material like the material of the substrate 31 in each of the above embodiments, or may be another inorganic material such as ceramics. The wavelength conversion member 30 may be formed, for example, by fixing the wavelength conversion portion 32 in the through hole 33h of the holding portion 33. The wavelength conversion section 32 can be produced, for example, by placing a mixed powder obtained by mixing a phosphor powder and a low-melting point glass powder in the through-hole 33h of the holding section 33, and sintering the low-melting point glass powder by applying pressure and heat to the mixed powder. Here, for example, a mass including portions corresponding to the plurality of wavelength conversion sections 32 may be formed inside a cylindrical member made of an inorganic material, and then the cylindrical member made of an inorganic material may be divided into a plurality of small pieces in the longitudinal direction of the cylindrical member, thereby producing a plurality of wavelength conversion members 30.

[0233] Here, for example, if the material of the holder 33 is a material having a higher thermal conductivity than the wavelength conversion unit 32, like the material of the substrate 31 in each of the above embodiments, the holder 33 can increase the rate at which heat dissipates from the wavelength conversion unit 32. This can reduce quenching (thermal quenching), in which the intensity of the fluorescence L1 emitted from the wavelength conversion unit 32 decreases as the temperature of the wavelength conversion unit 32 increases. In addition, the degree to which the wavelength conversion unit 32 deteriorates due to heat can be reduced. For example, a metal material with high thermal conductivity, such as Cu, Al, Mg, Au, Ag, Fe, Cr, Co, Be, Mo, W, or an alloy, is used as the material of the holder 33.

[0234] As in the above-described embodiments, the wavelength conversion unit 32 can emit the fluorescence L1 into the internal space 10is of the housing 10 in response to irradiation with the excitation light L0 from the light source 20. As described above, the wavelength conversion unit 32 has a first surface 32a located on the first optical system 40 side and a fourth surface 32b on the opposite side to the first surface 32a. The shape of the wavelength conversion unit 32 may be plate-like, block-like, or film-like. When the wavelength conversion unit 32 is plate-like or film-like, the thickness direction of the wavelength conversion unit 32 may be set in the first optical axis direction Dp1.

[0235] The wavelength conversion member 30 may be located in such a manner that the wavelength conversion portion 32 is located between the second optical system 60 and the first optical system 40. The wavelength conversion member 30 may be held, for example, inside the fourth side wall portion 111d. In other words, the wavelength conversion member 30 may be located, for example, in the seventh hollow space 7sp of the fourth side wall portion 111d.

[0236] Fig. 28 is a bottom view illustrating an example of the configuration of the wavelength conversion unit 32 and the first light shielding unit 50 according to the sixth embodiment. Fig. 28 illustrates the wavelength conversion unit 32 and the first light shielding unit 50 viewed along the +Z direction, which is the opposite direction to the first optical axis direction Dp1. In Fig. 28, an example of the outer edge of the wavelength conversion unit 32 hidden behind the first light shielding unit 50 is illustrated by a thin dashed line.

[0237] The first surface 32a of the wavelength conversion section 32 may face the -Z direction as the first optical axis direction Dp1. The fourth surface 32b of the wavelength conversion section 32 may face the +Z direction as the opposite direction to the first optical axis direction Dp1. The first surface 32a and the fourth surface 32b may each be, for example, a substantially flat surface. In the example of FIG. 26 and FIG. 27, the first surface 32a and the fourth surface 32b are each a flat surface along the XY plane. As in each of the above embodiments, the first surface 32a includes a first region 32a1 and a second region 32a2. The first region 32a1 is, for example, a region facing the first optical system 40. The first region 32a1 may be located on the first optical axis Ax1. The first optical axis Ax1 may pass through the center of the first region 32a1. The second region 32a2 is a region surrounding the first region 32a1. The second region 32a2 is covered by the first light-shielding portion 50. In other words, the first region 32a1 is a region that is not covered by the first light-shielding portion 50. The second region 32a2 may be, for example, a remaining region of the first surface 32a excluding the first region 32a1.

[0238] In the sixth embodiment, the wavelength conversion section 32 emits fluorescence L1 from the first region 32a1 of the first surface 32a toward the first optical system 40 in response to irradiation of the excitation light L0 from the light source 20 onto the fourth surface 32b.

[0239] The first optical system 40 is located in the internal space 10is of the housing 10, as in each of the above-described embodiments. The first optical system 40 is located between the wavelength conversion unit 32 and the irradiation opening 10a in the optical path of the fluorescence L1 emitted from the wavelength conversion unit 32. The first optical system 40 may include, for example, one or more first lenses 4121 as one or more optical components 41. In the example of FIG. 26 and FIG. 27, the one or more first lenses 4121 include a 1A lens 4121A and a 1B lens 4121B. Here, the one or more optical components 41 are not limited to two lenses 412, and may be one lens 412 or three or more lenses 412. In other words, the first optical system 40 may include, for example, one or more lenses 412 as one or more optical components 41.

[0240] As in the above-described embodiments, the first optical system 40 forms an image of the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side, and emits the fluorescence L1 from the irradiation opening 10a. Here, the first optical system 40 may focus the fluorescence L1 emitted from the wavelength conversion unit 32 on a virtual image plane Is1 on the irradiation opening 10a side located on the opposite side to the first surface 32a of the wavelength conversion unit 32 in the path of the fluorescence L1. In other words, the first optical system 40 may form an image of the wavelength conversion unit 32 as a real image on the image plane Is1. This may reduce, for example, the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. The first surface 32a of the wavelength conversion unit 32 may have a conjugate relationship with the image plane Is1. One or more lenses 412 in the first optical system 40 may be, for example, an imaging optical system that forms an image of the wavelength conversion unit 32 on the virtual image plane Is1.

[0241] As in the above-described embodiments, the first light-shielding portion 50 has a first through-hole 50h located between the first region 32a1 of the first surface 32a of the wavelength conversion portion 32 and the first optical system 40. The first light-shielding portion 50 covers the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. The second optical axis Ax2 may pass through the first through-hole 50h. The second optical axis Ax2 may pass through the center of the first through-hole 50h.

[0242] Also in this sixth embodiment, the first light-shielding portion 50 has a first through-hole 50h located between the first region 32a1 of the first surface 32a of the wavelength conversion portion 32 and the first optical system 40, and covers the second region 32a2 surrounding the first region 32a1 of the first surface 32a.

[0243] Here, for example, a case is assumed in which a part (partial excitation light) of the excitation light L0 emitted from the light source 20 and irradiated to the wavelength conversion unit 32 is not converted to the fluorescence L1 in the wavelength conversion unit 32, but is emitted toward the 1A lens 4121A, which is the first optical component 41, by transmission and scattering in the wavelength conversion unit 32. In this case, a part of the partial excitation light reflected in a direction toward the second region 32a2 of the first surface 32a of the wavelength conversion unit 32 at the surface (first lens surface) 412a of the 1A lens 4121A, which is the first optical component 41, may be blocked by the first light shielding unit 50. This may reduce the irradiation of the excitation light L0 to the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. This may reduce the emission of the fluorescence L1 from the second region 32a2. This may reduce the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32. As a result, the amount of fluorescence L1 irradiated to the inner surface of the housing 10 can be reduced. Thus, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, in a space different from the original target space to which the illumination light is intended to be projected, the amount of stray light irradiated from the illumination device 1 is reduced, and the conspicuousness of the presence of the illumination device 1 can be reduced. In other words, the conspicuousness of the illumination device 1 when emitting illumination light (when emitting light) can be reduced.

[0244] Furthermore, according to the illumination device 1 of the sixth embodiment, for example, in the wavelength conversion unit 32, in response to irradiation of the fourth surface 32b with the excitation light L0, the fluorescence L1 is emitted from the first surface 32a opposite to the fourth surface 32b toward the first optical system 40. This eliminates the need to include a wavelength separation filter 411 in one or more optical components 41 of the first optical system 40. As a result, the configuration of the illumination device 1 can be simplified. Also, the design of the optical path of the fluorescence L1 from the wavelength conversion unit 32 to the irradiation opening 10a can be made simpler.

[0245] Here, for example, as in the second embodiment, the first light-shielding portion 50 may be integrally formed with the wavelength conversion portion 32. If this configuration is adopted, alignment between the wavelength conversion portion 32 and the first light-shielding portion 50 may be facilitated when manufacturing the lighting device 1. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 may be easily reduced. Here, as in the second embodiment, the first light-shielding portion 50 may be a film (first coating film) 50A located on the second region 32a2 of the first surface 32a of the wavelength conversion portion 32. Here, the first coating film 50A may be located, for example, from the second region 32a2 of the first surface 32a of the wavelength conversion portion 32 to the surface of the holding portion 33. This first coating film 50A may be formed, for example, by performing a blackening treatment using a coating on the second region 32a2 of the first surface 32a of the wavelength conversion portion 32, etc. In this case, the second surface 50f of the first light shielding portion 50 may be a black surface. Also, for example, the first light shielding portion 50 may be integrated with the wavelength converting portion 32 when the wavelength converting portion 32 is produced by sintering.

[0246] Here, as shown in FIG. 26 and FIG. 27, for example, the illumination device 1 may include an aperture portion 112 having a second aperture 11b. Here, the second aperture 11b of the aperture portion 112 passes the fluorescence L1 having a predetermined spread angle θ1 or less of the fluorescence L1 from the wavelength conversion unit 32 to the first optical system 40 side. In other words, the light (blocked light) traveling at a spread angle larger than the predetermined spread angle θ1 of the fluorescence L1 from the wavelength conversion unit 32 is blocked by the aperture portion 112. The aperture portion 112 may be located on the first optical system 40 side of the first light shielding unit 50. The aperture portion 112 may be, for example, a plate-shaped member having a thickness direction along the optical axis direction Dp0. The second aperture 11b may be a through hole penetrating along the thickness direction of the aperture portion 112. The aperture portion 112 may be in contact with the first light shielding unit 50 or may not be in contact with the first light shielding unit 50. The opening portion 112 may include, for example, a portion (also referred to as an inner peripheral protrusion) 1121 that protrudes from the inner peripheral surface of the fourth side wall portion 111d toward the optical axis Ax0. In other words, the opening portion 112 may be a part of the housing 10. The opening portion 112 may have, for example, a first inner peripheral surface 1121a that surrounds the optical axis Ax0.

[0247] The second opening 11b may have a shape corresponding to the diaphragm opening 11ba of the first embodiment. Specifically, the first inner circumferential surface 1121a of the second opening 11b may be inclined with respect to the second optical axis Ax2. More specifically, the first inner circumferential surface 1121a may be inclined in such a manner that the area (opening area) of the second opening 11b increases toward the wavelength conversion section 32 side. The area (opening area) of the second opening 11b may be the area of ​​a cross section perpendicular to the second optical axis Ax2 in the second opening 11b. In other words, the first inner circumferential surface 1121a of the second opening 11b may be inclined in such a manner that it moves away from the central axis (e.g., the second optical axis Ax2) of the second opening 11b toward the wavelength conversion section 32 side. Since the wavelength conversion section 32 is located near the second opening 11b, most of the shielded light from the wavelength conversion section 32 may be incident on the first inner peripheral surface 1121a of the second opening 11b. The shielded light may be reflected or scattered by the first inner peripheral surface 1121a of the second opening 11b and travel in the opposite direction to the reflecting member 413, or a part of the shielded light may be absorbed by the opening portion 112, for example.

[0248] Here, of the fluorescence L1 output from the wavelength conversion unit 32, the fluorescence L1 having a divergence angle equal to or smaller than a predetermined divergence angle θ1 passes through the second opening 11b, and the shielded light outside the fluorescence L1 passing through the second opening 11b is shielded by the opening portion 112. This can reduce a portion of the fluorescence L1 emitted from the wavelength conversion unit 32 that travels toward the inner surface of the housing 10. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, the conspicuousness of the lighting device 1 during emission can be reduced.

[0249] Also, here, for example, as in each of the above-mentioned embodiments, the imaging optical system constituted by one or more optical components 41 of the first optical system 40 may be designed under the condition that the second spread angle θ2 is smaller than the first spread angle θ1. As a specific example of the second spread angle θ2, the orientation angle (e.g., half-value angle) of the fluorescence L1 in the illumination space S1 may be about 60 degrees or less, or may be less than 45 degrees, less than 30 degrees, or less than 15 degrees. As a result, for example, when a plurality of illumination devices 1 are positioned at regular intervals with respect to the illumination space S1, the glare of the illumination devices 1 entering the field of view in the illumination space S1 is reduced. As a result, the comfort of the illumination space S1 may be increased.

[0250] Also, here, for example, as in each of the above-mentioned embodiments, the imaging magnification of the imaging optical system constituted by one or more optical components 41 of the first optical system 40 may be set to a value equal to or less than the value obtained by dividing the size (third size) M3 of the irradiation opening 10a by the size (first size) M1 of the fluorescence L1 on the first surface 32a of the wavelength conversion unit 32. This can reduce the possibility that the fluorescence L1 will be incident on the peripheral portion of the irradiation opening 10a of the housing 10. As a result, it is possible to reduce stray light, which is unnecessary reflected and scattered light that is generated by reflection of the fluorescence L1 on the inner surface of the housing 10 and leaks out from the irradiation opening 10a. The imaging magnification may be a value obtained by dividing the size (second size) M2 of the fluorescence L1 on the image plane Is1 by the first size M1.

[0251] In the sixth embodiment, for example, the illumination device 1 includes a second optical system 60 and may further include a second light-shielding portion 52 covering a portion of the fourth surface 32b of the wavelength conversion portion 32, as shown in FIG. 29.

[0252] Fig. 29 is a cross-sectional view that illustrates a part of another example (also referred to as a first example) of the configuration of the illumination device 1 according to the sixth embodiment. Fig. 29 illustrates a part of the illumination device 1 according to the sixth embodiment that corresponds to Fig. 27. Fig. 30 is a plan view that illustrates a schematic example of the configuration of the wavelength conversion unit 32 and the second light blocking unit 52 according to the sixth embodiment.

[0253] In FIG. 29, as in FIG. 27, an example of the optical axis (first optical axis) Ax1 of the light source 20, an example of the optical axis (second optical axis) Ax2 of the 1A lens 4121A as the first optical component 41, and an example of the third optical axis Ax3 along the path through which the center of the optical path of the fluorescence L1 from the first optical system 40 toward the irradiation opening 10a passes are each shown by a thin dashed line. An example of the outer edge of the path of the excitation light L0 is shown by a thin broken line. An example of the outer edge of the path of the fluorescence L1 is shown by a thin two-dot chain line. The first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be the same or approximately the same. In this case, the first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be collectively simply referred to as the optical axis Ax0. The first optical axis direction Dp1 along the first optical axis Ax1, the second optical axis direction Dp2 along the second optical axis Ax2, and the third optical axis direction Dp3 along the third optical axis Ax3 may be the -Z direction as the first direction and the second direction, respectively. In this case, the first optical axis direction Dp1, the second optical axis direction Dp2, and the third optical axis direction Dp3 may be collectively referred to simply as the optical axis direction and Dp0. FIG. 30 shows a view of the wavelength conversion unit 32 and the second light-shielding unit 52 viewed along the -Z direction as the first optical axis direction Dp1. In FIG. 30, an example of the outer edge of the wavelength conversion unit 32 hidden behind the second light-shielding unit 52 is shown by a thin dashed line.

[0254] As shown in FIG. 30, the fourth surface 32b includes, for example, a third region 32b1 and a fourth region 32b2. The third region 32b1 may be a region located on the opposite side of the wavelength conversion unit 32 from the first region 32a1. For example, the third region 32b1 may be a region located on the opposite side of the first region 32a1 of the first surface 32a in the direction along the first optical axis Ax1 of the fourth surface 32b. From another perspective, the third region 32b1 may be a region facing the second optical system 60. The third region 32b1 may be located on the first optical axis Ax1. The first optical axis Ax1 may pass through the center of the third region 32b1. The center of the third region 32b1 may be, for example, the center of gravity of the third region 32b1. The fourth region 32b2 may be a region surrounding the third region 32b1. The fourth region 32b2 may be covered by the second light-shielding portion 52. In other words, the third region 32b1 may be a region that is not covered by the second light-shielding portion 52. The fourth region 32b2 may be, for example, a remaining region of the fourth surface 32b excluding the third region 32b1.

[0255] The second light-shielding portion 52 may be a portion capable of blocking light. The light blocked by the second light-shielding portion 52 includes, for example, the excitation light L0. The light blocked by the second light-shielding portion 52 may include, for example, the excitation light L0 and the fluorescence L1. The second light-shielding portion 52 may have, for example, a plate-like, film-like, or foil-like shape. In the example of FIG. 30, the outer edge of the second light-shielding portion 52 has a circular shape, but is not limited thereto. The outer edge of the second light-shielding portion 52 may have other shapes such as a circular shape, an elliptical shape, or a polygonal shape. The second light-shielding portion 52 may have a through hole (also referred to as a second through hole) 52h. The second through hole 52h may be located between the third region 32b1 of the fourth surface 32b of the wavelength conversion portion 32 and the second optical system 60. The second light-shielding portion 52 may cover the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32.

[0256] The second light-shielding portion 52 may be located along the fourth surface 32b of the wavelength conversion portion 32. More specifically, the second light-shielding portion 52 may be located along the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32. The second light-shielding portion 52 may be located, for example, in a state of contact with the fourth surface 32b of the wavelength conversion portion 32, or in a state of being close to the fourth surface 32b of the wavelength conversion portion 32. The excitation light L0 from the light source 20 passes through the second through-hole 52h and is irradiated onto the third region 32b1 of the fourth surface 32b of the wavelength conversion portion 32. The portion of the excitation light L0 from the light source 20 that is directed toward the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32 is blocked by the second light-shielding portion 52.

[0257] Here, for example, a case is assumed in which a part (partial excitation light) of the excitation light L0 irradiated from the light source 20 to the wavelength conversion unit 32 is not converted to the fluorescence L1 in the wavelength conversion unit 32 and is emitted toward the second optical system 60 by reflection and scattering in the wavelength conversion unit 32. In this case, a part of the partial excitation light reflected in a direction toward the fourth region 32b2 of the fourth surface 32b of the wavelength conversion unit 32 on the surface of the second optical system 60 (for example, one or more lenses 61) may be blocked by the second light blocking unit 52. This can reduce the irradiation of the excitation light L0 to the fourth region 32b2 of the fourth surface 32b of the wavelength conversion unit 32. Therefore, the emission of the fluorescence L1 from the second region 32a2 located on the opposite side of the fourth region 32b2 of the wavelength conversion unit 32 can be reduced. This can reduce the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32. As a result, the amount of the fluorescence L1 irradiated to the inner surface of the housing 10 can be reduced. This can reduce stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10. As a result, the amount of stray light irradiated from the lighting device 1 in a space different from the intended target space to which the illumination light is to be projected is reduced, and the visibility of the lighting device 1 can be reduced. In other words, the visibility of the lighting device 1 when it is emitting illumination light (when emitting light) can be reduced.

[0258] Also, here, for example, a case is assumed in which the excitation light L0 is a Gaussian beam having a Gaussian distribution of light intensity in a direction (radial direction) perpendicular to the light traveling direction. In this case, if the second light-shielding portion 52 covers the fourth region 32b2 of the wavelength conversion portion 32, the second light-shielding portion 52 can reduce irradiation of the portion of the excitation light L0 with a weak light intensity in the outer periphery in the radial direction to the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32. Therefore, emission of the fluorescence L1 from the second region 32a2 of the first surface 32a located on the opposite side of the fourth region 32b2 of the wavelength conversion portion 32 toward the first optical system 40 can be reduced. In other words, emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion portion 32 can be reduced. This can reduce the amount of the fluorescence L1 irradiated to the inner surface of the housing 10. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, in a space other than the original target space to which the illumination light is to be projected, the amount of stray light irradiated from the illumination device 1 is reduced, and the conspicuousness of the presence of the illumination device 1 can be reduced. Therefore, the conspicuousness of the illumination device 1 when emitting the illumination light (when emitting light) can be reduced.

[0259] Meanwhile, the second light-shielding portion 52 has, for example, a surface (also referred to as a back surface or a fifth surface) 52b located on the fourth region 32b2 side of the wavelength conversion portion 32. The second light-shielding portion 52 has, for example, a surface (also referred to as a front surface or a sixth surface) 52f located on the second optical system 60 side.

[0260] The second light-shielding portion 52 may be located in a state of contact with the fourth surface 32b of the wavelength conversion portion 32, or in a state of being close to the fourth surface 32b of the wavelength conversion portion 32. More specifically, for example, the fifth surface 52b of the second light-shielding portion 52 may be in contact with the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32, or in a state of being close to the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32. Here, the state in which the fifth surface 52b and the fourth region 32b2 are close to each other includes, for example, a state in which the distance between the fifth surface 52b and the fourth region 32b2 is several hundred μm or less. The second light-shielding portion 52 may be located in, for example, the internal space 10is of the housing 10. In the example of FIG. 29, the second light-shielding portion 52 is located in the seventh hollow space 7sp. When the fourth surface 32b and the second light-shielding portion 52 are viewed in a plane along a direction perpendicular to the fourth surface 32b, the shape of the second through hole 52h may be, for example, circular, elliptical, or another shape such as a shape including a notch.

[0261] For example, metal may be applied to the material of the second light-shielding part 52. In this case, the thermal conductivity of the second light-shielding part 52 is high, and the speed at which heat dissipates from the wavelength conversion part 32 can be increased. This can reduce thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion part 32 decreases as the temperature of the wavelength conversion part 32 increases. In addition, the degree to which the wavelength conversion part 32 deteriorates due to heat can be reduced. For example, metals such as stainless steel and aluminum can be applied to the material of the second light-shielding part 52. The second light-shielding part 52 may have a plate-like, film-like, or foil-like form. For example, the second light-shielding part 52 may have a film-like or foil-like form having a thickness of 50 μm to several hundred μm. This can reduce the amount of material used by making the second light-shielding part 52 thinner.

[0262] Here, for example, the second light-shielding portion 52 may have metal exposed on the fifth surface 52b. In this case, for example, the rate at which heat dissipates from the wavelength conversion portion 32 to the second light-shielding portion 52 can be increased. This can reduce thermal quenching, in which the intensity of the fluorescence L1 emitted from the wavelength conversion portion 32 decreases as the temperature of the wavelength conversion portion 32 increases. In addition, the degree to which the wavelength conversion portion 32 is deteriorated by heat can be reduced. Furthermore, for example, when the excitation light L0 from the light source 20 is incident on the wavelength conversion portion 32, the excitation light L0 traveling from the wavelength conversion portion 32 toward the second light-shielding portion 52 can be reflected toward the inside of the wavelength conversion portion 32 by the fifth surface 52b of the second light-shielding portion 52. This can increase the ratio of the excitation light L0 converted into the fluorescence L1 out of the excitation light L0 irradiated to the wavelength conversion portion 32. As a result, the luminous efficiency of the lighting device 1 can be increased.

[0263] The second light-shielding portion 52 may be in contact with, for example, the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32. In this case, the excitation light L0 irradiated to the fourth region 32b2 of the fourth surface 32b of the wavelength conversion portion 32 through a gap between the fourth surface 32b of the wavelength conversion portion 32 and the second light-shielding portion 52 may be reduced. Therefore, the emission of the fluorescence L1 from the second region 32a2 located on the opposite side of the fourth region 32b2 of the wavelength conversion portion 32 may be reduced. As a result, the stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 may be reduced. Therefore, the conspicuousness of the lighting device 1 during emission may be reduced.

[0264] Here, for example, like the first light-shielding part 50, the second light-shielding part 52 may be integrally formed with the wavelength conversion part 32. If this configuration is adopted, alignment between the wavelength conversion part 32 and the second light-shielding part 52 may be facilitated when manufacturing the lighting device 1. As a result, stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10 may be easily reduced. Here again, like the first light-shielding part 50, the second light-shielding part 52 may be a film (also referred to as a second film or a second coating film) 52A located on the fourth region 32b2 of the fourth surface 32b of the wavelength conversion part 32. Also, the second light-shielding part 52 may be a film (second coating film) 52A located, for example, from the fourth region 32b2 of the fourth surface 32b of the wavelength conversion part 32 to the surface of the holding part 33. This second coating film 52A may be formed, for example, by performing a blackening treatment using a coating on the fourth region 32b2 of the fourth surface 32b of the wavelength conversion part 32, etc. Furthermore, for example, the second light-shielding portion 52 may be integrated with the wavelength converting portion 32 when the wavelength converting portion 32 is produced by sintering.

[0265] Here, for example, as shown in FIG. 31, the illumination device 1 according to the sixth embodiment may include a second light-shielding portion 52 without including the first light-shielding portion 50. In this case, as shown in FIG.

[0266] Fig. 31 is a cross-sectional view illustrating a schematic view of a part of another example (also referred to as a second example) of the configuration of the illumination device 1 according to the sixth embodiment. Fig. 31 illustrates a part of the illumination device 1 according to the sixth embodiment that corresponds to Figs. 27 and 29.

[0267] In FIG. 31, as in FIG. 27 and FIG. 29, an example of the optical axis (first optical axis) Ax1 of the light source 20, an example of the optical axis (second optical axis) Ax2 of the 1A lens 4121A as the first optical component 41, and an example of the third optical axis Ax3 along the path through which the center of the optical path of the fluorescence L1 from the first optical system 40 toward the irradiation opening 10a passes are each shown by a thin dashed line. An example of the outer edge of the path of the excitation light L0 is shown by a thin broken line. An example of the outer edge of the path of the fluorescence L1 is shown by a thin two-dot chain line. The first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be the same or approximately the same. In this case, the first optical axis Ax1, the second optical axis Ax2, and the third optical axis Ax3 may be collectively simply referred to as the optical axis Ax0. The first optical axis direction Dp1 along the first optical axis Ax1, the second optical axis direction Dp2 along the second optical axis Ax2, and the third optical axis direction Dp3 along the third optical axis Ax3 may be the -Z direction as the first direction and the second direction, respectively. In this case, the first optical axis direction Dp1, the second optical axis direction Dp2, and the third optical axis direction Dp3 may be collectively referred to simply as the optical axis direction and Dp0.

[0268] <3.Other> In the first to third embodiments, for example, by appropriately changing the arrangement of the light source 20, the excitation light L0 from the light source 20 may be irradiated to the wavelength conversion unit 32 without passing through the wavelength separation filter 411. In this case, for example, the wavelength separation filter 411 is not necessary, and the wavelength separation filter 411 may be replaced with a reflecting mirror.

[0269] In the above-described fourth embodiment, for example, by appropriately changing the arrangement of the light source 20, the excitation light L0 from the light source 20 may be irradiated to the wavelength conversion unit 32 without passing through the wavelength separation filter 411. In this case, for example, the wavelength separation filter 411 may be omitted.

[0270] In the above first, second and fourth embodiments, the housing 10 has the main body 11, the lid 12, the frame 13 and the multiple inner housings 14, but is not limited to this. For example, as long as the light source 20, the wavelength conversion unit 32 and the first optical system 40 can be arranged and fixed, the housing 10 may have any number of parts greater than or equal to one.

[0271] In the third embodiment, the housing 10 has the main body 11, the frame 13, the inner housings 14, and the support 15, but is not limited to this. For example, the housing 10 may have any number of parts greater than or equal to one, as long as the light source 20, the wavelength conversion unit 32, the first optical system 40, and the first rotation mechanism 90 can be arranged and fixed therein.

[0272] In the above first to fifth embodiments, for example, the excitation light L0 from the light source 20 may be irradiated not only to the first region 32a1 of the first surface 32a of the wavelength conversion unit 32 but also to the first light-shielding unit 50. In other words, the diameter of the spot of the excitation light L0 on the wavelength conversion unit 32 may be made larger than that of the first region 32a1. In this case, for example, even if an error occurs in the arrangement of the light source 20 and various optical components during the manufacture of the illumination device 1 and the position of the spot of the excitation light L0 on the wavelength conversion unit 32 is slightly shifted, the excitation light L0 can be irradiated over a wide range of the first region 32a1. This can reduce the spread angle θ2 and the decrease in the light amount of the fluorescence L1 as illumination light emitted from the illumination device 1 to the illumination space S1.

[0273] In each of the above embodiments, for example, the wavelength conversion unit 32 may emit the fluorescence L1 by being re-irradiated with light of a part of the wavelengths (also referred to as the first wavelength light) of the fluorescence L1 emitted in response to the excitation light L0. The first wavelength light may include, for example, light of a wavelength close to the first peak wavelength of the excitation light L0 in the fluorescence L1. For example, when the excitation light L0 is purple light, the first wavelength light may include blue light. Here, the fluorescence L1 emitted from the wavelength conversion unit 32 in response to irradiation with the first wavelength light may be light of a wavelength longer than the wavelength of the first wavelength light. Here, it is assumed that a part of the first wavelength light of the fluorescence L1 emitted from the wavelength conversion unit 32 is reflected by the first optical system 40 toward the second region 32a2 of the wavelength conversion unit 32. In this case, the first wavelength light reflected by the first optical system 40 toward the second region 32a2 of the wavelength conversion unit 32 may be blocked by the first light blocking unit 50. This can reduce the irradiation of the first wavelength light to the second region 32a2 of the first surface 32a of the wavelength conversion unit 32. This can reduce the emission of the fluorescence L1 from the second region 32a2. This can reduce the emission of the fluorescence L1 from an unexpectedly wide region of the first surface 32a of the wavelength conversion unit 32. As a result, the amount of the fluorescence L1 irradiated to the inner surface of the housing 10 can be reduced. Thus, the amount of stray light that may be generated by the reflection of the fluorescence L1 on the inner surface of the housing 10 can be reduced. Therefore, in a space different from the original target space to which the illumination light is intended to be projected, the amount of stray light irradiated from the illumination device 1 is reduced, and the conspicuousness of the presence of the illumination device 1 can be reduced. In other words, the conspicuousness of the illumination device 1 when emitting the illumination light (when emitting light) can be reduced.

[0274] In each of the above embodiments, for example, at least a part of the inner surface of the housing 10 may have irregularities or may be subjected to a blackening treatment, which may further reduce stray light that may be generated by reflection of the fluorescence L1 on the inner surface of the housing 10.

[0275] Although the lighting device has been described in detail as above, the above description is merely an example in all respects, and this disclosure is not limited thereto. In addition, the various examples described above can be combined and applied as long as they are not mutually inconsistent. It is understood that countless examples not illustrated can be envisioned without departing from the scope of this disclosure.

[0276] This disclosure includes the following:

[0277] In one embodiment, (1) an illumination device includes a housing having a first opening, a light source that emits excitation light, a wavelength conversion unit that emits fluorescence having a wavelength spectrum different from that of the excitation light in response to irradiation of the excitation light into an internal space of the housing, a first optical system located in the internal space, and a first light-shielding unit, wherein the first optical system includes one or more optical components located between the wavelength conversion unit and the first opening in an optical path of the fluorescence, and images the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side and emits the fluorescence from the first opening, the wavelength conversion unit has a first surface located on the side of the first optical system, the first surface including a first region and a second region surrounding the first region, and the first light-shielding unit has a first through hole located between the first region and the first optical system and covers the second region.

[0278] (2) In the lighting device of (1) above, the first light blocking portion may have a second surface that is black and located on the side of the first optical system.

[0279] (3) In the lighting device of (1) or (2) above, the first light-shielding portion may include a metal film, a metal foil, or a metal plate-shaped member.

[0280] (4) In the lighting device of (3) above, the first light-shielding portion may have a third surface located on the second region side, and a metal may be exposed on the third surface.

[0281] (5) In the lighting device according to any one of (1) to (4) above, the first light-shielding portion may be in contact with the second region.

[0282] (6) In the lighting device according to (5) above, the first light-shielding portion may be integral with the wavelength converting portion.

[0283] (7) In the lighting device of (1) or (2) above, the first light-shielding portion may include a first coating film located on the second region.

[0284] (8) Any one of the lighting devices (1) to (4) above may further include a first rotation mechanism that rotates the wavelength conversion unit around a virtual first rotation axis, the first rotation axis being positioned offset from the first through hole in a first orthogonal direction that is perpendicular to a first normal line perpendicular to the first region and positioned along a first normal direction along the first normal line, the first light-shielding unit being positioned in a fixed state relative to the housing, and the first rotation mechanism may change a position of the first region on the first surface by rotating the wavelength conversion unit around the first rotation axis.

[0285] (9) In the illumination device according to any one of (1) to (8) above, the first light blocking portion may be located on an optical path of the excitation light traveling from the light source to the wavelength conversion portion.

[0286] (10) In the lighting device of (9) above, the one or more optical components may include a wavelength separation filter that guides the excitation light from the light source to the wavelength conversion unit and guides the fluorescence from the wavelength conversion unit to the first opening, wherein the light source, the wavelength separation filter, the first light-shielding unit and the wavelength conversion unit are aligned along a first direction, and the wavelength separation filter and the first opening are aligned along a second direction that intersects the first direction, and the wavelength separation filter transmits the excitation light from the light source toward the wavelength conversion unit and reflects the fluorescence from the wavelength conversion unit toward the first opening.

[0287] (11) In the lighting device of (9) above, the one or more optical components may include a wavelength separation filter that guides the excitation light from the light source to the wavelength conversion unit and guides the fluorescence from the wavelength conversion unit to the first opening, the light source and the wavelength separation filter are aligned along a first direction, the wavelength conversion unit, the first light-shielding unit, the wavelength separation filter and the first opening are aligned along a second direction intersecting the first direction, and the wavelength separation filter reflects the excitation light from the light source toward the wavelength conversion unit and transmits the fluorescence from the wavelength conversion unit toward the first opening.

[0288] (12) In the lighting device of any one of (1) to (7) above, the wavelength conversion unit may have a fourth surface opposite to the first surface, and the fourth surface may be irradiated with the excitation light from the light source.

[0289] (13) The illumination device of (12) above may further include a second optical system located between the light source and the fourth surface in an optical path of the excitation light from the light source to the fourth surface, and a second light-shielding portion, wherein the fourth surface includes a third region located on an opposite side of the wavelength conversion portion from the first region and a fourth region surrounding the third region, and the second light-shielding portion may have a second through hole located between the third region and the second optical system and cover the fourth region.

[0290] In one embodiment, (14) an illumination device includes a housing having a first opening, a light source that emits excitation light, a wavelength conversion unit that emits fluorescence having a wavelength spectrum different from that of the excitation light in response to irradiation of the excitation light into an internal space of the housing, a first optical system located in the internal space, a second optical system located between the light source and the wavelength conversion unit in an optical path of the excitation light from the light source to the wavelength conversion unit, and a second light blocking unit, wherein the first optical system is one or more optical elements located between the wavelength conversion unit and the first opening in an optical path of the fluorescence. the wavelength conversion unit includes an optical component above, and images the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side and emits the fluorescence from the first opening, the wavelength conversion unit has a first surface located on the side of the first optical system and a fourth surface opposite to the first surface, the fourth surface is irradiated with the excitation light from the light source, the fourth surface includes a third region and a fourth region surrounding the third region, and the second light-shielding unit has a second through hole located between the third region and the second optical system and covers the fourth region.

[0291] (15) In the lighting device according to (13) or (14) above, a material of the second light-shielding portion may include a metal.

[0292] (16) In the lighting device according to (15) above, the second light-shielding portion may have a fifth surface located on the fourth region side, and a metal may be exposed on the fifth surface.

[0293] (17) In the lighting device according to any one of (13) to (16) above, the second light-shielding portion may be in contact with the fourth region.

[0294] (18) In the lighting device according to (17) above, the second light-shielding portion may be integral with the wavelength converting portion.

[0295] (19) In the lighting device described above in (13) or (14), the second light-shielding portion may include a second coating film located on the fourth region.

[0296] (20) In the lighting device according to any one of (1) to (19) above, the one or more optical components may include one or more optical lenses.

[0297] (21) In the lighting device according to any one of (1) to (11) above, the one or more optical components may include a reflecting member having a concave, curved reflecting surface.

[0298] (22) Any one of the illumination devices described above in (1) to (21) may include an opening portion having a second opening that passes the fluorescence from the wavelength conversion unit having a predetermined spread angle or less to the first optical system side and blocks the fluorescence from the wavelength conversion unit having a spread angle larger than the predetermined spread angle.

[0299] (23) In the lighting device according to any one of (1) to (22) above, the light source may include a laser. [Explanation of symbols]

[0300] 1 Lighting equipment 10. Chassis 10a Irradiation aperture (1st aperture) 10is interior space 112 Opening part 11b 2nd opening 20 light source 32 Wavelength conversion section 32a 1st page 32a1 1st area 32a2 2nd area 32b Side 4 32b1 Third area 32b2 4th area 40 1st optical system 41 Optical Components 411 Wavelength separation filter 412 Lens (Optical Lens) 413 Reflective material 413m reflective surface 50 First light shielding part 50A 1st Coating 50b 3rd side (back side) 50f 2nd side (front) 50h 1st through hole 52 Second light shielding section 52A 2nd Coat 52b 5th page (back) 52h 2nd through hole 60 Second optical system 90 First Rotation Mechanism Ax4 1st rotation axis Is1 image plane L0 excitation light L1 fluorescence Ln1 First normal

Claims

1. a housing having a first opening; A light source that emits excitation light; a wavelength conversion unit that emits, in response to irradiation with the excitation light, fluorescence having a wavelength spectrum different from that of the excitation light into an internal space of the housing; A first optical system located in the internal space; and A first light-shielding portion, the first optical system includes one or more optical components located between the wavelength conversion unit and the first opening in an optical path of the fluorescence, and forms an image of the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side and emits the fluorescence from the first opening, the wavelength converting unit has a first surface located on the first optical system side, The first surface includes a first region and a second region surrounding the first region, The first light-shielding portion has a first through hole located between the first region and the first optical system, and covers the second region.

2. 2. The lighting device according to claim 1, An illumination device, wherein the first light blocking portion has a second black surface located on the side of the first optical system.

3. 3. The lighting device according to claim 1, The illumination device, wherein the first light-shielding portion includes a metal film, a metal foil, or a metal plate-shaped member.

4. 4. The lighting device according to claim 3, The first light-shielding portion has a third surface located on the second region side, and a metal is exposed on the third surface.

5. 3. The lighting device according to claim 1, The first light-shielding portion is in contact with the second region.

6. 6. The lighting device according to claim 5, The illumination device, wherein the first light blocking portion is integral with the wavelength converting portion.

7. 3. The lighting device according to claim 1, The first light-shielding portion includes a first coating film located on the second region.

8. 3. The lighting device according to claim 1, a first rotation mechanism that rotates the wavelength conversion unit around a virtual first rotation axis, the first rotation axis is positioned offset from the first through hole in a first orthogonal direction orthogonal to a first normal line perpendicular to the first region, and is positioned along a first normal direction along the first normal line, the first light-shielding portion is located in a fixed state relative to the housing, The first rotation mechanism changes a position of the first region on the first surface by rotating the wavelength converting unit about the first rotation axis.

9. 3. The lighting device according to claim 1, The first light blocking unit is located on an optical path of the excitation light traveling from the light source to the wavelength conversion unit.

10. 10. The lighting device according to claim 9, the one or more optical components include a wavelength separation filter that guides the excitation light from the light source to the wavelength conversion unit and guides the fluorescence from the wavelength conversion unit to the first opening, the light source, the wavelength separation filter, the first light blocking unit, and the wavelength converting unit are aligned along a first direction, the wavelength separation filter and the first opening are aligned along a second direction intersecting the first direction, The wavelength separation filter transmits the excitation light from the light source toward the wavelength conversion unit and reflects the fluorescence from the wavelength conversion unit toward the first opening.

11. 10. The lighting device according to claim 9, the one or more optical components include a wavelength separation filter that guides the excitation light from the light source to the wavelength conversion unit and guides the fluorescence from the wavelength conversion unit to the first opening, the light source and the wavelength separation filter are aligned along a first direction, the wavelength converting portion, the first light blocking portion, the wavelength separation filter, and the first opening are aligned along a second direction intersecting the first direction, The wavelength separation filter reflects the excitation light from the light source toward the wavelength conversion unit, and transmits the fluorescence from the wavelength conversion unit toward the first opening.

12. 3. The lighting device according to claim 1, the wavelength converting portion has a fourth surface opposite to the first surface, The fourth surface is irradiated with the excitation light from the light source.

13. 13. The lighting device according to claim 12, a second optical system located between the light source and the fourth surface in an optical path of the excitation light from the light source to the fourth surface; A second light-shielding portion, the fourth surface includes a third region located on an opposite side of the wavelength converting portion from the first region, and a fourth region surrounding the third region, The second light-shielding portion has a second through hole located between the third region and the second optical system, and covers the fourth region.

14. a housing having a first opening; A light source that emits excitation light; a wavelength conversion unit that emits, in response to irradiation with the excitation light, fluorescence having a wavelength spectrum different from that of the excitation light into an internal space of the housing; A first optical system located in the internal space; and a second optical system located between the light source and the wavelength converting unit in an optical path of the excitation light from the light source to the wavelength converting unit; A second light blocking portion, the first optical system includes one or more optical components located between the wavelength conversion unit and the first opening in an optical path of the fluorescence, and forms an image of the fluorescence emitted from the wavelength conversion unit on a virtual image plane on the first opening side and emits the fluorescence from the first opening, the wavelength converting unit has a first surface located on the first optical system side and a fourth surface located on an opposite side to the first surface, the fourth surface is irradiated with the excitation light from the light source, the fourth surface includes a third region and a fourth region surrounding the third region, The second light-shielding portion has a second through hole located between the third region and the second optical system, and covers the fourth region.

15. 14. The lighting device according to claim 13, A lighting device, wherein the material of the second light blocking portion includes a metal.

16. 16. The lighting device according to claim 15, The second light-shielding portion has a fifth surface located on the fourth region side, and a metal is exposed on the fifth surface.

17. 14. The lighting device according to claim 13, The second light-shielding portion is in contact with the fourth region.

18. 18. The lighting device according to claim 17, The second light blocking portion is integrally formed with the wavelength converting portion.

19. 14. The lighting device according to claim 13, The second light-shielding portion includes a second coating film located on the fourth region.

20. A lighting device according to any one of claims 1, 2 and 14, The one or more optical components include one or more optical lenses.

21. 3. The lighting device according to claim 1, The one or more optical components include a reflective member having a concave, curved reflective surface.

22. A lighting device according to any one of claims 1, 2 and 14, an opening portion having a second opening that allows the fluorescence from the wavelength converting unit to pass toward the first optical system, the fluorescence having a spread angle equal to or smaller than a predetermined spread angle, and blocks the fluorescence from the wavelength converting unit to have a spread angle larger than the predetermined spread angle.

23. A lighting device according to any one of claims 1, 2 and 14, An illumination device, wherein the light source includes a laser.

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