Lighting device

Abstract

This lighting device comprises a housing, a first light source, a first lens optical system, and a shielding part. The housing has a first opening. The first lens optical system includes at least one first lens positioned between a first emission section of the first light source and the first opening of the housing in the path of first light, and images the first light from the first emission part on a virtual image surface on the first opening side to emit the first light from the first opening. The shielding part has a second opening through which the first light L1 passes. Portion of the first light is incident on the shielding part. The angle formed at the first emission part by both outer-side light rays of the first light after passing through the second opening of the shielding part is smaller than the angle formed at the first emission part by both outer-side light rays of the first light before passing through the second opening of the shielding part.

Description

Cross - reference to related applications

[0001] This application claims the priority of Japanese Application No. 2021 - 108719 (filed on June 30, 2021) and International Application No. PCT / JP2022 / 006866 (filed on February 21, 2022), and the entire disclosure of the said applications is incorporated herein by reference for this purpose.

Technical Field

[0002] This disclosure relates to a lighting device.

Background Art

[0003] There is known a lighting device that reflects light from a light source with an elliptical mirror and irradiates an illumination space (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] A lighting device is disclosed.

[0006] In one embodiment, the lighting device includes a housing, a first light source, a first lens optical system, and at least one shielding portion. The housing has a first opening. The first light source has a first emitting portion that emits first light into the internal space of the housing. The first lens optical system includes at least one first lens positioned between the first emitting portion and the first opening of the housing in the path of the first light, and forms an image of the first light from the first emitting portion on a virtual image plane on the first opening side to emit the first light from the first opening. The shielding portion is positioned between the first emitting portion and the first lens optical system in the path of the first light and has a second opening through which the first light passes. A part of the first light is incident on the shielding portion. The at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction. The surface forming the second opening of the shielding portion is inclined so as to move away from the optical axis of the first light as it approaches the first lens optical system.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0008] <First Embodiment> FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a lighting device 1 according to the first embodiment. The lighting device 1 is a device that emits a first light L1 into an illumination space S1. The lighting device 1 is disposed, for example, on the ceiling of the illumination space S1.

[0009] As illustrated in FIG. 1, the lighting device 1 includes a first light source 2, a first lens optical system 3, a housing 4, and a first shielding portion 6.

[0010] The first light source 2 has a first emission portion (e.g., an emission surface) 21 that emits the first light L1 into the internal space of the housing 4. The first light L1 is, for example, visible light. The first light source 2 may include, for example, a semiconductor laser element such as a laser diode (LD), a light emitting diode element, a vertical cavity surface emitting laser (VCSEL), or a super luminescent diode (SLD). The first emission portion 21 of the first light source 2 may be the emission end of the light emitting element.

[0011] Alternatively, in addition to the light emitting element, the first light source 2 may further include a light guiding member such as a fiber and a rod lens. The fiber includes a linear core and a cladding. The cladding has a lower refractive index than the core and covers the core. The first light L1 can pass through the core while undergoing total internal reflection at the interface between the core and the cladding. The rod lens has, for example, a columnar shape. The first light L1 can pass through the inside of the rod lens while undergoing total internal reflection at the side surface of the rod lens.

[0012] The incident end of such a light guiding member corresponds to a first end surface located at the longitudinal end of the fiber or a first end surface located at the longitudinal end of the rod lens, and the emission end of the light guiding member corresponds to a second end surface on the side opposite to the first end surface of the fiber or a second end surface on the side opposite to the first end surface of the rod lens.

[0013] The first light L1 from the light-emitting element is incident on the incident end of the light guide member, travels inside the light guide member, and is emitted from the emission end of the light guide member into the internal space of the housing 4. In this case, the first emission portion 21 of the first light source 2 corresponds to the emission end of the light guide member.

[0014] The first emission portion 21 may include the wavelength conversion member 23, and the first light L1 may be fluorescence emitted from the wavelength conversion member 23. The wavelength conversion member 23 is, for example, BaMgAl 10 O 17 :Eu, or (Sr,Ca,Ba) 10 (PO4)6Cl2:Eu,(Sr,Ba) 10 (PO4)6Cl2:Eu or the like. The wavelength conversion member 23 is, for example, (Sr,Ba,Ca)5(PO4)3Cl:Eu,Sr4Al 14 O 25 :Eu or the like as a wavelength conversion material that converts excitation light into blue-green light. The wavelength conversion member 23 is, for example, SrSi2(O,Cl)2N2:Eu, (Sr,Ba,Mg)2SiO4:Eu 2+ , or ZnS:Cu,Al, Zn2SiO4:Mn or the like as a wavelength conversion material that converts excitation light into green light. The wavelength conversion member 23 is, for example, Y2O2S:Eu, Y2O3:Eu, SrCaClAlSiN3:Eu 2+ , CaAlSiN3:Eu, or CaAlSi(ON)3:Eu or the like as a wavelength conversion material that converts excitation light into red light. The wavelength conversion member 23 is, for example, 3Ga5O 12 :Cr or the like as a wavelength conversion material that converts excitation light into light having a wavelength in the near-infrared region.

[0015] Also, the first light source 2 in this case is excitation light. The excitation light may be, for example, purple light having a peak near 405 nm or blue light having a peak near 450 nm. When the excitation light has a peak in the range of 380 nm to 415 nm and the wavelength conversion member 23 has RGB phosphors, the color rendering property of the lighting device 1 can be improved.

[0016] The first light L1 from the first emission unit 21 of the first light source 2 travels while spreading. In other words, the size of the first light L1 in a cross-section perpendicular to the optical axis AX1 of the first light source 2 increases as it moves away from the first light source 2. The size of the first light L1 may be defined by a contour line having 1 / e of the peak value in the light quantity distribution of the first light L1 in a cross-section perpendicular to the optical axis AX1. Here, "e" is called the Napier's number. In other words, the light rays on both outer sides of the first light L1 in FIG. 1 are light rays having 1 / e of the peak value in the light quantity distribution in a cross-section perpendicular to the optical axis AX1. The light in the region outside the region surrounded by the above-mentioned contour line (i.e., the light rays on both outer sides) may be regarded as noise. 2 One over e of the peak value of the light quantity distribution in a cross-section perpendicular to the optical axis AX1. The light rays on both outer sides of the first light L1 in FIG. 1 are light rays having 1 / e of the peak value in the light quantity distribution in a cross-section perpendicular to the optical axis AX1. 2 The light in the region outside the region surrounded by the above-mentioned contour line (i.e., the light rays on both outer sides) may be regarded as noise.

[0017] The first shielding portion 6 is located on the path of the first light L1 inside the housing 4. In the example of FIG. 1, it is located between the first emission unit 21 and the first lens optical system 3. As a more specific example, the first shielding portion 6 is located immediately behind the first emission unit 21. The first shielding portion 6 has, for example, a plate-like shape, and an opening 6a (corresponding to the second opening) is formed in the central portion thereof. The opening 6a penetrates the first shielding portion 6 in the optical axis direction along the optical axis AX1.

[0018] Among the first light L1 emitted from the first emission unit 21, the light rays with a relatively small divergence angle travel straight through the opening 6a of the first shielding portion 6 and enter the first lens optical system 3.

[0019] On the other hand, among the first light L1 emitted from the first emission unit 21, the light rays with a relatively large divergence angle enter the opening surface 61 forming the opening 6a of the first shielding portion 6.

[0020] In the example of FIG. 1, the opening surface 61 that forms the opening 6a of the first shielding portion 6 is inclined so as to move away from the optical axis AX1 of the first light L1 as it goes forward in the traveling direction of the first light L1. In other words, the opening surface 61 is inclined so as to move away from the optical axis AX1 as it goes toward the first lens optical system 3 in the path of the first light L1. The opening surface 61 may have, for example, a shape similar to the side surface of a frustum of a cone with the optical axis direction as the height direction, or may have a curved surface. As the frustum of a cone, for example, a frustum of a circular cone can be adopted. In the example of FIG. 1, the opening surface 61 is linear in the cross section including the optical axis AX1, and the angle formed by the opening surface 61 and the optical axis AX1 in this cross section is, for example, about 45 degrees.

[0021] The opening surface 61 may be a reflective surface. That is, the reflectivity of the opening surface 61 with respect to the first light L1 may be high. For example, a highly reflective metal surface may be adopted for the opening surface 61. Such an opening surface 61 may be formed of, for example, a metal subjected to mirror finishing. The reflectivity of the opening surface 61 with respect to the first light L1 may be, for example, 60% or more, 80% or more, or 90% or more. The opening surface 61 may have a high reflectivity over the entire wavelength range of the first light L1, or may have a high reflectivity at the peak wavelength. The reflectivity of the opening surface 61 is, for example, higher than the reflectivity of the inner wall of the housing 4 with respect to the first light L1.

[0022] When the opening surface 61 is a reflective surface, the light rays of the first light L1 emitted from the first emitting portion 21 at a large divergence angle can be reflected toward the first lens optical system 3. In other words, the inclination angle of the opening surface 61 is set to an angle at which the first light L1 from the first emitting portion 21 can be reflected toward the first lens optical system 3. According to this, the amount of the first light L1 incident on the first lens optical system 3 can be improved.

[0023] Also, the opening surface 61 may be an absorbing surface. In this case, since scattering inside can be reduced compared with the case where the opening surface 61 is a reflective surface, a comfortable lighting space with less glare can be realized.

[0024] The divergence angle θ1 of the first light L1 passing through the opening 6a of the first shielding portion 6 is smaller than the divergence angle θ0 of the first light L1 at the first light-emitting portion 21. Conversely, the size of the opening 6a of the first shielding portion 6, the thickness of the first shielding portion 6, and the position of the first shielding portion 6 are designed such that the divergence angle θ1 of the first light L1 passing through the opening 6a is smaller than the divergence angle θ0 of the first light L1 at the first light-emitting portion 21.

[0025] Note that the divergence angle θ1 mentioned here is, for example, the angle formed by the outermost light rays among the first light L1 passing through the opening 6a in a cross-section including the optical axis AX1 at the first light-emitting portion 21. When the first light-emitting portion 21 of the first light source 2 includes the light-emitting surface of a light-emitting diode, the divergence angle θ0 of the first light L1 at the first light-emitting portion 21 (see also FIG. 2) is, for example, about 180 degrees. The first shielding portion 6 is designed such that the divergence angle θ1 of the first light L1 passing through the opening 6a is a value smaller than 180 degrees (for example, about 90 degrees).

[0026] In the example of FIG. 1, the first shielding portion 6 is attached to the inner wall of the first member 42 of the housing 4. The first shielding portion 6 may be integrally formed of the same material as the housing 4. Alternatively, the first shielding portion 6 may be formed of a different material and fixed to the housing 4 by a predetermined fixing member. First When the shielding portion 6 is formed integrally with the housing 4, First the heat transfer property from the shielding portion 6 to the housing 4 can be enhanced, and the durability of the lighting device 1 can be enhanced.

[0027] The first lens optical system 3 is located on the optical path of the first light L1 from the first light source 2 in the internal space of the housing 4. The first lens optical system 3 includes a first lens 31, and condenses the first light L1 from the first light source 2 on a virtual image plane IS1 on the side opposite to the first light-emitting portion 21. In other words, the first lens optical system 3 is an imaging optical system that forms the light source image of the first light source 2 as a real image on the image plane IS1. The first light-emitting portion 21 has a conjugate relationship with the image plane IS1. Here, the so-called conjugate relationship does not mean in a strict sense. On the opening 4a side from the first light-emitting portion 21, the portion where the first light L1 is most condensed (the portion where the size of the first light L1 in the cross section perpendicular to the optical axis AX1 of the first light source 2 is the smallest) can be regarded as the image plane IS1.

[0028] As illustrated in FIG. 1, the first lens optical system 3 may be constituted by a single first lens 31. The first lens 31 may be a spherical biconvex lens. The first lens 31 is formed of a material including at least one of glass such as optical glass and resin such as acrylic resin, for example.

[0029] In the example of FIG. 1, the first light-emitting portion 21 of the first light source 2 is attached to the housing 4 and emits the first light L1 toward the first lens optical system 3. After passing through the first lens optical system 3, the first light L1 passes through an irradiation opening 4a (corresponding to the first opening) formed in the housing 4 and is emitted to an illumination space S1 outside the housing 4. The irradiation opening 4a is an opening connecting the internal space of the housing 4 and the external illumination space S1.

[0030] In the example of FIG. 1, the housing 4 has a side wall 41, a first member 42, and a second member 43. The side wall 41 has a cylindrical shape (for example, a circular cylindrical shape). In the example of FIG. 1, the central axis of the cylindrical side wall 41 substantially coincides with the optical axis AX1 of the first light source 2. The first member 42 is located at the first peripheral edge of the side wall 41. The first member 42 has, for example, a plate-like shape, and the periphery of the first member 42 is connected to the first peripheral edge of the side wall 41. The second member 43 is located at the second peripheral edge on the side opposite to the first peripheral edge of the side wall 41. The second member 43 has, for example, a plate-like shape, and the periphery of the second member 43 is connected to the second peripheral edge of the side wall 41. The internal space of the housing 4 is formed by the side wall 41, the first member 42, and the second member 43.

[0031] In the example of FIG. 1, a through hole that penetrates the first member 42 in the central axis direction is formed in the central portion of the first member 42, and the first light source 2 is located in the through hole. In the example of FIG. 1, an irradiation opening 4a that penetrates the second member 43 in the central axis direction is formed in the central portion of the second member 43. In the example of FIG. 1, the second member 43 extends from the lower end of the side wall 41 toward the optical axis AX1 and reaches the periphery of the irradiation opening 4a. That is, the diameter of the irradiation opening 4a is smaller than the inner diameter of the side wall 41. By having such a second member 43 in the housing 4, the irradiation opening 4a can be formed small, and the first lens optical system 3 can be made less visible from the outside of the housing 4, so that a comfortable illumination space with less glare can be realized.

[0032] The first lens optical system 3 is located inside the housing 4 between the first emission part 21 of the first light source 2 and the irradiation opening 4a of the housing 4. The first lens optical system 3 condenses the first light L1 from the first light source 2 onto the image plane IS1. In the example of FIG. 1, the image plane IS1 is located inside the irradiation opening 4a. That is, the position of the first light source 2, the position of the first lens optical system 3, and the optical conditions of the first lens optical system 3 are designed such that the image plane IS1 is located inside the irradiation opening 4a. As a result, since the portion where the first light L1 is most condensed is located at the opening 4a, when the housing 4 has the second member 43, the opening 4a can be designed small. Thereby, the first lens optical system 3 can be made less visible from the outside of the housing 4. As a result, a comfortable illumination space with less glare can be realized.

[0033] Note that the image plane IS1 does not necessarily have to be located inside the irradiation aperture 4a. The image plane IS1 may be located slightly deviated from the irradiation aperture 4a in the traveling direction of the first light L1 passing through the irradiation aperture 4a. That is, the image plane IS1 may be located slightly inside the housing 4 with respect to the irradiation aperture 4a, or may be located slightly on the illumination space S1 side.

[0034] In this lighting device 1, the imaging magnification of the first lens optical system 3 is equal to or less than the ratio (=M3 / M1) of the size M3 of the irradiation aperture 4a to the size M1 of the first light L1 at the first emission portion 21 of the first light source 2. The size M1 of the first light L1 at the first emission portion 21 can also be said to be the size of the first emission portion 21 itself. For example, it corresponds to the area of the end face of the core of the fiber or the area of the end face of the rod lens. Alternatively, when the first emission portion 21 is the end face of the light emitting element, the size of the end face of the light emitting element itself corresponds to the size M1 of the first light L1 at the first emission portion 21. Alternatively, when the first emission portion 21 is the surface of the wavelength conversion member 23, the size of the surface of the wavelength conversion member 23 corresponds to the size M1 of the first light L1 at the first emission portion 21.

[0035] Since the first light source 2 is, for example, an LD, the emission diameter can be made smaller compared to an LED or a VCSEL, and the size M2 of the first light L1 at the image plane IS1 can be made relatively smaller. As a result, a comfortable illumination space with less glare can be realized.

[0036] When the cross-sectional shape of the first light L1 is circular, the size M1 may be regarded as the diameter of the first light L1. When the cross-sectional shape of the first light L1 is rectangular, the size M1 may be regarded as the diagonal length of the first light L1. The size M1 of the first light L1 at the first emission portion 21 is, for example, about 2 mm to 3 mm.

[0037] The size M3 of the irradiation aperture 4a refers to the area of the irradiation aperture 4a in a cross-section perpendicular to the optical axis AX1 in the irradiation aperture 4a. When the shape of the irradiation aperture 4a as viewed along the optical axis AX1 is circular or rectangular, the diameter or diagonal length of the irradiation aperture 4a is, for example, on the order of several millimeters to several tens of millimeters. The diameter of the irradiation aperture 4a may be, for example, on the order of 5 mm to 15 mm. When the surface forming the irradiation aperture 4a is inclined, the size M3 of the irradiation aperture 4a varies at each position of the optical axis AX1. In this case, for example, the minimum value can be adopted as the size M3 of the irradiation aperture 4a.

[0038] The imaging magnification is the ratio of the size M2 of the first light L1 on the image plane IS1 to the size M1 of the first light L1 at the first emission part 21 of the first light source 2.

[0039] Since the imaging magnification is equal to or less than the above ratio, the size M2 of the first light L1 on the image plane IS1 can be made equal to or less than the size M3 of the irradiation aperture 4a. Therefore, the possibility of the first light L1 entering the second member 43 can be reduced, and thus the possibility of the first light L1 being reflected or scattered by the inner surface of the cylindrical side wall 41 or the second member 43 can be reduced. Thereby, unnecessary reflected and scattered light leaking from the irradiation aperture 4a can be reduced.

[0040] The imaging magnification of the first lens optical system 3 may be set such that the size of the first light L1 passing through the irradiation aperture 4a is smaller than the irradiation aperture 4a. According to this, the reflected and scattered light can be further reduced.

[0041] Next, the relationship between the divergence angle θ1 and the numerical aperture of the first lens optical system 3 will be described. In the illumination device 1, the divergence angle θ1 is equal to or less than the angle θ2 that defines the numerical aperture of the first lens optical system 3. The numerical aperture is the product of the sine of half of the angle θ2 and the refractive index. FIG. 2 is a diagram for explaining the angle θ2 that defines the numerical aperture of the first lens optical system 3. The angle θ2 referred to here is, for example, the angle formed by the outermost light rays of the virtual light passing through the effective region of the first lens optical system 3. The effective region referred to here corresponds to the light passing region where the optical performance of the first lens optical system 3 can be exhibited. For example, the effective region of the first lens 31 is the region excluding a predetermined peripheral width from the main surface of the first lens 31. As a more specific example, the effective region of the first lens 31 may be the region surrounded by the inner peripheral edge of the housing 4 (i.e., the lens holder) that holds the periphery of the first lens 31. Here, the outermost light rays on both sides of the first light L1 may be, for example, the light rays that define the emission diameter of the first light L1. Also, the outermost light rays on both sides of the first light L1 may be the light rays that define the size of the first light L1 in a cross section perpendicular to the optical axis AX1 of the first light source 2.

[0042] Since the divergence angle θ1 is equal to or less than the angle θ2, the first light L1 that has passed through the aperture 6a of the first shielding portion 6 can pass through the effective region of the first lens optical system 3. Therefore, the first light L1 hardly enters the edge of the first lens 31, and unnecessary reflection and scattering of the first light L1 generated at the edge can be suppressed or avoided.

[0043] Also, the angle θ2 that defines the numerical aperture of the first lens optical system 3 may be larger than the divergence angle θ1 of the first light L1 that has passed through the aperture 6a of the first shielding portion 6 and smaller than the divergence angle θ0 of the first light L1 at the first light emitting portion 21 (before passing through the aperture 6a of the first shielding portion 6). Thereby, unnecessary reflection and scattering of the first light L1 at the periphery of the first lens optical system 3 and the irradiation aperture 4a can be suppressed or avoided. Therefore, the reflected and scattered light leaking into the illumination space S1 can be reduced, and unevenness such as glare of the first light L1 emitted into the illumination space S1 can be suppressed.

[0044] As described above, in the lighting device 1, the imaging magnification of the first lens optical system 3 is equal to or less than the above ratio, and the divergence angle θ1 is equal to or less than the angle θ2. Therefore, unnecessary reflection and scattering of the first light L1 at the periphery of the first lens optical system 3 and the irradiation aperture 4a can be suppressed or avoided. Accordingly, the reflected and scattered light leaking into the illumination space S1 can be reduced, so that unevenness such as glare of the first light L1 emitted into the illumination space S1 can be suppressed. For this reason, the lighting device 1 can irradiate the illumination space S1 with high-quality first light L1.

[0045] Also, the first light L1 may be emitted from the irradiation aperture 4a so as not to contact the housing 4. Here, "not to contact" does not mean in a strict sense. As long as the light rays on both outer sides of the first light L1 in the space from the first emission unit 21 to the irradiation aperture 4a do not contact the housing 4, for example, noise such as scattered light may contact the housing 4.

[0046] FIG. 3 is a cross-sectional view schematically showing a first aspect of the configuration of the lighting device 1. In the example of FIG. 3, the image plane IS1 is curved. As a specific example, the image plane IS1 is curved so as to be convex toward the illumination space S1. Such a first lens optical system 3 can be configured by an inexpensive first lens 31. Therefore, the manufacturing cost of the lighting device 1 can be reduced. The first lens 31 may have a continuous curved surface. For example, the main surface of the first lens 31 through which the first light L1 passes may be configured only by a curved surface having no step. In other words, the first lens 31 does not have to be a Fresnel lens. Thereby, scattering or reflection in the first lens 31 can be reduced. As a result, a comfortable illumination space with less glare can be realized.

[0047] FIG. 4 is a cross-sectional view schematically showing a second aspect of the configuration of the lighting device 1. In the example of FIG. 4, the first lens optical system 3 includes a plurality of first lenses 31. The plurality of first lenses 31 are arranged side by side in the path of the first light L1. The plurality of first lenses 31 may be positioned side by side in the optical axis direction of the first light L1. Such a plurality of first lenses 31 may also be referred to as a combined lens. By combining such a plurality of first lenses 31, the optical characteristics required for the first lens optical system 3 can be easily obtained even when a special optical element such as a Fresnel lens is not used. FIG. 5 is a cross-sectional view schematically showing a third aspect of the configuration of the lighting device 1. The configuration of the third aspect is the same as that of the second aspect. As shown in the third aspect, between the plurality of first lenses 31, there may be a portion (waist portion LW1) where the light diameter of the first light L1 is smaller than the light diameter passing through each of the plurality of first lenses 31. Specifically, the minimum value of the light diameter between two adjacent first lenses 31 (that is, the diameter of the waist portion LW1) may be smaller than the minimum value of the light diameter of the first light L1 in each of the two first lenses 31. According to the second and third aspects, for example, a first lens optical system 3 with a high imaging magnification can be easily obtained. Also, the first lens optical system 3 may have, for example, three or more lenses arranged side by side in the optical axis direction of the first light L1. Thereby, the optical characteristics required for the first lens optical system 3 can be obtained more easily.

[0048] In addition, in the examples of FIGS. 1 to 5, although each first lens 31 is a spherical lens, each first lens 31 may be an aspherical lens or a free-form surface lens.

[0049] The orientation angle of the first light L1 emitted from the irradiation aperture 4a of the lighting device 1 may be less than 60 degrees. Thereby, for example, in the lighting space S1 where a plurality of lighting devices 1 are installed at regular intervals, the glare of the lighting device 1 that enters the field of view can be reduced. As a result, the comfort of the lighting device 1 can be improved. 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.

[0050] FIG. 6 is a cross-sectional view schematically showing a fourth aspect of the configuration of the lighting device 1. In the example of FIG. 6, the opening surface 61 of the first shielding portion 6 is substantially parallel to the optical axis AX1. The opening surface 61 has, for example, the same shape as the side surface of a columnar shape with the optical axis direction as the height direction. The first shielding portion 6 has, for example, a ring shape.

[0051] Also in the fourth aspect, among the first light L1 emitted from the first light-emitting portion 21, the light rays with a small divergence angle pass through the opening 6a of the first shielding portion 6 and enter the first lens optical system 3. On the other hand, among the first light L1 emitted from the first light-emitting portion 21, the light rays with a large divergence angle enter the opening surface 61 of the first shielding portion 6. Here, the opening surface 61 is, for example, an absorption surface. That is, the absorption rate of the opening surface 61 for the first light L1 is high. The absorption rate of the opening surface 61 may be, for example, 60% or more, 80% or more, or 90% or more. The opening surface 61 may have a high absorption rate for the entire wavelength range of the first light L1, or may have a high absorption rate for the peak wavelength. For example, the opening surface 61 is formed by performing, for example, a blackening treatment. As a specific example, as the blackening treatment, a blackening treatment such as chemical conversion treatment, plating, and painting can be adopted. As the blackening treatment, a non-glossy blackening treatment may be adopted, or a glossy blackening treatment may be adopted. Such an opening surface 61 is composed of a black material. The material includes, for example, at least one of black metal, black metal oxide film, and black resin.

[0052] Alternatively, the opening surface 61 may be formed by 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, for example, one or more materials among titanium oxide (TiO2), SiO2, niobium pentoxide (Nb2O5), tantalum pentoxide (Ta2O5), and magnesium fluoride (MgF2) are adopted. Such a dielectric multilayer film can also be called an antireflection film or an antireflection coating.

[0053] Also in the fourth aspect, the divergence angle θ1 of the first light L1 that has passed through the opening 6a of the first shielding portion 6 becomes smaller than the divergence angle of the first light L1 at the first light-emitting portion 21.

[0054] In the fourth aspect as well, the divergence angle θ1 is equal to or less than the angle θ2 that defines the numerical aperture of the first lens optical system 3. Therefore, the first light L1 that has passed through the aperture 6a of the first shielding portion 6 can pass through the effective region of the first lens optical system 3. Accordingly, it is possible to suppress the reflected and scattered light within the housing 4 and suppress the unevenness of the first light L1 emitted from the irradiation aperture 4a.

[0055] FIG. 7 is a cross-sectional view schematically showing a part of the configuration of the fifth aspect of the illumination device 1. In the example of FIG. 7, an aperture for allowing the light from the first light-emitting portion 21 to pass through is formed in the first member 42 of the housing 4. The aperture of this first member 42 functions as the aperture 6a of the first shielding portion 6. That is, the first shielding portion 6 is integrally formed with the first member 42. In the example of FIG. 7, the housing 4 further includes a transparent connecting member 44, and the transparent connecting member 44 connects the first light source 2 to the first member 42. For example, the connecting member 44 has an annular shape surrounding the optical axis AX1, the outer peripheral edge portion of the lower surface of the connecting member 44 is connected to the upper surface of the first member 42, and the inner peripheral portion of the connecting member 44 is connected to the first light source 2. The inner peripheral edge portion of the lower surface of the connecting member 44 faces the aperture 6a of the first shielding portion 6. The connecting member 44 has a high transmittance with respect to the first light L1. The transmittance is, for example, 60% or more, and may be 70% or more, 80% or more, or 90% or more.

[0056] A part of the light emitted from the first light-emitting portion 21 of the first light source 2 passes through the opening 6a of the first shielding portion 6, and the remaining part is reflected or scattered by the opening surface 61 of the first shielding portion 6. As shown in FIG. 7, the opening surface 61 forming the opening 6a of the first shielding portion 6 is inclined so as to approach the optical axis AX1 of the first light L1 as it goes forward in the traveling direction of the first light L1. According to this structure, since the scattering of light occurring at the opening surface 61 is directed toward the first light-emitting portion 21 side, it is possible to make it difficult for scattered light to be generated inside the housing 4. The scattered light travels outside the housing 4 through the transparent connecting member 44. In other words, the inclination angle of the opening surface 61 is set to a value such that the scattered light is directed toward the connecting member 44 around the first light-emitting portion 21. Therefore, compared with the case where the opening surface 61 is inclined so as to move away from the optical axis AX1, scattering inside can be reduced, and a comfortable lighting space with less glare can be realized.

[0057] Also, as shown in FIGS. 6 and 7, the first light-emitting portion 21 and the first shielding portion 6 may be separated in a direction perpendicular to the optical axis AX1. That is, the opening surface 61 forming the opening 6a of the first shielding portion 6 may be separated from the first light-emitting portion 21 in a direction perpendicular to the optical axis AX1. In other words, the size M1 of the first light-emitting portion 21 may be smaller than the size M4 (that is, the opening area) of the opening 6a of the first shielding portion 6. Further in other words, the width of the first light-emitting portion 21 may be smaller than the width of the opening 6a of the first shielding portion 6. However, it is not necessarily limited to this. As shown in FIG. 8, the width of the emission end of the first light-emitting portion 21 and the width of the opening 6a of the first shielding portion 6 (that is, the diameter of the through-hole of the first member 42) may coincide. According to this structure, compared with the structure in which the first light-emitting portion 21 and the first shielding portion 6 are separated in a direction perpendicular to the optical axis AX1, glare can be further reduced. Here, the coincidence means that an error is allowed. That is, the meaning of coincidence includes a state in which A and B are deviated within the range of the allowable error.

[0058] Further, the first light emitting portion 21 and the first shielding portion 6 may partially overlap in a direction perpendicular to the optical axis AX1. For example, the width of the opening 6a of the first shielding portion 6 (that is, the diameter of the through hole of the first member 42) may be smaller than the width of the emission end of the first light emitting portion 21. According to this structure, compared with the structure in which the width of the emission end of the first light emitting portion 21 and the width of the opening 6a of the first shielding portion 6 (that is, the diameter of the through hole of the first member 42) are substantially the same, glare can be further reduced.

[0059] Further, as shown in FIGS. 6, 7, and 8, the first light emitting portion 21 and the first shielding portion 6 may be continuous in the optical axis direction, or may partially overlap. However, as shown in FIG. 9, the first light emitting portion 21 and the first shielding portion 6 may be separated in the optical axis direction. In this structure, the housing 4 may further include a transparent connecting member 44, and the transparent connecting member 44 may connect the first light source 2 to the first member 42.

[0060] Further, as shown in FIG. 10, the opening surface 61 of the first shielding portion 6 may be inclined so as to move away from the optical axis AX1 as it goes toward the first lens optical system 3 in the path of the first light L1. In this structure, light rays having a large divergence angle among the first light L1 may enter the upper end portion of the opening surface 61. The upper end portion here is, for example, the connecting portion between the opening surface 61 of the first shielding portion 6 and the surface 62 on the first light source 2 side. Also, in this structure, light rays having a large divergence angle among the first light L1 may enter the surface 62 on the first light source 2 side of the first shielding portion 6. In this structure, for example, the surface 62 may be a light absorbing surface. Here, the light absorbing surface may be, for example, a surface having an absorption rate of 60% or more in the visible light region.

[0061] As shown in FIG. 10, the first light L1 from the first light-emitting unit 21 does not necessarily have to be directly incident on the opening surface 61 of the first shielding unit 6. That is, the opening surface 61 may be more inclined with respect to the optical axis AX1 than the outermost light ray spreading among the first light L1 that has passed through the opening surface 61. In other words, the acute angle formed by the opening surface 61 and the optical axis AX1 may be larger than the acute angle formed by the light ray and the optical axis AX1. However, it is not necessarily limited to this. The opening surface 61 may be inclined so that the acute angle formed by the opening surface 61 and the optical axis AX1 becomes smaller. According to this, the first light L1 from the first light-emitting unit 21 can be directly incident on the opening surface 61. In this structure, at least one of the opening surface 61 and the surface 62 may be an absorbing surface.

[0062] Also, in the examples of FIGS. 1, 3 to 6, and 8 to 10, the distance between the first light-emitting unit 21 and the irradiation opening 4a is larger than the inner diameter of the housing 4. The distance between the first light-emitting unit 21 and the irradiation opening 4a referred to here is, for example, the distance in the path along the optical axis AX1. When this distance is large, the distance between the first lens optical system 3 and the irradiation opening 4a can be increased. When the first lens optical system 3 includes a plurality of first lenses 31, the distance between the first lens 31 closest to the irradiation opening 4a and the irradiation opening 4a can be increased. Therefore, it is possible to make the first lens optical system 3 less visible from the outside of the housing 4, and a more comfortable lighting space with less glare can be realized. Note that the distance between the first lens optical system 3 and the irradiation opening 4a may be made larger than the inner diameter of the housing 4.

[0063] <Second Embodiment> FIG. 11 is a cross-sectional view showing an example of the configuration of the lighting device 1A according to the second embodiment. The lighting device 1A is different from the lighting device 1 in terms of the position of the first shielding portion 6. In the lighting device 1A, the first shielding portion 6 is located behind the frontmost first lens 31 in the first lens optical system 3, and as a specific example, it is located near the aperture position of the first lens optical system 3. The aperture position referred to here is, for example, the position where the ratio of the area where the first lights L1 emitted from each point of the first light emitting portion 21 overlap on the plane A1 is the highest when the plane A1 perpendicular to the optical axis AX1 is moved along the optical axis direction. Here, the first lights L1 emitted from three points on the first light emitting portion 21 are called the first partial light L1a, the first partial light L1b, and the first partial light L1c, respectively. As illustrated in FIG. 11, the first partial light L1a, the first partial light L1b, and the first partial light L1c overlap each other on the plane A1 at the aperture position. That is, on the plane A1 shown in FIG. 11, the ratio of the area where the first partial lights L1a to L1c overlap each other with respect to the entire area of the first light L1 is the highest.

[0064] In the example of FIG. 11, the first lens optical system 3 includes a single first lens 31, and the aperture position of the first lens optical system 3 is the position immediately behind the first lens 31. Therefore, the first shielding portion 6 is provided immediately behind the first lens 31. The central side portion of the first light L1 that has passed through the first lens 31 passes through the aperture 6a of the first shielding portion 6, and the remaining outer peripheral side portion is shielded by the first shielding portion 6. The first light L1 that has passed through the aperture 6a of the first shielding portion 6 forms an image on the image plane IS1 and is emitted into the illumination space S1 through the illumination aperture 4a in the same manner as in the first embodiment.

[0065] Also in the lighting device 1A, the spread angle θ1 is equal to or less than the angle θ2 that defines the numerical aperture of the first lens optical system 3. The spread angle θ1 is the angle formed by the outermost light rays among the first lights L1 that have passed through the aperture 6a of the first shielding portion 6 in the cross-section including the optical axis AX1 at the first light emitting portion 21.

[0066] According to this, the first shielding portion 6 can allow the first light L1 passing through the effective region of the first lens optical system 3 to pass through the aperture 6a. Therefore, the lighting device 1A can also emit the first light L1 with less unevenness from the irradiation aperture 4a.

[0067] Also, in the above example, the first shielding portion 6 is located near the aperture position. According to this, the light rays passing through the centers of the first partial lights L1a to L1c emitted from each point of the first emitting portion 21 pass through the center of the aperture 6a of the first shielding portion 6. Thus, the first partial lights L1a to L1c emitted from each point are shielded more evenly by the first shielding portion 6.

[0068] Therefore, the lighting device 1A can maintain the in-plane distribution of the intensity of the first light L1 in the first emitting portion 21 and emit the first light L1 from the irradiation aperture 4a. That is, the lighting device 1A can emit the first light L1 into the illumination space S1 with an in-plane distribution that directly reflects the in-plane distribution of the first light L1 in the first emitting portion 21. For example, if the in-plane distribution of the first light L1 in the first emitting portion 21 is uniform, the lighting device 1A can emit the first light L1 into the illumination space S1 with a uniform in-plane distribution.

[0069] As described above, in terms of evenly blocking the first partial lights L1a to L1c emitted from each point, it is preferable that the first shielding portion 6 is located at the aperture position. However, in terms of emitting the first light L1 passing through the effective region of the first lens optical system 3 from the irradiation aperture 4a, the first shielding portion 6 does not necessarily have to be located at the aperture position. For example, as shown by the virtual line in FIG. 11, the first shielding portion 6 may be located closer to the irradiation aperture 4a side than the aperture position. Even in this case, the first light L1 that has passed through the effective region of the first lens optical system 3 can be emitted from the irradiation aperture 4a.

[0070] In addition, when the first lens optical system 3 includes a plurality of first lenses 31 as illustrated in FIG. 4 or FIG. 5, the first shielding portion 6 may be located closer to the first light source 2 side than the last-stage first lens 31 in the first lens optical system 3. According to this, even if the first light L1 is reflected and scattered on the opening surface 61 of the first shielding portion 6, the reflected and scattered light enters the first lens 31 at a stage subsequent to the first shielding portion 6. According to this, compared with the case where the first lens 31 is not located at a stage subsequent to the first shielding portion 6, the reflected and scattered light emitted from the irradiation opening 4a can be reduced.

[0071] In addition, in the first and second embodiments, although the single first shielding portion 6 is located inside the housing 4, two first shielding portions 6 may be located. Specifically, one first shielding portion 6 (see FIG. 1) may be located between the first emission portion 21 and the first lens optical system 3, and the other first shielding portion 6 (see FIG. 11) may be located, for example, at the aperture position of the first lens optical system 3.

[0072] <Third Embodiment> In the present embodiment, a part of the first light L1 can be reflected and scattered by the first shielding portion 6. And if such reflected and scattered light deviates from the path of the first light L1 that forms an image on the image plane IS1 and leaks out from the irradiation opening 4a without forming an image on the image plane IS1, unevenness of the first light L1 may occur. Hereinafter, the reflected and scattered light of the first light L1 reflected and scattered inside the housing 4 is also referred to as reflected and scattered light L11. The reflected and scattered light L11 is a part of the first light L1 that has deviated from the path of the first light L1 that forms an image on the image plane IS1, and may be either reflected light or scattered light.

[0073] In the third embodiment, it is intended to further suppress unevenness of the first light L1 irradiated to the illumination space S1.

[0074] FIG. 12 is a cross-sectional view schematically showing an example of the configuration of the illumination device 1B according to the third embodiment. The illumination device 1B is different from the illumination device 1 in terms of the presence or absence of the light reduction structure 5. The light reduction structure 5 is located inside the housing 4. The light reduction structure 5 is arranged to reduce the reflected and scattered light L11 emitted from the irradiation opening 4a.

[0075] The first lens optical system 3 of the lighting device 1B includes a plurality of first lenses 31 and one or more spacers 32. In the example of FIG. 12, the first lens optical system 3 includes two first lenses 31 and one spacer 32. The spacer 32 is a member that defines the interval between the two first lenses 31. The spacer 32 is positioned between two adjacent first lenses 31 and is in contact with both first lenses 31. Thereby, the interval between the two first lenses 31 can be made to coincide with the thickness of the spacer 32 (the thickness along the optical axis AX1). The spacer 32 has, for example, an annular shape surrounding the optical axis AX1.

[0076] In the example of FIG. 12, the light reduction structure 5 is located on the inner wall of the spacer 32 and is exposed to the internal space of the housing 4. The light reduction structure 5 includes, for example, a reflection reduction portion 51. The reflection reduction portion 51 may include an absorption film having a high absorption rate for the first light L1. The absorption rate may be, for example, 60% or more, 80% or more, or 90% or more. The reflection reduction portion 51 may have a high absorption rate for the entire wavelength range of the first light L1, or may have a high absorption rate for the peak wavelength. The absorption rate of the reflection reduction portion 51 with respect to the first light L1 is higher than the absorption rate of the spacer 32 with respect to the first light L1.

[0077] Such a reflection reduction portion 51 is formed, for example, by performing a blackening process on the inner wall of the spacer 32. As a specific example, the reflection reduction portion 51 is formed on the inner wall of the spacer 32 by a blackening process such as a forming process, plating, and painting. As the blackening process, a non-glossy blackening process may be employed, or a glossy blackening process may be employed. Such a reflection reduction portion 51 is composed of a black material. The material includes, for example, at least one of a black metal, a black metal oxide film, and a black resin.

[0078] Alternatively, the reflection reducing portion 51 may include 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, for example, one or more materials among titanium oxide (TiO2), SiO2, niobium pentoxide (Nb2O5), tantalum pentoxide (Ta2O5), and magnesium fluoride (MgF2) are adopted. Such a dielectric multilayer film may also be called an antireflection film or an anti-reflective film.

[0079] The reflection reducing portion 51 may be formed directly on the inner wall of the spacer 32, or may be formed on a predetermined film-like base material, and the base material may be attached to the inner wall of the spacer 32. For example, the base material may be attached to the inner wall of the spacer 32 by an adhesive.

[0080] Alternatively, the reflection reducing portion 51 may include flocked paper. For example, the flocked paper may be composed of a base material such as paper and cloth, and chemical fibers attached to the base material in an upright state. By adopting black flocked paper, the reflection of the scattered reflected light L11 can be further suppressed compared to other colored flocked papers.

[0081] In such a lighting device 1B, for example, when the reflected and scattered reflected scattered light L11 reflected and scattered by at least any one of the first shielding portion 6, the first lens optical system 3, and the housing 4 travels toward the inner wall of the spacer 32, it enters the reflection reducing portion 51. Since the reflection reducing portion 51 suppresses the reflection of the reflected scattered light L11, the reflected scattered light L11 emitted from the irradiation opening 4a can be reduced. Therefore, the lighting device 1B can further emit a higher quality first light L1 into the illumination space S1.

[0082] FIG. 13 is an enlarged view schematically showing a part of another example of the light reduction structure 5. The light reduction structure 5 includes an uneven shape 52. The uneven shape 52 is, for example, the shape of the inner wall surface of the spacer 32, and in FIG. 13, a part of it is schematically shown. The uneven shape 52 has unevenness in the optical axis direction parallel to the optical axis AX1. That is, the uneven shape 52 has a shape in which concave portions and convex portions are arranged alternately in a cross section including the optical axis AX1.

[0083] In the example of FIG. 13, the concavo-convex shape 52 has a saw blade shape, and each tooth of the saw blade (i.e., the convex portion) is formed by a first surface 521 on the side of the first light source 2 and a second surface 522 on the side of the irradiation opening 4a. In the example of FIG. 13, the first surface 521 is inclined so as to approach the optical axis AX1 as it goes toward the irradiation opening 4a in the optical axis direction, and the second surface 522 is inclined so as to move away from the optical axis AX1 as it goes toward the irradiation opening 4a. In the concavo-convex shape 52, the first surface 521 and the second surface 522 are alternately continuous. As illustrated in FIG. 13, the length of the first surface 521 and the length of the second surface 522 may be substantially the same. In other words, the first surface 521 and the second surface 522 may be the equal sides of an isosceles triangle in a cross section (e.g., the paper surface of FIG. 13) including the optical axis AX1. Such a concavo-convex shape 52 may have a spiral shape similar to a female screw, or may have a shape in which a plurality of ring shapes are arranged in the optical axis direction. The pitch of the concavo-convex shape 52 is set to, for example, about several mm or less.

[0084] Now, on the inner wall of the spacer 32, the reflected and scattered light L11 mainly enters obliquely from the side of the first light source 2. Therefore, on the inner wall of the spacer 32, more of the reflected and scattered light L11 enters the first surface 521 than the second surface 522. The first surface 521 reflects and scatters the incident reflected and scattered light L11 mainly in an oblique direction opposite to the irradiation opening 4a. Thereby, the number of times the reflected and scattered light L11 is reflected and scattered in the housing 4 can be increased, and the reflected and scattered light L11 can be attenuated in the housing 4. Therefore, the possibility of the reflected and scattered light L11 being emitted from the irradiation opening 4a can be reduced.

[0085] Further, even if the reflected and scattered light L11 enters the second surface 522 from the side of the first light source 2, the reflected and scattered light L11 reflected and scattered by the second surface 522 mainly enters the first surface 521 and is reflected and scattered by the first surface 521 in an oblique direction toward the first light source 2 side. Therefore, the possibility of the reflected and scattered light L11 being emitted from the irradiation opening 4a can be reduced.

[0086] As described above, even when the concavo-convex shape 52 is adopted as the light reduction structure 5, the reflected and scattered light L11 emitted from the irradiation aperture 4a can be reduced. That is, the illumination device 1B can emit the higher-quality first light L1 into the illumination space S1.

[0087] In the example of FIG. 13, although the lengths of the first surface 521 and the second surface 522 are substantially the same, they may be different from each other. FIG. 14 is a diagram schematically showing another example of the concavo-convex shape 52. Also in the example of FIG. 14, the concavo-convex shape 52 is the shape of the inner wall surface of the spacer 32. However, in the example of FIG. 14, the length of the second surface 522 that moves away from the optical axis AX1 as it approaches the irradiation aperture 4a is longer than that of the first surface 521. In the example of FIG. 14, since the first surface 521 is substantially orthogonal to the optical axis AX1, in the cross section including the optical axis AX1, the first surface 521 corresponds to the adjacent side of a right triangle, and the second surface 522 is corresponds to the hypotenuse of the right triangle.

[0088] Also on the inner wall surface of such a spacer 32, the reflected and scattered light L11 mainly enters obliquely from the side of the first light source 2. The first surface 521 reflects and scatters the incident reflected and scattered light L11 mainly toward the side opposite to the irradiation aperture 4a. That is, the first surface 521 reflects and scatters the reflected and scattered light L11 mainly in the oblique direction on the side of the first light source 2. Although a part of the reflected and scattered light L11 from the first surface 521 may enter the second surface 522, since the second surface 522 is inclined, most of the reflected and scattered light L11 can be reflected and scattered in the oblique direction on the side of the first light source 2.

[0089] Further, even if the reflected and scattered light L11 from the side of the first light source 2 enters the second surface 522, the reflected and scattered light L11 reflected and scattered by the second surface 522 enters the first surface 521 and is reflected and scattered in the oblique direction on the side of the first light source 2 by the first surface 521.

[0090] As described above, the reflected and scattered light L11 incident on the uneven shape 52 from the side of the first light source 2 can be mainly reflected and scattered in the diagonal direction on the side of the first light source 2. Therefore, the possibility of the reflected and scattered light L11 being emitted from the irradiation aperture 4a can be reduced.

[0091] In the above example, although the light reduction structure 5 is located on the inner wall of the spacer 32, it is not necessarily limited to this. FIG. 15 is a cross-sectional view schematically showing the first aspect of the lighting device 1B. In the example of FIG. 15, the light reduction structure 5 is located on the inner wall of the housing 4. The light reduction structure 5 may include a reflection reduction portion 51. According to this, since the reflection of the reflected and scattered light L11 incident on the reflection reduction portion 51 is suppressed, the reflected and scattered light L11 emitted from the irradiation aperture 4a into the illumination space S1 can be reduced.

[0092] The reflection reduction portion 51 may be located on substantially the entire surface of the inner wall of the housing 4 as illustrated in FIG. 15, or may be located only on a part thereof. For example, the reflection reduction portion 51 may be located only on all or a part of the inner wall of the side wall 41 surrounding the optical axis AX1. For example, the reflection reduction portion 51 is located on the entire circumference of the inner wall of the side wall 41. Further, the reflection reduction portion 51 may be located on the surface of the first shielding portion 6 on the side of the first lens optical system 3.

[0093] FIG. 16 is a cross-sectional view schematically showing the second aspect of the lighting device 1B. As illustrated in FIG. 16, the light reduction structure 5 located on the inner wall of the housing 4 may have an uneven shape 52. That is, the inner wall of the housing 4 may have an uneven shape 52 as the light reduction structure 5. In this case, the uneven shape 52 may be formed on the entire surface of the inner wall surface of the housing 4, or may be formed only on a part thereof. The uneven shape 52 can be formed on at least all or a part of the inner wall surface of the side wall 41. For example, the uneven shape 52 is formed on the entire circumference of the inner wall surface of the side wall 41.

[0094] The reflected and scattered light L11 that is incident on the uneven shape 52 of the inner wall of the side wall 41 in an oblique direction from the side of the first light source 2 is mainly reflected and scattered in the oblique direction toward the side of the first light source 2. Therefore, the reflected and scattered light L11 emitted from the irradiation aperture 4a into the illumination space S1 can be reduced.

[0095] FIG. 17 is a cross-sectional view schematically showing a third aspect of the lighting device 1B according to the third embodiment. The lighting device 1B according to the third aspect is different from the lighting device 1A in terms of the presence or absence of the light reduction structure 5. In the third aspect, the first shielding portion 6 is located near the aperture position, and the light reduction structure 5 is located on the first shielding portion 6. In the example of FIG. 17, the light reduction structure 5 is located on the opening surface 61 that forms the opening 6a of the first shielding portion 6. The light reduction structure 5 may be located over the entire circumference of the opening surface 61. Further, the light reduction structure 5 may include a reflection reduction portion 51 and may have an uneven shape 52.

[0096] According to this, the reflection of the reflected and scattered light L11 incident on the opening surface 61 of the first shielding portion 6 in an oblique direction from the side of the first light source 2 is suppressed, or the reflected and scattered light L11 is mainly reflected and scattered in the oblique direction toward the side of the first light source 2. Therefore, the reflected and scattered light L11 emitted from the irradiation aperture 4a into the illumination space S1 can be reduced.

[0097] The light reduction structure 5 may be located on the first shielding portion 6 while avoiding the side surface 63 of the surface of the first shielding portion 6. the first light source 2 This is because the reflected and scattered light L11 hardly enters the surface 63 of the first shielding portion 6 compared to the opening surface 61. Further, the light reduction structure 5 may be located on the first shielding portion 6 while avoiding the surface 62 on the irradiation aperture 4a side of the first shielding portion 6. This is because the reflected and scattered light L11 incident on the surface 62 of the first shielding portion 6 is reflected and scattered toward the side of the first light source 2 and thus is difficult to be emitted from the irradiation aperture 4a.

[0098] Note that, in the above example, the light reduction structure 5 is located on at least one of the inner wall of the spacer 32, the inner wall of the housing 4, and the first shielding portion 6. However, it is not necessarily limited to this. In short, the light reduction structure 5 is exposed in the internal space of the housing 4 and is arranged at a position where it does not interfere with the first light L1 that passes through the first lens optical system 3 and forms an image on the image plane IS1. For example, the light reduction structure 5 First may be located on the surface of a lens holder (not shown) that holds the lens 31.

[0099] Also, the light reduction structure 5 may include both the reflection reduction portion 51 and the concavo-convex shape 52. In this case, the reflection reduction portion 51 is located on the surface of the concavo-convex shape 52.

[0100] <Fourth Embodiment> FIG. 18 is a cross-sectional view schematically showing an example of the configuration of the illumination device 1C according to the fourth embodiment. The illumination device 1C is different from the illumination device 1 in terms of the specific configuration of the first lens optical system 3. In the illumination device 1C, the first lens optical system 3 includes a plurality of first lenses 31 and constitutes a bilateral telecentric optical system. The bilateral telecentric optical system is an optical system in which the principal ray of the first light L1 is parallel to the optical axis AX1 on the first light source 2 side and the principal ray of the first light L1 is parallel to the optical axis AX1 on the irradiation aperture 4a side. In the example of FIG. 18, the principal rays of the first light L1 emitted from each point of the first emission portion 21 are shown by thick dashed lines.

[0101] The principal ray is a ray that passes through the center of the first light L1 in the plane A1 perpendicular to the optical axis AX1 at the aperture position. As illustrated in FIG. 18, among the rays of the first partial light L1a, the principal ray that passes through the center of the first light L1 in the plane A1 is parallel to the optical axis AX1 on both the first light source 2 side and the irradiation aperture 4a side. Similarly, the principal ray of the first partial light L1b is parallel to the optical axis AX1 on both the first light source 2 side and the irradiation aperture 4a side, and the principal ray of the first partial light L1c is parallel to the optical axis AX1 on both the first light source 2 side and the irradiation aperture 4a side.

[0102] In the example of FIG. 18, although three first lenses 31 are schematically shown, the number of the first lenses 31 can be appropriately changed. Further, in the example of FIG. 18, although a biconvex lens is shown as the first lens 31, other lenses such as a concave lens may be appropriately adopted.

[0103] According to this lighting device 1C, the principal rays of the first light L1 irradiated from the irradiation aperture 4a are substantially parallel and hardly spread. According to this, the divergence angle of the first light L1 irradiated from the irradiation aperture 4a can be reduced. Therefore, the first light L1 can be irradiated to a narrower irradiation area, and the presence of the lighting device 1C can be further reduced.

[0104] <Fifth Embodiment> FIGS. 19 and 20 are cross-sectional views schematically showing an example of the configuration of a lighting device 1D according to the fifth embodiment. The lighting device 1D is different from the lighting device 1 in terms of the presence or absence of a zoom mechanism 35.

[0105] The zoom mechanism 35 zooms, that is, adjusts, the divergence angle of the first light L1 from the irradiation aperture 4a by adjusting the positions of the respective first lenses 31 constituting the first lens optical system 3 on the optical axis AX1. Although the zoom mechanism 35 is not particularly limited, for example, it may have a ball screw mechanism. Such a ball screw mechanism includes a lead screw extending in the optical axis direction, a carriage coupled to the lead screw by a screw action, a lens holder connected to the carriage and holding the first lens 31, and a motor for rotating the lead screw. When the lead screw rotates, the carriage, the lens holder, and the first lens 31 move integrally along the optical axis direction. The motor is controlled by, for example, the control unit 20.

[0106] The control unit 20 can also be said to be a control circuit. The control unit 20 includes at least one processor in order to provide control and processing capabilities for executing various functions, as will be described in more detail below.

[0107] According to various embodiments, at least one processor may be implemented as a single integrated circuit (IC), or as multiple communicatively connected integrated circuit ICs and / or discrete circuits. At least one processor can be implemented according to various known techniques.

[0108] In one embodiment, the processor includes one or more circuits or units configured to perform one or more data computation procedures or processes, for example, by executing instructions stored in an associated memory. In other embodiments, the processor may be firmware (e.g., discrete logic components) configured to perform one or more data computation procedures or processes.

[0109] According to various embodiments, the processor may include one or more processors, controllers, microprocessors, microcontrollers, application specific integrated circuits (ASICs), digital signal processing devices, programmable logic devices, field programmable gate arrays, or any combination of these devices or configurations, or combinations of other known devices and configurations, and may perform the functions described below.

[0110] Further, the housing 4 may be composed of a plurality of cylindrical bodies and may move along the optical axis direction together with each first lens 31. That is, the zoom mechanism 35 may move the first lens 31 and the cylindrical bodies integrally. According to this, the size of the housing 4 in the optical axis direction changes according to the position of each first lens 31.

[0111] In FIG. 20, the distance D1 between the first light emitting portion 21 of the first light source 2 and the first lens 31, and the distance D2 between two adjacent first lenses 31 are wider than those in the case of FIG. 19. Thereby, the divergence angle of the first light L1 emitted from the irradiation aperture 4a of the illumination device 1D can be reduced.

[0112] As described above, according to the lighting device 1D, by adjusting the position of each first lens 31 by the zoom mechanism 35, the divergence angle of the first light L1 emitted from the irradiation aperture 4a can be adjusted. Therefore, the size of the irradiation area can be adjusted.

[0113] Note that, when the zoom mechanism 35 adjusts the position of the first lens 31, the numerical aperture of the first lens optical system 3 also changes, so the angle θ2 defining the numerical aperture also changes. Here, the divergence angle θ1 may be set to be equal to or less than the minimum value within the range that the angle θ2 can take due to the movement of the first lens 31, or the divergence angle θ1 may change according to the angle θ2. That is, the first shielding portion 6 may include a diaphragm mechanism 64 that changes the size of the aperture 6a.

[0114] FIG. 21 is a plan view schematically showing an example of the configuration of the first shielding portion 6. The diaphragm mechanism 64 includes a plurality of diaphragm blades 641 and a rotating member 642. The plurality of diaphragm blades 641 are arranged circumferentially around the optical axis AX1, and the tip of each diaphragm blade 641 forms a part of the aperture surface 61. The rotating member 642 is a member that displaces the diaphragm blades 641. For example, it has an annular plate shape surrounding the optical axis AX1. The rotating member 642 is displaceably coupled to the diaphragm blades 641, and by rotating around the optical axis AX1, the plurality of diaphragm blades 641 are displaced, and the size of the aperture 6a changes. The diaphragm mechanism 64 includes a driving unit such as a motor (not shown) that rotates the rotating member 642. The diaphragm mechanism 64 is controlled by, for example, the control unit 20.

[0115] The control unit 20 controls the diaphragm mechanism 64 according to the position of the first lens 31 so that the divergence angle θ1 is equal to or less than the angle θ2. For example, the control unit 20 receives a signal from the outside that designates the divergence angle of the first light L1 emitted by the lighting device 1D. The control unit 20 controls the zoom mechanism 35 and the diaphragm mechanism 64 based on the signal. Specifically, the control unit 20 controls the zoom mechanism 35 to adjust the positions of the first lenses 31 so that the lighting device 1D emits the first light L1 at the divergence angle indicated by the signal. doAt the same time, the aperture mechanism 64 is controlled to adjust the size of the aperture 6a so that the divergence angle θ1 is equal to or less than the angle θ2 of the first lens optical system 3 after the movement of the first lens 31.

[0116] According to this, even if each first lens 31 is moved by the zoom mechanism 35, the first light L1 from the first light source 2 can pass through the effective region of the first lens optical system 3. In other words, the first light L1 from the first light source 2 hardly passes through the edge of the first lens 31. Therefore, the illumination device 1D can emit high-quality first light L1 into the illumination space S1 regardless of the position of the first lens 31.

[0117] The control unit 20 may control the aperture mechanism 64 so that the divergence angle θ1 increases as the angle θ2 increases. According to this, when the angle θ2 is large, more first light L1 can be made incident on the first lens optical system 3, so that more first light L1 can be emitted from the irradiation aperture 4a. That is, the first light L1 emitted from the first emission unit 21 of the first light source 2 can be used more effectively.

[0118] In the above example, although the first shielding unit 6 is located between the first emission unit 21 and the first lens optical system 3, it may be located at the aperture position. In this case, the zoom mechanism 35 may move not only the first lens 31 but also the first shielding unit 6. That is, when the zoom mechanism 35 moves the first lens 31, the aperture position can also move, so the first shielding unit 6 may be moved so that the first shielding unit 6 is located near the aperture position.

[0119] <Sixth Embodiment> FIG. 22 is a cross-sectional view schematically showing an example of the configuration of the illumination device 1E according to the sixth embodiment. The illumination device 1E is different from the illumination device 1 in terms of the presence or absence of the reflecting member 7 and the position of the irradiation aperture 4a.

[0120] The reflecting member 7 is located inside the housing 4, reflects the first light L1, and changes its traveling direction. The reflecting member 7 includes, for example, a mirror or a prism. In the example of FIG. 22, the reflecting member 7 is located downstream of the first lens optical system 3 in the path of the first light L1. The reflecting member 7 reflects the first light L1 that has passed through the first lens optical system 3 toward the irradiation aperture 4a.

[0121] In the example of FIG. 22, the irradiation aperture 4a is not formed in the second member 43 of the housing 4, but is formed in the side wall 41. The irradiation aperture 4a penetrates the side wall 41 in its thickness direction, connecting the internal space of the housing 4 and the illumination space S1. In the example of FIG. 22, the irradiation aperture 4a is formed at a position facing the reflecting member 7 in the radial direction centered on the central axis of the side wall 41. The first light L1 from the reflecting member 7 passes through the irradiation aperture 4a and is emitted into the illumination space S1.

[0122] According to such an illumination device 1E, since the traveling direction of the first light L1 can be made different from the traveling direction of the first light L1 by the first light source 2 by the reflecting member 7, the degree of freedom in the installation position of the irradiation aperture 4a can be improved.

[0123] Also, in the example of FIG. 22, the reflecting member 7 reflects the first light L1 substantially vertically downward at a right angle in the downstream of the first lens optical system 3. When such an illumination device 1E is provided on the ceiling of the illumination space S1, the illumination device 1E can be arranged in the ceiling space with the traveling direction of the first light L1 in the first light source 2 being substantially parallel to the horizontal direction. In the example of FIG. 22, the ceiling plate 100 forming the ceiling surface of the illumination space S1 is also shown. An opening 10a penetrating the ceiling plate 100 along the vertical direction is formed in the ceiling plate 100, and the illumination device 1E is arranged above the ceiling plate 100 at a position where the irradiation aperture 4a faces the opening 10a.

[0124] In such a lighting device 1E, since the plurality of first lenses 31 of the first lens optical system 3 are arranged along the horizontal direction, although the horizontal size of the lighting device 1E increases, the vertical size of the lighting device 1E can be reduced. Therefore, even when the height of the ceiling space is low, the lighting device 1E can be arranged. That is, the lighting device 1E is suitable for installation on the ceiling portion of the lighting space S1.

[0125] FIG. 23 is a cross-sectional view schematically showing another aspect of the lighting device 1E. In the example of FIG. 23, the reflecting member 7 is located between the two first lenses 31 in the path of the first light L1. Hereinafter, the first lens 31 located on the first light source 2 side is referred to as the first A lens 31, and the first lens 31 located on the irradiation opening 4a side is referred to as the first B lens 31.

[0126] In the example of FIG. 23, the side wall 41 of the housing 4 forms an L-shaped internal space. That is, the side wall 41 extends from the periphery of the first member 42 along the traveling direction of the first light L1, bends at a position corresponding to the reflecting member 7, extends along the traveling direction of the first light L1 from the reflecting member 7, and reaches the periphery of the second member 43. Such a side wall 41 has a shape similar to that of a so-called L-shaped tube. Hereinafter, the portion of the side wall 41 corresponding to the front stage of the reflecting member 7 is referred to as the first portion 411, the portion of the side wall 41 corresponding to the rear stage of the reflecting member 7 is also referred to as the second portion 412, and the portion connecting the first portion 411 and the second portion 412 is also referred to as the connecting portion 413.

[0127] Between the first light source 2 and the reflecting member 7, some of the first A lenses 31 constituting the first lens optical system 3 are located. The first A lens 31 is located within the first portion 411. Between the reflecting member 7 and the irradiation opening 4a of the second member 43, the remaining first B lenses 31 constituting the first lens optical system 3 are located. The first B lens 31 is located within the second portion 412. The reflecting member 7 is located within the connecting portion 413.

[0128] When the lighting device 1E according to such another aspect is arranged on the ceiling of the lighting space S1, it can be arranged in the ceiling space in a posture where the traveling direction of the first light L1 in the first light source 2 is substantially parallel to the horizontal direction. According to this, even if the height of the ceiling space is low, the lighting device 1E can be arranged. Further, according to the lighting device 1E according to another aspect, the second part 412 can be inserted into the opening 10a of the ceiling board 100. According to this, the size of the lighting device 1D in the ceiling space can be reduced.

[0129] <Seventh Embodiment> FIG. 24 is a cross-sectional view schematically showing an example of the configuration of a lighting device 1F according to the seventh embodiment. The lighting device 1F is different from the lighting device 1 in terms of the presence or absence of the second light source 8, the second shielding part 65, the second lens optical system 9, and the merging element 10. Further, as illustrated in FIG. 24, the housing 4 houses at least the first lens optical system 3, the second lens optical system 9, the first shielding part 6, the second shielding part 65, and the merging element 10. For this reason, the shape of the housing 4 is also different from that of the housing 4 of the lighting device 1.

[0130] The second light source 8 has a second emission part 81 and emits a second light L2 different from the first light L1 from the first light source 2 from the second emission part 81. The second light L2 is light having a wavelength range different from that of the first light L1 and is, for example, visible light. An example of the specific configuration of the second light source 8 is the same as that of the first light source 2.

[0131] In the example of FIG. 24, the second light source 8 is also attached to the housing 4. The second light source 8 emits the second light L2 into the internal space of the housing 4. In the example of FIG. 24, the second light source 8 emits the second light L2 along the traveling direction of the first light L1 from the first light source 2. The second light L2 from the second light source 8 also travels while spreading in the same manner as the first light L1.

[0132] The second shielding part 65 is located inside the housing 4. The second shielding part 65 has an opening 65a, and the second light L2 passes through the opening 65a. The second shielding part 65 has the same shape as the first shielding part 6, and in the example of FIG. 24, it is located between the second emitting part 81 and the second lens optical system 9. The second shielding part 65 may be located near the aperture position of the second lens optical system 9, similar to the first shielding part 6.

[0133] The second lens optical system 9 is located inside the housing 4. The second lens optical system 9 is an imaging optical system that forms an image of the second light L2 from the second light source 8 on a virtual image plane on the side of the irradiation opening 4a. This image plane is also located, for example, inside the irradiation opening 4a, similar to the image plane IS1. The second lens optical system 9 includes one or more second lenses 91. In the example of FIG. 24, a plurality (here, two) of second lenses 91 are arranged at intervals in the path of the second light L2. A specific example of the second lens 91 is the same as the first lens 31.

[0134] In the example of FIG. 24, a set of the second light source 8 and the second lens optical system 9 is arranged in parallel with a set of the first light source 2 and the first lens optical system 3. In the example of FIG. 24, a reflecting member 71 is located downstream of the second lens optical system 9, and the reflecting member 71 reflects the second light L2 from the second lens optical system 9 toward the confluence element 10. In the example of FIG. 24, the reflecting member 71 is arranged inside the housing 4 at a position above the confluence element 10 and facing the confluence element 10 in the vertical direction. The reflecting member 71 includes, for example, a mirror or a prism.

[0135] The confluence element 10 is an element that combines the first light L1 and the second light L2. For example, the confluence element 10 includes a first prism 11, a second prism 12, and a filter film 13. In the example of FIG. 24, the first prism 11 and the second prism 12 have a right-angled isosceles triangular prism shape and are arranged such that their inclined surfaces face each other.

[0136] The filter film 13 is located on the inclined surfaces of the first prism 11 and the second prism 12, reflects the first light L1, and transmits the second light L2. That is, the transmittance of the filter film 13 for the wavelength range of the second light L2 is higher than the transmittance for the wavelength range of the first light L1, and the reflectance of the filter film 13 for the wavelength range of the first light L1 is higher than the reflectance for the wavelength range of the second light L2. Such a filter film 13 can be realized, for example, by a dielectric multilayer film. The dielectric multilayer film has, for example, a structure in which a plurality of thin dielectric films are laminated. As the dielectric, for example, one or more materials among titanium oxide (TiO2), SiO2, niobium pentoxide (Nb2O5), tantalum pentoxide (Ta2O5), and magnesium fluoride (MgF2) are adopted.

[0137] In the example of FIG. 24, the first light L1 passes through the first prism 11 of the combining element 10 and is incident on the filter film 13 at an incident angle of 45 degrees. The first light L1 is reflected by the filter film 13. In the example of FIG. 24, the reflected first light L1 travels downward along the vertical direction. The second light L2 passes through the second prism 12 and is incident on the filter film 13 at an incident angle of 45 degrees. The second light L2 passes through the filter film 13 and merges with the first light L1 reflected by the filter film 13. That is, behind the filter film 13, the first light L1 and the second light L2 travel together.

[0138] The irradiation aperture 4a of the housing 4 is formed at a position where the first light L1 and the second light L2 from the combining element 10 can pass through, and in the example of FIG. 24, it is formed at a position facing the combining element 10 in the vertical direction. The first light L1 and the second light L2 from the combining element 10 pass through the irradiation aperture 4a of the housing 4 and are emitted into the illumination space S1.

[0139] In such an illumination device 1F, the imaging magnification of the second lens optical system 9 is equal to or less than the ratio of the size of the irradiation aperture 4a to the size of the second light L2 at the second emission portion 81 of the second light source 8. Therefore, the second light L2 can also pass through the irradiation aperture 4a as a spot equal to or smaller than the size of the irradiation aperture 4a. Therefore, the possibility that the second light L2 is reflected or scattered at the periphery of the irradiation aperture 4a can be reduced.

[0140] The imaging magnification of the second lens optical system 9 may be set such that the size of the second light L2 passing through the irradiation aperture 4a is smaller than the irradiation aperture 4a. According to this, the reflected scattered light can be further reduced.

[0141] Further, in the illumination device 1F, the divergence angle formed by the light rays on both outer sides of the second light L2 passing through the aperture 65a of the second shielding portion 65 at the second emission portion 81 is equal to or less than the angle defining the numerical aperture of the second lens optical system 9. According to this, the second light L2 passing through the aperture 65a of the second shielding portion 65 can pass through the effective region of the second lens optical system 9. Therefore, the second light L2 passing through the aperture 65a of the second shielding portion 65 hardly enters the edge of the second lens 91, and unnecessary scattering of the second light L2 can be suppressed or avoided.

[0142] Therefore, the illumination device 1F can emit the second light L2 into the illumination space S1 with high quality. Further, since the illumination device 1F emits light including the first light L1 and the second light L2 into the illumination space S1, light in a wider wavelength range can be emitted into the illumination space S1.

[0143] FIG. 25 is a cross-sectional view schematically showing the first aspect of the illumination device 1F. In the example of FIG. 25, the filter film 13 of the merging element 10 transmits the first light L1 and reflects the second light L2. Therefore, in the example of FIG. 25, the irradiation aperture 4a of the housing 4 is formed at a position facing the merging element 10 in the left-right direction.

[0144] FIG. 26 is a view schematically showing the second aspect of the illumination device 1F. In the example of FIG. 26, a lens 39 is positioned between the merging element 10 and the irradiation aperture 4a of the housing 4. Therefore, the first light L1 and the second light L2 from the merging element 10 are incident on the lens 39. That is, in the example of FIG. 26, the first lens 31 and the lens 39 constitute the first lens optical system 3, and the second lens 91 and the lens 39 constitute the second lens optical system 9. For this reason, the lens 39 can be said to be the first lens 31 and can also be said to be the second lens 91.

[0145] Since the lens 39 is shared by the first lens optical system 3 and the second lens optical system 9, the size and manufacturing cost of the lighting device 1F can be reduced.

[0146] As described above, the lighting devices 1, 1A to 1F have been described in detail. However, the above description is illustrative in all aspects and the lighting devices 1, 1A to 1F are not limited thereto. Innumerable modifications not illustrated can be assumed without departing from the scope of this disclosure. Each configuration described in each of the above embodiments and each modification can be appropriately combined or omitted as long as they do not conflict with each other.

[0147] Needless to say, all or part of each of the above embodiments and various modifications can be appropriately combined within a non - conflicting range.

[0148] As illustrated in FIG. 1, when the first shielding portion 6 is located between the first light emitting portion 21 and the first lens optical system 3 and the opening surface 61 is a reflecting surface inclined with respect to the optical axis AX1, the first lens optical system 3 receives the first light L1 that travels straight through the opening 6a and the first light L1 reflected by the opening surface 61. Hereinafter, the light ray that travels straight through the opening 6a is called a straight - traveling ray, and the light ray reflected by the opening surface 61 is called a reflected ray. Optically, this reflected ray can be regarded as a ray that is emitted from a point outside the first light emitting portion 21 and enters the first lens optical system 3. Therefore, the reflected ray forms an image outside the region where the straight - traveling ray forms an image on the image plane IS1.

[0149] Such reflected light rays may also be passed through the irradiation aperture 4a. Therefore, regarding the imaging magnification of the first lens optical system 3, as the size M1 of the first light L1, for example, the size of the aperture 6a of the first shielding portion 6 may be adopted. Specifically, the size of the aperture 6a on the surface of the first shielding portion 6 on the side of the first lens optical system 3 may be adopted. That is, the imaging magnification of the first lens optical system 3 may be set to be equal to or less than the ratio of the size of the irradiation aperture 4a to the size of the aperture 6a. According to this, the size of the image of the first light L1 formed by the direct light rays and the reflected light rays on the image plane IS1 can be made equal to or less than the size of the irradiation aperture 4a. Therefore, the reflected and scattered light within the housing 4 can be further suppressed, and the first light L1 with less unevenness can be emitted.

Explanation of Signs

[0150] 1 Lighting device 2 First light source 21 First emission portion 3 First lens optical system 31 First lens, first A lens, first B lens 39 Lens 4 Housing 4a First opening (irradiation aperture) 411 First portion 412 Second portion 413 Connecting portion 6 Shielding portion (first shielding portion) 61 Surface (aperture surface) 6a Second opening (aperture) 7 Reflective member 8 Second light source 81 Second emission portion 9 Second lens optical system 91 Second lens IS1 Image plane L1 First light L2 Second light L11 Reflected and scattered light θ1 Divergence angle

Claims

1. A housing having a first opening, A first light source having a first emitting portion that emits a first light into the internal space of the housing, In the path of the first light, including at least one first lens located between the first emitting portion and the first opening of the housing, imaging the first light from the first emitting portion on a virtual image plane on the first opening side, and a first lens optical system that emits the first light from the first opening, At least one shielding portion located between the first emitting portion and the first lens optical system in the path of the first light and having a second opening through which the first light passes Comprising, A part of the first light is incident on the shielding portion, The at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction, The surface forming the second opening of the shielding portion is inclined so as to move away from the optical axis of the first light as it approaches the first lens optical system. An illumination device.

2. The illumination device according to claim 1, The shielding portion includes a member having an absorption rate of 60% or more with respect to the incident first light. An illumination device.

3. The illumination device according to claim 1 or claim 2, The shielding portion is away from the first emitting portion in the optical axis direction. An illumination device.

4. The illumination device according to claim 1 or claim 2, The surface forming the second opening of the shielding portion is away from the first emitting portion in a direction perpendicular to the optical axis direction. An illumination device.

5. The illumination device according to claim 1 or claim 2, The width of the second opening of the shielding portion matches the width of the first emitting portion. An illumination device.

6. The illumination device according to claim 1 or claim 2, The imaging magnification of the first lens optical system is not more than the ratio of the size of the first opening to the size of the first light at the first emitting portion, The angle defining the numerical aperture of the first lens optical system is larger than the angle formed by the outermost light rays among the first lights passing through the second opening of the shielding portion at the first emitting portion. An illumination device.

7. The illumination device according to claim 1 or claim 2, The shielding portion is located between the first emitting portion and the first lens optical system. An illumination device.

8. The illumination device according to claim 6, The surface forming the second opening of the shielding portion is inclined so as to approach the optical axis of the first light as it approaches the first lens optical system. An illumination device.

9. The lighting device according to claim 1 or claim 2, wherein the surface forming the second opening of the shielding portion includes a reflecting surface that reflects the first light, the lighting device.

10. The lighting device according to claim 1 or claim 2, wherein the first A lens and the first B lens are positioned side by side in the optical axis direction of the first light, the lighting device.

11. The lighting device according to claim 10, wherein between the first A lens and the first B lens, the light diameter of the first light is smaller than the light diameter passing through the first A lens and the first B lens, the lighting device.

12. The lighting device according to claim 1 or claim 2, wherein the at least one first lens further includes a first C lens, the first A lens, the first B lens, and the first C lens are positioned side by side in the optical axis direction of the first light, the lighting device.

13. The lighting device according to claim 1 or claim 2, wherein the image plane is located at the first opening, the lighting device.

14. The lighting device according to claim 1 or claim 2, wherein in the internal space of the housing, reflected and scattered light of the first light is incident, and the lighting device further includes a light reduction structure that absorbs the reflected and scattered light.

15. The lighting device according to claim 1 or claim 2, wherein in the internal space of the housing, reflected and scattered light of the first light is incident, and the lighting device further includes a light reduction structure that reflects or scatters the reflected and scattered light toward the first light source side.

16. The lighting device according to claim 15, wherein the light reduction structure has an uneven shape in a cross section including the optical axis for the first light, the lighting device.

17. A housing having a first opening, a first light source having a first emitting portion that emits the first light into the internal space of the housing, including at least one first lens positioned between the first emitting portion and the first opening of the housing in the path of the first light, and imaging the first light from the first emitting portion on a virtual image plane on the first opening side to emit the first light from the first opening, a first lens optical system, at least one shielding portion having a second opening positioned between the first emitting portion and the first lens optical system in the path of the first light and allowing the first light to pass through, A light reduction structure in which reflected and scattered light, which is the first light reflected or scattered in the internal space of the housing, is incident, and the reflected and scattered light is reflected or scattered toward the first light source side, and comprising a part of the first light is incident on the shielding portion, the at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction, the light reduction structure has an uneven shape in a cross section including the optical axis of the first light, the uneven shape has a shape in which concave portions and convex portions are alternately arranged in the cross section, the convex portion has a first surface and a second surface on the first opening side relative to the first surface, in the cross section, the length of the second surface is equal to or greater than the length of the first surface, a lighting device.

18. The lighting device according to claim 14, wherein the light reduction structure is located on an inner wall of the housing, a lighting device.

19. The lighting device according to claim 14, wherein the first lens optical system further includes a spacer located between the first A lens and the first B lens and defining a distance between the first A lens and the first B lens, wherein the light reduction structure is located on an inner wall of the spacer, a lighting device.

20. The lighting device according to claim 14, wherein the light reduction structure is located on the shielding portion, a lighting device.

21. The lighting device according to claim 1 or claim 2, wherein the first lens optical system includes a double-sided telecentric optical system, a lighting device.

22. The lighting device according to claim 1 or claim 2, further comprising a zoom mechanism for moving the at least one first lens along the optical axis of the first light, a lighting device.

23. A housing having a first opening, a first light source having a first emitting portion for emitting the first light into the internal space of the housing, a first lens optical system including at least one first lens located between the first emitting portion and the first opening of the housing in the path of the first light, for forming an image of the first light from the first emitting portion on a virtual image plane on the first opening side and emitting the first light from the first opening, at least one shielding portion located between the first emitting portion and the first lens optical system in the path of the first light and having a second opening for passing the first light, and a zoom mechanism for moving the at least one first lens along the optical axis of the first light comprising a part of the first light is incident on the shielding portion, The at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction, The shielding portion has a diaphragm mechanism that changes the size of the second opening according to the position of the at least one first lens, and the lighting device.

24. A housing having a first opening, A first light source having a first emitting portion that emits first light into the internal space of the housing, In the path of the first light, including at least one first lens located between the first emitting portion and the first opening of the housing, the first light from the first emitting portion is imaged on a virtual image plane on the first opening side, and a first lens optical system that emits the first light from the first opening, At least one shielding portion having a second opening located between the first emitting portion and the first lens optical system in the path of the first light and allowing the first light to pass through Comprising A part of the first light is incident on the shielding portion, The at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction, Located inside the housing, and further comprising a reflecting member that reflects the first light toward the first opening, the lighting device.

25. The lighting device according to claim 24, The housing is A first portion that houses the first A lens, A second portion that houses the first B lens and has the first opening, A connecting portion that connects the first portion and the second portion Having The reflecting member is located inside the connecting portion and reflects the first light from the first A lens toward the first B lens, The first opening is formed at a position where the first light from the first B lens passes through, the lighting device.

26. A housing having a first opening, A first light source having a first emitting portion that emits first light into the internal space of the housing, In the path of the first light, including at least one first lens located between the first emitting portion and the first opening of the housing, the first light from the first emitting portion is imaged on a virtual image plane on the first opening side, and a first lens optical system that emits the first light from the first opening, At least one shielding portion having a second opening located between the first emitting portion and the first lens optical system in the path of the first light and allowing the first light to pass through, A second light source having a second emitting portion that emits second light different from the first light into the internal space of the housing, In the path of the second light, it includes at least one second lens located between the second light emitting portion and the first aperture, and forms an image of the second light from the second light emitting portion on a virtual image plane on the side of the first aperture. A second lens optical system; A combining element that is located in the housing and combines the first light and the second light; Comprising: A part of the first light is incident on the shielding portion; The at least one first lens includes a first A lens and a first B lens arranged in the optical axis direction. A lighting device.

27. A lighting device according to claim 26, A lighting device that is located between the combining element and the first aperture and includes a lens shared by the first lens optical system and the second lens optical system.

Images