Luminaire

Abstract

To provide a luminaire which can enhance a color mixing property of light emitted from a plurality of light sources having different light emission spectrums, and which can improve a heat dissipation property of the heat generated in the plurality of light sources.SOLUTION: A luminaire 1 includes: a light emitting module 10 having a plurality of light sources 11 having different light emission spectrums; and a long light guide member 20 having an incident surface 20a where light emitted from the plurality of light sources 11 enters and an emission surface 20b from which the light which has entered from the incident surface 20a emits. The plurality of light sources 11 is arranged in one or a plurality of linear rows. The incident surface 20a has a shape along the rows of the plurality of light sources 11. The emission surface 20b overlaps at least part of the light emitting module 10 when viewed from the longer direction of the light guide member 20, and is a closed surface without a gap.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lighting device such as a spotlight.

Background Art

[0002] Solid light-emitting elements such as LEDs (Light Emitting Diodes) or semiconductor lasers are widely used as light sources for various devices in various fields including the lighting field and the display field. For example, in the lighting field, lighting devices using LEDs (LED lighting) are known.

[0003] Lighting devices are used not only in houses, facilities, or stores but also for production purposes. One of the lighting devices for production purposes is a spotlight used in a hall, a stage, or a studio.

[0004] As this type of spotlight, a full-color lighting device capable of irradiating illumination light of an arbitrary color is known. A full-color lighting device using LEDs includes, for example, an RGB light-emitting module having a red LED light source, a green LED light source, and a blue LED light source, and a color mixing optical system that mixes the red light, green light, and blue light emitted from the RGB light-emitting module. In the full-color lighting device configured in this way, by controlling the light output of each of the red LED light source, the green LED light source, and the blue LED light source to mix the red light, the green light, and the blue light, illumination light of an arbitrary color can be irradiated.

[0005] Conventionally, as one of the full-color lighting devices, a spotlight using a plurality of block-shaped light guide rods as a color mixing optical system and a plurality of RGB light-emitting modules arranged corresponding to each of the plurality of light guide rods has been proposed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, in the spotlight disclosed in Patent Document 1, since the color mixing optical system is composed of a block-shaped light guide rod, the number of total internal reflections of the light from the RGB light emitting module incident on the light guide rod in the light guide rod is small, so the color mixing property is low. On the other hand, if the number of total internal reflections in the light guide rod is increased to improve the color mixing property, it is necessary to lengthen the light guide rod, and the spotlight becomes larger.

[0008] Moreover, in the spotlight disclosed in Patent Document 1, since the red LED light source, the green LED light source, and the blue LED light source are concentrated and arranged in a narrow range within one RGB light emitting module, the heat dissipation property of the heat generated in the RGB light emitting module is poor. That is, the heat dissipation property of the heat generated by the red LED light source, the green LED light source, and the blue LED light source is poor.

[0009] The present invention has been made to solve such problems, and an object of the present invention is to provide an illumination device capable of improving the color mixing property of light emitted from a plurality of light sources having different emission spectra and improving the heat dissipation property of heat generated by the plurality of light sources.

MEANS FOR SOLVING THE PROBLEMS

[0010] To achieve the above object, one aspect of the illumination device according to the present invention includes a light emitting module having a plurality of light sources having different emission spectra, and a long light guide member having an incident surface on which light emitted from the plurality of light sources is incident and an exit surface from which the light incident from the incident surface exits, wherein the plurality of light sources are arranged in one or a plurality of linear rows, the incident surface has a shape along the rows of the plurality of light sources, and the exit surface overlaps at least a part of the light emitting module and is a closed surface without a gap when viewed from the longitudinal direction of the light guide member.

EFFECTS OF THE INVENTION

[0011] It is possible to enhance the color mixing property of light emitted from a plurality of light sources having different emission spectra, and to improve the heat dissipation property of heat generated by the plurality of light sources.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are all specific examples of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions 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, the components not described in the independent claims indicating the highest concept of the present invention are described as optional components.

[0014] Note that each figure is a schematic diagram and is not necessarily drawn precisely. Also, in each figure, the same reference numerals are given to substantially the same configurations, and duplicate descriptions are omitted or simplified. Further, in this specification, the terms "upper" and "lower" do not necessarily refer to the upward direction (vertically upward) and the downward direction (vertically downward) in an absolute spatial perception.

[0015] (Embodiment) First, the configuration of the lighting device 1 according to the embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram schematically showing the configuration of the lighting device 1 according to the embodiment. FIG. 2 is a perspective view of the light-emitting module 10 and the light guide member 20 in the lighting device 1 according to the embodiment. FIG. 3 is a cross-sectional view of the light-emitting module 10 and the light guide member 20 in the lighting device 1 according to the embodiment. In FIG. 3, only the lines appearing in the cross-section are shown. FIG. 4 is a top view of the light-emitting module 10 in the lighting device 1 according to the embodiment. Note that FIG. 4 also shows the relationship between the light-emitting module 10 and the incident surface 20a and the exit surface 20b of the light guide member 20.

[0016] As shown in FIG. 1, the lighting device 1 includes a light-emitting module 10 and a light guide member 20 that guides the light emitted from the light-emitting module 10. In the present embodiment, the lighting device 1 further includes a projection lens 30. The lighting device 1 also includes a housing 40 that houses the light-emitting module 10, the light guide member 20, and the projection lens 30. The housing 40 may be made of metal or resin.

[0017] The lighting device 1 is a projection-type lighting fixture that projects illumination light 1a of a predetermined color. The lighting device 1 is a full-color lighting device that can irradiate illumination light 1a of any color. As an example, the lighting device 1 is a spotlight.

[0018] As shown in FIGS. 2 to 4, the light-emitting module 10 includes a plurality of light sources 11 having different emission spectra and a substrate 12 on which the plurality of light sources 11 are arranged.

[0019] The light-emitting module 10 is an LED module of a full-color light source that can emit light of any color. In the present embodiment, the light-emitting module 10 includes, as a plurality of light sources 11 having different emission spectra, a red LED light source 11R that emits red light, a green LED light source 11G that emits green light, and a blue LED light source 11B that emits blue light. That is, the light-emitting module 10 is an RGB light-emitting module. Further, the light-emitting module 10 also includes a white LED light source 11W that emits white light.

[0020] Each of the plurality of light sources 11 is an LED element having an SMD structure that is individually packaged. That is, each of the red LED light source 11R, the green LED light source 11G, the blue LED light source 11B, and the white LED light source 11W is an LED element having an SMD structure. Therefore, the light-emitting module 10 is an SMD-type LED module. Each of the plurality of light sources 11 that are SMD elements 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.

[0021] The substrate 12 is a mounting substrate for mounting a plurality of light sources 11. The substrate 12 is, for example, a printed wiring board on which metal wiring is formed in a predetermined pattern. The substrate 12 is a resin substrate having an insulating resin material as a base material, a ceramic substrate having a ceramic material such as alumina as a base material, or a metal base substrate having a metal material such as aluminum or copper as a base material.

[0022] The planar shape of the substrate 12 is circular, but it is not limited to this. The planar shape of the substrate 12 may be a polygon such as a rectangle. The substrate 12 has a first surface on which a plurality of light sources 11 are mounted and a second surface facing away from the first surface.

[0023] A plurality of light sources 11 are mounted on the substrate 12. Specifically, a plurality of red LED light sources 11R, a plurality of green LED light sources 11G, a plurality of blue LED light sources 11B, and a plurality of white LED light sources 11W are mounted on the first surface of the substrate 12.

[0024] The plurality of light sources 11 are arranged in one or more linear rows. In the present embodiment, the plurality of light sources 11 are arranged in a plurality of non-intersecting linear rows. Specifically, the plurality of light sources 11 are arranged in two non-intersecting linear rows. In the plurality of light sources 11 arranged in a plurality of linear rows, the shape of the line forming each of the plurality of linear rows is a closed line. In the present embodiment, this closed line is a circle. That is, the plurality of light sources 11 are arranged in a plurality of rows so as to form a plurality of circles. As shown in FIG. 4, the plurality of light sources 11 are arranged in two rows so as to form two concentric circles with different diameters.

[0025] Further, the plurality of light sources 11 are alternately arranged periodically one by one for each emission spectrum. Specifically, when the red LED light source 11R is "R", the green LED light source 11G is "G", the blue LED light source 11B is "B", and the white LED light source 11W is "W", R→G→B→W is taken as one cycle and repeated a plurality of times. In the present embodiment, 32 light sources 11 forming the inner row among the plurality of light sources 11 arranged in two annular rows are arranged by repeating R→G→B→W eight times as one cycle. Also, 68 light sources 11 forming the outer row among the plurality of light sources 11 arranged in two annular rows are arranged by repeating R→G→B→W 17 times as one cycle.

[0026] Each of the plurality of light sources 11 emits light by a direct current supplied from a power supply device (not shown). Each of the plurality of red LED light sources 11R, the plurality of green LED light sources 11G, the plurality of blue LED light sources 11B, and the plurality of white LED light sources 11W emits light by a direct current supplied from a separate power supply device. Also, each of the plurality of red LED light sources 11R, the plurality of green LED light sources 11G, the plurality of blue LED light sources 11B, and the plurality of white LED light sources 11W is connected by separate current paths and is configured to be independently controllable. For example, as a power supply device for causing the plurality of light sources 11 to emit light, a first power supply device that controls the light output of the plurality of red LED light sources 11R, a second power supply device that controls the light output of the plurality of green LED light sources 11G, a third power supply device that controls the light output of the plurality of blue LED light sources 11B, and a fourth power supply device that controls the light output of the plurality of white LED light sources 11W are provided. Note that the power supply devices that drive the red LED light source 11R, the green LED light source 11G, the blue LED light source 11B, and the white LED light source 11W may be integrally configured.

[0027] These power supply devices may be housed in the housing 40 or may not be housed in the housing 40. That is, the lighting device 1 may be a built-in power supply type in which the power supply device is built in, or may be a separate power supply type in which the power supply device is separately placed outside.

[0028] Also, these power supply devices and the metal wiring formed on the substrate 12 are electrically connected. For example, the power supply device and an electrode or a connector terminal formed on the substrate 12 are connected by an electric wire such as a lead wire. The electric wire that connects the substrate 12 and the power supply device is inserted through, for example, a through hole 12a provided in the substrate 12.

[0029] The light-emitting module 10 configured as described above is arranged on the heat sink 50 as shown in FIG. 1. Specifically, the substrate 12 of the light-emitting module 10 is placed on and fixed to the heat sink 50. A thermal sheet may be inserted between the substrate 12 and the heat sink 50. The heat sink 50 is made of, for example, a metal material such as copper, aluminum, or iron. The heat sink 50 may have a plurality of heat-radiating fins.

[0030] The light guide member 20 is an optical member that guides the incident light. The light guide member 20 is a long light guide rod. The light guide member 20 extends in a direction orthogonal to the substrate 12 in the light-emitting module 10.

[0031] The light guide member 20 has an incident surface 20a on which the light emitted from the plurality of light sources 11 is incident, and an exit surface 20b from which the light incident from the incident surface 20a exits. The incident surface 20a of the light guide member 20 is one end face (the first end face) in the longitudinal direction of the light guide member 20, and the exit surface 20b of the light guide member 20 is the other end face (the second end face) in the longitudinal direction of the light guide member 20. In the present embodiment, the incident surface 20a and the exit surface 20b are parallel.

[0032] Since the plurality of light sources 11 include a red LED light source 11R, a green LED light source 11G, a blue LED light source 11B, and a white LED light source 11W, red light emitted from the red LED light source 11R, green light emitted from the green LED light source 11G, blue light emitted from the blue LED light source 11B, and white light emitted from the white LED light source 11W are incident on the incident surface 20a of the light guide member 20. The red light, green light, blue light, and white light incident on the light guide member 20 are mixed and homogenized while being guided by the light guide member 20. Therefore, this mixed light is emitted from the exit surface 20b of the light guide member 20. In this case, light of a color mixed according to the light incident on the light guide member 20 among the red light, green light, blue light, and white light and the intensity of that light is emitted from the exit surface 20b of the light guide member 20. Thus, the light guide member 20 is a color mixing optical system for mixing different colors of light emitted from a plurality of light sources 11 having different emission spectra.

[0033] In addition, when only one of the red LED light source 11R, the green LED light source 11G, the blue LED light source 11B, and the white LED light source 11W emits light, only light of one color enters the light guide member 20. In this case, the light incident on the light guide member 20 is not mixed with light of other colors, and only light of the same color is mixed and homogenized and emitted from the emission surface 20b of the light guide member 20.

[0034] As shown in FIG. 4, the incident surface 20a and the emission surface 20b of the light guide member 20 overlap at least a part of the light emitting module 10 when viewed from the longitudinal direction of the light guide member 20. In the present embodiment, the incident surface 20a has a shape along the rows of the plurality of light sources 11 and faces the plurality of light sources 11.

[0035] Specifically, when viewed from the longitudinal direction of the light guide member 20, the incident surface 20a of the light guide member 20 overlaps each of the plurality of inner light sources 11 and the plurality of outer light sources 11 arranged in two rows so as to form two concentric circles. On the other hand, the emission surface 20b of the light guide member 20 overlaps the plurality of light sources 11 forming the inner row among the plurality of light sources 11 arranged in two rows, but does not overlap the plurality of light sources 11 forming the outer row. Note that there is a slight gap between the incident surface 20a and the light emitting surfaces of the plurality of light sources 11. As an example, the distance between the incident surface 20a and the light emitting surfaces of the plurality of light sources 11 is 0.5 mm, but it is not limited to this.

[0036] The light guide member 20 has a plurality of light guides equal in number to the rows of the plurality of light sources 11. In the present embodiment, since the plurality of light sources 11 are arranged in two rows, as shown in FIGS. 2 and 3, the light guide member 20 has two light guides, a first light guide 21 and a second light guide 22. Both the first light guide 21 and the second light guide 22 are elongated. Specifically, the first light guide 21 and the second light guide 22 extend in a direction orthogonal to the first surface of the substrate 12 in the light emitting module 10. In the present embodiment, the lengths of the first light guide 21 and the second light guide 22 in the longitudinal direction are the same.

[0037] Each of the plurality of light guides constituting the light guide member 20 has an individual incident surface on which light emitted from the corresponding column among the columns of the plurality of light sources 11 is incident, and an individual emission surface from which the light incident from this individual incident surface is emitted.

[0038] In the present embodiment, the light guide member 20 has a first light guide 21 and a second light guide 22 as the plurality of light guides. Accordingly, the first light guide 21 has a first individual incident surface 21a on which light emitted from the plurality of light sources 11 forming the inner column among the columns of the plurality of light sources 11 arranged in two columns is incident, and a first individual emission surface 21b from which the light incident from the first individual incident surface 21a is emitted. Further, the second light guide 22 has a second individual incident surface 22a on which light emitted from the plurality of light sources 11 forming the outer column among the columns of the plurality of light sources 11 arranged in two columns is incident, and a second individual emission surface 22b from which the light incident from the second individual incident surface 22a is emitted.

[0039] In the first light guide 21, the first individual incident surface 21a is an end surface on the light emitting module 10 side of the first light guide 21 and faces the plurality of light sources 11 forming the inner column among the columns of the plurality of light sources 11 arranged in two columns. On the other hand, in the second light guide 22, the second individual incident surface 22a is an end surface on the light emitting module 10 side of the second light guide 22 and faces the plurality of light sources 11 forming the outer column among the columns of the plurality of light sources 11 arranged in two columns.

[0040] Since the first individual incident surface 21a of the first light guide 21 faces the red LED light source 11R, the green LED light source 11G, the blue LED light source 11B, and the white LED light source 11W, red light, green light, blue light, and white light can be incident on the first individual incident surface 21a. The red light, green light, blue light, and white light incident on the first light guide 21 will be mixed while guiding through the first light guide 21.

[0041] Similarly, since the second individual incident surface 22a of the second light guide 22 faces the red LED light source 11R, the green LED light source 11G, the blue LED light source 11B, and the white LED light source 11W, red light, green light, blue light, and white light can be incident on the second individual incident surface 22a. The red light, green light, blue light, and white light incident on the second light guide 22 will be mixed while guiding through the second light guide 22.

[0042] The first light guide 21 is located inside the second light guide 22. That is, the second light guide 22 is located outside the first light guide 21. Specifically, the second light guide 22 surrounds the entire first light guide 21. In the present embodiment, the second light guide 22 is a cylindrical (pipe-shaped) cylinder. That is, openings are formed at each of the ends on both sides in the longitudinal direction of the second light guide 22. On the other hand, an opening is formed at one end in the longitudinal direction of the first light guide 21 (the light emitting module 10 side), but no opening is formed at the other end in the longitudinal direction of the first light guide 21 (the side opposite to the light emitting module 10 side), and the other end in the longitudinal direction of the first light guide 21 is closed.

[0043] The light guide member 20 is in an extruded shape. That is, each of the first light guide 21 and the second light guide 22 is in an extruded shape. Specifically, in any cross section orthogonal to the longitudinal direction of the first light guide 21, the outer shape of the first light guide 21 is of the same shape. Similarly, in any cross section orthogonal to the longitudinal direction of the second light guide 22, the outer shape of the second light guide 22 is of the same shape. In the present embodiment, the outer shapes in any cross section of the first light guide 21 and the second light guide 22 are both circular.

[0044] In the first light guide 21, the shape of the first individual incident surface 21a is an annular belt shape with a constant width, and the shape of the first individual emission surface 21b is circular. The end face of the closed end in the first light guide 21 is the first individual emission surface 21b. On the other hand, in the second light guide 22, the shapes of the second individual incident surface 22a and the second individual emission surface 22b are both annular belt shapes with a constant width.

[0045] The outer size of each cross-section of the first light guide 21 and the second light guide 22 may be constant without change, or may be changing. In the present embodiment, the outer size of each cross-section of the first light guide 21 and the second light guide 22 is changing. That is, the outer shapes of the first light guide 21 and the second light guide 22 are the same, but the sizes are changing.

[0046] Specifically, each of the first light guide 21 and the second light guide 22 has a portion where the outer diameter becomes smaller as it goes from the incident surface 20a to the exit surface 20b. More specifically, each of the first light guide 21 and the second light guide 22 has a constricted portion where the outer diameter gradually becomes smaller at the central portion in the longitudinal direction. For this reason, in the first light guide 21, the outer diameter of the annular first individual exit surface 21b is smaller than the diameter of the circular first individual incident surface 21a. Also, in the second light guide 22, the outer diameter and the inner diameter of the second individual exit surface 22b are smaller than the outer diameter and the inner diameter of the second individual incident surface 22a.

[0047] Also, the thickness of each of the first light guide 21 and the second light guide 22 may be constant without change, or may be changing. In the present embodiment, the thickness of each of the first light guide 21 and the second light guide 22 is changing. Specifically, as shown in FIG. 3, the thickness of each of the first light guide 21 and the second light guide 22 increases as it goes from the incident surface 20a to the exit surface 20b. That is, the thickness of the first light guide 21 increases as it goes from the first individual incident surface 21a to the first individual exit surface 21b. Similarly, the thickness of the second light guide 22 increases as it goes from the second individual incident surface 22a to the second individual exit surface 22b.

[0048] The incident surface 20a of the light guide member 20 is a surface where the individual incident surfaces of the plurality of light guides constituting the light guide member 20 are separated from each other. On the other hand, the exit surface 20b of the light guide member 20 is a surface where the individual exit surfaces of the plurality of light guides constituting the light guide member 20 are combined.

[0049] In the present embodiment, the light guide member 20 has a first light guide body 21 and a second light guide body 22 as a plurality of light guide bodies. Therefore, the incident surface 20a of the light guide member 20 is a surface in which the first individual incident surface 21a of the first light guide body 21 and the second individual incident surface 22a of the second light guide body 22 are separated from each other. Specifically, the end on the first individual incident surface 21a side of the first light guide body 21 and the end on the second individual incident surface 22a side of the second light guide body 22 are not in contact with each other, and there is a gap between the end on the first individual incident surface 21a side of the first light guide body 21 and the end on the second individual incident surface 22a side of the second light guide body 22.

[0050] On the other hand, the emission surface 20b of the light guide member 20 is a surface where the first individual emission surface 21b of the first light guide body 21 and the second individual emission surface 22b of the second light guide body 22 are combined. In the present embodiment, the first light guide body 21 is connected to the second light guide body 22 at the emission surface 20b. Specifically, the end on the first individual emission surface 21b side in the longitudinal direction of the first light guide body 21 is fitted into the opening on the second individual emission surface 22b side in the longitudinal direction of the second light guide body 22. Further, the first light guide body 21 and the second light guide body 22 are connected such that the first individual emission surface 21b of the first light guide body 21 and the second individual emission surface 22b of the second light guide body 22 are flush. Thereby, the first individual emission surface 21b of the first light guide body 21 and the second individual emission surface 22b of the second light guide body 22 are combined without a gap to form one emission surface 20b. That is, the emission surface 20b of the light guide member 20 is a closed surface without a gap when viewed from the longitudinal direction of the light guide member 20. In the present embodiment, the emission surface 20b is a surface where the circular first individual emission surface 21b and the annular belt-shaped second individual emission surface 22b are combined without a gap, and the outer shape of the emission surface 20b is a circle.

[0051] The light-emitting surface 20b of the light guide member 20 is a diffusing surface. That is, the light-emitting surface 20b has a function of scattering and diffusing the light that guides through the light guide member 20. Thereby, the light-emitting surface 20b can be made into a pseudo light source surface (pseudo light-emitting surface). Also, by making the light-emitting surface 20b a diffusing surface, the light that is guided through the light guide member 20 and emitted can be effectively color-mixed. When making the light-emitting surface 20b a diffusing surface, for example, it is preferable to form minute irregularities on the light-emitting surface 20b. In this case, minute irregularities can be formed on the light-emitting surface 20b by forming dimples or performing embossing on the light-emitting surface 20b. Note that the light-emitting surface 20b may be a non-diffusing surface.

[0052] The light guide member 20 configured as described above is made of a light-transmitting material. That is, the first light guide 21 and the second light guide 22 are made of a light-transmitting material. The first light guide 21 and the second light guide 22 are made of a light-transmitting resin material such as an acrylic resin or a polycarbonate resin. In this case, the first light guide 21 and the second light guide 22 are preferably made of a transparent resin material with a high transmittance such that the opposite side can be seen through. Note that the first light guide 21 and the second light guide 22 are not limited to resin materials and may be made of a glass material.

[0053] As shown in FIG. 3, when the length of the light guide member 20 in the longitudinal direction is L [mm], the outer diameter of the incident surface 20a of the light guide member 20 is φ1 [mm], and the outer diameter of the light-emitting surface 20b of the light guide member 20 is φ2 [mm], if the relationship of φ1 / φ2 ≧ 1.2×L / 100 is satisfied, leakage light from the light guide member 20 is likely to occur. For this reason, it is preferable that a reflecting member is provided on the outer peripheral surface of the light guide member 20. For example, a reflecting member is provided on the outer peripheral surface of the second light guide 22 that forms the outer contour of the light guide member 20. The reflecting member may be a light reflection film formed on the outer peripheral surface of the light guide member 20, or may be a light reflection plate provided separately from the light guide member 20. Thus, by providing a reflecting member on the outer peripheral surface of the light guide member 20, the light leaking from the light guide member 20 can be reflected by the reflecting member and returned to the light guide member 20. Thereby, the light utilization efficiency in the light guide member 20 can be improved.

[0054] The light of the light-emitting module 10 incident from the incident surface 20a of the light guide member 20 is emitted to the outside of the light guide member 20 from the emission surface 20b of the light guide member 20. The light emitted from the emission surface 20b of the light guide member 20 is incident on the projection lens 30. As shown in FIG. 1, the light incident on the projection lens 30 is irradiated as the illumination light 1a of the illumination device 1. The projection lens 30 is a projection lens that projects the illumination light 1a onto the projection surface. In the present embodiment, the projection lens 30 enlarges and projects the light emitted from the light guide member 20. As the projection lens 30, for example, a convex lens can be used. Note that the optical axis of the projection lens 30 is parallel to the central axis of the light guide member 20. Specifically, the optical axis of the projection lens 30 coincides with the central axis of the light guide member 20.

[0055] Here, the optical action of the light guide member 20 in the illumination device 1 will be described with reference to FIGS. 5 and 6. FIGS. 5 and 6 show the ray trajectories when the light emitted from the light-emitting module 10 is incident on the light guide member 20. FIG. 5 is a cross-sectional view of the light-emitting module 10 and the light guide member 20, and FIG. 6 is a perspective view of the light-emitting module 10 and the light guide member 20.

[0056] In FIGS. 5 and 6, the ray trajectory when the light emitted from one light source 11 is incident on the second light guide 22 of the light guide member 20 is shown. As shown in FIGS. 5 and 6, the light of the light source 11 incident on the second individual incident surface 22a of the second light guide 22 guides the second light guide 22 while repeatedly total reflecting on the inner surface of the second light guide 22 and is emitted from the second individual emission surface 22b. At this time, since the second light guide 22 is cylindrical, as shown in FIG. 6, it guides the light while repeatedly total reflecting not only in the cylinder axis direction of the second light guide 22 but also in the circumferential direction of the second light guide 22. In particular, as shown in FIG. 6, even for one light source 11, the light incident on the second light guide 22 reaches all over the second light guide 22. Therefore, when lights of different colors (red light, green light, blue light, white light) are incident on the second light guide 22, the lights of different colors are efficiently mixed while guiding the second light guide 22.

[0057] Although not shown in the drawings, the light of the light source 11 incident on the first individual incident surface 21a of the first light guide 21 is also guided by the first light guide 21 while repeatedly undergoing total internal reflection on the inner surface of the first light guide 21 and is emitted from the first individual emission surface 21b. At this time, also in the first light guide 21, the light is guided while repeatedly undergoing total internal reflection not only in the axial direction of the first light guide 21 but also in the circumferential direction of the first light guide 21, and the light incident on the first light guide 21 reaches throughout the entire first light guide 21. Therefore, when lights of different colors (red light, green light, blue light, white light) are incident on the first light guide 21, the lights of different colors are efficiently mixed while being guided by the first light guide 21.

[0058] In this way, the light of the light source 11 incident on the incident surface 20a of the light guide member 20 is guided by the light guide member 20 and emitted from the emission surface 20b. At this time, when lights of different colors (red light, green light, blue light, white light) are incident on the light guide member 20, the lights of different colors are efficiently mixed while being guided by the light guide member 20.

[0059] As described above, the lighting device 1 according to the present embodiment includes a light emitting module 10 having a plurality of light sources 11 with different emission spectra and a long light guide member 20. The plurality of light sources 11 are arranged in a linear row, the incident surface 20a of the light guide member 20 has a shape along the row of the plurality of light sources 11, and the emission surface 20b of the light guide member 20 overlaps at least a part of the light emitting module 10 and is a closed surface without a gap when viewed from the longitudinal direction of the light guide member 20.

[0060] In this way, since the incident surface 20a of the light guide member 20 has a shape along the linear row of the plurality of light sources 11, the number of times of total internal reflection of the light incident on the light guide member 20 within the light guide member 20 can be increased. Thereby, for lights of different colors emitted from a plurality of light sources 11 having different emission spectra, the color mixing effect per unit length can be improved. Moreover, since the plurality of light sources 11 are arranged in a linear row, the heat generated by the plurality of light sources 11 can be efficiently dissipated.

[0061] Therefore, according to the lighting device 1 according to the present embodiment, it is possible to enhance the color mixing property of the light emitted from the plurality of light sources 11 having different emission spectra, and it is also possible to improve the heat dissipation property of the heat generated by the plurality of light sources 11.

[0062] Further, in the lighting device 1 according to the present embodiment, the plurality of light sources 11 are arranged in a plurality of linear rows that do not intersect, and the light guide member 20 has a plurality of light guides equal in number to the rows of the plurality of light sources 11. Specifically, since the plurality of light sources 11 are arranged in two rows, the light guide member 20 has two light guides, a first light guide 21 and a second light guide 22. The first light guide 21 has a first individual incident surface 21a and a first individual emission surface 21b, and the second light guide 22 has a second individual incident surface 22a and a second individual emission surface 22b. And the incident surface 20a of the light guide member 20 is a surface in which the first individual incident surface 21a and the second individual incident surface 22a are separated from each other, and the emission surface 20b of the light guide member 20 is a surface in which the first individual emission surface 21b and the second individual emission surface 22b are combined.

[0063] In this way, by separating the light guide member 20 into the first light guide 21 and the second light guide 22 and making the incident surface 20a a surface separated by the first individual incident surface 21a and the second individual incident surface 22a, the interval between the plurality of light sources 11 arranged in two rows can be increased. Thereby, the heat dissipation property of the heat generated by the plurality of light sources 11 can be improved. Moreover, by making the emission surface 20b a surface combined by the first individual emission surface 21b and the second individual emission surface 22b, even if the incident surface 20a is separated into the first individual incident surface 21a and the second individual incident surface 22a that are spaced apart, the light of different colors of the light source 11 incident on the incident surface 20a can be efficiently color-mixed.

[0064] Further, in the lighting device 1 according to the present embodiment, the second light guide 22 in the light guide member 20 is in a cylindrical shape surrounding the first light guide.

[0065] With this configuration, the light of the light source 11 incident on the light guide member 20 is more likely to be totally reflected not only in the longitudinal direction of the light guide member 20 but also in the circumferential direction of the light guide member 20, and the number of total reflections can be increased. Thereby, the color mixing effect per unit length can be further improved.

[0066] In addition, in the lighting device 1 according to the present embodiment, the shape of the line forming each of the rows of the plurality of light sources 11 is a closed line.

[0067] With this configuration, the plurality of light sources 11 can be arranged in an annular shape or the like without being concentrated in the center. That is, the plurality of light sources 11 can be arranged dispersedly. Thereby, the heat dissipation performance of the heat generated by the plurality of light sources 11 can be further improved.

[0068] In addition, in the present embodiment, the closed line forming each of the rows of the plurality of light sources 11 is a circle, and the outer shape of each of the first light guide 21 and the second light guide 22 constituting the light guide member 20 is a circle.

[0069] With this configuration, the outer shape of the light emitting surface 20b of the light guide member 20 can be easily made circular. Thereby, the light emitted from the light emitting surface 20b serving as the pseudo light source surface can be made circular, so that the light emitted from the light emitting surface 20b can be easily projected by the projection lens 30. That is, the projection lens 30 can easily form illumination light having a general circular profile on the illumination surface.

[0070] In addition, in the lighting device 1 according to the present embodiment, each of the first light guide 21 and the second light guide 22 has a portion where the outer diameter becomes smaller as it goes from the incident surface 20a of the light guide member 20 toward the light emitting surface 20b.

[0071] With this configuration, even if the outer diameter of the incident surface 20a of the light guide member 20 increases due to the dispersion arrangement of the plurality of light sources 11, the outer diameter of the emission surface 20b of the light guide member 20 can be reduced. As a result, the light emitted from the emission surface 20b can be constricted and condensed, so that the light distribution of the light emitted from the emission surface 20b can be made narrow-angle. Therefore, for the light emitted from the emission surface 20b and incident on the projection lens 30, the light incident efficiency on the projection lens 30 can be improved.

[0072] Moreover, by providing each of the first light guide 21 and the second light guide 22 with a portion where the outer diameter decreases as it goes from the incident surface 20a to the emission surface 20b, the ratio of the light that is incident on the first light guide 21 and the second light guide 22 and directly goes toward the emission surface 20b without total reflection can be reduced. As a result, the light incident on the first light guide 21 and the second light guide 22 can be more efficiently mixed in color, so that the color mixing property of the light emitted from the plurality of light sources 11 can be further enhanced.

[0073] Also, in the lighting device 1 according to the present embodiment, the wall thickness of each of the first light guide 21 and the second light guide 22 increases as it goes from the incident surface 20a to the emission surface 20b.

[0074] With this configuration, the light distribution of the light emitted from each of the first light guide 21 and the second light guide 22 can be made narrow-angled. Thereby, the light incident efficiency of the light incident on the projection lens 30 can be improved. This optical effect will be confirmed with reference to FIG. 7. FIG. 7 is a diagram showing the locus of the light rays of the light emitted from the light guide when the thickness of the light guide changes. (a) of FIG. 7 shows the locus of the light rays in the light guide 20X with no change in thickness, (b) of FIG. 7 shows the locus of the light rays in the light guide 20Y with the thickness gradually increasing from the incident surface 20a to the emission surface 20b, and (c) of FIG. 7 shows the locus of the light rays in the light guide 20Z with the thickness changing even more greatly from the incident surface 20a to the emission surface 20b than in (b) of FIG. 7. As shown in FIGS. 7(a) to 7(c), it can be seen that as the thickness increases from the incident surface 20a to the emission surface 20b, the light distribution angle of the light emitted decreases in the order of the light guide 20X → the light guide 20Y → the light guide 20Z. Therefore, by increasing the thickness of each of the first light guide 21 and the second light guide 22 from the incident surface 20a to the emission surface 20b, the light distribution angle of the light emitted from each of the first light guide 21 and the second light guide 22 can be made small.

[0075] Also, in the lighting device 1 according to the present embodiment, the plurality of light sources 11 are alternately and periodically arranged one by one for each emission spectrum. Specifically, assuming that the red LED light source 11R is "R", the green LED light source 11G is "G", the blue LED light source 11B is "B", and the white LED light source 11W is "W", with R→G→B→W as one cycle, it is arranged by repeating a plurality of times.

[0076] With this configuration, the color mixing property of the light emitted from the plurality of light sources 11 can be made higher than the case where the plurality of light sources 11 are not alternately and periodically arranged one by one, such as R→R→R→G→G→G→B→B→B→W→W→W.

[0077] (Modification example) As described above, the lighting device according to the present invention has been described based on the embodiments, but the present invention is not limited to the above embodiments.

[0078] For example, in the above-described embodiment, the closed line forming each of the rows of the plurality of light sources 11 was a circle, but it is not limited to this. Specifically, like the light-emitting module 10A shown in FIG. 8, the closed line forming each of the rows of the plurality of light sources 11 may be a rectangle. In FIG. 8, the plurality of light sources 11 are arranged in two rows so as to form two concentric squares. That is, the plurality of light sources 11 are arranged in a circular shape in two rows of squares. Also, as shown in FIG. 8, in this modified example, the incident surface 20a of the light guide member 20A has a shape along the rows of the plurality of light sources 11. That is, the shape of the first individual incident surface 21a of the first light guide 21A and the shape of the second individual incident surface 22a of the second light guide 22A are both rectangles. On the other hand, the exit surface 20b of the light guide member 20A is circular, similar to the above-described embodiment. Specifically, the outer shape of the first individual exit surface 21b of the first light guide 21A and the outer shape of the second individual exit surface 22b of the second light guide 22A are both circular. Also in this modified example, the exit surface 20b of the light guide member 20A overlaps at least a part of the light-emitting module 10A when viewed from the longitudinal direction of the light guide member 20A, and is a closed surface without a gap. Therefore, the same effects as those of the above-described embodiment can be obtained. Note that the closed line forming each of the rows of the plurality of light sources 11 is not limited to a circle or a rectangle, and may be other free closed curves such as polygons other than rectangles.

[0079] Also, in the above-described embodiment, the shape of the line forming each of the columns of the plurality of light sources 11 was a closed line, but it is not limited to this. That is, the shape of the line forming each of the columns of the plurality of light sources 11 may be an unclosed line. For example, as in the light-emitting module 10B shown in FIG. 9, the line forming each of the columns of the plurality of light sources 11 may be a non-intersecting straight line. In this modification, as shown in FIG. 9, the plurality of light sources 11 are arranged in four parallel straight columns. Also, as shown in FIG. 9, in this modification, the incident surface 20a of the light guide member 20B has a shape along the columns of the plurality of light sources 11 and is a straight line. On the other hand, the exit surface 20b of the light guide member 20B is circular, as in the above-described embodiment. Also in this modification, the exit surface 20b of the light guide member 20B overlaps at least a part of the light-emitting module 10B when viewed from the longitudinal direction of the light guide member 20B and is a closed surface without a gap. Therefore, the same effects as in the above-described embodiment can be obtained.

[0080] Also, in the above-described embodiment and modification, the first individual incident surface 21a of the first light guide 21 and the second individual incident surface 22a of the second light guide 22 are each a figure (circle, rectangle, straight line, etc.) formed by a single line, and the plurality of light sources 11 forming a linear column facing each of the first individual incident surface 21a and the second individual incident surface 22a were each arranged in a single column, but it is not limited to this. For example, each of the first individual incident surface 21a of the first light guide 21 and the second individual incident surface 22a of the second light guide 22 is a figure formed by a plurality of two or more lines (for example, a double circle, a double rectangle, two straight lines, etc.), and the plurality of light sources 11 forming a linear column may be arranged in a plurality of two or more columns corresponding to the plurality of lines in each of the first individual incident surface 21a and the second individual incident surface 22a. Also, in this case, in the lines forming each of the first individual incident surface 21a and the second individual incident surface 22a and the lines forming the columns of the plurality of light sources 11, the thickness of one line may be, for example, thicker only at the ends. Specifically, in one line, the light sources 11 are arranged in a single column in the center and in two columns at the ends.

[0081] In addition, in the above embodiment, the plurality of light sources 11 were arranged in a plurality of linear arrays, but the present invention is not limited to this. For example, the plurality of light sources 11 may be arranged in a single linear array.

[0082] In addition, in the above embodiment, the light guide member 20 was composed of two light guides, i.e., the first light guide 21 and the second light guide 22, but the present invention is not limited to this. For example, the light guide member 20 may be integrated without being separated into a plurality of light guides, or may be composed of three or more light guides.

[0083] In addition, in the above embodiment, the lighting device 1 was a spotlight, but the present invention is not limited to this. The present invention can be applied to lighting devices other than spotlights.

[0084] Furthermore, forms obtained by applying various modifications that can be conceived by those skilled in the art to the above embodiments, and forms realized by arbitrarily combining the components and functions in the above embodiments without departing from the gist of the present invention are also included in the present invention. Also, combinations of one or more components in each of the plurality of claims described in the claims of the present application at the time of filing are also included in the present invention. Also, when the dependent claims described in the claims of the present application at the time of filing are made into multi-claims or multi-multi-claims so as to cite any plurality of claims (for example, when making multi-claims or multi-multi-claims so as to cite all the upper claims for each claim), all forms obtained by combinations of all the claims included in the multi-claims or multi-multi-claims are also included in the present invention.

Explanation of Reference Numerals

[0085] 1 Lighting device 10, 10A, 10B Light emitting module 11 Light source 20, 20A, 20B Light guide member 20a Incident surface 20b Exit surface 21, 21A First light guide 21a First individual incident surface 21b First individual exit surface 22, 22A Second light guide 22a Second individual incident surface 22b Second individual exit surface

Claims

1. A light-emitting module having a plurality of light sources with different emission spectra, A long light guide member having an incident surface on which light emitted from the plurality of light sources is incident and an emission surface from which the light incident from the incident surface is emitted, The plurality of light sources are arranged in one or more linear rows, The incident surface has a shape along the rows of the plurality of light sources, The emission surface, when viewed from the longitudinal direction of the light guide member, overlaps at least a part of the light-emitting module and is a closed surface without a gap, An illumination device.

2. The plurality of light sources are arranged in a plurality of non-intersecting linear rows, The light guide member has a plurality of light guides equal in number to the rows of the plurality of light sources, Each of the plurality of light guides has an individual incident surface on which light emitted from the corresponding row of the plurality of light sources is incident and an individual emission surface from which the light incident from the individual incident surface is emitted, The incident surface is a surface in which the individual incident surfaces of each of the plurality of light guides are separated from each other, The emission surface is a surface in which the individual emission surfaces of each of the plurality of light guides are combined, The illumination device according to claim 1.

3. The light guide member has, as the plurality of light guides, a first light guide and a cylindrical second light guide surrounding the first light guide, The illumination device according to claim 2.

4. The shape of the line forming each of the rows of the plurality of light sources is a closed line, The illumination device according to claim 3.

5. The outer shape of the emission surface is a circle, The illumination device according to claim 4.

6. The closed line is a circle, The outer shape of each of the plurality of light guides is a circle, The illumination device according to claim 5.

7. Each of the plurality of light guides has a portion where the outer diameter becomes smaller as it goes from the incident surface to the emission surface, The illumination device according to claim 6.

8. The thickness of each of the plurality of light guides increases as it goes from the incident surface to the emission surface, The illumination device according to any one of claims 3 to 7.

9. The plurality of light sources are arranged alternately and periodically one by one for each emission spectrum, The illumination device according to any one of claims 1 to 7.

10. The emission surface is a diffusing surface, The illumination device according to any one of claims 1 to 7.

11. A reflecting member is provided on the outer peripheral surface of the light guide member, The illumination device according to any one of claims 1 to 7.

Images