Illumination system

Abstract

To provide an illumination system capable of radiating illumination light of a desired color temperature in an object space without using a lighting fixture.SOLUTION: An illumination system 1 includes: a light source unit 10 including a laser light source 11; and a color temperature conversion unit 20 arranged being separated from the light source unit 10, and for radiating light source light L1 emitted from the light source unit 10 to an object space TS as illumination light L2 by changing its color temperature. The color temperature conversion unit 20 includes a filter 21 which attenuates the light of part of the wavelength out of the light source light L1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an illumination system for irradiating a target space with illumination light. [Background technology]

[0002] A lighting system that irradiates illumination light into a target space is disclosed in Patent Document 1. The lighting system disclosed in Patent Document 1 includes a lighting fixture installed on the ceiling of a room in a building. The lighting fixture has a housing and a light-emitting module that is a light source unit housed in the housing, and irradiates illumination light into the room that is the target space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-161347 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional lighting systems, lighting fixtures equipped with light source units are used, so the lighting fixtures have a large presence in the target space, making the target space look cluttered. Therefore, it is possible to irradiate the target space with illumination light without using lighting fixtures, but it is difficult to irradiate the target space with illumination light of a desired color temperature without using lighting fixtures.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a lighting system that can irradiate a target space with illumination light of a desired color temperature without using a lighting fixture. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one aspect of the lighting system of the present invention comprises a light source unit including a laser light source, and a color temperature conversion unit arranged separately from the light source unit and configured to change the color temperature of light source light emitted from the light source unit and irradiate the light as illumination light to a target space, the color temperature conversion unit having a filter that attenuates light of some wavelengths of the light source light. Effect of the Invention

[0007] According to the lighting system of the present invention, the color temperature of the light source light emitted from the light source unit can be changed, so that illumination light of a desired color temperature can be irradiated to a target space without using a lighting fixture. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a lighting system according to an embodiment; [Diagram 2] 2 is a diagram showing a configuration of a laser light source in a light source unit of a lighting system in an embodiment; [Diagram 3] 5A and 5B are diagrams illustrating a configuration of a projection section in a light source unit of the lighting system according to the embodiment. [Figure 4] FIG. 2 is a diagram showing a configuration of a color temperature conversion unit of the lighting system according to the embodiment. [Diagram 5] 4 is a diagram showing an example of the emission spectrum of light source light emitted from a light source unit and illumination light emitted from a color temperature conversion unit; FIG. [Figure 6] 5A and 5B are diagrams for explaining optical actions of an illumination system according to an embodiment and an illumination system of a comparative example. [Figure 7] FIG. 13 is a diagram showing optical spectra of illumination light irradiated into a target space in the lighting system according to the embodiment and the lighting system of the comparative example. [Figure 8] 4 is an xy chromaticity diagram showing the chromaticity of illumination light irradiated into a target space in a lighting system according to an embodiment and a lighting system of a comparative example. FIG. [Figure 9]FIG. 13 is a diagram showing a configuration of a color temperature conversion unit in a lighting system according to a first modified example. [Figure 10] FIG. 11 is a diagram showing the configuration of a color temperature conversion unit in a lighting system according to a second modification. [Figure 11] FIG. 11 is a diagram showing the configuration of a color temperature conversion unit in a lighting system according to a third modification. [Figure 12] FIG. 11 is a diagram showing the configuration of a color temperature conversion unit in a lighting system according to a fourth modified example. [Figure 13] FIG. 13 is a diagram showing the configuration of a color temperature conversion unit in a lighting system according to a fifth modified example. [Figure 14] FIG. 13 is a diagram showing the configuration of a color temperature conversion unit in a lighting system according to a sixth modification. [Figure 15] FIG. 13 is a diagram illustrating a schematic configuration of a lighting system according to a seventh modification. [Figure 16] FIG. 13 is a diagram illustrating a schematic configuration of a lighting system according to Modification 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described 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, 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, components that are not described in the independent claims showing the highest concept of the present invention will be described as optional components.

[0010] Note that each figure is a schematic diagram and is not necessarily a precise illustration. In addition, in each figure, substantially the same configuration is given the same reference numeral, and duplicated explanations are omitted or simplified. In addition, in this specification, the terms "upper" and "lower" do not necessarily refer to the upper direction (vertically upward) and the lower direction (vertically downward) in absolute spatial recognition.

[0011] (Embodiment) An overview of a lighting system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of a lighting system 1 according to an embodiment.

[0012] The lighting system 1 is used, for example, for irradiating a predetermined target space TS in a building with illumination light. Specifically, the lighting system 1 irradiates the target space TS with illumination light of a predetermined color temperature, with the target space TS being the interior of a room in a building such as a facility, a building, a house, a store, or a factory. The target space TS is an illumination space illuminated by the lighting system 1. The target space TS is, for example, a space surrounded by a ceiling 101, a wall 102, and a floor 103.

[0013] 1, the lighting system 1 includes a light source unit 10 and a color temperature conversion unit 20. In the lighting system 1, a beam-shaped light source light L1 (e.g., white light) emitted from the light source unit 10 is incident on the color temperature conversion unit 20, and the color temperature of the light source light L1 is changed in the color temperature conversion unit 20 to produce color temperature changed light (color temperature converted light), which is then irradiated as illumination light L2 into a target space TS.

[0014] Hereinafter, specific configurations of the light source unit 10 and the color temperature conversion unit 20 will be described with reference to Fig. 1 and Fig. 2 to Fig. 4. Fig. 2 is a diagram showing the configuration of a laser light source 11 in the light source unit 10. Fig. 3 is a diagram showing the configuration of a projection section 13 in the light source unit 10. Fig. 4 is a diagram showing the configuration of the color temperature conversion unit 20.

[0015] The light source unit 10 includes a laser light source 11 that emits a laser beam. In this embodiment, the light source unit 10 further includes an optical fiber 12 and a projection unit 13.

[0016] As shown in FIG. 2, the laser light source 11 includes a semiconductor laser 11a that emits laser light Lb, a mirror 11b, a condenser lens 11c, and a housing 11d.

[0017] The semiconductor laser 11a is, for example, a TO-CAN package semiconductor laser, and includes a semiconductor laser chip that emits laser light Lb, a stem having a post on which the semiconductor laser chip is mounted and a disk-shaped base that supports the post, a pair of lead pins that penetrate the base, and a metal cap that is placed on the base so as to cover the post on which the semiconductor laser chip is mounted. The laser light Lb emitted from the semiconductor laser chip is radiated to the outside through an opening of the cap. The semiconductor laser chip is, for example, made of a nitride-based semiconductor material such as GaN.

[0018] In this embodiment, the semiconductor laser 11a is a blue semiconductor laser that emits blue laser light Lb in a blue band having a peak wavelength in the range of 430 nm to 480 nm, inclusive. The laser light source 11 has two semiconductor lasers 11a.

[0019] 2, the mirror 11b reflects the laser light Lb emitted from the semiconductor laser 11a toward the condenser lens 11c. The mirrors 11b are provided in one-to-one correspondence with the two semiconductor lasers 11a. That is, the laser light source 11 has two mirrors 11b.

[0020] The condenser lens 11c condenses the laser light Lb reflected by the mirror 11b and makes it incident on the optical fiber 12. In the present embodiment, the condenser lens 11c condenses the laser light Lb emitted from each of the two semiconductor lasers 11a and makes it incident on the optical fiber 12.

[0021] The housing 11d is a case that houses the semiconductor laser 11a, the mirror 11b, and the condenser lens 11c. In this embodiment, the housing 11d houses two semiconductor lasers 11a, two mirrors 11b, and one condenser lens 11c.

[0022] In the laser light source 11 configured in this manner, the two laser beams Lb emitted from the two semiconductor lasers 11a are reflected by the respective mirrors 11b, and are collected by the collecting lens 11c to enter the optical fiber 12. Specifically, since the two semiconductor lasers 11a emit blue laser beams Lb, the blue laser beams Lb enter the optical fiber 12.

[0023] The optical fiber 12 shown in Fig. 1 is an example of a light-guiding member that guides light. The optical fiber 12 is a double-structure transmission body composed of a core and a cladding that has a lower refractive index than the core and surrounds the core. The optical fiber may have a coating made of a resin or the like that covers the outer circumferential surface of the cladding. The diameter of the core of the optical fiber 12 is, for example, 20 µm to 1000 µm. The length of the optical fiber 12 is, for example, 1 m to 100 m.

[0024] 1, the optical fiber 12 has a first end 12a and a second end 12b in the length direction. The second end 12b is the end opposite to the first end 12a. The first end 12a of the optical fiber 12 includes an incident end surface into which the laser light Lb from the laser light source 11 is incident. The second end 12b of the optical fiber 12 includes an exit end surface from which the laser light Lb, which is incident from the incident end surface and propagates through the optical fiber 12, exits.

[0025] 1 and 3, the laser light Lb emitted from the second end 12b of the optical fiber 12 is incident on the projection unit 13. In the present embodiment, the blue laser light Lb is emitted from the laser light source 11 and enters the optical fiber 12, so that the blue laser light Lb is incident on the projection unit 13.

[0026] As shown in FIG. 1, the projection unit 13 generates light source light L1 to be irradiated onto the color temperature conversion unit 20 based on the laser light Lb emitted from the laser light source 11, and projects the light source light L1 toward the color temperature conversion unit 20 through the target space TS.

[0027] The projection unit 13 is installed, for example, on the wall 102. The projection unit 13 is also installed at a position higher than a height position that is equal to or higher than a predetermined height (for example, 2 m 30 cm) from the floor 103. The projection unit 13 is also installed so that the light source light L1 is emitted upward rather than horizontally (i.e., diagonally upward). This makes the projection unit 13 inconspicuous in the lighting system 1, improving the design of the wall 102 on which the projection unit 13 is provided, and preventing people from peering into the projection unit 13. The projection unit 13 may be installed in a place other than the wall 102.

[0028] As shown in FIG. 3, the projection unit 13 includes a wavelength conversion member 13a, a collimator lens 13b, and a housing 13c.

[0029] The wavelength conversion member 13a converts the wavelength of the laser light Lb emitted from the laser light source 11 to generate source light L1 containing light of a wavelength different from that of the laser light Lb. In this embodiment, the wavelength conversion member 13a converts the wavelength of the blue laser light Lb emitted from the laser light source 11 to generate white source light L1 containing light of a color different from blue.

[0030] The wavelength conversion member 13a is, for example, a phosphor device made of phosphor. In this case, the wavelength conversion member 13a includes a phosphor layer and a substrate supporting the phosphor layer, and emits fluorescence using light incident on the phosphor layer as excitation light. In this embodiment, the wavelength conversion member 13a is a transmissive phosphor device, and the excitation light incident on the phosphor layer passes through the wavelength conversion member 13a. Therefore, the substrate supporting the phosphor layer is a translucent substrate having translucency.

[0031] The substrate supporting the phosphor layer is preferably a transparent substrate having a high transmittance so that the other side can be seen through. The phosphor layer is formed on the main surface of the transparent substrate. The transparent substrate may be an alumina substrate made of Al2O3, an aluminum nitride substrate made of AlN, a gallium nitride substrate made of GaN, a sapphire substrate, a glass substrate, or the like.

[0032] The phosphor layer is a light-emitting layer that emits light, and is excited by excitation light to emit fluorescent light of a predetermined wavelength in the visible region. Specifically, the phosphor layer is excited by laser light Lb (excitation light) from the optical fiber 12 to emit fluorescent light. The phosphor layer emits fluorescent light using light with a shorter wavelength than the fluorescent light to be generated as excitation light.

[0033] As an example, the phosphor layer is a yellow phosphor layer made of a yellow phosphor, which emits fluorescence using light having a shorter wavelength than yellow light (for example, ultraviolet light to blue light) as excitation light.

[0034] The phosphor layer may be, for example, a phosphor ceramic layer made of sintered phosphor particles of a single crystal phase, or a phosphor sealing resin layer in which countless phosphor particles are sealed in a light-transmitting resin material (binder) such as silicone resin. As yellow phosphor particles that emit yellow fluorescence, for example, YAG phosphor of YAG (yttrium aluminum garnet) can be used. The emission spectrum of light emitted from the yellow phosphor particles has a peak wavelength in the wavelength range of, for example, 530 nm to 580 nm. As such yellow phosphor particles, for example, Y3Al5O activated with Ce can be used. 12 can be used.

[0035] The phosphor particles of the wavelength conversion member 13a are not limited to yellow phosphor particles. For example, the wavelength conversion member 13a may have other phosphor particles such as yellow-green phosphor particles, green phosphor particles, and / or red phosphor particles in addition to yellow phosphor particles. In other words, the wavelength conversion member 13a may have multiple types of phosphor particles.

[0036] In this embodiment, since the wavelength conversion member 13a has yellow phosphor particles, when the wavelength conversion member 13a is irradiated with blue laser light, the yellow phosphor particles absorb a part of the blue laser light Lb (excitation light) and are excited to emit yellow fluorescence. In the wavelength conversion member 13a, the yellow light from the yellow phosphor particles and the blue light not absorbed by the yellow phosphor particles are mixed to generate white light, and the white light is emitted from the wavelength conversion member 13a as the light source light L1. In other words, the white light is extracted from the wavelength conversion member 13a.

[0037] The source light L1, which is white light emitted from the wavelength conversion member 13a, is incident on the collimator lens 13b. As a result, the source light L1, which is white light emitted from the wavelength conversion member 13a, is collimated by the collimator lens 13b to become the beam-shaped source light L1. The collimator lens 13b is an example of a projection lens that projects the source light L1 into the target space TS toward the color temperature conversion unit 20. Note that the projection lens that projects the source light L1 toward the color temperature conversion unit 20 is not limited to the collimator lens 13b.

[0038] The housing 13c houses the wavelength conversion member 13a and the collimating lens 13b. The housing 13c has a passage portion that passes the white light collimated by the collimating lens 13b. The passage portion may be made of a light-transmitting material or may be a through hole.

[0039] In the light source unit 10 configured in this manner, the blue laser light Lb emitted from the laser light source 11 is transmitted to the projection unit 13 by the optical fiber 12 and converted into white light source light L1 by the wavelength conversion member 13a of the projection unit 13. Then, this white light source light L1 is collimated by the collimating lens 13b and emitted from the projection unit 13. In other words, the light source unit 10 emits white light source light L1.

[0040] 1, the light source unit 10 is disposed outside the wall 102. Therefore, when a person present in the target space TS sees the wall 102, the light source unit 10 is hidden by the wall 102.

[0041] The light source light L1 emitted from the light source unit 10 is incident as incident light into the color temperature conversion unit 20. Specifically, as shown in FIG. 1, the light source light L1, which is a beam of white light emitted from the projection unit 13, is incident on the color temperature conversion unit 20.

[0042] The color temperature conversion unit 20 is disposed separately from the light source unit 10. Specifically, the color temperature conversion unit 20 and the light source unit 10 are not in physical contact with each other, and a spatial region exists between the color temperature conversion unit 20 and the light source unit 10.

[0043] The color temperature conversion unit 20 is installed in the construction materials of a building. In this embodiment, the color temperature conversion unit 20 is installed on a ceiling 101 as shown in FIG. 1. That is, the ceiling 101 serves as a mounting portion to which the color temperature conversion unit 20 is attached. For example, the color temperature conversion unit 20 is attached to the ceiling surface of the ceiling 101 by a joining member. The color temperature conversion unit 20 may be detachably attached to the ceiling 101. This allows the color temperature conversion unit 20 to be replaced. For example, the color temperature conversion unit 20 may be detachably attached to the ceiling 101 by a locking structure using an elastic member, or the color temperature conversion unit 20 may be detachably attached to the ceiling 101 by a cassette structure that allows the color temperature conversion unit 20 (or the filter 21) to be inserted and removed.

[0044] 1 and 4, the color temperature conversion unit 20 changes the color temperature of the light source light L1 emitted from the light source unit 10 and irradiates the light as illumination light L2 to the target space TS. Specifically, the color temperature conversion unit 20 has a filter 21 that attenuates light of some wavelengths in the light source light L1. That is, the color temperature conversion unit 20 changes the color temperature of the light source light L1 by attenuating light of some wavelengths in the light source light L1 using the filter 21 to generate color temperature-converted light, and irradiates the color temperature-converted light to the target space TS as illumination light L2.

[0045] In this embodiment, the color temperature conversion unit 20 lowers the color temperature of the light source light L1 emitted from the light source unit 10. Therefore, the light source light L1 of the light source unit 10 is converted into color temperature converted light having a lower color temperature than the light source light L1 by entering the color temperature conversion unit 20. That is, the color temperature conversion unit 20 shifts the color temperature of the light source light L1 to the low color temperature side. For example, the color temperature conversion unit 20 changes the color temperature of the light source light L1 to 2700K or more and 5000K or less. As an example, the color temperature conversion unit 20 converts the light source light L1, which is a daylight white light that is a composite light of blue light and yellow light, into an incandescent white light having a lower color temperature than the light source light L1.

[0046] The color temperature conversion unit 20 is of a reflective type. That is, in the color temperature conversion unit 20, the light incident surface through which the light source light L1 of the light source unit 10 enters the color temperature conversion unit 20 is the same as the light exit surface through which the illumination light L2 generated by the color temperature conversion unit 20 exits from the color temperature conversion unit 20. Therefore, the color temperature conversion unit 20 irradiates the illumination light L2 toward the light source light L1 side.

[0047] The filter 21 of the color temperature conversion unit 20 is, for example, an absorption filter having a characteristic of high absorption rate (low transmittance) in a specific wavelength range. The absorption filter is made of a light-transmitting material in which a light-absorbing substance that absorbs light in a predetermined wavelength range is dispersed. For example, an absorption filter having a transmittance of 10% or less for wavelengths in the blue band (430 nm to 480 nm) or less can be used as the filter 21. By using such a filter 21, the wavelength components of the light source light L1 that is incident on the color temperature conversion unit 20 and that is below the blue band are absorbed by the filter 21. In this case, for example, as shown in FIG. 5, the light source light L1 (light before entering the color temperature conversion unit 20), which is white light with a color temperature of 5000 K, is incident on the color temperature conversion unit 20 having the filter 21, and the wavelength components of the light source light L1 that is below the blue band are absorbed, and the light source light L2 (color temperature converted light) is white light with a color temperature of 3000 K. FIG. 5 is a diagram showing an example of the emission spectrum of the source light L1 emitted from the light source unit 10 and the illumination light L2 emitted from the color temperature conversion unit 20. As shown in FIG.

[0048] The illumination light L2 (color temperature converted light) generated by the color temperature conversion unit 20 has a light distribution characteristic with lower directivity than the light source light L1. That is, the illumination light L2 has a larger luminous flux spread angle than the light source light L1, and the illumination light L2 has a larger light distribution than the light source light L1. The illumination light L2 is light with relatively low coherence (incoherent light) compared to the light source light L1.

[0049] The color temperature conversion unit 20 is a thin, flat sheet-like member. The filter 21 constituting the color temperature conversion unit 20 is also sheet-like. The shape of the color temperature conversion unit 20 in a plan view is, for example, a circular shape, but is not limited thereto. For example, the shape of the color temperature conversion unit 20 in a plan view may be a polygon such as a rectangle.

[0050] Although not shown, the lighting system 1 may have a power supply device (power supply circuit) for supplying power to the light source unit 10. The power supply device may supply power to each of the two semiconductor lasers 11a individually. This allows the optical output ratio of the two semiconductor lasers 11a to be changed, thereby adjusting the brightness of the illumination light L2. The lighting system 1 does not necessarily have to include the power supply device. In other words, the power supply device may be an external power source that is provided separately from the lighting system 1.

[0051] In the lighting system 1 configured as above, as shown in Fig. 1, when blue laser light Lb is emitted from the laser light source 11, the laser light Lb propagates through the optical fiber 12 and enters the projection unit 13, and white light source light L1 is generated in the wavelength conversion member 13a of the projection unit 13 by the blue laser light Lb that entered the projection unit 13. The white light source light L1 generated in the projection unit 13 is collimated by the collimating lens 13b and projected into the target space TS, and enters the color temperature conversion unit 20 through the target space TS. The white light source light L1 that entered the color temperature conversion unit 20 has its color temperature changed as a result of attenuation of light of some wavelengths of the light source light L1 by the filter 21 of the color temperature conversion unit 20, and is turned into white illumination light L2 with a color temperature different from that of the light source light L1, and is irradiated into the target space TS.

[0052] Next, the features of the lighting system 1 according to the present embodiment will be described in comparison with a lighting system 1X of a comparative example with reference to Figs. 6 to 8. Fig. 6 is a diagram for explaining the optical action of the lighting system 1 according to the embodiment and the lighting system 1X of the comparative example. Fig. 7 is a diagram showing the optical spectrum of the illumination light irradiated to the target space TS in the lighting system 1 according to the embodiment and the lighting system 1X of the comparative example. Fig. 8 is an xy chromaticity diagram showing the chromaticity of the illumination light irradiated to the target space TS in the lighting system 1 according to the embodiment and the lighting system 1X of the comparative example. The dashed line in Fig. 8 indicates the blackbody locus for duv=0.

[0053] As shown in FIG. 6, in a lighting system 1X of a comparative example ([Comparative Example] in FIG. 6), when blue laser light Lb emitted from a laser light source 11 is incident on a wavelength conversion member 13a (phosphor), the wavelength conversion member 13a converts the wavelength of the laser light Lb to generate white light. In the lighting system 1X of the comparative example, the white light generated by the wavelength conversion member 13a is irradiated to the target space TS as illumination light Lx. In this case, the illumination light Lx irradiated to the target space TS has, as an example, an optical spectrum shown by a dashed line in FIG. 7. Moreover, the color temperature of the illumination light Lx is, as an example, 5850K as shown in FIG. 8.

[0054] On the other hand, in the lighting system 1 according to the present embodiment ([Example] in FIG. 6), when the blue laser light Lb emitted from the laser light source 11 is incident on the wavelength conversion member 13a (phosphor), the wavelength conversion member 13a converts the wavelength of the laser light Lb to generate white light, as in the lighting system 1X of the comparative example. However, in the lighting system 1 according to the present embodiment, a color temperature conversion unit 20 having a filter 21 that absorbs wavelength components below the blue band is used, and the white light generated by the wavelength conversion member 13a is made incident on the color temperature conversion unit 20 as the light source light L1. As a result, the wavelength components below the blue band of the light source light L1, which is white light, are absorbed by the filter 21 of the color temperature conversion unit 20, and the color temperature is changed. In the lighting system 1 according to the present embodiment, the color temperature converted light with the changed color temperature is irradiated to the target space TS as the illumination light L2. In this case, the illumination light L2 irradiated to the target space TS has an optical spectrum shown by a solid line in FIG. 7. Moreover, the color temperature of the illumination light L2 is, for example, 3200K as shown in FIG. 8.

[0055] In the lighting system 1 according to the present embodiment, the light source light L1 (white light generated by the wavelength conversion member 13a) before entering the color temperature conversion unit 20 is the same as the illumination light Lx in the lighting system 1X of the comparative example. That is, the optical spectrum of the light source light L1 before entering the color temperature conversion unit 20 is the same as the optical spectrum of the illumination light Lx in the lighting system 1X of the comparative example (the optical spectrum shown by the dashed line in FIG. 7), and the color temperature of the light source light L1 before entering the color temperature conversion unit 20 is 5850K, which is the same as the color temperature of the illumination light Lx in the lighting system 1X of the comparative example. Therefore, in the lighting system 1 according to the present embodiment, the color temperature of the light source light L1 with a color temperature of 5850K is lowered by the color temperature conversion unit 20 to generate the illumination light L2 with a color temperature of 3200K.

[0056] As described above, the lighting system 1 according to this embodiment includes a light source unit 10 including a laser light source 11, and a color temperature conversion unit 20 arranged separately from the light source unit 10, which changes the color temperature of the light source light L1 emitted from the light source unit 10 and irradiates the light to the target space TS as illumination light L2, and the color temperature conversion unit 20 has a filter 21 that attenuates light of some wavelengths of the light source light L1.

[0057] In this way, in the lighting system 1 according to the present embodiment, the light source unit 10 and the color temperature conversion unit 20 are arranged separately, and the color temperature of the light source light L1 emitted from the light source unit 10 is changed by the color temperature conversion unit 20, and the illumination light L2 is irradiated from the color temperature conversion unit 20 to the target space TS. This makes it possible to irradiate the illumination light L2 of a desired color temperature to the target space TS without using a lighting fixture equipped with a light source unit as in the past. In this way, since it is no longer necessary to install a lighting fixture equipped with a light source unit in the target space TS, the target space TS can be made neat. Therefore, the design of the target space TS can be easily improved.

[0058] Moreover, by disposing the light source unit 10 and the color temperature conversion unit 20 separately, it is possible to improve the maintainability of each of the light source unit 10 and the color temperature conversion unit 20. For example, each of the light source unit 10 and the color temperature conversion unit 20 can be replaced individually.

[0059] In the lighting system 1 according to the present embodiment, the source light L1 emitted from the light source unit 10 is white light.

[0060] As a result, even if the light source light L1 emitted from the light source unit 10 through the target space TS to be illuminated is incident on the color temperature conversion unit 20, a user present in the target space TS is unlikely to notice that the light source light L1 is emitted from the light source unit 10. Therefore, the illumination light L2, which is white light with a changed color temperature, can be irradiated onto the target space TS without giving a sense of incongruity to the user present in the target space TS.

[0061] In the lighting system 1 according to the present embodiment, the source light L1 emitted from the light source unit 10 is in the form of a beam.

[0062] This makes it even more difficult for a user present in the target space TS to notice that the light source light L1 is being emitted from the light source unit 10. Therefore, the illumination light L2, which is white light with a changed color temperature, can be irradiated into the target space TS without giving any discomfort to the user present in the target space TS.

[0063] In the lighting system 1 according to the present embodiment, the color temperature conversion unit 20 has only the filter 21 as an optical member that imparts an optical effect to the source light L1, but this is not limiting.

[0064] For example, as in the lighting system 1A shown in FIG. 9, the color temperature conversion unit 20A may further include a light distribution change section 22 having a function of changing the light distribution in addition to the filter 21. The light distribution change section 22 has a function of changing the light distribution of the illumination light L2 generated by the color temperature conversion unit 20A and irradiating the illumination light L2 to the target space TS. The light distribution change section 22 is, for example, a light reflecting member that reflects the illumination light L2 generated by the light source light L1 passing through the filter 21 toward the target space TS. In this modification, the light distribution change section 22 is disposed on the ceiling 101 side of the filter 21. As a result, the illumination light L2 generated by the color temperature conversion unit 20A (i.e., the light that has passed through the filter 21 without being absorbed by the filter 21) is reflected by the light reflecting member and travels toward the floor side. By using the light distribution change section 22 as a light reflecting member, a reflection type color temperature conversion unit 20A can be easily realized. Note that the light distribution change section 22 is not limited to a light reflecting member.

[0065] As described above, in the lighting system 1A of this modification, the color temperature conversion unit 20A has the light distribution changing section 22, so that the illumination light L2 generated by the color temperature conversion unit 20A can be irradiated to the target space TS with a desired light distribution.

[0066] Also, as in the lighting system 1B shown in FIG. 10, the color temperature conversion unit 20B may further include a light reflection prevention unit 23 in addition to the filter 21 and the light distribution change unit 22. The light reflection prevention unit 23 has a function of reducing the reflection of the light source light L1 incident on the color temperature conversion unit 20B at the color temperature conversion unit 20B. The light reflection prevention unit 23 is disposed on the floor side of the filter 21 so as to be the outermost surface layer of the color temperature conversion unit 20B. For example, an AR coating film (anti-reflection film) can be used as the light reflection prevention unit 23. The AR coating film can be formed of, for example, a dielectric multilayer film.

[0067] In this manner, in the lighting system 1B of this modification, the color temperature conversion unit 20B has the light reflection prevention portion 23, so that the light source light L1 of the light source unit 10 can be efficiently incident on the color temperature conversion unit 20B. As a result, the light extraction efficiency of the illumination light L2 emitted from the color temperature conversion unit 20B can be improved.

[0068] In this modification, the color temperature conversion unit 20B has the light distribution changing section 22, but is not limited to this. That is, the color temperature conversion unit 20B may not have the light distribution changing section 22 and may be composed of only the filter 21 and the light reflection prevention section 23.

[0069] Also, as in the lighting system 1C shown in FIG. 11, the color temperature conversion unit 20C may further include a heat dissipation unit 24 in addition to the filter 21, the light distribution change unit 22, and the light reflection prevention unit 23. The heat dissipation unit 24 is a heat sink and has a function of dissipating heat generated in the color temperature conversion unit 20C. The heat dissipation unit 24 is attached to the ceiling 101, for example. Also, the light distribution change unit 22 is provided on the floor side of the heat dissipation unit 24. The heat dissipation unit 24 may be a metal member made of a metal material such as aluminum or copper. In this case, the metal member may be a sheet-shaped or block-shaped member. Alternatively, the heat dissipation unit 24 may be a thermoelectric element such as a Peltier element.

[0070] In this manner, in the lighting system 1C of this modification, the color temperature conversion unit 20C has the heat dissipation section 24, so that the heat generated in the color temperature conversion unit 20C can be efficiently dissipated. This makes it possible to suppress deterioration of the color temperature conversion unit 20C due to heat and suppress deterioration of its function.

[0071] In this modification, the color temperature conversion unit 20C has the light distribution changing section 22 and the light reflection prevention section 23, but is not limited to this. That is, the color temperature conversion unit 20C may have only one of the light distribution changing section 22 and the light reflection prevention section 23, or may have only the filter 21 and the heat dissipation section 24 without having the light distribution changing section 22 or the light reflection prevention section 23.

[0072] In the above embodiment, the filter 21 of the color temperature conversion unit 20 is an absorption filter, but is not limited thereto. For example, as in the lighting system 1D shown in FIG. 12, the filter 21D of the color temperature conversion unit 20D may be a dielectric multilayer filter. The dielectric multilayer filter is a laminated film in which a plurality of dielectric films with different refractive indices are laminated. The dielectric films constituting the dielectric multilayer filter are composed of, for example, SiO2, TiO2, Al2O3, MgF, etc. The dielectric multilayer filter reflects light in a predetermined wavelength range and transmits light in other wavelength ranges. Therefore, the color temperature conversion unit 20D may have a light absorbing member 25 that absorbs the light L3 transmitted through the filter 21D (dielectric multilayer filter). As a result, the light reflected by the filter 21 is emitted from the color temperature conversion unit 20D to the target space TS as the illumination light L2.

[0073] The wavelength range of light transmitted by filter 21D, which is a dielectric multilayer film filter, is preferably set so that illumination light L2 emitted from color temperature conversion unit 20D becomes white light. In this case, the wavelength range of light transmitted by filter 21D is preferably set so that the color temperature of illumination light L2 emitted from color temperature conversion unit 20D is lower than the color temperature of light source light L1. In this modification, in order to change the color temperature of light source light L1 to illumination light L2 of a predetermined color temperature, unnecessary wavelength component light L3 of light source light L1 is transmitted through filter 21D and absorbed and removed by light absorbing member 25.

[0074] The light absorbing member 25 may absorb light in the entire visible light range, rather than absorbing light in a specific wavelength range of the visible light range. The light absorbing member 25 also functions as a light distribution control unit that changes the light distribution.

[0075] In this manner, in the lighting system 1D of this modification, the color temperature conversion unit 20D is composed of the filter 21D made of a dielectric multilayer film filter and the light absorbing member 25, so that, similarly to the lighting system 1 in the above embodiment, the color temperature of the light source light L1 emitted from the light source unit 10 can be changed by the color temperature conversion unit 20D, and the illumination light L2 can be irradiated from the color temperature conversion unit 20D to the target space TS. This makes it possible to irradiate the illumination light L2 of a desired color temperature to the target space TS without using a conventional lighting fixture.

[0076] In addition, in the lighting system 1 of the above embodiment, the color temperature conversion unit 20 is a reflective type in which the light incident surface and the light exit surface are the same surface, but this is not limited to this. For example, as in the lighting system 1E shown in FIG. 13, the color temperature conversion unit 20E may be a transmissive type in which the light incident surface and the light exit surface are different surfaces. That is, in the color temperature conversion unit 20E, the light incident surface through which the light source light L1 of the light source unit 10 enters the color temperature conversion unit 20E is different from the light exit surface through which the illumination light L2 generated by the color temperature conversion unit 20E exits from the color temperature conversion unit 20E. Specifically, in the color temperature conversion unit 20E, the light exit surface is the surface opposite to the light incident surface.

[0077] In this modification, the color temperature conversion unit 20E has a light-transmitting substrate 26 and a filter 21 formed on the light-transmitting substrate 26. The light-transmitting substrate 26 is preferably a transparent substrate having high transmittance. As the transparent substrate, an alumina substrate made of Al2O3, an aluminum nitride substrate made of AlN, a gallium nitride substrate made of GaN, a sapphire substrate, a glass substrate, or the like can be used. In the color temperature conversion unit 20E, the surface of the light-transmitting substrate 26 opposite to the filter 21 side is a light incident surface, and the surface of the filter 21 opposite to the light-transmitting substrate 26 side is a light exit surface.

[0078] In the lighting system 1E configured as above, when the white light source light L1 is incident on the color temperature conversion unit 20E, the light of some wavelengths of the light source light L1 is attenuated by the filter 21 when passing through the color temperature conversion unit 20E, and the color temperature of the white light source light L1 is changed, and the white illumination light L2 with a color temperature different from that of the light source light L1 is irradiated to the target space TS. In other words, the color temperature conversion unit 20E in this modification transmits only the light of a desired wavelength of the light source light L1, and absorbs the light of the other wavelengths by the filter 21, thereby generating the illumination light L2 with a color temperature different from that of the light source light L1. In this way, even if the transmissive color temperature conversion unit 20E is used, the illumination light L2 with a desired color temperature can be irradiated to the target space TS without using a conventional lighting fixture.

[0079] In this modification, the color temperature conversion unit 20E may have a light distribution control section that controls the light distribution of the illumination light L2 by scattering or reflecting the illumination light L2.

[0080] 14, even when the color temperature conversion unit 20F has a dielectric multilayer filter as the filter 21D, a transmissive type may be used as the color temperature conversion unit 20F. In this modification, the color temperature conversion unit 20F has a light-transmitting substrate 26 and a filter 21D made of a dielectric multilayer filter formed on the light-transmitting substrate 26.

[0081] In the lighting system 1F configured as above, when the white light source light L1 enters the color temperature conversion unit 20F, the light L3 in a predetermined wavelength range is reflected from the white light source light L1 entering the color temperature conversion unit 20F when passing through the filter 21D of the color temperature conversion unit 20F, and the light in the other wavelength ranges is transmitted. Then, the light transmitted through the filter 21D is emitted to the target space TS as the illumination light L2. This makes it possible to irradiate the illumination light L2 of a desired color temperature to the target space TS without using a conventional lighting fixture. In this manner, in this modification, the light L3 of unnecessary wavelength components of the light source light L1 is reflected and removed by the filter 21D in order to change the color temperature of the light source light L1 to the illumination light L2 of a predetermined color temperature.

[0082] In this modification, the color temperature conversion unit 20F may also have a light distribution control section that controls the light distribution of the illumination light L2 by scattering or reflecting the illumination light L2.

[0083] (Other variations) Although the lighting system according to the present invention has been described based on the embodiment, the present invention is not limited to the above embodiment.

[0084] For example, in the above embodiment, the lighting system 1 includes one color temperature conversion unit 20, but this is not limiting. That is, the lighting system 1 may include multiple color temperature conversion units 20. In this case, one light source unit 10 may be used to cause one light source light L1 to be incident on multiple color temperature conversion units 20, or multiple light source units 10 may be used in a one-to-one relationship with multiple color temperature conversion units 20.

[0085] As an example, a lighting system 1G shown in Fig. 15 includes one light source unit 10, a color temperature conversion unit 20, and a color temperature conversion unit 20G. In Fig. 15, one light source light L1 emitted from the light source unit 10 is incident on the color temperature conversion units 20 and 20G. Note that the illumination light L2 emitted from the color temperature conversion unit 20 (first color temperature conversion unit) and the illumination light L2' emitted from the color temperature conversion unit 20G (second color temperature conversion unit) may have different color temperatures and light distributions.

[0086] 15, the color temperature conversion unit 20 (first color temperature conversion unit) and the color temperature conversion unit 20G (second color temperature conversion unit) are arranged close to each other, but this is not limited thereto. For example, as in the lighting system 1H shown in FIG. 16, the color temperature conversion unit 20 (first color temperature conversion unit) and the color temperature conversion unit 20G (second color temperature conversion unit) may be arranged apart from each other. In this case, as shown in FIG. 16, a plurality of light source lights L1 may be emitted from one light source unit 10 into the target space TS, and the light source light L1 may be incident on each of the color temperature conversion unit 20 and the color temperature conversion unit 20G. When emitting multiple light source lights L1 from one light source unit 10, multiple light source lights L1 may be emitted from the projection unit 13 as shown in FIG. 16 by adding optical components such as lenses and mirrors to the projection unit 13, but one light source light L1 emitted from the projection unit 13 may be split into multiple light source lights L1 by using optical components such as lenses and mirrors provided separately from the light source unit 10.

[0087] In the lighting system 1 according to the above embodiment, the laser light source 11 has the semiconductor laser 11a that emits blue laser light, but this is not limited thereto. For example, the laser light source 11 may have a semiconductor laser that emits purple laser light. In this case, the wavelength conversion member 13a of the projection unit 13 may include blue phosphor particles, yellow phosphor particles, green phosphor particles, and red phosphor particles.

[0088] In addition, in the lighting system 1 in the above embodiment, the optical fiber 12 is used, but this is not limited thereto. For example, a light guide member other than an optical fiber may be used. Alternatively, a light guide member such as an optical fiber may not be used. In other words, the laser light source 11 and the projection unit 13 may be directly connected. In this case, a light source unit 10 in which the laser light source 11 and the projection unit 13 are housed in a single housing may be used.

[0089] In addition, the present invention also includes forms obtained by applying various modifications to the above-mentioned embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions in the embodiments within the scope of the present invention. In addition, the present invention also includes any combination of two or more claims from among the multiple claims described in the claims at the time of filing of this application, within the scope of technical compatibility. For example, when a dependent claim described in the claims at the time of filing of this application is made into a multiple claim or multiple multiple claim so as to cite all of the higher claims within the scope of technical compatibility, the present invention also includes all combinations of claims included in the multiple claim or multiple multiple claim. [Explanation of symbols]

[0090] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H Lighting System 10 Light source unit 11 Laser light source 20, 20A, 20B, 20C, 20D, 20E, 20F, 20G Color temperature conversion unit 21, 21D Filter 22 Light distribution change section 23 Light reflection prevention part 24 Heat dissipation part TS target space L1 light source light L2, Lx illumination light

Claims

1. a light source unit including a laser light source; a color temperature conversion unit that is disposed separately from the light source unit and changes the color temperature of the light source light emitted from the light source unit and irradiates the light as illumination light to a target space; The color temperature conversion unit has a filter that attenuates light of some wavelengths of the light source light. Lighting system.

2. The color temperature conversion unit further includes a light distribution change unit that changes a light distribution of the illumination light and irradiates the illumination light to the target space.

10. The lighting system of claim 1.

3. The color temperature conversion unit has a light reflection prevention portion that reduces reflection of the light source light incident on the color temperature conversion unit.

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

4. The color temperature conversion unit has a heat dissipation part.

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

5. The color temperature conversion unit reduces the color temperature of the light source light.

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

6. The light source light emitted from the light source unit is white light.

6. A lighting system according to claim 5.

7. The light source light emitted from the light source unit is in the form of a beam.

7. A lighting system according to claim 6.

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