Lighting fixture

Abstract

To provide a lighting fixture capable of reducing unevenness of radiated light, in a constitution where light from a light source is condensed and then radiated.SOLUTION: A lighting fixture includes a light source, a collimator, an aperture body, and a Fresnel lens. The collimator is arranged opposing to the light source, and emits light incident from a light emitting element of the light source so as to be along an optical axis. The aperture body is arranged being separated from the collimator on the opposite side from the light source. The Fresnel lens includes an uneven surface where a plurality of grooves are formed concentrically, and a flat surface facing the opposite side from the uneven surface, and is arranged between the collimator and the aperture body in a state where the uneven surface faces the side on which the collimator is positioned. The Fresnel lens condenses the light made incident from the collimator toward an aperture of the aperture body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a lighting fixture. [Background technology]

[0002] In stages, studios, etc., lighting fixtures are used that use a condensing lens to condense light from a light source and then irradiate it. For example, in a lighting fixture in which a light source is provided with multiple types of light-emitting elements that emit light of different colors, the light from the multiple types of light-emitting elements is condensed to mix the colors of the light and irradiate the mixed light. In a lighting fixture that condenses light from a light source and then irradiates it, the light emitted from the condensing lens passes through, for example, an aperture and a diffusion optical component and enters a projection lens, and the light emitted from the projection lens is irradiated onto an irradiation surface.

[0003] In a lighting fixture that radiates light after collecting it from a light source, it is required to reduce unevenness in the radiated light (uneven color, uneven brightness, etc.). One way to achieve this is to appropriately ensure the accuracy of light collection by a collecting lens. For example, in both cases where the radial dimension of the light source is large and the focal length of the collecting lens is small, it is possible to reduce unevenness in the radiated light by appropriately collecting the light from the light source using the collecting lens. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7231831 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a lighting device capable of reducing unevenness in irradiated light in a configuration in which light from a light source is collected and then irradiated. [Means for solving the problem]

[0006] According to an embodiment, the lighting device includes a light source, a collimator, an aperture body, and a Fresnel lens. The light source includes a substrate and a light-emitting element mounted on the substrate. The collimator is disposed opposite the light source and emits light incident from the light-emitting element of the light source along an optical axis. The aperture body is disposed away from the collimator on the opposite side to the light source, forming an aperture. The Fresnel lens includes a convex-concave surface on which a plurality of grooves are concentrically formed, and a flat surface facing the opposite side to the convex-concave surface, and is disposed between the collimator and the aperture body with the convex-concave surface facing the side where the collimator is located. The Fresnel lens focuses the light incident from the collimator toward the aperture. Effect of the Invention

[0007] According to the present invention, it is possible to provide a lighting device capable of reducing unevenness in the emitted light in a configuration in which light from a light source is concentrated and then emitted. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of a lighting device according to an embodiment, and mainly showing the configuration of an optical system of the lighting device. [Diagram 2] FIG. 2 is a schematic diagram showing an example of a light source and a collimator in the lighting device according to the embodiment, as viewed from one side in the axial direction. [Diagram 3] FIG. 3 is a schematic diagram showing an example of a Fresnel lens in a lighting fixture according to an embodiment, as viewed from the side in which a convex and concave surface faces in the axial direction. [Figure 4] FIG. 4 is a schematic diagram showing an example of a path of light incident on a Fresnel lens serving as a condenser lens in a comparative example. [Diagram 5] FIG. 5 is a diagram showing an example of a result of tracing a path of light emitted from a light source in an optical system of a lighting device according to this embodiment. [Figure 6]FIG. 6 is a diagram showing an example of a result of tracing the path of light emitted from a light source in an optical system having a configuration of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The lighting device (1) of the embodiment includes a light source (11), a collimator (13), an aperture body (16), and a Fresnel lens (15). The light source (11) includes a substrate (21) and a light-emitting element (22) mounted on the substrate (21). The collimator (13) is disposed opposite the light source (11) and emits light incident from the light-emitting element (22) of the light source (11) along an optical axis (C). The aperture body (16) is disposed away from the collimator (13) on the opposite side to the light source (11), and forms an aperture (25). The Fresnel lens (15) has a convex-concave surface (31) on which a plurality of grooves (33) are formed concentrically, and a flat surface (32) facing the opposite side to the convex-concave surface (31), and is disposed between the collimator (13) and the aperture body (16) with the convex-concave surface (31) facing the side where the collimator (13) is located. The Fresnel lens (15) collects the light incident from the collimator (13) toward the aperture (25). This ensures appropriate accuracy in collecting light in a configuration in which the light from the light source (11) is collected and then irradiated.

[0010] In the lighting fixture (1) of the embodiment, a plurality of light-emitting elements (22) are mounted on a substrate (21) as light-emitting elements (22) in a light source (11). In the light source (11), five or more element rows are formed concentrically, and in each of the five or more element rows, two or more of the plurality of light-emitting elements (22) are aligned along the circumferential direction. In the embodiment, even if the dimensions of the light source (11) and the Fresnel lens (15) in the radial direction are increased, the Fresnel lens (15) appropriately focuses light toward the aperture (25).

[0011] In the lighting fixture (1) of the embodiment, the distance (L1) from the Fresnel lens (15) to the aperture body (16) in the axial direction along the optical axis (C) is smaller than the dimension (D1) of the Fresnel lens (15) in the radial direction. Also, the dimension (D2) of the aperture (25) in the radial direction is smaller than the distance (L1) from the Fresnel lens (15) to the aperture body (16). In the embodiment, even if the focal length of the Fresnel lens (15) is reduced, the Fresnel lens (15) appropriately focuses light toward the aperture (25).

[0012] The lighting device (1) of the embodiment further includes a diffusion optical component (17). The diffusion optical component (17) is disposed near the aperture body (16) and diffuses the light incident from the Fresnel lens (15). This appropriately realizes a configuration in which the light collected by the Fresnel lens (15) is diffused and incident on the projection lens (18).

[0013] The lighting fixture (1) of the embodiment further includes a projection lens (18). The projection lens (18) is disposed on the opposite side of the aperture body (16) from the Fresnel lens (15), and irradiates the light that has passed through the aperture (25) onto the irradiation surface. The focal position (F1) of the Fresnel lens (15) is located near the aperture body (16), and the focal position (F2) of the projection lens (18) can be positioned near the aperture body (16). This appropriately realizes a configuration in which the light emitted from the Fresnel lens (15) passes through the aperture (25) and then irradiates the irradiation surface.

[0014] In the lighting device (1) of the embodiment, the projection lens (18) is movable along the optical axis (C). Regardless of the position of the projection lens (18), the focal position (F2) of the projection lens (18) coincides with the focal position (F1) of the Fresnel lens (15) or is located closer to the light source (11) than the focal position (F1) of the Fresnel lens (15). This appropriately realizes a configuration that changes the size of the illumination range of light from the lighting device (1) on the illumination surface.

[0015] Hereinafter, an embodiment will be described with reference to the drawings.

[0016] Fig. 1 shows an example of a lighting fixture 1 according to an embodiment. The lighting fixture 1 is used, for example, on a stage or in a studio. The lighting fixture 1 is, for example, any one of a moving light, a spotlight, a horizon light, a border light, a flood light, and a downlight. Fig. 1 mainly shows the configuration of the optical system of the lighting fixture 1.

[0017] 1, the lighting fixture 1 includes a light source 11, a heat sink 12, a collimator 13, a Fresnel lens 15, an aperture body 16, a diffusion optical component 17, and a projection lens 18. In the lighting fixture 1, the light source 11, the heat sink 12, the collimator 13, the Fresnel lens 15, the aperture body 16, the diffusion optical component 17, and the projection lens 18 are arranged, for example, inside a housing (not shown). In addition, the lighting fixture 1 is provided with a power source (not shown) that supplies power to the light source 11, and the like.

[0018] In the optical system of the lighting fixture 1, an optical axis C is defined. In the optical system of the lighting fixture 1, the direction along the optical axis C is defined as the axial direction, and the direction around the optical axis C is defined as the circumferential direction. In the optical system, a direction perpendicular or nearly perpendicular to both the axial direction and the circumferential direction is defined as the radial direction. Moreover, the side approaching the optical axis C in the radial direction is the inner peripheral side, and the side away from the optical axis C in the radial direction is the outer peripheral side. Moreover, the central axes of the light source 11, the collimator 13, the Fresnel lens 15, the aperture body 16, the diffusion optical component 17, and the projection lens 18 are coaxial or nearly coaxial with the optical axis C.

[0019] Fig. 2 shows the light source 11 and the collimator 13 as viewed from one side in the axial direction. Fig. 2 shows the state as viewed from the side from which the light source 11 emits light in the axial direction. As shown in Figs. 1 and 2, the light source 11 includes a substrate 21 and a light-emitting element 22 mounted on the substrate 21. In the example shown in Figs. 1 and 2, a plurality of light-emitting elements 22 are mounted on the substrate 21. Each of the light-emitting elements 22 may be an LED or a light-emitting element other than an LED. In the light source 11, the center of the substrate 21 is coaxial or approximately coaxial with the optical axis C.

[0020] The light source 11 can emit light from each of the light-emitting elements 22. Each of the light-emitting elements 22 performs a light-emitting operation when power is supplied from a power source. In addition, the multiple light-emitting elements 22 installed on the substrate 21 are composed of multiple types of light-emitting elements 22 that emit light of different colors from each other, for example.

[0021] 1, the light source 11 (substrate 21) is attached to the heat sink 12. The heat sink 12 is adjacent to the light source 11 from the side opposite to the side from which light is emitted. When the light source 11 is emitting light from the light emitting element 22, the heat generated in the light source 11 is transferred to the heat sink 12. As a result, the heat generated in the light source 11 is dissipated via the heat sink 12.

[0022] Furthermore, in the light source 11, an element row is formed in which two or more of the plurality of light-emitting elements 22 are aligned along the circumferential direction. In the light source 11, a plurality of the above-mentioned element rows are formed, and the plurality of element rows are formed concentrically. In each of the element rows, two or more light-emitting elements 22 are aligned along the entire circumference in the circumferential direction. In one example of the embodiment, five or more element rows in which two or more light-emitting elements 22 are aligned along the circumferential direction are formed, and the five or more element rows are arranged concentrically.

[0023] In one example of FIG. 2, eight element rows are formed along each of the imaginary surrounding lines α1 to α8. The eight element rows are formed concentrically with the optical axis C as the center or approximately the center. In one example of FIG. 2, the first element row along the surrounding line α1, the second element row along the surrounding line α2, the third element row along the surrounding line α3, the fourth element row along the surrounding line α4, the fifth element row along the surrounding line α5, the sixth element row along the surrounding line α6, the seventh element row along the surrounding line α7, and the eighth element row along the surrounding line α8 are arranged in this order from the inner periphery side to the outer periphery side. In the eight element rows, the number of light emitting elements 22 arranged in the circumferential direction is greater in the rows located closer to the outer periphery side. In the example of FIG. 2, among the eight element rows, the eighth element row along the encircling line α8 is the outermost element row, and a plurality of light emitting elements 22 are arranged on the outer periphery side of the eighth element row along the encircling line α8. The ninth element row may be formed by the plurality of light emitting elements 22 on the outer periphery side of the eighth element row. In this way, an element row that does not completely fill the encircling line α may also be considered to be an element row. In the example of FIG. 2, the elements are arranged in a triangular shape in the first element row closest to the center (optical axis C), and the elements are arranged in a hexagonal shape in the second element row to the eighth element row outside the first element row, but the present invention is not limited to this form. For example, the first element row closest to the center (optical axis C) may have elements arranged in a quadrangle (or other polygonal shape), and the second element row to the eighth element row that are located outside the first element row may also have elements arranged in a quadrangle (or other polygonal shape to match the first element row) that surrounds the first element row. As will be described in detail later, the number of element rows is preferably more than five, so the number of element rows may be more than eight.

[0024] As shown in FIG. 1 and FIG. 2, the collimator 13 is disposed adjacent to the light source 11 from the side from which light is emitted and facing the light source 11 from the side from which light is emitted. The collimator 13 includes lens portions 23, and the same number of lens portions 23 as the light-emitting elements 22 of the light source 11 are formed in the collimator 13. Then, one corresponding lens portion 23 is formed for each of the plurality of light-emitting elements 22. The lens portion 23 is adjacent to the corresponding one of the light-emitting elements 22 from the side from which light is emitted and faces the corresponding one of the light-emitting elements 22 from the side from which light is emitted. Then, the collimator 13 refracts or (total) reflects the light incident on the collimator 13 so that the traveling direction of the light emitted from the collimator 13 is along the optical axis C.

[0025] In the example of Fig. 1 and Fig. 2, in the collimator 13, each of the lens portions 23 is formed in a convex shape convex toward the side where the light source 11 is located (light incident side). In each of the lens portions 23, the cross-sectional area in a cross section perpendicular or substantially perpendicular to the axial direction increases as it moves away from the light source 11 in the axial direction. Since each of the lens portions 23 has a convex shape convex toward the side where the light source 11 is located, in the collimator 13, the surface facing the side where the light source 11 is located is formed in an uneven shape. In addition, in the collimator 13, the surface facing the opposite side to the light source 11 (light exit side) is formed flat or substantially flat.

[0026] As described above, the light source 11 has a plurality of element rows in which two or more light emitting elements 22 are arranged in the circumferential direction. Therefore, the collimator 13 has the same number of lens row rows in which two or more lens portions 23 are arranged in the circumferential direction. In addition, in the example of FIG. 2, the cross-sectional shape of each of the lens portions 23 in a cross section perpendicular or substantially perpendicular to the axial direction is circular or substantially circular. However, the cross-sectional shape of each of the lens portions 23 in a cross section perpendicular or substantially perpendicular to the axial direction is not limited to a circular shape or the like.

[0027] Light is incident on each of the lens units 23 from a corresponding one of the light-emitting elements 22 of the light source 11. In each of the lens units 23, the light incident from the corresponding one of the light-emitting elements 22 is aligned along the optical axis C by at least one of refraction and reflection. Each of the lens units 23 emits light along the optical axis C, for example, in a state parallel or approximately parallel to the optical axis C. Therefore, the collimator 13 emits the light incident from the light-emitting elements 22 of the light source 11 in a state parallel to the optical axis C.

[0028] In the lighting device 1, the aperture body 16 is disposed away from the collimator 13 on the opposite side to the light source 11, and the Fresnel lens 15 is disposed between the collimator 13 and the aperture body 16 in the axial direction. The Fresnel lens 15 is disposed away from the aperture body 16 on the side where the light source 11 is located. In the example of FIG. 1, the Fresnel lens 15 is disposed adjacent to the collimator 13 from the opposite side to the light source 11, that is, from the side from which light is emitted. The Fresnel lens 15 faces the collimator 13 from the opposite side to the light source 11. An aperture 25 is formed in the aperture body 16. The central axis of the aperture 25 is coaxial or approximately coaxial with the optical axis C.

[0029] Fig. 3 shows the Fresnel lens 15 as viewed from one side in the axial direction. As shown in Figs. 1 and 3, the Fresnel lens 15 has a convex-concave surface 31 and a flat surface 32. The convex-concave surface 31 faces one side in the axial direction, and the flat surface 32 faces the opposite side in the axial direction to the side to which the convex-concave surface 31 faces. Fig. 3 shows a state as viewed from the side to which the convex-concave surface 31 faces in the axial direction. The flat surface 32 is formed to be flat or approximately flat.

[0030] As shown in Fig. 1, Fig. 3, etc., a plurality of grooves 33 are formed in the concave-convex surface 31 of the Fresnel lens 15. Each of the plurality of grooves 33 extends along the circumferential direction and is formed over the entire circumference in the circumferential direction. In the concave-convex surface 31, the plurality of grooves 33 are formed concentrically with the optical axis C as the center or approximately the center. The concave-convex surface 31 is formed in an concave-convex shape by the plurality of grooves 33.

[0031] Further, a central convex portion 35 and a plurality of annular convex portions 36 are formed on the convex-concave surface 31. Each of the central convex portion 35 and the annular convex portion 36 is formed in a convex shape that is convex toward the side where the light source 11 and the collimator 13 are located. In the Fresnel lens 15, the optical axis C passes through the central convex portion 35, and the central axis of the central convex portion 35 is coaxial or approximately coaxial with the optical axis C. The plurality of annular convex portions 36 are disposed on the outer periphery side of the central convex portion 35. Each of the annular convex portions 36 is extended along the circumferential direction and is formed over the entire circumference in the circumferential direction. In the convex-concave surface 31, the plurality of annular convex portions 36 are formed concentrically with the optical axis C as the center or approximately the center.

[0032] In the convex-concave surface 31, one groove 33 is formed between the central convex portion 35 and the annular convex portion 36 adjacent to the outer periphery. In addition, in the convex-concave surface 31, one groove 33 is formed between two annular convex portions 36 adjacent to each other in the radial direction. The Fresnel lens 15 is disposed with the convex-concave surface 31 facing the side where the collimator 13 is located. Therefore, in the Fresnel lens 15, the convex-concave surface 31 faces the collimator 13. In addition, in the Fresnel lens 15, the convex-concave surface 31 serves as an entrance surface into which light from the collimator 13 enters, and the plane 32 serves as an exit surface from which light exits.

[0033] In the lighting device 1, the Fresnel lens 15 functions as a condensing lens that condenses the incident light. The light from the collimator 13 is incident on the Fresnel lens 15 along the optical axis C. The Fresnel lens 15 condenses the light incident from the collimator 13 toward the aperture 25 of the aperture body 16. At this time, the light is condensed in a state where the light emitted from the Fresnel lens 15 is collected at the focal position F1 of the Fresnel lens 15. Then, the light is condensed in a state where the light emitted from the Fresnel lens 15 passes through the aperture 25. In one example, in the light source 11, light is emitted from a plurality of types of light-emitting elements 22 that have different emission colors from each other. In this case, the light is condensed by the Fresnel lens 15, thereby mixing the colors of the light. As a result, the color unevenness of the light irradiated from the lighting device 1 is reduced.

[0034] Here, a dimension D1 of the Fresnel lens 15 in the radial direction, such as the outer diameter (diameter) of the Fresnel lens 15, and a dimension D2 of the aperture 25 in the radial direction, such as the diameter (diameter) of the aperture 25, are specified. Also, a distance L1 from the Fresnel lens 15 to the aperture body 16 in the axial direction is specified. The distance L1 is the shortest distance from the surface (plane 32 in this embodiment) of the Fresnel lens 15 from which the light is emitted to the surface of the aperture body 16 on the Fresnel lens 15 side. The distance L1 from the Fresnel lens 15 to the aperture body 16 is smaller than the dimension D1 of the Fresnel lens 15 in the radial direction. And the dimension D2 of the aperture 25 in the radial direction is smaller than the distance L1 from the Fresnel lens 15 to the aperture body 16. The radial dimension D1 of the Fresnel lens 15 is the same or approximately the same as the radial dimension (outer diameter) of the light source 11 and the radial dimension (outer diameter) of the collimator 13.

[0035] In one example, the radial dimension D1 of the Fresnel lens 15, the radial dimension of the light source 11, and the radial dimension of the collimator 13 each have a value in the range of 140 mm or more and 200 mm or less. The axial distance L1 from the Fresnel lens 15 to the aperture body 16 has a value in the range of 90 mm or more and 150 mm or less, provided that it is smaller than the dimension D1. The radial dimension D2 of the aperture 25 has a value in the range of 50 mm or more and 100 mm or less, provided that it is smaller than the distance L1 and the dimension D1.

[0036] Moreover, the focal position F1 of the Fresnel lens 15 is located in the vicinity of the aperture body 16. In the example of Fig. 1, the focal position F1 of the Fresnel lens 15 is located slightly shifted on the opposite side of the light source 11 with respect to the aperture body 16. Therefore, in the example of Fig. 1, the focal length of the Fresnel lens 15 is slightly larger than the distance L1 from the Fresnel lens 15 to the aperture body 16 in the axial direction.

[0037] In this embodiment, the diffusion optical component 17 is disposed near the aperture body 16 and near the focal position F1 of the Fresnel lens 15. Therefore, the diffusion optical component 17 is disposed on the opposite side to the light source 11 and away from the Fresnel lens 15. In the example of FIG. 1, the focal position F1 of the Fresnel lens 15 is slightly shifted on the opposite side to the light source 11 with respect to the diffusion optical component 17. Light from the Fresnel lens 15 is incident on the diffusion optical component 17, and the diffusion optical component 17 diffuses the light incident from the Fresnel lens 15. As the diffusion optical component 17, for example, any one of a fly's eye lens, a diffusion plate, or the like is used.

[0038] The projection lens 18 is disposed on the opposite side of the aperture body 16 and the diffusing optical component 17 to the Fresnel lens 15 and the light source 11. The focal position F1 of the Fresnel lens 15 is located between the Fresnel lens 15 and the projection lens 18. Light that has passed through the aperture 25 is incident on the projection lens 18. Light that has been emitted from the diffusing optical component 17 is incident on the projection lens 18. In the lighting device 1, the light that has been emitted from the projection lens 18 is irradiated onto the irradiation surface. Therefore, the projection lens 18 irradiates the irradiation surface with the light that has passed through the aperture 25, and irradiates the irradiation surface with the light that has been incident from the diffusing optical component 17.

[0039] 1, the diffusing optical component 17 is adjacent to the aperture 25 from the side opposite to the side where the light source 11 is located. Therefore, the light emitted from the Fresnel lens 15 is diffused by the diffusing optical component 17 after passing through the aperture 25. Note that in one example, the diffusing optical component 17 is adjacent to the aperture 25 from the side where the light source 11 is located. In this case, the light emitted from the diffusing optical component 17, i.e., the light diffused by the diffusing optical component 17, passes through the aperture 25.

[0040] Here, in the lighting device 1, an edge that is a boundary between the illuminated range and the non-illuminated range is formed in the aperture 25. In a configuration in which the light that has passed through the aperture 25 is incident on the diffusion optical component 17 as in the example of FIG. 1, the light is diffused by the diffusion optical component 17 after the edge is formed in the aperture 25. Therefore, on the illumination surface illuminated with the light from the lighting device 1, the edge that is a boundary between the illuminated range and the non-illuminated range is likely to be blurred. On the other hand, in a configuration in which the light emitted from the diffusion optical component 17 passes through the aperture 25, the edge is formed in a state in which the light is diffused by the diffusion optical component 17. Therefore, on the illumination surface illuminated with the light from the lighting device 1, the edge that is a boundary between the illuminated range and the non-illuminated range is likely to be clear.

[0041] In the example of FIG. 1, a Fresnel lens is used as the projection lens 18. Therefore, just as the Fresnel lens 15 is provided with the convex-concave surface 31 and the plane 32, the projection lens 18 has a convex-concave surface 41 and a plane 42. The convex-concave surface 41 has a structure similar to that of the convex-concave surface 31 of the Fresnel lens 15, and the plane 42 has a structure similar to that of the plane 32 of the Fresnel lens 15. The projection lens 18 is disposed with the plane 42 facing the side where the aperture body 16 and the light source 11 are located. Therefore, in the projection lens 18, the plane 42 is an entrance surface into which light enters, and the convex-concave surface 41 is an exit surface from which light exits.

[0042] In one example, a plano-convex lens is used instead of a Fresnel lens as the projection lens 18. The plano-convex lens has a flat or nearly flat plane surface and a convex surface facing the opposite side to the plane surface. In this case, the projection lens 18 is disposed with the plane surface facing the side where the aperture body 16 and the light source 11 are located. Therefore, in the projection lens 18, the plane surface is the entrance surface where light enters, and the convex surface is the exit surface where light exits.

[0043] Here, we define a dimension D3 of the projection lens 18 in the radial direction, such as the outer diameter (diameter) of the projection lens 18. The dimension D3 of the projection lens 18 in the radial direction is equal to or larger than the dimension D1 of the Fresnel lens 15 in the radial direction.

[0044] In the example of FIG. 1, the projection lens 18 is movable along the axial direction, that is, along the optical axis C. Therefore, in response to the movement of the projection lens 18, the distance between the aperture body 16 and the projection lens 18 in the axial direction changes, and the distance between the diffusion optical component 17 and the projection lens 18 in the axial direction changes. In addition, in response to the movement of the projection lens 18, the focal position F2 of the projection lens 18 changes. Note that it is not the projection lens 18 that is configured to be movable along the optical axis C, but the light source 11, the heat sink 12, the collimator 13, the Fresnel lens 15, the aperture body 16, and the diffusion optical component 17 may be configured to be movable along the optical axis C as a single body.

[0045] In the example of FIG. 1, the projection lens 18 is movable between the position shown by the solid line and the position shown by the dashed line. The projection lens 18 is farthest from the aperture body 16 and the diffusing optical component 17 at the position shown by the solid line, and is closest to the aperture body 16 and the diffusing optical component 17 at the position shown by the dashed line. In a configuration in which the projection lens 18 is movable, the closer the projection lens 18 is to the aperture body 16 and the diffusing optical component 17, the wider the irradiation range of the light from the projection lens 18 on the irradiation surface. Therefore, the closer the projection lens 18 is to the aperture body 16 and the diffusing optical component 17, the more the light irradiated from the lighting device 1 changes from a spot state to a flood state.

[0046] Moreover, the projection lens 18 can position the focal position F2 in the vicinity of the aperture body 16 and the diffusion optical component 17. In the example of Fig. 1, the closer the projection lens 18 is to the aperture body 16 and the diffusion optical component 17, the more the focal position F2 of the projection lens 18 moves to the side where the light source 11 is located. Note that Fig. 1 shows a focal position F2a of the projection lens 18 when the projection lens 18 is located farthest from the aperture body 16, and a focal position F2b of the projection lens 18 when the projection lens 18 is located closest to the aperture body 16. In response to the movement of the projection lens 18, the focal position F2 of the projection lens 18 changes between the focal positions F2a and F2b.

[0047] In the embodiment, the focal length of the Fresnel lens 15 is preferably smaller than the focal length of the projection lens 18. In addition, in a configuration in which the projection lens 18 moves as in the example of Fig. 1, when the projection lens 18 is positioned at the furthest position from the aperture body 16, the distance from the aperture body 16 to the projection lens 18 in the axial direction is preferably larger than the distance L1 from the Fresnel lens 15 to the aperture body 16 in the axial direction.

[0048] In the example of Fig. 1, regardless of the position of the projection lens 18, the focal position F2 of the projection lens 18 is located closer to the light source 11 and the Fresnel lens 15 than the focal position F1 of the Fresnel lens 15. Also, in the example of Fig. 1, at least in a state in which the projection lens 18 is located farthest from the aperture body 16, the focal position F2 (F2a) of the projection lens 18 is located near the aperture body 16. And, in a state in which the projection lens 18 is located closest to the aperture body 16, the focal position F2 (F2b) of the projection lens 18 is located away from the aperture body 16 to the side where the light source 11 is located, and is located between the Fresnel lens 15 and the aperture body 16 in the axial direction.

[0049] In one example, when the projection lens 18 is located at the furthest position from the aperture body 16, the focal position F2 of the projection lens 18 coincides with the focal position F1 of the Fresnel lens 15. However, even in this example, except for the state in which the projection lens 18 is located at the furthest position from the aperture body 16, the focal position F2 of the projection lens 18 is located on the side closer to the light source 11 and the Fresnel lens 15 than the focal position F1 of the Fresnel lens 15. Therefore, in any position in which the projection lens 18 is located, the focal position F2 of the projection lens 18 coincides with the focal position F1 of the Fresnel lens 15 or is located on the side closer to the light source 11 than the focal position F1 of the Fresnel lens 15.

[0050] Here, a comparative example is a configuration in which the Fresnel lens 15 serving as a condensing lens is disposed with the flat surface 32, not the convex / concave surface 31, facing the side where the collimator 13 is located. In the comparative example, unlike the above-described embodiment, in the Fresnel lens 15 serving as a condensing lens, the flat surface 32 serves as an entrance surface on which the light from the collimator 13 enters, and the convex / concave surface 31 serves as an exit surface from which the light exits.

[0051] Fig. 4 shows an example of a path of light incident on Fresnel lens 15 serving as a condenser lens in the comparative example. As shown in Fig. 4, in the configuration of the comparative example, light incident on Fresnel lens 15 in the outer peripheral region of plane 32 is emitted from annular convex portion 36 located in the outer peripheral region of convex-concave surface 31. In the configuration of the comparative example in which convex-concave surface 31 serves as the emission surface, light emitted from annular convex portion 36 located in the outer peripheral region may enter Fresnel lens 15 again from annular convex portion 36 located on the inner peripheral side of the emission position (arrow B1), or may be reflected by annular convex portion 36 located on the inner peripheral side of the emission position (arrow B2).

[0052] Since the above-mentioned phenomenon may occur, in the configuration of the comparative example, light emitted from the outer peripheral region of the convex-concave surface 31 tends to be difficult to collect. In particular, when the radial dimension of the light source 11 is large due to an increase in size of the light source 11, the radial dimension of the Fresnel lens 15 becomes large, and the tendency that the light emitted from the outer peripheral region of the convex-concave surface 31 is difficult to collect becomes prominent. Also, when the focal length of the Fresnel lens 15, which is a collecting lens, is small, the tendency that the light emitted from the outer peripheral region of the convex-concave surface 31 is difficult to collect becomes prominent.

[0053] In contrast, in the embodiment, the Fresnel lens 15 serving as a condensing lens is disposed with the convex-concave surface 31 facing the side where the collimator 13 is located, and therefore the plane 32 serves as the exit surface from which light is emitted. Since the plane 32 serves as the exit surface, it is difficult for the phenomenon to occur in which the light emitted from the region on the outer periphery side of the plane 32 reenters the Fresnel lens 15 or is reflected by the Fresnel lens 15. As a result, in the configuration of the embodiment, the light emitted from the region on the outer periphery side of the convex-concave surface 31 is also easily condensed.

[0054] In fact, the light emitted from the light source 11 was irradiated using each of the optical system of the lighting device 1 according to the embodiment and the optical system of the comparative example, and the path of the light emitted from the light source 11 was traced. FIG. 5 shows the result of tracing the path of the light emitted from the light source 11 in the optical system of the lighting device 1 according to the embodiment. FIG. 6 shows the result of tracing the path of the light emitted from the light source 11 in the optical system of the comparative example. In tracing the path of the light, in both the configuration of the embodiment and the configuration of the comparative example, the light emitted from the light source 11 was made to pass through the collimator 13, the Fresnel lens 15 serving as a condenser lens, the aperture 25, the diffusion optical component 17, and the projection lens 18 in this order, and was irradiated onto the irradiation surface.

[0055] In the configuration of the embodiment, as described above, the Fresnel lens 15 is disposed with the convex and concave surfaces 31 facing the side where the collimator 13 is located, and in the configuration of the comparative example, as described above, the Fresnel lens 15 is disposed with the flat surface 32 facing the side where the collimator 13 is located. Except for the fact that the directions in which the convex and concave surfaces 31 face in the Fresnel lens 15 are different from each other, the other conditions are the same for the configuration of the embodiment and the configuration of the comparative example. In other words, except for the directions in which the convex and concave surfaces 31 face in the Fresnel lens 15 are different from each other, the positions at which the optical components are disposed, and the focal positions of the Fresnel lens 15 and the projection lens 18, etc. are the same for the configuration of the embodiment and the configuration of the comparative example. In both the configuration of the embodiment and the configuration of the comparative example, the light source 11 is configured in the same manner as the example light source of Figure 2, with eight element rows formed concentrically around the optical axis C at or approximately the center, and with two or more light-emitting elements 22 lined up around the entire circumference in each of the eight element rows.

[0056] As shown in Fig. 6, in the configuration of the comparative example, the light emitted from the light-emitting elements 22 arranged in the region on the outer periphery side was not collected by the Fresnel lens 15. In particular, in the four element rows on the outer periphery side among the eight element rows, the light emitted from the light-emitting elements 22 tended to be difficult to be collected by the Fresnel lens 15. For this reason, it was demonstrated that in the configuration of the comparative example, when five or more element rows are concentrically arranged in the light source 11, the light emitted from the light-emitting elements 22 is difficult to be collected by the Fresnel lens 15 in the element rows other than the four element rows on the inner periphery side among the five or more element rows.

[0057] 5, in the configuration of the embodiment, the light emitted from the light-emitting elements 22 arranged in the outer circumferential region was also appropriately collected by the Fresnel lens 15. In fact, even in the outermost element row of the eight element rows, the light emitted from the light-emitting elements 22 was appropriately collected by the Fresnel lens 15. Therefore, it was demonstrated that in the configuration of the embodiment, even if five or more element rows are concentrically arranged in the light source 11, the light emitted from the light-emitting elements 22 arranged in the outer circumferential region was appropriately collected by the Fresnel lens 15.

[0058] As described above, in the configuration of the embodiment, the Fresnel lens 15 serving as a condensing lens is disposed between the collimator 13 and the aperture body 16 with the convex and concave surfaces 31 facing the side where the collimator 13 is located. The collimator 13 emits the light incident from the light source 11 along the optical axis C, and the Fresnel lens 15 condenses the light incident from the collimator 13 toward the aperture 25. With this configuration, the Fresnel lens 15 appropriately condenses the light toward the aperture 25. For example, in both cases where the dimension of the light source 11 in the radial direction is large and where the focal length of the Fresnel lens 15 serving as a condensing lens is small, the Fresnel lens 15 appropriately condenses the light from the light source. Therefore, in the configuration where the light from the light source 11 is condensed and then irradiated, the accuracy of condensation is appropriately ensured, and unevenness of the irradiated light (uneven color, uneven brightness, etc.) can be reduced.

[0059] Since the light is appropriately collected by the Fresnel lens 15, the light emitted from the light emitting elements 22 arranged in the outer peripheral region of the light source 11 is also appropriately collected and irradiated onto the irradiation surface. Therefore, the desired brightness and light color, etc. are appropriately realized in the irradiation range of the light from the lighting device 1. That is, it is effectively prevented that the brightness of the light irradiated from the lighting device 1 is reduced and some light colors are not mixed.

[0060] In one embodiment, five or more element rows are concentrically formed in the light source 11, and two or more of the light emitting elements 22 are arranged in the circumferential direction in each of the five or more element rows. In this case, the dimension of the light source 11 in the radial direction is large, and therefore the dimension D1 of the Fresnel lens 15 in the radial direction is also large. In the embodiment, the Fresnel lens 15 is disposed with the convex and concave surface 31 facing the side where the collimator 13 is located, so that even if the dimensions of the light source 11 and the Fresnel lens 15 in the radial direction are large, the Fresnel lens 15 appropriately focuses light toward the aperture 25.

[0061] In addition, in one example of the embodiment, the distance L1 from the Fresnel lens 15 to the aperture body 16 in the axial direction is smaller than the dimension D1 of the Fresnel lens 15 in the radial direction. And the dimension D2 of the aperture 25 in the radial direction is smaller than the distance L1 from the Fresnel lens 15 to the aperture body 16. For example, when a Fresnel lens 15 with a small focal length is used, the distance L1 from the Fresnel lens 15 to the aperture body 16 becomes smaller than the dimension D1 of the Fresnel lens 15 in the radial direction. In the embodiment, the Fresnel lens 15 is disposed with the convex and concave surfaces 31 facing the side where the collimator 13 is located, so that even if the focal length of the Fresnel lens 15 becomes small, the Fresnel lens 15 appropriately focuses light toward the aperture 25.

[0062] In the embodiment, a diffusion optical component 17 is disposed near the aperture body 16, and the diffusion optical component 17 diffuses the light incident from the Fresnel lens 15. This appropriately realizes a configuration in which the light collected by the Fresnel lens 15 is diffused and incident on the projection lens 18.

[0063] In the embodiment and the like, the projection lens 18 is disposed on the opposite side of the aperture body 16 to the Fresnel lens 15. The focal position F1 of the Fresnel lens 15 is located near the aperture body 16, and the projection lens 18 can have a focal position F2 located near the aperture body 16. This appropriately realizes a configuration in which the light emitted from the Fresnel lens 15 passes through the aperture 25 and then irradiates the irradiation surface.

[0064] In one embodiment, the projection lens 18 is movable along the optical axis C. Regardless of the position of the projection lens 18, the focal position F2 of the projection lens 18 coincides with the focal position F1 of the Fresnel lens 15, or is located closer to the light source 11 than the focal position F1 of the Fresnel lens 15. This appropriately realizes a configuration that changes the size of the illumination range of the light from the lighting device 1 on the illumination surface.

[0065] According to at least one of these embodiments, the Fresnel lens is disposed between the collimator and the aperture body with the convex and concave surfaces facing the side where the collimator is located. The collimator emits light incident from the light source along the optical axis, and the Fresnel lens collects the light incident from the collimator toward the aperture. This makes it possible to provide a lighting device that can appropriately ensure the accuracy of light collection in a configuration in which light from the light source is collected and then irradiated, and can reduce unevenness in the irradiated light (uneven color, uneven brightness, etc.).

[0066] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0067] 1...lighting device, 11...light source, 13...collimator, 15...Fresnel lens, 16...aperture body, 17...diffusion optical component, 18...projection lens, 21...substrate, 22...light-emitting element, 31...concave surface, 32...flat surface, C...optical axis, F1, F2...focal position.

Claims

1. A light source including a substrate and a light emitting element disposed on the substrate; a collimator disposed opposite the light source and configured to emit light incident from the light emitting element of the light source along an optical axis; an aperture body disposed on a side opposite to the light source and away from the collimator, the aperture body having an aperture formed therein; a Fresnel lens including a convex-concave surface on which a plurality of grooves are formed concentrically and a flat surface facing the opposite side to the convex-concave surface, the Fresnel lens being disposed between the collimator and the aperture body with the convex-concave surface facing the side where the collimator is located, the Fresnel lens focusing light incident from the collimator toward the aperture; A lighting fixture comprising:

2. In the light source, a plurality of light-emitting elements are disposed on the substrate as the light-emitting element, In the light source, five or more element rows are formed concentrically, and in each of the five or more element rows, two or more of the plurality of light-emitting elements are arranged along a circumferential direction.

2. The lighting fixture of claim 1.

3. A distance from the Fresnel lens to the aperture body in an axial direction along the optical axis is smaller than a dimension of the Fresnel lens in a radial direction, The size of the aperture in the radial direction is small compared to the distance from the Fresnel lens to the aperture body.

3. A lighting fixture according to claim 1 or 2.

4. 3. The lighting device according to claim 1, further comprising a diffusion optical component disposed in the vicinity of said aperture body for diffusing the light incident from said Fresnel lens.

5. a projection lens disposed on the opposite side of the aperture body from the Fresnel lens and configured to project the light having passed through the aperture onto an illumination surface; The focal position of the Fresnel lens is located near the aperture body, The projection lens is capable of positioning a focal position in the vicinity of the aperture body.

3. A lighting fixture according to claim 1 or 2.

6. the projection lens is movable along the optical axis; Regardless of the position of the projection lens, the focal position of the projection lens coincides with the focal position of the Fresnel lens, or is located closer to the light source than the focal position of the Fresnel lens.

6. The lighting fixture of claim 5.

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