Luminaire

Abstract

To provide a luminaire which can achieve improvement in the uniformity of brightness of a light emitting surface, and which can condense illumination light in a predetermined region in front of the light emitting surface.SOLUTION: A luminaire 100 includes: a light source part 23; a first optical member 180 arranged in front of the light source part 23; and a second optical member 190 arranged in front of the first optical member 180. The light source part 23 includes a plurality of light emitting elements 23a which is the plurality of light emitting elements 23a arrayed in an annular manner, and each of which emits light frontward. The first optical member 180 emits light emitted from each of the plurality of light emitting elements 23a by narrowing down the light distribution angle, in the direction orthogonal to an array direction Ad of the plurality of light emitting elements 23a in the case of viewing from front. The second optical member 190 emits the light emitted from the first optical member 180 by narrowing down the light distribution angle, in the array direction Ad.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] Patent Document 1 discloses an illumination device including a plurality of LED light-emitting units and a metal substrate on which the LED light-emitting units are mounted. The metal substrate is strip-shaped and curved such that the central axis in the longitudinal direction of the strip forms an arc shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-147180 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above conventional lighting device, the inner surface of the ring-shaped metal substrate is inclined so as to face diagonally downward, and multiple LED light-emitting units are mounted evenly in the circumferential direction on the inner surface of the metal substrate. In a lighting device configured in this way, each of the multiple LED light-emitting units arranged in a ring shape is easily recognized as a high-luminance point (a particle of light). Therefore, for example, it is conceivable to cover the multiple LED light-emitting units with a cover or the like that scatters the light that passes through. However, in this case, a problem occurs in that it becomes difficult to concentrate the light emitted from the multiple LED light-emitting units in a predetermined area.

[0005] The present invention was made by the inventor of the present application with a new focus on the above-mentioned problems, and aims to provide an illumination device that can improve the uniformity of the brightness of the light-emitting surface and can concentrate illumination light on a specified area in front. [Means for solving the problem]

[0006] An illumination device according to one aspect of the present invention includes a light source unit having a plurality of light-emitting elements arranged in a ring shape, each of which emits light forward; a first optical member arranged in front of the light source unit and configured to narrow the light distribution angle of light emitted from each of the plurality of light-emitting elements in a direction perpendicular to the arrangement direction of the plurality of light-emitting elements when viewed from the front; and a second optical member arranged in front of the first optical member and configured to narrow the light distribution angle of the light emitted from the first optical member in the arrangement direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide an illumination device that can improve the uniformity of the brightness of the light-emitting surface and can focus illumination light on a predetermined area in front of the illumination device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a lighting device according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the lighting device according to the embodiment. [Diagram 3] FIG. 3 is an exploded perspective view of the optical members according to the embodiment. [Figure 4] FIG. 4 is a rear view of the optical members according to the embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing a part of the lighting device according to the embodiment. [Figure 6A] FIG. 6A is a front view showing a state in which only a primary light source unit is turned on in the illumination device according to the embodiment. [Figure 6B] FIG. 6B is a front view showing a light emitting surface in a state where only the secondary light source unit is turned on in the illumination device according to the embodiment. [Figure 6C] FIG. 6C is a front view showing a state in which only the light source unit is turned on in the illumination device according to the embodiment. [Figure 7] FIG. 7 is a first schematic diagram showing the light distribution characteristic of the first optical member according to the embodiment. [Figure 8] FIG. 8 is a second schematic diagram showing the light distribution characteristic of the first optical member according to the embodiment. [Figure 9] FIG. 9 is a perspective view showing a part of a lenticular lens which is a second optical member according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an outline of a configuration of a second optical member according to a modified example of the embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing an outline of a configuration of a second optical member according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following, a lighting device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangements and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0010] In addition, each figure is a schematic diagram and is not necessarily illustrated precisely. Therefore, for example, the scales in each figure do not necessarily match. In addition, in each figure, substantially the same configuration is given the same reference numerals, and duplicated explanations are omitted or simplified. The posture of the lighting device when in use is not limited to the posture shown in each figure, and can be appropriately determined according to the purpose or use.

[0011] In this specification, terms indicating relationships between elements, terms indicating the shapes of elements such as a circle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0012] (Embodiment) [1. Overall configuration of lighting device 100] First, the overall configuration of a lighting device 100 according to an embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is a perspective view showing the appearance of the lighting device 100 according to the embodiment. Fig. 2 is an exploded perspective view of the lighting device 100 according to the embodiment. The downward direction (Z-axis minus direction) in Figs. 1 and 2 corresponds to the direction of an object (e.g., a ceiling (not shown)) on which the lighting device 100 is installed. In other words, the lighting device 100 in Figs. 1 and 2 is shown upside down from the case where it is placed on a ceiling. Fig. 3 is an exploded perspective view of an optical member group 120 according to the embodiment.

[0013] 1, the lighting device 100 of the present embodiment is, for example, a ceiling light attached to the ceiling of a building. The lighting device 100 according to the present embodiment includes a main body 110, and a light-emitting module 10 and an optical member group 120 attached to the main body 110.

[0014] 2, the light emitting module 10 has a substrate 11, a light source section 23 arranged on a main surface 11a of the substrate 11, a first light source section 21, and a second light source section 22. Light emitted forward from the light source section 23, the first light source section 21, and the second light source section 22 is used as light emitted from the lighting device 100 (illumination light).

[0015] The light source unit 23 has a plurality of light-emitting elements 23a arranged in an annular shape on the main surface 11a of the substrate 11. More specifically, the plurality of light-emitting elements 23a are arranged in an annular shape. In this embodiment, the arrangement direction of the plurality of light-emitting elements 23a is referred to as the "arrangement direction Ad". Also, the direction perpendicular to the arrangement direction Ad and the front-rear direction (the Z-axis direction in this embodiment) is referred to as the "radial direction Rd". In this embodiment, the first optical member 180, the second optical member 190, the first light guide plate 160, and the substrate 11 are also formed in an annular shape, and their circumferential directions coincide with the "arrangement direction Ad", and their radial directions coincide with the "radial direction Rd". Each of the plurality of light-emitting elements 23a emits light forward. That is, in this embodiment, the Z-axis positive direction is treated as the main light emission direction (i.e., forward) from the light-emitting element 23a. In other words, in this embodiment, the optical axis of the light-emitting element 23a is directed in the Z-axis positive direction.

[0016] The first light source section 21 has a plurality of first light-emitting elements 21a arranged in a circular ring shape on the main surface 11a of the substrate 11. The second light source section 22 has a plurality of second light-emitting elements 22a arranged in a circular ring shape on the main surface 11a of the substrate 11. That is, when viewed from the front, the light source section 23, the first light source section 21, and the second light source section 22 are each formed in a circular ring shape. In this embodiment, when the light-emitting module 10 is viewed from the front, the second light source section 22, the light source section 23, and the first light source section 21 are concentrically arranged in this order from the center toward the outside. That is, the light source section 23 is located between the first light source section 21 and the second light source section 22.

[0017] In this embodiment, each of the light emitting element 23a, the first light emitting element 21a, and the second light emitting element 22a is an individually packaged SMD (Surface Mount Device) type LED element (LED light source). That is, each of the light emitting element 23a, the first light emitting element 21a, and the second light emitting element 22a includes a white container (package) made of resin or ceramic, an LED chip (bare chip) disposed in the container, and a sealing member that seals the LED chip.

[0018] The substrate 11 is a mounting substrate for mounting light emitting elements such as the light emitting element 23a. In this embodiment, the substrate 11 is formed in a circular ring shape when viewed from the front. The thickness of the substrate 11 is, for example, 1.0 mm. The substrate 11 is, for example, a printed wiring board (printed circuit board) on which metal wiring is formed in a predetermined pattern. The substrate 11 may be a single-sided wiring board on which wiring is formed only on the main surface 11a on which the light emitting elements are mounted, or a double-sided wiring board on which wiring is formed on both sides. The substrate 11 may be formed by connecting multiple substrates in the circumferential direction. The substrate 11 may include a first substrate on which the first light source unit 21 is arranged, a second substrate on which the second light source unit 22 is arranged, and a third substrate on which the light source unit 23 is arranged. In other words, the substrate 11 of the light emitting module 10 may be realized by arranging multiple substrates that are separate from each other side by side.

[0019] The main body 110 has a cylindrical first main body 110a and a second main body 110b that closes an opening at the rear (negative Z-axis direction) of the first main body 110a. The first main body 110a has a flange 111 that protrudes inward at its front end. An opening 112 is formed inside the flange 111 (see FIG. 2). The light-emitting module 10 is fixed to the first main body 110a or the second main body 110b by a predetermined means such as a screw (not shown). As a result, the light source 23, the first light source 21, and the second light source 22 are exposed forward from the opening 112 of the first main body 110a.

[0020] The second main body portion 110b forming the rear end portion of the main body portion 110 has a structure (not shown) that can be fitted with the mounting member 300, and is detachably attached to the ceiling via the mounting member 300. That is, in this embodiment, the lighting device 100 is detachably attached to the ceiling via the mounting member 300.

[0021] In this embodiment, a control unit 80 is fixed to the second body portion 110b. The control unit 80 includes a control circuit board that controls the light emission state of each of the light source portion 23, the first light source portion 21, and the second light source portion 22. The control unit 80 is electrically connected to each of the light source portion 23, the first light source portion 21, and the second light source portion 22 via a cable 90. In FIG. 2, the cable 90 is diagrammatically represented by a thick dotted line.

[0022] More specifically, the control unit 80 changes the amount of light emitted by each of the light source unit 23, the first light source unit 21, and the second light source unit 22 by controlling the current supplied to each of the light source unit 23, the first light source unit 21, and the second light source unit 22. As a method of this control, for example, Pulse Width Modulation (PWM) control is adopted. This changes the amount of illumination light emitted by each of the light source unit 23, the first light source unit 21, and the second light source unit 22. In other words, in this embodiment, each of the light source unit 23, the first light source unit 21, and the second light source unit 22 of the light-emitting module 10 can be dimmed (brightness controlled) independently of each other.

[0023] Each of the light source unit 23, the first light source unit 21, and the second light source unit 22 may include two or more types of light-emitting elements having different emission colors (color temperatures). For example, assume that the light source unit 23 includes two or more types of light-emitting elements 23a having different emission colors (color temperatures). In this case, when the light-emitting elements 23a are divided into a first group and a second group having different emission colors (color temperatures), the control unit 80 can independently perform dimming control of one or more light-emitting elements 23a included in the first group and one or more light-emitting elements 23a included in the second group. This changes the color of the illumination light emitted by the light source unit 23. That is, the control unit 80 may perform color adjustment control (control of the emission color) of the light source unit 23. The same applies to the first light source unit 21 and the second light source unit 22.

[0024] In this embodiment, the control unit 80 has a function as a power supply unit that converts AC power from an external power supply such as a commercial power supply into DC power of a predetermined level by rectifying, smoothing, stepping down, etc., and supplies the DC power to the light-emitting module 10. In other words, the control unit 80 is supplied with AC power via a power line (such as a VVF cable) not shown.

[0025] The optical member group 120 is a member that emits the light incident from the light emitting module 10 .

[0026] In the present embodiment, the optical member group 120 includes a first optical member 180, a second optical member 190, a first light guide plate 160, and a second light guide plate 170. The first optical member 180 is disposed between the first light guide plate 160 and the second light guide plate 170.

[0027] The first light guide plate 160 emits light incident from the first light source unit 21 forward. The second light guide plate 170 emits light incident from the second light source unit 22 forward. The first optical member 180 emits light incident from the light source unit 23 towards the second optical member 190 in front.

[0028] The lighting device 100 according to this embodiment includes the optical member group 120 configured as above, and three light-emitting elements (the light-emitting element 23a, the first light-emitting element 21a, and the second light-emitting element 22a) whose light-emitting state can be changed independently of each other. This allows an increase in the variety of light effects. The following describes the optical member group 120 and its surrounding configuration according to this embodiment with reference to Figs. 4 to 9 in addition to Figs. 1 to 3 above.

[0029] [2. Overview of the Optical Member Group 120 and Its Peripheral Configuration] FIG. 4 is a diagram (back view) of the optical member group 120 according to the embodiment when viewed from the negative Z-axis direction. FIG. 5 is a cross-sectional view showing a part of the illumination device 100 according to the embodiment. In FIG. 5, the VV line cross section of FIG. 4 is shown, and the main body 110 is omitted. In FIG. 5, the side surfaces of the light emitting element 23a, the first light emitting element 21a, and the second light emitting element 22a arranged at the position closest to the cross section of the optical member group 120 are shown, and the other light emitting elements arranged further back (in the positive Y-axis direction) than the cross section are omitted. FIG. 6A is a front view showing a state in which only the first light source unit 21 is turned on in the illumination device 100 according to the embodiment. FIG. 6B is a front view showing a state in which only the second light source unit 22 is turned on in the illumination device 100 according to the embodiment. FIG. 6C is a front view showing a state in which only the light source unit 23 is turned on in the illumination device 100 according to the embodiment. 6A to 6C all show the illumination device 100 as viewed from the front, with the range of the light-emitting surface being indicated by a dotted area.

[0030] 3 to 5, the optical member group 120 according to this embodiment includes an annular first optical member 180, an annular first light guide plate 160 arranged on the outside of the first optical member 180, and a disk-shaped second light guide plate 170 arranged on the inside of the first optical member 180. Specifically, the first optical member 180 is arranged in a central opening 168 of the first light guide plate 160, and the second light guide plate 170 is arranged in a central opening 188 of the first optical member 180. The first optical member 180 includes a plurality of outer peripheral protrusions 189b provided on the outer periphery, and each of the plurality of outer peripheral protrusions 189b engages with an inner peripheral recess 169 provided on the inner periphery of the first light guide plate 160. First optical member 180 has a plurality of inner peripheral protrusions 189a provided on the inner peripheral edge, and each of the plurality of inner peripheral protrusions 189a engages with an outer peripheral recess 179 provided on the outer peripheral edge of second light guide plate 170. The positions and attitudes of first light guide plate 160 and second light guide plate 170 relative to first optical member 180 are determined by this engagement relationship.

[0031] The optical member group 120 according to this embodiment further includes an annular second optical member 190 that covers the multiple lenses 181 included in the first optical member 180. In this embodiment, a lenticular lens 191 having multiple convex portions 192 arranged in an annular shape is used as the second optical member 190. Details of the second optical member 190, which is the lenticular lens 191, will be described later with reference to Figs. 8 to 10.

[0032] Each of the first optical member 180, the first light guide plate 160, the second light guide plate 170, and the second optical member 190 of the optical member group 120 is formed using a translucent (e.g., transparent) resin material such as acrylic resin. In this embodiment, the first optical member 180, the first light guide plate 160, and the second light guide plate 170 are separate members, but these three members may be integrated. In other words, one optical member may have portions corresponding to the first optical member 180, the first light guide plate 160, and the second light guide plate 170.

[0033] As shown in FIG. 5, the first optical member 180 has a lens 181 disposed in front of the light source unit 23, a first incident portion 183 disposed in front of the first light source unit 21, and a second incident portion 184 disposed in front of the second light source unit 22. The lens 181 has a concave housing portion 181a that houses the light emitting element 23a. The light emitted by the light emitting element 23a is incident on the lens 181 from the housing portion 181a and emitted forward. The lens 181 is disposed at a position facing each of the multiple light emitting elements 23a of the light source unit 23 in the front-rear direction (Z-axis direction). That is, the first optical member 180 has multiple lenses 181 that correspond one-to-one to the multiple light emitting elements 23a, and the multiple lenses 181 are disposed in a ring shape like the multiple light emitting elements 23a. Each of the multiple lenses 181 changes the light distribution angle (1 / 2 beam angle in this embodiment, the same applies below) of the light incident from the light emitting element 23a and emits it. The light emitted from the multiple lenses 181 is emitted forward via the second optical member 190. The optical action of the lenses 181 of the first optical member 180 and the second optical member 190 on the incident light will be described later.

[0034] The first incident portion 183 and the second incident portion 184 are provided in the first optical member 180 as grooves recessed forward (Z-axis positive direction). The first incident portion 183 faces the first light-emitting elements 21a of the first light source unit 21 in the front-rear direction and extends in the arrangement direction of the first light-emitting elements 21a. The second incident portion 184 faces the second light-emitting elements 22a of the second light source unit 22 in the front-rear direction and extends in the arrangement direction of the second light-emitting elements 22a. In other words, the second incident portion 184 is formed in an annular shape along the second light source unit 22.

[0035] When the first light source unit 21 is turned on under the control of the control unit 80, light is incident from the first light source unit 21 to the first incident unit 183. The light incident on the first incident unit 183 reaches the first light guide plate 160 while being repeatedly reflected by the first curved portion 185 of the first optical member 180, and is emitted forward from the front surface of the first light guide plate 160. As a result, an annular, planar light-emitting surface is formed on the peripheral portion of the illumination device 100, as shown in FIG. 6A .

[0036] When the second light source unit 22 is turned on under the control of the control unit 80, light is incident from the second light source unit 22 to the second incident unit 184. The light incident on the second incident unit 184 reaches the second light guide plate 170 while being repeatedly reflected by the second curved portion 186, and is emitted forward from the front surface of the second light guide plate 170. As a result, a circular, planar light emitting surface is formed in the center of the illumination device 100, as shown in FIG. 6B.

[0037] When the light source unit 23 is turned on under the control of the control unit 80, light is incident from the light source unit 23 to the first optical member 180. The light incident on the first optical member 180 is emitted further forward via the second optical member 190 in front of it. As a result, an annular light-emitting surface is formed at the radial intermediate position of the illumination device 100, as shown in FIG. 6C.

[0038] The first optical member 180 and the second optical member 190 in the optical member group 120 configured in this manner will be described in further detail with reference to FIGS.

[0039] [2-1. First Optical Member 180 and Second Optical Member 190] FIG. 7 is a first schematic diagram showing the light distribution characteristic of the first optical member 180 according to the embodiment. In FIG. 7, a part of the cross section of FIG. 5 is enlarged and illustrated. That is, the cross section shown in FIG. 7 is a cross section of the lens 181, and is illustrated in a plane that passes through the light emitting element 23a and is parallel to the radial direction Rd and the front-rear direction. FIG. 8 is a second schematic diagram showing the light distribution characteristic of the first optical member 180 according to the embodiment. In FIG. 8, a cross section of two lenses 181 is illustrated, and is illustrated in a plane that passes through the light emitting element 23a facing each lens 181 and is parallel to the arrangement direction Ad and the front-rear direction. In FIG. 7 and FIG. 8, the two light emitting elements 23a are illustrated not in cross section but in side view, and the main body 110 is omitted. In FIG. 7 and FIG. 8, the traveling direction of some of the light emitted from the light source unit 23 (light emitting element 23a) is illustrated typically by a dotted arrow. FIG. 9 is a perspective view showing a part of a lenticular lens 191 which is a second optical member 190 according to the embodiment. Fig. 9 is a perspective view of a portion in the circumferential direction of an annular lenticular lens 191. Fig. 10 is a cross-sectional view showing an example of the shapes of convex portions 192 and concave portions 195 of a lenticular lens 191 according to the embodiment.

[0040] As shown in FIG. 7, the light emitted from the light emitting element 23a of the light source unit 23 is incident on the second optical member 190 through the lens 181 of the first optical member 180. Specifically, each of the lenses 181 of the first optical member 180 is configured to narrow the light distribution angle of the light emitted from each of the light emitting elements 23a in the radial direction Rd perpendicular to the arrangement direction (arrangement direction Ad) of the light emitting elements 23a. As a result, the light emitted from the light source unit 23 is efficiently incident on the second optical member 190 arranged in front of the first optical member 180. Specifically, the light emitting element 23a has a light distribution characteristic called, for example, a Lambertian light distribution, and the light distribution angle of the light emitted from the light emitting element 23a is, for example, about 110°. The first optical member 180 narrows the light distribution angle of the light incident from the light emitting element 23a having such light distribution characteristic in the radial direction Rd and emits the light forward.

[0041] 9 and 10, the lenticular lens 191, which is the second optical member 190, has a plurality of convex portions 192. However, each of the plurality of convex portions 192 extends along the radial direction Rd. Therefore, the lenticular lens 191 is unlikely to affect the light distribution angle in the radial direction Rd of the light incident from the plurality of lenses 181. As a result, the light incident from the plurality of lenses 181 is emitted forward from the second optical member 190 in a state in which the light distribution angle in the radial direction Rd is almost maintained, that is, in a state in which the light distribution angle in the radial direction Rd is narrowed by the plurality of lenses 181.

[0042] In this embodiment, each of the multiple lenses 181 possessed by the first optical member 180 acts to narrow the light distribution angle of the incident light in the radial direction Rd, as described above, while acting to widen the light distribution angle of the incident light in the arrangement direction Ad.

[0043] Specifically, in this embodiment, the light emitting elements 23a are arranged in a ring shape at a predetermined interval in the arrangement direction Ad, as shown in Figs. 2 and 8. This allows, for example, a relatively large ring-shaped light source unit 23 to be formed with a relatively small number of light emitting elements 23a. However, if the distance between two adjacent light emitting elements 23a in the arrangement direction Ad is increased, a problem occurs in that each of the light emitting elements 23a is easily recognized as a high-luminance point (particle of light) when the light source unit 23 is turned on. Regarding such a problem, the first optical member 180 according to this embodiment widens the light distribution angle of the light emitted from each of the multiple light emitting elements 23a in the arrangement direction Ad and emits it, as shown in Fig. 8. In other words, when focusing on one light emitting element 23a, the first optical member 180 (lens 181) directs a part of the light emitted from the light emitting element 23a in a direction approaching the other adjacent light emitting element 23a in the arrangement direction Ad and forward. 8, a portion of the light emitted from the two light-emitting elements 23a is directed toward the region between the two light-emitting elements 23a when viewed from the front. As a result, the light from the two light-emitting elements 23a can reach the portion (middle portion) between the two light-emitting elements 23a in the second optical member 190 when viewed from the front. This effect is particularly beneficial when the distance between the two light-emitting elements 23a aligned in the arrangement direction Ad is long.

[0044] It is not necessary for the lens 181 to widen the light distribution angle for all of the light incident from the light-emitting element 23a. For example, the lens 181 may bend the direction of light passing through the end of the lens 181 in the arrangement direction Ad (i.e., the portion farther from the optical axis of the light-emitting element 23a in the arrangement direction Ad) inward (toward the optical axis) and emit the light. In other words, the lens 181 may widen the light distribution angle of light in the arrangement direction Ad in the central portion centered on the front of the light-emitting element 23a, and narrow the light distribution angle of light in the arrangement direction Ad in the outer portions.

[0045] In this embodiment, the second optical member 190 (see FIG. 6C) forming the light-emitting surface that emits illumination light is formed so as to improve the uniformity of brightness on the light-emitting surface formed by using the light incident from the first optical member 180. Specifically, as shown in FIG. 8, the second optical member 190 acts to narrow the light distribution angle of the light emitted from the first optical member 180 in the arrangement direction Ad and emit the light. That is, the second optical member 190 is formed so as to narrow the light distribution angle in the arrangement direction Ad, which is widened by the lens 181 of the first optical member 180, in the arrangement direction Ad. This reduces the graininess of the light of the two light-emitting elements 23a when the second optical member 190 is viewed from the front. Also, as described above, the light emitted from the first optical member 180 reaches the portion (intermediate portion) between the two light-emitting elements 23a in the second optical member 190. Therefore, the intermediate portion of the second optical member 190 can be made to appear illuminated. That is, in the lighting device 100 according to the present embodiment, the first optical member 180 and the second optical member 190 having the above-mentioned optical properties are disposed in front of the light source unit 23. As a result, the lighting device 100 can provide, for example, a person in front of the lighting device 100, with a light-emitting surface formed on the second optical member 190 and having high brightness uniformity, and can provide illumination light with a narrow-angle light distribution from the light-emitting surface.

[0046] More specifically, as shown in Fig. 8 to Fig. 10, the second optical member 190 according to the present embodiment is a lenticular lens 191 having a plurality of protruding portions 192 arranged in the arrangement direction Ad, each of which protrudes forward. Each of the plurality of protruding portions 192 extends in the radial direction Rd. In the lenticular lens 191, a recessed portion 195 is formed between two of the plurality of protruding portions 192 adjacent to each other in the arrangement direction Ad.

[0047] In this embodiment, each of the cross sections (shapes of cross sections along the front-rear direction and arrangement direction Ad) of the convex portion 192 and the concave portion 195 has an arc shape. Specifically, as shown in Fig. 10, the tip portion 192a of the cross section (convex portion cross section) of each of the two convex portions 192 has an arc shape with a radius of R1 (R1>0). The bottom portion 195a of the cross section (concave portion cross section) of the concave portion 195 has an arc shape with a radius of R2 (R2>0). By having such an uneven shape, the lenticular lens 191 can narrow the light distribution angle of the light incident from the first optical member 180 and emit it forward.

[0048] More specifically, the radius (R1) of the tip 192a is equal to or larger than the radius (R2) of the bottom 195a. That is, the two convex portions 192 aligned in the arrangement direction Ad are arranged relatively close to each other. This contributes to further uniformity of the brightness of the light-emitting surface in the arrangement direction Ad. More preferably, the radius (R1) of the tip 192a is larger than the radius (R2) of the bottom 195a. More specifically, R1 is, for example, about 0.3 mm, and R2 is about 0.2 mm. For the lenticular lens 191 in which the convex portions 192 and the concave portions 195 of such sizes are aligned in the arrangement direction Ad, the distance between the two light-emitting elements 23a aligned in the arrangement direction Ad in the light source unit 23 is, for example, about 30 mm. That is, for the light source unit 23 having a plurality of light-emitting elements 23a, the fine convex portions 192 and the concave portions 195 are alternately aligned in the arrangement direction Ad. This contributes to further uniformity of the brightness of the light-emitting surface.

[0049] In this embodiment, the lenticular lens 191 is formed in a circular ring shape as shown in Figs. 2 and 3. Therefore, the radius (R1) of the tip 192a and the radius (R2) of the bottom 195a are smallest on the inside in the radial direction Rd and increase toward the outside in the radial direction Rd. In this case, the minimum value of R1 may be about 0.3 mm, and the minimum value of R2 may be about 0.2 mm. The ratio (R1:R2) of the radius (R1) of the tip 192a to the radius (R2) of the bottom 195a may be constant (e.g., 3:2) regardless of the position in the radial direction Rd.

[0050] The inventors of the present application have thoroughly investigated the relationship between the rise angle θ of the convex portion 192 and the uniformity of the brightness of the light-emitting surface in a lenticular lens 191 (made of transparent acrylic resin) configured in this manner, and have obtained results regarding a preferred range for the rise angle θ.

[0051] Specifically, as shown in FIG. 10, if a straight line that passes through starting point 193 of tip 192a, which is the arc-shaped portion in the cross section of convex portion 192, and is parallel to arrangement direction Ad is taken as reference line 193a, the angle between tangent 196 of tip 192a at starting point 193 and reference line 193a is defined as the rise angle θ.

[0052] The inventors of the present application found that the larger the rise angle θ, the higher the proportion of light directed diagonally forward (for example, light L in FIG. 10) and forward in the light emitted from the convex portion 192, and that if the rise angle θ is too large, a part of the light emitted from the convex portion 192 is likely to leak sideways. In this embodiment, the leaked sideways light refers to light (illumination light) emitted from the second optical member 190 that does not head toward a predetermined area including the front center of the illumination device 100, which is an area where the illumination light is desired to be collected, but heads in a direction close to the arrangement direction Ad (sideways).

[0053] That is, the portion of the light-emitting surface of the lenticular lens 191 in front of the light-emitting element 23a tends to be a portion with higher brightness than the other portions, and the portion between the two light-emitting elements 23a tends to be a portion with lower brightness. Therefore, from the viewpoint of reducing such a difference in brightness, it is preferable to increase the rise angle θ of the convex portion 192 to increase the amount of light directed diagonally forward from the convex portion 192 and the amount of light directed forward. Specifically, the inventors of the present application found that the rise angle θ of the convex portion 192 is preferably greater than 50°.

[0054] On the other hand, increasing the rise angle θ makes it difficult to focus light on a predetermined area including the center in front of the lighting device 100. The inventors of the present application have found that, when the rise angle θ is increased, for example, when the lighting device 100 is installed on the ceiling of a room, light (light leaking to the side) toward the wall of the room is generated or increased, resulting in the appearance of a streak of light on the wall. Based on this knowledge, the inventors of the present application have investigated the maximum value of the rise angle θ and found that the rise angle θ is preferably 70° or less.

[0055] That is, in the lenticular lens 191 which is the second optical member 190, the rise angle θ of the convex portion 192 is preferably 70° or less, and more preferably 70° or less and 50° or more. That is, when the rise angle θ of the convex portion 192 is 70° or less, streaks of light are less likely to be formed on the wall portion. Furthermore, when the rise angle θ of the convex portion 192 is 50° or more, the uniformity of the brightness (luminance) of the light emitting surface (see FIG. 6C) formed by the lenticular lens 191 is more reliably improved.

[0056] According to the lighting device 100 of this embodiment configured as described above, it is possible to create an illumination effect generally called a spotlight, in which the light distribution angle of the illumination light is about 30°, for example.

[0057] In this embodiment, the tip 192a of the convex portion 192 and the bottom 195a of the concave portion 195 are connected at the starting point 193 of the tip 192a (see FIG. 10). In other words, the tip 192a and the bottom 195a are continuous. However, this is not essential. In the cross section of the lenticular lens 191, the tip 192a of the convex portion 192 and the bottom 195a of the concave portion 195 may be spaced apart. In this case, the tip 192a and the bottom 195a may be connected by a straight line or a curved line in the cross section of the lenticular lens 191.

[0058] [3. Modifications] 11 is a cross-sectional view showing an outline of the configuration of a second optical member 190a according to a modified example of the embodiment. The position of the cross section in FIG. 11 corresponds to the position of the cross section in FIG.

[0059] The illumination device 100a according to this modification includes a light source unit 23, a first optical member 180, and a second optical member 190a. The first optical member 180 narrows the light distribution angle of the light emitted from the light source unit 23 in the radial direction Rd. The second optical member 190a narrows the light distribution angle of the light emitted from the first optical member 180 in the arrangement direction Ad and emits the light. These configurations are common to the illumination device 100 according to the embodiment. In addition, other components of this modification, such as the main body unit 110 and the mounting member 300, which are not shown in FIG. 11, are also common to the above embodiment.

[0060] In the illumination device 100a according to this modification, a second optical member 190a has a plurality of Fresnel lens portions 291 arranged in the arrangement direction Ad, and in this respect, it differs from the illumination device 100 according to the embodiment.

[0061] More specifically, each of the multiple Fresnel lens portions 291 has multiple convex portions 292 aligned in the arrangement direction Ad, each of which protrudes forward and extends in a direction (radial direction Rd) perpendicular to the arrangement direction Ad. In other words, each of the multiple Fresnel lens portions 291 has the same structure as or a structure similar to a lens called a linear Fresnel lens, for example.

[0062] In this way, when the Fresnel lens portion 291 is employed as a member constituting the second optical member 190a, the proportion of forward-directed light among the light emitted from the Fresnel lens portion 291 is greater than the proportion of forward-directed light among the light emitted from the lenticular lens 191 (see FIGS. 8 to 10). That is, the light-collecting ability of the second optical member 190a constituted by the multiple Fresnel lens portions 291 is higher than that of the second optical member 190 which is the lenticular lens 191. As a result, the illumination device 100a according to this modification can emit illumination light with a light distribution angle of, for example, 10° or less.

[0063] In this embodiment, the multiple Fresnel lens portions 291 of the second optical member 190a correspond one-to-one to the multiple lenses 181 of the first optical member 180, as shown in Fig. 11. That is, the multiple Fresnel lens portions 291 are arranged to form a ring shape. Therefore, the size and shape of the second optical member 190a when viewed from the front are substantially the same as the size and shape of the second optical member 190 when viewed from the front.

[0064] The multiple Fresnel lens portions 291 may be fabricated as separate components, or two or more Fresnel lens portions 291 may be integrally provided in one component. When second optical member 190a is formed by arranging multiple components, each including one or more Fresnel lens portions 291, in a ring shape, the components may be connected to each other by adhesion, engagement, press fitting, or the like. A frame that supports the multiple components may be provided in second optical member 190a.

[0065] As described above, the Fresnel lens portion 291 has a high light-collecting ability. Therefore, when viewed from diagonally forward in the arrangement direction Ad (for example, from the upper right in FIG. 11), a state may occur in which the brightness due to the right light-emitting element 23a is easy to observe, while the brightness due to the left light-emitting element 23a is difficult to observe. In this regard, with the lenticular lens 191, which does not have as high a light-collecting ability as the Fresnel lens portion 291, the difference in brightness due to the left and right light-emitting elements 23a is difficult to recognize even when viewed from diagonally forward. From this viewpoint, the lenticular lens 191 is advantageous.

[0066] [4. Summary] As described above, the lighting device according to the first aspect of the present invention is, for example, the lighting device 100 according to the embodiment, and includes the light source unit 23, the first optical member 180 arranged in front of the light source unit 23, and the second optical member 190 arranged in front of the first optical member 180. The light source unit 23 has a plurality of light-emitting elements 23a arranged in an annular shape, each of which emits light forward. The first optical member 180 narrows the light distribution angle of the light emitted from each of the plurality of light-emitting elements 23a in a direction perpendicular to the arrangement direction Ad of the plurality of light-emitting elements 23a when viewed from the front. The second optical member 190 narrows the light distribution angle of the light emitted from the first optical member 180 in the arrangement direction Ad.

[0067] According to this configuration, the first optical member 180 narrows the light distribution angle of the light from the plurality of light-emitting elements 23a in a direction perpendicular to the arrangement direction Ad (the radial direction Rd in the embodiment). Therefore, the light emitted from each of the plurality of light-emitting elements 23a is efficiently incident on the second optical member 190 arranged in front of the first optical member 180. Furthermore, the second optical member 190 narrows the light distribution angle of the light incident from the first optical member 180 in the arrangement direction Ad and emits the light. As a result, the uniformity of the brightness on the light-emitting surface of the second optical member 190 when the second optical member 190 is viewed from the front is improved. In addition, it is possible to collect (concentrate) the illumination light emitted forward from the second optical member 190 in a predetermined area in front of the second optical member 190. In other words, a lighting device 100 having a light distribution characteristic called a narrow angle light distribution can be obtained.

[0068] In this manner, the illumination device 100 according to the present embodiment is an illumination device capable of improving the uniformity of the brightness of the light-emitting surface and of concentrating illumination light on a predetermined area.

[0069] An illumination device according to a second embodiment of the present invention is the illumination device according to the first embodiment, in which the first optical member 180 widens the light distribution angle of the light emitted from each of the plurality of light-emitting elements 23a in the arrangement direction Ad.

[0070] According to this configuration, the light distribution angle of the light emitted from each of the plurality of light-emitting elements 23a is widened in the arrangement direction Ad. Therefore, even if the interval between two light-emitting elements 23a arranged in the arrangement direction Ad is relatively large, each of the plurality of light-emitting elements 23a is suppressed from being recognized as a grain of light. This contributes to improving the uniformity of the brightness of the light-emitting surface of the second optical member 190. In other words, it is possible to reduce the number of light-emitting elements 23a that the light source unit 23 should have while maintaining or improving the uniformity of the brightness of the light-emitting surface of the second optical member 190.

[0071] An illumination device according to a third aspect of the present invention is the illumination device according to the first or second aspect, in which the second optical member 190 is a lenticular lens 191. The lenticular lens 191 includes a plurality of convex portions 192 aligned in the arrangement direction Ad, each of which protrudes forward and extends in a direction perpendicular to the arrangement direction Ad.

[0072] According to this configuration, the second optical member 190 can be realized as a lenticular lens 191 in which a plurality of convex portions 192 are arranged in the arrangement direction Ad. In this case, for example, by changing the size or shape of the convex portions 192, the light distribution characteristics of the second optical member 190 (lenticular lens 191) can be changed.

[0073] The lighting device according to a fourth embodiment of the present invention is the lighting device according to the third embodiment, and a recess 195 is formed between two of the multiple protrusions 192 that are aligned in the arrangement direction Ad. A tip 192a of each of the two protrusions 192 in a cross section along the arrangement direction Ad and the front-rear direction is an arc shape with a radius of R1 (R1>0). A bottom 195a of the recess 195 in a cross section along the arrangement direction Ad and the front-rear direction is an arc shape with a radius of R2 (R2>0). R1 ​​is greater than or equal to R2.

[0074] According to this configuration, the interval between two adjacent convex portions 192 in the arrangement direction Ad becomes relatively small. Therefore, the multiple convex portions 192 can be densely arranged in the arrangement direction Ad. This contributes to uniforming the brightness of the light-emitting surface of the second optical member 190.

[0075] An illumination device according to a fifth embodiment of the present invention is the illumination device according to the fourth embodiment, in which the rise angle θ of the tip 192a in a cross section (convex cross section) of the convex 192 with respect to the arrangement direction Ad is 70° or less (see FIG. 10).

[0076] This configuration suppresses the occurrence of side leakage light caused by an excessively large rise angle θ of the convex portion 192 in the lenticular lens 191. As a result, the occurrence of unnecessary light streaks caused by the leakage light is suppressed.

[0077] An illumination device according to a sixth embodiment of the present invention is the illumination device according to the first or second embodiment, and is realized, for example, as the illumination device 100a according to the above-mentioned modified example. In the illumination device 100a, the second optical member 190a has a plurality of Fresnel lens portions 291 arranged in the arrangement direction Ad. Each of the plurality of Fresnel lens portions 291 includes a plurality of convex portions 292 arranged in the arrangement direction Ad, each of which protrudes forward and extends in a direction perpendicular to the arrangement direction Ad.

[0078] According to this configuration, the second optical member 190a has a plurality of Fresnel lens portions 291, and therefore the light collecting ability of the illumination light emitted from the second optical member 190a is increased. As a result, the light distribution angle of the illumination light emitted from the lighting device 100a can be narrowed.

[0079] The lighting device according to a seventh aspect of the present invention is the lighting device according to any one of the first to sixth aspects, and includes a main body 110 to which a light source unit 23 is attached, and a mounting member 300 for mounting the main body 110 to a ceiling of a building.

[0080] According to this configuration, the lighting device 100 or 100a can be realized as a lighting device arranged on a ceiling (for example, a "ceiling light"). That is, the lighting device 100 or 100a can be installed on the ceiling of a room forming a living space, for example. This makes it possible to provide the living space with illumination light from a light-emitting surface with high brightness uniformity and with a relatively narrow light distribution angle.

[0081] In the present embodiment, as described above, the lighting devices 100 and 100a include the first light source unit 21 for emitting illumination light from the first light guide plate 160, and the second light source unit 22 for emitting illumination light from the second light guide plate 170. Therefore, the lighting devices 100 and 100a can perform dimming control (including turning on and off) and / or color adjustment control of the light source unit 23, the first light source unit 21, and the second light source unit 22, respectively, to produce a wide variety of light presentations.

[0082] [5. Other Modifications] Although the present invention has been described above based on the embodiment and its modifications, the present invention is not limited to the above embodiment and its modifications.

[0083] The light-emitting module 10 included in the lighting device 100 may not have the first light source section 21 and the second light source section 22. That is, the light-emitting module 10 may have at least the light source section 23 as a light source for emitting illumination light. Even in this case, the lighting device 100 can create illumination light from a light-emitting surface with high brightness uniformity and a relatively narrow light distribution angle by using light from a plurality of light-emitting elements 23a arranged in an annular shape. When the light-emitting module 10 has only the light source section 23 as a light source for emitting illumination light, the first optical member 180 may include only a required number of lenses 181. For example, the first optical member 180 may include only a plurality of lenses 181 arranged in the arrangement direction Ad, which correspond one-to-one to the plurality of light-emitting elements 23a included in the light-emitting module 10.

[0084] It is not essential that each of the multiple lenses 181 of the first optical member 180 widens the light distribution angle of the incident light in the arrangement direction Ad. For example, when the light source unit 23 has a relatively large number of light-emitting elements 23a, the distance between two adjacent light-emitting elements 23a in the arrangement direction Ad is short, which may reduce the graininess of the light of each of the multiple light-emitting elements 23a. In this case, each of the multiple lenses 181 does not need to widen the light distribution angle of the incident light in the arrangement direction Ad. However, from the viewpoint of further uniforming the brightness of the light-emitting surface formed by the second optical member 190, it is preferable that each of the multiple lenses 181 is formed to widen the light distribution angle of the incident light in the arrangement direction Ad.

[0085] The material forming the first optical member 180 and the second optical member 190 may be other than acrylic resin. For example, the first optical member 180 and the second optical member 190 may be formed of a resin material with high transparency (light transmittance), such as polycarbonate. Polycarbonate is advantageous in that it has higher impact resistance than acrylic resin, for example. On the other hand, acrylic resin is advantageous in that it has higher transparency (light transmittance) than polycarbonate, for example.

[0086] Each of the first optical member 180 and the first light guide plate 160 does not need to be a single member (component). For example, the first optical member 180 may be formed by joining a plurality of optical members in the circumferential direction (arrangement direction Ad in the embodiment). This makes it easier to manufacture the first optical member 180, which has a relatively large outer diameter, for example. The same applies to the first light guide plate 160.

[0087] The first optical member 180 has the lenses 181 at positions facing the multiple light-emitting elements 23a. However, the first optical member 180 may be provided with lenses extending along the arrangement direction of the multiple light-emitting elements 23a. For example, one lens formed in an annular shape when viewed from the front may be disposed at a position facing the multiple light-emitting elements 23a. Even in this case, the one lens can narrow the light distribution angle of the light incident from each of the multiple light-emitting elements 23a in the radial direction Rd and emit the light.

[0088] The light-emitting elements 23a are arranged in a circular ring shape, but this is not essential. For example, the light-emitting elements 23a may be arranged to form a polygonal shape such as a rectangle when viewed from the front. In this case, the size and shape of the first optical member 180 and the like of the optical member group 120 may be appropriately determined according to the arrangement layout of the light-emitting elements 23a.

[0089] Regardless of whether the multiple light emitting elements 23a are arranged in a circular ring shape or not, the substrate 11 on which the multiple light emitting elements 23a are arranged does not have to be circular. The substrate 11 may be, for example, a substrate having a polygonal outer shape when viewed from the front. The same applies to the shapes of the first light guide plate 160 and the second light guide plate 170. For example, the first light guide plate 160 may be a light guide plate having a shape other than a circle, such as a polygonal or elliptical outer shape when viewed from the front.

[0090] In the present embodiment, the control unit 80 has a function as a power supply unit that supplies power for light emission to the light-emitting module 10. However, it is not essential that the control unit 80 has a function as a power supply unit. For example, the lighting device 100 may include a power supply unit that converts AC power from a commercial power source or the like into DC power of a predetermined level by rectifying, smoothing, stepping down, etc., and a control unit 80 that controls the power supply unit and is separate from the power supply unit.

[0091] The control unit 80 does not have to be housed in the main body 110 of the lighting device 100. For example, the control unit 80 may be housed in a case installed outside the main body 110. Even in this case, as long as the control unit 80 and the light-emitting module 10 are electrically connected by a cable 90 or the like, it is possible to control the light emission pattern of the light-emitting module 10, etc.

[0092] The lighting device 100 does not necessarily have to be detachably attached to a ceiling or the like. For example, the lighting device 100 may be installed in a predetermined location in a substantially unremovable state by embedding a part of the main body 110 in concrete or the like.

[0093] Although the light emitting elements such as the first light emitting element 21a included in the light emitting module 10 are SMD type LED elements, this is not limiting. For example, each of the multiple light emitting elements included in the light emitting module 10 may be an LED chip. In other words, the light emitting module 10 may have a COB (Chip On Board) structure in which the light emitting element, which is an LED chip, is directly mounted on the substrate 11. In this case, illumination light with a predetermined color temperature can be obtained by sealing the multiple LED chips mounted on the substrate 11 collectively or individually with a sealing member containing a wavelength conversion material.

[0094] The light-emitting elements such as the first light-emitting element 21a included in the light-emitting module 10 may be semiconductor light-emitting elements such as semiconductor lasers, or other types of solid-state light-emitting elements such as organic EL (Electro Luminescence) or inorganic EL elements.

[0095] The various supplementary points regarding the lighting device 100 according to the embodiment above may also be applied to the lighting device 100a according to the modified example.

[0096] In addition, the present invention also includes forms obtained by applying various modifications to the above-described embodiments and their modifications that would come to mind by a person skilled in the art, and forms realized by arbitrarily combining the components and functions of each embodiment and its modifications without departing from the spirit of the present invention. [Explanation of symbols]

[0097] 23 Light source section 23a Light emitting element 100, 100a Lighting equipment 180 First Optical Component 181 Lens 181a Storage unit 183 First entrance part 184 Second entrance part 185 First curved part 186 Second curved part 189a Inner circumferential protrusion 189b Peripheral protrusion 190, 190a Second optical member 191 Lenticular Lens 192, 292 convex part 192a Tip 291 Fresnel lens part 300 Mounting material Ad Array direction Rd Radial direction

Claims

1. a light source unit having a plurality of light-emitting elements arranged in an annular shape, each of which emits light forward; a first optical member that is disposed in front of the light source unit and that narrows a light distribution angle of light emitted from each of the plurality of light-emitting elements in a direction perpendicular to an arrangement direction of the plurality of light-emitting elements when viewed from the front; a second optical member disposed in front of the first optical member and configured to narrow a light distribution angle of the light emitted from the first optical member in the arrangement direction; A lighting device comprising:

2. The first optical member widens a light distribution angle of the light emitted from each of the plurality of light-emitting elements in the arrangement direction.

2. The lighting device according to claim 1.

3. The second optical member is a lenticular lens including a plurality of convex portions arranged in the arrangement direction, each of the convex portions protruding forward and extending in a direction perpendicular to the arrangement direction.

3. The lighting device according to claim 1 or 2.

4. a recess is formed between two of the plurality of protrusions aligned in the arrangement direction, a tip end portion of each of the two protrusions in a cross section along the arrangement direction and the front-rear direction has an arc shape with a radius R1 (R1>0); a bottom portion of the recess in a cross section along the arrangement direction and the front-rear direction has an arc shape with a radius R2 (R2>0); The R1 is equal to or greater than the R2.

4. The lighting device according to claim 3.

5. a rise angle of the tip portion in a cross section of the convex portion with respect to the arrangement direction is 70° or less; 5. The lighting device according to claim 4.

6. the second optical member has a plurality of Fresnel lens portions aligned in the arrangement direction, Each of the plurality of Fresnel lens portions includes a plurality of convex portions arranged in the arrangement direction, each of the convex portions protruding forward and extending in a direction perpendicular to the arrangement direction.

3. The lighting device according to claim 1 or 2.

7. A main body to which the light source unit is attached; and a mounting portion for mounting the main body portion to a ceiling of a building.

3. The lighting device according to claim 1 or 2.

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