JP7515102B2 - Lighting System - Google Patents

Description

The present disclosure relates generally to lighting systems. The present disclosure relates specifically to lighting systems that illuminate the interior of tunnels.

Patent Document 1 discloses a lighting control system (lighting system) used to illuminate tunnel entrances on motorways. The lighting control system of Patent Document 1 includes multiple lighting fixtures with variable dimming levels, a control device that controls the dimming of the lighting fixtures, and a measuring device that measures the luminance around the tunnel entrance.

JP 2015-204150 A

In Patent Document 1, the lighting fixtures are placed on the ceiling or in the corners of the tunnel at a predetermined interval along the direction of vehicle travel. For this reason, it is preferable that the lighting fixtures are lightweight. In addition, since the lighting fixtures are placed on the ceiling or in the corners, maintenance (especially of the light source) is time-consuming.

The challenge is to provide a lighting system that reduces the weight of lighting fixtures and improves maintainability.

A lighting system according to an aspect of the present disclosure includes a plurality of lighting fixtures that are installed in a tunnel and illuminate the interior of the tunnel, and a control device that controls the plurality of lighting fixtures. At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber. The optical fiber has a wavelength conversion unit that includes a wavelength conversion element that is excited by excitation light to generate spontaneous emission light with a longer wavelength than the excitation light and is excitable by amplified spontaneous emission light. The light source unit includes a first light source that causes the excitation light to be incident on the optical fiber, and one or more second light sources that cause seed light to be incident on the optical fiber to generate stimulated emission light from the wavelength conversion element excited by the excitation light or the amplified spontaneous emission light. At least one of the plurality of lighting fixtures includes the light source unit, a plurality of the optical fibers, and a plurality of light irradiation units that illuminate the interior of the tunnel with light from the plurality of the optical fibers. A ratio of the amount of light received by the light irradiation unit to the total amount of light from the plurality of the optical fibers is set for each of the plurality of light irradiation units. The plurality of light irradiation units include two or more light irradiation units having different ratios.

A lighting system according to an aspect of the present disclosure includes a plurality of lighting fixtures that are installed in a tunnel and illuminate the interior of the tunnel, and a control device that controls the plurality of lighting fixtures. At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber. The optical fiber has a wavelength conversion unit that includes a wavelength conversion element that converts the wavelength of at least a portion of light incident on the optical fiber. The light source unit includes a first light source that causes a first light to be incident on the optical fiber, and one or more second light sources that cause a second light having a wavelength different from that of the first light to be incident on the optical fiber. At least one of the plurality of lighting fixtures includes the light source unit, a plurality of the optical fibers, and a plurality of light irradiation units that illuminate the interior of the tunnel with light from the plurality of the optical fibers. A ratio of the amount of light received by the light irradiation unit to the total amount of light from the plurality of the optical fibers is set for each of the plurality of light irradiation units. The plurality of light irradiation units include two or more light irradiation units having different ratios.
A lighting system according to an aspect of the present disclosure includes a plurality of lighting fixtures that are installed in a tunnel and illuminate the interior of the tunnel, and a control device that controls the plurality of lighting fixtures. At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber. The optical fiber has a wavelength conversion unit that includes a wavelength conversion element that is excited by excitation light to generate spontaneous emission light with a longer wavelength than the excitation light and is excitable by amplified spontaneous emission light. The light source unit includes a first light source that causes the excitation light to enter the optical fiber, and one or more second light sources that cause seed light to enter the optical fiber to generate stimulated emission light from the wavelength conversion element excited by the excitation light or the amplified spontaneous emission light. The control device controls the plurality of lighting fixtures based on environmental information related to the environment around the tunnel. The environmental information includes brightness information related to the brightness around the tunnel, chromaticity information related to the chromaticity around the tunnel, and meteorological information related to the weather around the tunnel.
A lighting system according to an aspect of the present disclosure includes a plurality of lighting fixtures that are installed in a tunnel and illuminate the interior of the tunnel, and a control device that controls the plurality of lighting fixtures. At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber. The optical fiber has a wavelength conversion unit that includes a wavelength conversion element that converts the wavelength of at least a portion of light incident on the optical fiber. The light source unit includes a first light source that causes a first light to enter the optical fiber, and one or more second light sources that cause a second light having a wavelength different from that of the first light to enter the optical fiber. The control device controls the plurality of lighting fixtures based on environmental information related to the environment around the tunnel. The environmental information includes brightness information related to the brightness around the tunnel, chromaticity information related to the chromaticity around the tunnel, and meteorological information related to the weather around the tunnel.

The present disclosure has the advantage of making the lighting fixture lighter and easier to maintain.

FIG. 1 is an explanatory diagram of a lighting system according to an embodiment. FIG. 2 is a block diagram of the lighting system. FIG. 3 is a cross-sectional view of an optical fiber in the illumination system. FIG. 4 is an explanatory diagram of the operating principle of the above lighting system. FIG. 5 is an explanatory diagram of the operating principle of the above lighting system. FIG. 6 is a diagram illustrating the operating principle of the above lighting system. FIG. 7 is an explanatory diagram of the operation of the above lighting system. FIG. 8 is a block diagram of a lighting fixture of a lighting system according to a modified example.

Below, embodiments of the present disclosure will be described, with reference to the drawings where appropriate. However, the following embodiments are merely examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content. Positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings, unless otherwise specified. Each figure described in the following embodiments is a schematic diagram, and the ratios of size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

1 shows a tunnel 100 to which a lighting system 10 is applied. The lighting system 10 is used to illuminate an interior 110 of the tunnel 100.

In this embodiment, the tunnel 100 is a road tunnel. The tunnel 100 has an entrance (pile entrance) that leads to the interior 110. In this embodiment, the automobile 300 is used as a reference, and the pile entrance through which the automobile 300 enters the interior 110 of the tunnel 100 is defined as the entrance 120, and the pile entrance through which the automobile 300 exits the interior 110 of the tunnel 100 is defined as the exit 130 (see FIG. 7).

As shown in FIG. 2, the lighting system 10 is installed in the tunnel 100 and includes a plurality of lighting fixtures 20 that illuminate the interior 110 of the tunnel 100, and a control device 30 that controls the plurality of lighting fixtures 20. At least one of the plurality of lighting fixtures 20 includes a light source unit 23 and an optical fiber 24. The optical fiber 24 has a wavelength conversion unit 24c that is excited by the excitation light P1 (see FIG. 3) and can generate spontaneous emission light with a longer wavelength than the excitation light P1, and includes a wavelength conversion element that can be excited by the amplified spontaneous emission light. The light source unit 23 has a first light source 231 and one or more second light sources 232. The first light source 231 inputs the excitation light P1 into the optical fiber 24. The one or more second light sources 232 input seed light P2 (see FIG. 3) for generating stimulated emission light from the wavelength conversion element excited by the excitation light P1 or the amplified spontaneous emission light into the optical fiber 24.

In the lighting system 10, the optical fiber 24 converts the wavelength of light. In the lighting system 10, the wavelength conversion element that is the heat source is distributed in the optical fiber 24, so that the temperature rise during use can be suppressed. Therefore, heat dissipation members and the like can be omitted or reduced in weight, and the lighting fixture 20 can be made lighter. In the lighting system 10, the optical fiber 24 can guide light from the light source unit 23. Therefore, the light source unit 23 can be installed in a place that is easier to maintain than the ceiling of the tunnel 100. Furthermore, the light source unit 23 itself does not need to be installed on the ceiling of the tunnel 100, and the part of the lighting fixture 20 that is installed on the ceiling of the tunnel 100 can be made lighter. Therefore, the lighting system 10 can reduce the weight of the lighting fixture 20 and improve maintainability.

(1-2) Details The lighting system 10 of this embodiment will be described in more detail below with reference to the drawings. The lighting system 10 is used to illuminate the interior 110 of a tunnel 100, as shown in FIG.

As shown in Fig. 2, the lighting system 10 includes a plurality of lighting fixtures 20, a control device 30, and an environment detection unit 40. In this embodiment, the plurality of lighting fixtures 20 all have the same structure. In the following description, for the sake of simplicity, it is assumed that the lighting system 10 includes six lighting fixtures 20 (20a to 20f) as shown in Fig. 7. The lighting fixtures 20a to 20f are lined up in this order from the entrance 120 to the exit 130 inside 110 of the tunnel 100. However, in many cases, the lighting fixtures 20 are provided in two rows, one on the left and one on the right, inside 110 of the tunnel 100 (see Fig. 1).

(1-2-1) Lighting Fixture The lighting fixture 20 includes a light source unit 21 and a light emitting section 22.

As shown in FIG. 3, the light source unit 21 inputs the excitation light P1 and the seed light P2. The excitation light P1 is light for exciting the wavelength conversion element (element) added to the optical fiber 24. The seed light P2 is light for generating the stimulated emission light P3 (see FIG. 6) from the wavelength conversion element excited by the excitation light P1. The optical fiber 24 outputs the light L1 including the excitation light P1 and the stimulated emission light P3. FIGS. 4 to 6 are explanatory diagrams of the operation principle of the light-emitting system 1. The vertical axis of FIGS. 4, 5, and 6 is the electron energy. The upward arrow in FIG. 4 indicates the absorption of the excitation light P1. The downward arrow in FIG. 6 indicates the transition related to the spontaneous emission light or the stimulated emission light P3. In the light source unit 21, the excitation light P1 input to the optical fiber 24 excites the electron e ⁻ that was in the ground level E0 (including a plurality of energy levels) of the wavelength conversion element to the excitation level E2. Then, the electron e ⁻ of the excited level E2 transitions to a metastable level E1 having lower energy than the excited level E2. The seed light P2 (P22) has a wavelength corresponding to the energy difference between the metastable level E1 and a higher energy level among a plurality of energy levels of the ground level E0, for example. When the electron e ⁻ of the metastable level E1 transitions to a higher energy level among a plurality of energy levels of the ground level E0 by the seed light P2 (P22), stimulated emission light P3 (P32) is generated. The seed light P2 (P21) has a wavelength corresponding to the energy difference between the metastable level E1 and another energy level lower than the metastable level E1. When the electron e ⁻ of the metastable level E1 transitions to the other energy level by the seed light P2 (P21), stimulated emission light P3 (P31) is also generated.

The light source unit 21 includes a light source section 23 and an optical fiber 24. The light source section 23 includes a first light source 231 and a second light source 232. The first light source 231 causes a first light (excitation light) P1 to enter the optical fiber 24. The second light source 232 causes a second light (seed light) P2 having a wavelength different from that of the first light P1 to enter the optical fiber 24. In detail, the second light source 232 causes a seed light P2 (hereinafter also referred to as external seed light P2) for generating stimulated emission light P3 from the wavelength conversion element excited by the excitation light P1 to enter the optical fiber 24.

As shown in FIG. 3, the optical fiber 2 has a core 241, a clad 242, and a coating portion 243. The clad 242 covers the outer peripheral surface of the core 241. The coating portion 243 covers the outer peripheral surface of the clad 242. The cross-sectional shape of the core 241 perpendicular to the optical axis direction is circular. The clad 242 is arranged coaxially with the core 241.

The core 241 has a first end face and a second end face opposite the first end face in the longitudinal direction of the core 241. The core 241 includes a light-transmitting material and a wavelength conversion element (element). The concentration of the wavelength conversion element in the core 241 may or may not be substantially uniform over the entire length of the core 241. The refractive index of the core 241 is substantially the same as the refractive index of the above-mentioned light-transmitting material that is the main component of the core 241.

The light-transmitting material is, for example, a fluoride, an oxide, or a nitride. The fluoride is, for example, a fluoride glass. The oxide is, for example, silicon oxide, quartz, etc.

The wavelength conversion element is a rare earth element. Here, the wavelength conversion element includes, for example, an element selected from the group of Pr, Tb, Ho, Dy, Er, Eu, Nd, and Mn. The wavelength conversion element is contained in the core 241 as an ion of a rare earth element, for example, as an ion of Pr (Pr ³⁺ ) or an ion of Tb (Tb ³⁺ ). Here, the wavelength conversion element may be excited by the pumping light P1, or may be excited by amplified spontaneous emission (ASE), which is light amplified using spontaneous emission light emitted from a wavelength conversion element other than itself as internal seed light. Through such excitation, the wavelength conversion element emits ASE specific to the element of the wavelength conversion element, and also generates stimulated emission light having the same wavelength as the wavelength of the external seed light P2, and these are combined and emitted as stimulated emission light P3. The wavelengths of the ASE and the external seed light P2 are longer than the wavelength of the pumping light P1 (for example, 440 to 450 nm). The wavelength of the seed light P2 will be described later.

Pr ³⁺ is a wavelength conversion element that can emit ASE or amplified light of the seed light in the cyan to red range. The intensity of the stimulated emission light depends on the intensities of the internal seed light (spontaneous emission light) and the external seed light. When the core 241 contains Pr ³⁺ and Tb ³⁺ , Tb ³⁺ can absorb the ASE from Pr ³⁺ and be excited to generate ASE with a wavelength specific to Tb ³⁺ .

The refractive index of the cladding 242 is smaller than the refractive index of the core 241. The cladding 242 does not contain the wavelength conversion element contained in the core 241.

The covering portion 243 covers the outer peripheral surface of the clad 242. The material of the covering portion 243 is, for example, resin.

The optical fiber 24 has an input section 24a, an output section 24b, and a wavelength conversion section 24c.

The incident portion 24a is a portion where the excitation light P1 is incident, and includes, for example, a first end face of the core 241. The exit portion 24b includes a second end face of the core 241 from which light L1 including the excitation light P1 and stimulated emission light P3 including ASE is emitted.

The incident portion 24a may include a reflection reduction portion that reduces the reflection of the excitation light P1 incident on the incident portion 24a from outside the optical fiber 24. The reflection reduction portion may be, for example, an anti-reflection coating that covers the first end face of the core 241. It is desirable to have an anti-reflection coating for light in the deep infrared region with a wavelength of 700 nm or more.

The wavelength conversion unit 24c is provided between the input unit 24a and the output unit 24b. The wavelength conversion unit 24c includes a wavelength conversion element that is excited by the excitation light P1 and emits light with a longer wavelength than the excitation light P1. The wavelength conversion element is an element that can absorb the excitation light P1 and amplify spontaneous emission light or seed light with a longer wavelength than the excitation light P1 by stimulated emission. In other words, the wavelength conversion unit 24c includes a wavelength conversion element that converts the wavelength of at least a portion of the light incident on the optical fiber 24.

The diameter of the core 241 is, for example, 25 μm to 500 μm. The length of the optical fiber 24 is, for example, 3 m to 10 m. The lower the concentration of the wavelength conversion elements in the wavelength conversion section 24c, the longer the length of the wavelength conversion section 24c is. The numerical aperture of the optical fiber 24 is, for example, 0.22. The concentration of the wavelength conversion elements in the wavelength conversion section 24c is the concentration of the wavelength conversion elements in the core 241.

The first light source 231 emits excitation light P1 for exciting the wavelength conversion element included in the wavelength conversion section 24c of the optical fiber 24. The excitation light P1 emitted from the first light source 231 is incident on the incident section 24a of the optical fiber 24. From the viewpoint of more efficiently exciting the wavelength conversion element, it is preferable that the wavelength of the excitation light P1 is 350 nm or more and 500 nm or less.

The first light source 231 includes, for example, a laser light source. The laser light source emits laser light. The excitation light P1 emitted from the first light source 231 (laser light emitted from the laser light source) is incident on the incident portion 24a. The laser light source is, for example, a semiconductor laser that emits blue laser light. In this case, the excitation light P1 is, for example, 440 to 450 nm. The first light source 231 includes a drive circuit that drives the laser light source, and is capable of adjusting the intensity of the excitation light P1.

The second light source 232 emits seed light P2. The seed light P2 emitted from the second light source 232 is incident on the incident portion 24a of the optical fiber 2. The second light source 232 includes, for example, a laser light source. The laser light source emits laser light. The seed light P2 emitted from the second light source 232 (laser light emitted from the laser light source) is incident on the incident portion 24a. The second light source 232 includes a drive circuit that drives the laser light source, and is capable of adjusting the intensity of the seed light P2.

The light source unit 23 includes a plurality of (for example, two) second light sources 232. The two second light sources 232 emit, for example, a seed light P2 having a wavelength different from each other. Hereinafter, for convenience of explanation, one of the two second light sources 232 may be referred to as the second light source 232a, and the remaining one second light source 232 may be referred to as the second light source 232b. In the second light source 232a, the laser light source is, for example, a semiconductor laser that emits green light. In the second light source 232b, the laser light source is, for example, a semiconductor laser that emits red light. When the wavelength conversion element of the wavelength conversion unit 24c includes Pr ³⁺ , it is preferable that the wavelength of the green seed light P21 is, for example, about 520 nm, and the wavelength of the red seed light P22 is, for example, about 640 nm. Each second light source 232 is a light source that emits quasi-monochromatic light. Here, quasi-monochromatic light is light included in a narrow wavelength range (e.g., 10 nm). The number of second light sources 232 in the light-emitting system 1 is not limited to two, and may be three or more, or may be one. When the light-emitting system 1 includes three second light sources 232, the three second light sources 232 may include a semiconductor laser that emits green light, a semiconductor laser that emits red light, and a semiconductor laser that emits orange light. The wavelength of the orange seed light is preferably about 600 nm, for example.

The light emitted from the second light source 232a is incident on the entrance part 24a of the optical fiber 24 as the seed light P2 (P21). The light emitted from the second light source 232b is incident on the entrance part 24a of the optical fiber 24 as the seed light P2 (P22).

In the light source unit 21 described above, the first light source 231 emits the excitation light P1, and the second light source 232 emits the seed light P2. As a result, the excitation light P1 and the seed light P2 are incident on the incident portion 24a of the optical fiber 24. A part of the excitation light P1 incident on the incident portion 24a is emitted from the exit portion 24b. The light L1 emitted from the exit portion 24b of the optical fiber 24 is a mixed light of the excitation light P1, the ASE having a wavelength of about 480 nm generated from the wavelength conversion element, and the stimulated emission light P3 having the same wavelength as the wavelength of the seed light P2. The two types of stimulated emission light P3 having different wavelengths and corresponding one-to-one to the multiple seed lights P21 and P22 are, for example, green light and red light. In this case, the mixed light is, for example, white light. In FIG. 6, the stimulated emission light P31 on the lower side is green light, and the stimulated emission light P32 on the upper side is red light.

In the optical fiber 24, stimulated emission occurs due to the spontaneous emission light and the seed light P2, so the excitation light P1 incident on the input portion 24a and stimulated emission light P3 amplified by stimulated emission are output from the output portion 24b. The intensity of stimulated emission light P3 having the same wavelength as the seed light P21 among the light output from the output portion 24b of the optical fiber 24 is greater than the intensity of the seed light P21 input from the second light source 232a to the input portion 24a. Also, the intensity of stimulated emission light P3 having the same wavelength as the seed light P22 among the light output from the output portion 24b of the optical fiber 24 is greater than the intensity of the seed light P22 input from the second light source 232b to the input portion 24a. The mixed color light (light L1) output from the output portion 24b of the optical fiber 24 is incoherent light. In the light source unit 21, the stimulated emission light P3 increases or decreases as it approaches the exit part 24b from the entrance part 24a of the optical fiber 24. In the light source unit 21, the chromaticity, color temperature, color rendering, etc. of the light (illumination light) emitted from the lighting fixture 20 are determined according to the wavelength of the ASE and the wavelength of the seed light P2. Note that the operation of the light source unit 21 differs from the operation of a fiber laser that oscillates.

In the light source unit 21, the wavelength conversion element that is the heat source is distributed in the core 241 of the optical fiber 24, so that the temperature rise during use can be suppressed.

The light irradiation unit 22 is used to illuminate the interior 110 with light L1 from the optical fiber 24. The light irradiation unit 22 includes an optical system for supplying the light L1 from the optical fiber 24 to the interior 110 as irradiation light. The optical system includes one or more optical members. Examples of optical members include a reflector and a lens. The light irradiation unit 22 itself does not have a light source, and has the function of irradiating the light L1 from the light source unit 21 toward the interior 110. In this embodiment, the light irradiation unit 22 further includes a housing that houses the optical system and is installed on the ceiling of the interior 110. The housing may have a structure similar to that of a housing of a conventionally known tunnel lighting.

The lighting fixture 20 includes a light source unit 21 and a light irradiation unit 22, and the light source unit 21 includes a light source unit 23 and an optical fiber 24. Therefore, in the lighting fixture 20, the light source unit 23 and the light irradiation unit 22 can be arranged in different locations using the optical fiber 24. In this embodiment, as shown in FIG. 7, the light irradiation unit 22 is installed so as to be exposed to the interior 110 of the tunnel 100. In the example shown in FIG. 7, the light irradiation unit 22 is installed on the ceiling of the interior 110 of the tunnel 100. The light source unit 23 is installed so as not to be exposed to the interior 110 of the tunnel 100. In the example shown in FIG. 7, the light source unit 23 is installed below the light irradiation unit 22. In particular, the light source unit 23 is located near the ground (road surface) in the interior 110 of the tunnel 100. The light source unit 23 is located in a position where a person can install it without using equipment such as a ladder. This improves the maintainability of the light source unit 23. The optical fiber 24 is installed in the tunnel 100 so as to connect the light source unit 23 and the light irradiation unit 22.

(1-2-2) Environmental Detection Unit The environmental detection unit 40 provides environmental information to the control device 30. The environmental information is information related to the environment around the tunnel 100. In this embodiment, the surroundings of the tunnel 100 are assumed to be an area that affects the visibility of the interior 110 of the tunnel 100. The environment is assumed to be a situation that affects visibility. Examples of situations that affect visibility include brightness, chromaticity, and weather. In this embodiment, the environmental information includes brightness information related to the brightness around the tunnel 100, chromaticity information related to the chromaticity around the tunnel 100, and meteorological information related to the weather around the tunnel 100.

The environment detection unit 40 includes a plurality of environment sensors (first environment sensor 41 and second environment sensor 42) that detect the environment around the tunnel 100. The first environment sensor 41 is installed outside the tunnel 100 and detects the environment around the entrance 120 of the tunnel 100 (see FIG. 7). That is, the first environment sensor 41 acquires environment information about the entrance 120 of the tunnel 100 (hereinafter referred to as first environment information as necessary). The second environment sensor 42 is installed outside the tunnel 100 and detects the environment around the exit 130 of the tunnel 100 (see FIG. 7). That is, the second environment sensor 42 acquires environment information about the exit 130 of the tunnel 100 (hereinafter referred to as second environment information as necessary). Each of the first environment sensor 41 and the second environment sensor 42 includes an illuminance meter, a colorimeter (such as a spectrophotometer), and a visibility meter. The illuminance meter detects illuminance as an index of the brightness around the tunnel 100. The brightness information is obtained by the illuminance meter. The colorimeter detects the color (chromaticity) of the surroundings of the tunnel 100. The colorimeter provides chromaticity information. The visibility meter detects visibility as an index of the weather around the tunnel 100. Visibility is a measure of the turbidity of the atmosphere, and is generally the horizontal distance that can be seen. Examples of visibility meters include a transmittance meter that converts transmittance into visibility, and a scattering type visibility meter that converts the state of scattered light into visibility. The occurrence of snow, fog, and smoke around the tunnel 100 contribute to a decrease in visibility. Therefore, visibility is an index related to weather. Therefore, weather information is obtained from the visibility meter. Therefore, both the environmental information from the first environmental sensor 41 and the environmental information from the second environmental sensor 42 include brightness information, chromaticity information, and weather information.

In this embodiment, the lighting fixtures 20a to 20c are associated with the first environmental sensor 41, and the lighting fixtures 20d to 20f are associated with the second environmental sensor 42. The lighting fixtures 20a to 20c are the lighting fixtures 20 on the entrance 120 side of the tunnel 100, and the lighting fixtures 20d to 20f are the lighting fixtures 20 on the exit 130 side of the tunnel 100. In other words, the multiple lighting fixtures 20 include one or more (in this embodiment, multiple) first lighting fixtures 20a to 20c associated with the first environmental sensor 41. The multiple lighting fixtures 20 include one or more (in this embodiment, multiple) second lighting fixtures 20d to 20f that are different from the one or more first lighting fixtures 20a to 20c associated with the second environmental sensor 42.

(1-2-3) Control Device The control device 30 controls the lighting devices 20. In particular, the control device 30 controls the lighting devices 20 based on environmental information related to the environment around the tunnel 100. The control device 30 acquires the environmental information from the environmental detection unit 40. In this embodiment, the control device 30 acquires first environmental information and second environmental information from the environmental detection unit 40.

The control device 30 can be realized by a computer system. The computer system includes, for example, one or more input/output interfaces, one or more memories, and one or more processors (microprocessors). In other words, the one or more processors execute one or more programs (applications) stored in one or more memories to function as the control device 30. Here, the programs are pre-recorded in the memory of the control device 30, but they may also be provided via a telecommunications line such as the Internet, or recorded on a non-transitory recording medium such as a memory card. The input/output interface is an interface for inputting information to the control device 30 and outputting information from the control device 30, and includes a communication interface and a human interface.

The control device 30 includes a dimming unit 31 and a color adjustment unit 32. In FIG. 2, the dimming unit 31 and the color adjustment unit 32 do not represent physical components, but rather represent functions realized by the control device 30.

The dimming unit 31 controls the intensity of light output from the multiple lighting devices 20. In particular, the dimming unit 31 controls the multiple lighting devices 20 based on environmental information (first environmental information and second environmental information). The dimming unit 31 controls each of the multiple lighting devices 20 by adjusting the output of at least one of the first light source 231 and one or more second light sources 232 (in this embodiment, two second light sources 232a and 232b) of the light source unit 23 based on the environmental information. As described above, in the light source unit 21 of the lighting device 20, the intensity of the illumination light can be adjusted by adjusting the intensity of at least one of the seed light P2, P21, and P22 and the excitation light P1. Therefore, the dimming unit 31 adjusts the intensity of the illumination light by adjusting the intensity of at least one of the seed light P2, P21, and P22 and the excitation light P1. Specifically, the dimming unit 31 provides a control signal to the drive circuits (first and second drive circuits) of the first light source 231 and the second light source 232 of the light source unit 23 via the input/output interface to adjust the output of the laser light sources of the first light source 231 and the second light source 232.

The dimming unit 31 controls the first lighting fixtures 20a to 20c based on the environmental information (first environmental information) from the first environmental sensor 41, and controls the second lighting fixtures 20d to 20f based on the environmental information (second environmental information) from the second environmental sensor 42.

Based on the environmental information, the dimming unit 31 controls the multiple lighting devices 20 so that the brightness of the interior 110 of the tunnel 100 changes from the tunnel mouth toward the center. In particular, the dimming unit 31 controls the multiple lighting devices 20 so that visibility at the tunnel mouth of the tunnel 100 is improved. In this embodiment, the dimming unit 31 controls the intensity of light output from the multiple lighting devices 20 so that the brightness of the interior 110 of the tunnel 100 changes from the tunnel mouth toward the center, based on the brightness information included in the environmental information.

Based on the brightness information included in the first environmental information, the dimming unit 31 controls the intensity (brightness) of the light output from the lighting devices 20a to 20c so that the brightness of the inside 110 of the tunnel 100 changes from the entrance 120 of the tunnel 100 toward the center. Based on the brightness of the entrance 120 of the tunnel 100, the dimming unit 31 determines whether there is a sudden change in brightness between the inside 110 of the tunnel 100 and the outside at the entrance 120 of the tunnel 100. If the brightness of the entrance 120 of the tunnel 100 is less than a first threshold, the dimming unit 31 determines that there is no sudden change in brightness between the inside 110 of the tunnel 100 and the outside at the entrance 120 of the tunnel 100. In this case, the dimming unit 31 adjusts the intensity of the light output from the lighting devices 20a to 20c to a first reference value. For example, the first threshold value is a value that can distinguish between the brightness near the entrance 120 of the tunnel 100 during the day and the brightness near the entrance 120 of the tunnel 100 at night. The first reference value corresponds to the brightness necessary for the driver of the automobile 300 traveling in the tunnel 100 to visually recognize an obstacle ahead from a safe distance. If the brightness of the entrance 120 of the tunnel 100 is equal to or greater than the first threshold value, the light control unit 31 determines that there is a sudden change in brightness between the inside 110 of the tunnel 100 and the outside at the entrance 120 of the tunnel 100. In this case, the light control unit 31 controls the intensity of the light output from the lighting devices 20a to 20c so that the brightness of the inside 110 of the tunnel 100 changes from the post mouth (entrance 120) of the tunnel 100 toward the center. More specifically, the light control unit 31 adjusts the intensity of the light output from the lighting devices 20a to 20c so that the inside 110 of the tunnel 100 becomes brighter from the center of the tunnel 100 toward the entrance 120. Specifically, the light control unit 31 sets the intensity of the light output from the lighting device 20a to a first value greater than the first reference value. This is to mitigate the sudden change in luminance that occurs when the driver approaches the tunnel 100 at the entrance 120 of the tunnel 100 and the delay in eye adaptation that occurs immediately after entering the tunnel. The light control unit 31 sets the intensity of the light output from the lighting device 20c to a first reference value. The light control unit 31 sets the intensity of the light output from the lighting device 20b to a second value between the first reference value and the first value. In other words, the light output from the lighting device 20b is set to an intensity between the light output from the lighting device 20a and the light output from the lighting device 20c. This is to mitigate the sudden change in the intensity of the light. In this way, the light control unit 31 controls the lighting devices 20a to 20c so that the brightness of the interior 110 of the tunnel 100 increases from the center of the tunnel 100 toward the entrance 120. This can reduce the effect of the black hole phenomenon. This reduces the decrease in visibility for people moving into the interior 110 of the tunnel 100.

Based on the brightness information included in the second environmental information, the dimming unit 31 controls the intensity (brightness) of the light output from the lighting devices 20d to 20f so that the brightness of the interior 110 of the tunnel 100 changes from the exit 130 of the tunnel 100 toward the center. Based on the brightness of the exit 130 of the tunnel 100, the dimming unit 31 determines whether there is a sudden change in brightness between the interior 110 and the outside of the tunnel 100 at the exit 130 of the tunnel 100. If the brightness of the exit 130 of the tunnel 100 is less than the second threshold, the dimming unit 31 determines that there is no sudden change in brightness between the interior 110 and the outside of the tunnel 100 at the exit 130 of the tunnel 100. In this case, the dimming unit 31 adjusts the intensity of the light output from the lighting devices 20d to 20f to the second reference value. For example, the second threshold value is a value that can distinguish between the brightness near the exit 130 of the tunnel 100 during the day and the brightness near the exit 130 of the tunnel 100 at night. The second reference value corresponds to the brightness necessary for a driver traveling through the tunnel 100 to see an obstacle ahead from a safe distance. The second reference value may be the same as the first reference value. If the brightness of the exit 130 of the tunnel 100 is equal to or greater than the second threshold value, the light control unit 31 determines that there is a sudden change in brightness between the inside 110 of the tunnel 100 and the outside at the exit 130 of the tunnel 100. In this case, the light control unit 31 controls the intensity of the light output from the lighting devices 20d to 20f so that the brightness of the inside 110 of the tunnel 100 changes from the post mouth (exit 130) of the tunnel 100 toward the center. More specifically, the light control unit 31 adjusts the intensity of the light output from the lighting devices 20d to 20f so that the inside 110 of the tunnel 100 becomes brighter from the center of the tunnel 100 toward the exit 130. Specifically, the light control unit 31 sets the intensity of the light output from the lighting device 20f to a third value greater than the second reference value. This is to improve the visibility of obstacles and preceding vehicles near the exit 130 of the tunnel 100 at the exit 130. The light control unit 31 sets the intensity of the light output from the lighting device 20d to a second reference value. The light control unit 31 sets the intensity of the light output from the lighting device 20e to a fourth value between the second reference value and the third value. In other words, the light output from the lighting device 20e is set to an intensity between the light output from the lighting device 20d and the light output from the lighting device 20f. This is to mitigate a sudden change in the light intensity. In this way, the light control unit 31 controls the lighting devices 20d to 20f so that the brightness of the interior 110 of the tunnel 100 increases from the center of the tunnel 100 toward the exit 130. This reduces the effect of the white hole phenomenon. Therefore, it is possible to reduce the decrease in visibility of people moving to the outside of the tunnel 100.

The color adjustment unit 32 controls the color (chromaticity) of the light output from the multiple lighting devices 20. In particular, the color adjustment unit 32 controls the multiple lighting devices 20 based on environmental information (first environmental information and second environmental information). The color adjustment unit 32 controls each of the multiple lighting devices 20 by adjusting the output of at least one of the first light source 231 and one or more second light sources 232 (in this embodiment, two second light sources 232a and 232b) of the light source unit 23 based on the environmental information. As described above, in the light source unit 21 of the lighting device 20, the color (chromaticity) of the illumination light can be adjusted by adjusting the intensity of at least one of the seed light P2, P21, and P22 and the excitation light P1. Therefore, the color adjustment unit 32 adjusts the color of the illumination light by adjusting the intensity of at least one of the seed light P2, P21, and P22 and the excitation light P1. Specifically, the color adjustment unit 32 provides a control signal to the drive circuits (first and second drive circuits) of the first light source 231 and the second light source 232 of the light source unit 23 via the input/output interface to adjust the output of the laser light sources of the first light source 231 and the second light source 232.

The color adjustment unit 32 controls the first lighting fixtures 20a to 20c based on the environmental information (first environmental information) from the first environmental sensor 41, and controls the second lighting fixtures 20d to 20f based on the environmental information (second environmental information) from the second environmental sensor 42.

The color adjustment unit 32 controls the multiple lighting fixtures 20 based on the environmental information so that the color (chromaticity) of the interior 110 of the tunnel 100 changes from the tunnel's 100 post opening toward the center. In particular, the color adjustment unit 32 controls the multiple lighting fixtures 20 so that visibility at the tunnel's 100 post opening is improved. In this embodiment, the color adjustment unit 32 controls the color of light output from the multiple lighting fixtures 20 based on the chromaticity information included in the environmental information so that the chromaticity of the interior 110 of the tunnel 100 changes from the tunnel's 100 post opening toward the center.

Based on the chromaticity information included in the first environmental information, the color adjustment unit 32 controls the color (chromaticity) of the light output from the lighting fixtures 20a to 20c so that the color (chromaticity) of the interior 110 of the tunnel 100 changes from the post mouth (entrance 120) of the tunnel 100 toward the center. More specifically, the color adjustment unit 32 adjusts the color of the light output from the multiple lighting fixtures 20 so that the difference between the chromaticity at the entrance 120 of the tunnel 100 and the chromaticity outside the tunnel 100 becomes small. Furthermore, the color adjustment unit 32 adjusts the color of the light output from the multiple lighting fixtures 20 so that the chromaticity of the interior 110 of the tunnel 100 becomes the standard chromaticity from the entrance 120 of the tunnel 100 toward the center of the tunnel 100. This reduces the sense of incongruity caused by the difference in chromaticity at the entrance 120 of the tunnel 100. For example, the standard chromaticity corresponds to white. Specifically, the color adjustment unit 32 adjusts the chromaticity of the light output from the lighting fixture 20a to the chromaticity at the entrance 120 of the tunnel 100 (e.g., orange). The color adjustment unit 32 adjusts the chromaticity of the light output from the lighting fixture 20c to a reference chromaticity (e.g., white). The color adjustment unit 32 sets the chromaticity of the light output from the lighting fixture 20b to a value between the chromaticity of the light output from the lighting fixture 20a and the light output from the lighting fixture 20c. This is to mitigate sudden changes in the color of the light.

Based on the chromaticity information included in the second environmental information, the color adjustment unit 32 controls the color (chromaticity) of the light output from the lighting fixtures 20d to 20f so that the color (chromaticity) of the interior 110 of the tunnel 100 changes from the post mouth (exit 130) of the tunnel 100 toward the center. More specifically, the color adjustment unit 32 adjusts the color of the light output from the multiple lighting fixtures 20 so that the difference between the chromaticity at the exit 130 of the tunnel 100 and the chromaticity outside the tunnel 100 becomes small. Furthermore, the color adjustment unit 32 adjusts the color of the light output from the multiple lighting fixtures 20 so that the chromaticity of the interior 110 of the tunnel 100 becomes the reference chromaticity from the exit 130 of the tunnel 100 toward the center of the tunnel 100. This reduces the sense of incongruity caused by the difference in chromaticity at the exit 130 of the tunnel 100. Specifically, the color adjustment unit 32 sets the chromaticity of the light output from the lighting fixture 20f to the chromaticity at the exit 130 of the tunnel 100 (for example, orange). The color adjustment unit 32 sets the chromaticity of the light output from the lighting device 20d to a reference chromaticity (e.g., white). The color adjustment unit 32 sets the chromaticity of the light output from the lighting device 20e to a value between the chromaticity of the light output from the lighting device 20d and the light output from the lighting device 20f. This is to mitigate sudden changes in the color of the light.

Based on the weather information included in the first environmental information, the color adjustment unit 32 controls the color of the light output from the lighting devices 20a to 20c so that the chromaticity of the interior 110 of the tunnel 100 changes from the entrance 120 of the tunnel 100 toward the center. In this embodiment, the weather information is expressed as visibility. Based on the visibility at the entrance 120 of the tunnel 100, the color adjustment unit 32 determines whether the visibility is reduced due to snow, rain, fog, smoke, etc. around the entrance 120 of the tunnel 100. If the visibility at the entrance 120 of the tunnel 100 is equal to or greater than the third threshold, the color adjustment unit 32 determines that there is no influence of snow, rain, fog, smoke, etc. around the entrance 120 of the tunnel 100. In this case, the color adjustment unit 32 adjusts the color of the light output from the lighting devices 20a to 20c to the first color temperature. The first color temperature is light with a relatively high color temperature. The first color temperature is, for example, daylight white (for example, 5000K in color temperature). If the visibility at the entrance 120 of the tunnel 100 is less than the third threshold, the color adjustment unit 32 determines that there is an influence of snow, rain, fog, smoke, or the like around the entrance 120 of the tunnel 100. The color adjustment unit 32 adjusts the color (particularly the color temperature) of the light output from the lighting devices 20a to 20c so as to improve the visibility at the entrance 120 of the tunnel 100. Specifically, the color adjustment unit 32 sets the color of the light output from the lighting device 20a to a second color temperature lower than the first color temperature. The second color temperature is light with a relatively low color temperature. The second color temperature is, for example, orange-white (for example, 2100K in color temperature). This is because light with a low color temperature can ensure visibility even under the influence of snow, rain, fog, smoke, or the like, better than light with a high color temperature. The color adjustment unit 32 sets the color of the light output from the lighting device 20c to the first color temperature. This is because the center of the tunnel 100 is less susceptible to snow, rain, fog, smoke, etc., unlike the entrance 120, and light with a high color temperature can ensure better visibility than light with a low color temperature. The color adjustment unit 32 sets the color of the light output from the lighting device 20b to a third color temperature. The third color temperature is a color between the first color temperature and the second color temperature. The third color temperature is, for example, warm white (for example, a color temperature of 3500K). In other words, the light output from the lighting device 20b is set to a color temperature between the light output from the lighting device 20a and the light output from the lighting device 20c. This is to mitigate a sudden change in color temperature. In this way, the color adjustment unit 32 controls the lighting devices 20a to 20c so that the color temperature of the interior 110 of the tunnel 100 increases from the entrance 120 to the center of the tunnel 100. This reduces the decrease in visibility of people moving to the interior 110 of the tunnel 100.

Based on the weather information included in the second environmental information, the color adjustment unit 32 controls the color of the light output from the lighting devices 20d to 20f so that the chromaticity of the interior 110 of the tunnel 100 changes from the exit 130 of the tunnel 100 toward the center. Based on the visibility at the exit 130 of the tunnel 100, the color adjustment unit 32 determines whether the visibility is reduced due to snow, rain, fog, smoke, etc. around the exit 130 of the tunnel 100. If the visibility at the exit 130 of the tunnel 100 is equal to or greater than the fourth threshold, the color adjustment unit 32 determines that there is no influence of snow, rain, fog, smoke, etc. around the exit 130 of the tunnel 100. In this case, the color adjustment unit 32 adjusts the color of the light output from the lighting devices 20d to 20f to the first color temperature. If the visibility at the exit 130 of the tunnel 100 is less than the fourth threshold, the color adjustment unit 32 determines that there is an influence of snow, rain, fog, smoke, etc. around the exit 130 of the tunnel 100. The color adjustment unit 32 adjusts the color of the light output from the lighting device 20f to a second color temperature so as to improve visibility at the exit 130 of the tunnel 100. The color adjustment unit 32 sets the color of the light output from the lighting device 20d to a first color temperature. The color adjustment unit 32 sets the color of the light output from the lighting device 20e to a third color temperature. In this way, the color adjustment unit 32 controls the lighting devices 20d to 20f so that the color temperature of the interior 110 of the tunnel 100 increases from the exit 130 of the tunnel 100 toward the center. This reduces the decrease in visibility of people moving to the outside of the tunnel 100.

As described above, the control device 30 controls the multiple lighting devices 20 based on the environmental information so that at least one of the brightness and chromaticity of the interior 110 of the tunnel 100 changes from the outside to the center of the tunnel 100. In particular, the control device 30 controls the multiple lighting devices 20 so as to improve visibility at the entrance of the tunnel 100.

(1-3) Summary As described above, the lighting system 10 includes a plurality of lighting fixtures 20 that are installed in the tunnel 100 and illuminate the interior 110 of the tunnel 100, and a control device 30 that controls the plurality of lighting fixtures 20. At least one of the plurality of lighting fixtures 20 includes a light source unit 23 and an optical fiber 24. The optical fiber 24 includes a wavelength conversion unit 24c that is excited by the excitation light P1 to generate spontaneous emission light having a longer wavelength than the excitation light P1 and includes a wavelength conversion element that can be excited by the amplified spontaneous emission light. The light source unit 23 includes a first light source 231 and one or more second light sources 232 (232a, 232b). The first light source 231 inputs the excitation light P1 into the optical fiber 24. One or more second light sources 232 (232a, 232b) emit seed light P2 (P21, P22) for generating stimulated emission light from a wavelength conversion element excited by the excitation light P1 or the amplified spontaneous emission light, into the optical fiber 24. According to this lighting system 10, the weight of the lighting fixture 20 can be reduced and the maintainability can be improved.

From another perspective, the lighting system 10 has the following configuration. That is, the lighting system 10 includes a plurality of lighting fixtures 20 that are installed in the tunnel 100 and illuminate the interior 110 of the tunnel 100, and a control device 30 that controls the plurality of lighting fixtures 20. At least one of the plurality of lighting fixtures 20 includes a light source unit 23 and an optical fiber 24. The optical fiber 24 has a wavelength conversion unit 24c that includes a wavelength conversion element that converts the wavelength of at least a portion of the light incident on the optical fiber 24. The light source unit 23 includes a first light source 231 that causes the first light P1 to enter the optical fiber 24, and one or more second light sources 232 (232a, 232b) that cause the second light P2 (P21, P22) that has a different wavelength from the first light P1 to enter the optical fiber 24. According to this lighting system 10, the weight of the lighting fixture 20 can be reduced and the maintainability can be improved.

(2) Modifications The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design and the like as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combination.

Figure 8 shows a lighting fixture 20A of a modified lighting system. The lighting fixture 20A includes a light source unit 21A and multiple light irradiation units 22 (four light irradiation units 22a to 22d in Figure 8). The light source unit 21A includes a light source unit 23 and multiple optical fibers 24 (six optical fibers 24A to 24F in Figure 8). The multiple light irradiation units 22 illuminate the interior 110 of the tunnel 100 with light from the multiple optical fibers 24.

In the lighting fixture 20A, light from the light source unit 23 enters the input portion 24a of each of the six optical fibers 24A to 24F. Light from the output portion 24b of the optical fiber 24A enters the light irradiation portion 22a. Light from the output portion 24b of the optical fiber 24B enters the light irradiation portion 22b. Light from the output portion 24b of the optical fiber 24C enters the light irradiation portion 22b. Light from the output portion 24b of the optical fiber 24D enters the light irradiation portion 22c. Light from the output portion 24b of the optical fiber 24E enters the light irradiation portion 22d. Light from the output portion 24b of the optical fiber 24F enters the light irradiation portion 22d. In other words, the light irradiation portions 22a and 22c each receive light from one optical fiber 24, and the light irradiation portions 22b and 22d each receive light from two optical fibers 24. All six optical fibers 24A to 24F have the same structure. Therefore, the amount of light incident on light irradiation units 22b and 22d is twice the amount of light incident on light irradiation units 22a and 22c.

In this way, in the lighting device 20A, the ratio of the amount of light that the light irradiation unit 22 receives to the total amount of light from the multiple optical fibers 24 (24A-24F) is set for each of the multiple light irradiation units 22 (22a-22d). The ratio is determined by the ratio of the number of multiple optical fibers 24. The ratio of the light irradiation units 22a and 22c is 1/6, and the ratio of the light irradiation units 22b and 22d is 1/3. In this way, the multiple light irradiation units 22a-22d include two light irradiation units 22a (22c) and 22b (22d) with different ratios. In this lighting device 20A, it is easy to set the brightness of the light irradiation unit 22. In particular, since the ratio can be easily set by the number of optical fibers 24, it becomes even easier to set the brightness of the light irradiation unit 22.

The ratio of the multiple light irradiation units 22 is not limited to the above numerical values and may be set appropriately. The multiple light irradiation units 22 may include three or more light irradiation units 22 with different ratios. The multiple light irradiation units 22 may include two or more light irradiation units 22 with the same ratio. The ratio may be determined by the ratio of the numbers of the multiple optical fibers 24 as well as the cross-sectional area of the optical fibers 24.

In one variation, not all of the multiple lighting fixtures 20 of the lighting system 10 need to include an optical fiber 24. At least one of the multiple lighting fixtures 20 may include an optical fiber 24. That is, the multiple lighting fixtures 20 may include one or more lighting fixtures that do not include an optical fiber 24. The lighting system 10 may include one or more lighting fixtures 20 and one or more lighting fixtures 20A.

In the lighting system 10, the number of lighting fixtures 20 and the number of control devices 30 are not particularly limited. Furthermore, the lighting fixtures 20 and the control devices 30 do not need to be in a many-to-one correspondence, and multiple lighting fixtures 20 may be controlled by multiple control devices 30.

In one modified example, the lighting device 20 may further include a light guide that guides the light L1 from the optical fiber 24 to the light irradiation section 22. This makes it easier to arrange the light source unit 21 at a position away from the light irradiation section 22. The lighting device 20 may further include an optical coupling section for inputting the excitation light P1 and the seed light P2 to the input section 24a of the optical fiber 24. The optical coupling section may be, but is not limited to, a grating. The grating is a transmissive diffraction grating. The material of the grating may be, for example, quartz, but is not limited to this. In the lighting device 20, the optical fiber 24 does not necessarily need to include the wavelength conversion section 24c, and the optical fiber 24 does not necessarily need to be included.

In one modified example, the control device 30 does not necessarily have to include both the dimming unit 31 and the color adjustment unit 32. The control device 30 may have at least one of the dimming unit 31 and the color adjustment unit 32. In the above embodiment, the control device 30 (dimming unit 31 and color adjustment unit 32) adjusts the intensity of the excitation light P1 and the intensity of each of the multiple seed light beams P2. In one modified example, the control device 30 (dimming unit 31 and color adjustment unit 32) may adjust the intensity and color of the illumination light by adjusting the intensity of at least one of the excitation light P1 and the seed light P2. The adjustment of the intensity of the light from the first light source 231 or the second light source 232 may be performed by controlling the first light source 231 or the second light source 232 itself, or may be performed by using a liquid crystal filter, a micromirror array, or the like arranged between the light source unit 23 and the optical fiber 24.

In one variant, the environment detection unit 40 may include one or more environment sensors that detect the environment around the tunnel 100. In other words, it is not essential to include both the first environment sensor 41 and the second environment sensor 42. The environment detection unit 40 may obtain environment information from an external device. The external device may include a car near the tunnel 100 or an information terminal (such as a mobile terminal).

In one modified example, the environmental information may include at least one of brightness information, chromaticity information, and weather information. The environmental information is not limited to brightness information, chromaticity information, and weather information. The environmental information may include traffic information related to traffic around the tunnel 100, time information related to the time around the tunnel 100, temperature information related to the temperature around the tunnel 100, and crime prevention information related to crime prevention around the tunnel 100. The traffic information may include information on traffic volume, occurrence of congestion/stagnation, road regulations, and traffic accidents. As an example, if the traffic volume is low, the light intensity of the lighting device 20 may be reduced. The time information assumes the time in the time zone to which the tunnel 100 belongs. As an example, the light intensity or color of the lighting device 20 may be changed depending on the time. The temperature information assumes the temperature of the interior 110 of the tunnel 100 or the location where the tunnel 100 is located. As an example, the light intensity or color of the lighting device 20 may be changed depending on the temperature of the interior 110 of the tunnel 100. The crime prevention information may include a crime rate related to the location where the tunnel 100 is located. As an example, if the crime rate is high, the light intensity of the lighting fixture 20 may be increased, or the color of the light from the lighting fixture 20 may be changed to a color that is expected to have a calming effect, such as blue.

In one variant, when the environmental information includes multiple elements (such as brightness information, chromaticity information, and weather information), the multiple elements may have a priority order. For example, the control device 30 may give priority to control based on brightness information over control based on chromaticity information.

The lighting system 10 (particularly the control device 30) in the present disclosure includes, for example, a computer system. The computer system is mainly composed of a processor and a memory as hardware. The function of the lighting system 10 in the present disclosure is realized by the processor executing a program recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, may be provided through an electric communication line, or may be recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. The processor of the computer system is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The integrated circuits such as IC or LSI referred to here are called differently depending on the degree of integration, and include integrated circuits called system LSI, VLSI (Very Large Scale Integration), or ULSI (Ultra Large Scale Integration). Furthermore, a field-programmable gate array (FPGA) that is programmed after the manufacture of the LSI, or a logic device that can reconfigure the connection relationship inside the LSI or reconfigure the circuit partition inside the LSI, can also be adopted as a processor. The multiple electronic circuits may be integrated into one chip, or may be distributed across multiple chips. The multiple chips may be integrated into one device, or may be distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller is also composed of one or more electronic circuits including a semiconductor integrated circuit or a large-scale integrated circuit.

In addition, it is not essential for the lighting system 10 that multiple functions in the lighting system 10 (particularly the control device 30) are concentrated in one housing, and the components of the lighting system 10 may be distributed across multiple housings. Furthermore, at least some of the functions of the lighting system 10, for example, some of the functions of the control device 30, may be realized by the cloud (cloud computing) or the like.

In the above embodiment, the tunnel 100 is described as a road tunnel. However, the tunnel 100 is not limited to a road tunnel. The tunnel 100 may be a railway (railroad) tunnel or a waterway tunnel. The tunnel 100 may be an underground space constructed for the purpose of transportation between two points, transporting materials, or storing materials.

(3) Aspects As is apparent from the above embodiment and modified examples, the present disclosure includes the following aspects. In the following, reference symbols are given in parentheses only to clarify the correspondence with the embodiment.

The first aspect is a lighting system (10) that is installed in a tunnel (100) and includes a plurality of lighting fixtures (20; 20A) that illuminate the interior (110) of the tunnel (100), and a control device (30) that controls the plurality of lighting fixtures (20; 20A). At least one of the plurality of lighting fixtures (20; 20A) includes a light source unit (23) and an optical fiber (24; 24A to 24F). The optical fiber (24; 24A to 24F) has a wavelength conversion unit (24c) that is excited by excitation light (P1) to generate spontaneous emission light having a longer wavelength than the excitation light (P1) and includes a wavelength conversion element that can be excited by amplified spontaneous emission light. The light source unit (23) has a first light source (231) and one or more second light sources (232, 232a, 232b). The first light source (231) causes the excitation light (P1) to enter the optical fiber (24; 24A to 24F). The one or more second light sources (232, 232a, 232b) cause seed light (P2, P21, P22) to enter the optical fiber (24; 24A to 24F). The seed light (P2, P21, P22) is light for generating stimulated emission light from the wavelength conversion element excited by the excitation light (P1) or the amplified spontaneous emission light. According to this aspect, the lighting device (20; 20A) can be made lighter and easier to maintain.

The second aspect is a lighting system (10) based on the first aspect. In the second aspect, the control device (30) has at least one of a dimming unit (31) that controls the intensity of the light output from the plurality of lighting devices (20; 20A) and a color adjustment unit (32) that controls the color of the light output from the plurality of lighting devices (20; 20A). According to this aspect, it is possible to adjust the color and dimming of the lighting devices (20; 20A).

The third aspect is a lighting system (10) based on the first or second aspect. In the third aspect, the control device (30) controls the plurality of lighting devices (20; 20A) based on environmental information related to the environment around the tunnel (100). According to this aspect, it is possible to control the lighting devices (20; 20A) according to the environment around the tunnel (100).

The fourth aspect is a lighting system (10) based on the third aspect. In the fourth aspect, the environmental information is obtained from an environmental detection unit (40) including one or more environmental sensors (41, 42) that detect the environment around the tunnel (100). According to this aspect, it is possible to control the lighting devices (20; 20A) according to the environment around the tunnel (100).

The fifth aspect is a lighting system (10) based on the fourth aspect. In the fifth aspect, the environment detection unit (40) includes at least one of a first environment sensor (41) and a second environment sensor (42). The first environment sensor (41) is installed outside the tunnel (100) and detects the environment around the entrance (120) of the tunnel (100). The second environment sensor (42) is installed outside the tunnel (100) and detects the environment around the exit (130) of the tunnel (100). According to this aspect, it is possible to control the lighting device (20; 20A) according to the environment around the entrance (120) and the exit (130) of the tunnel (100).

A sixth aspect is a lighting system (10) based on the fifth aspect. In the sixth aspect, the environment detection unit (40) includes the first environment sensor (41) and the second environment sensor (42). The plurality of lighting devices (20; 20A) includes one or more first lighting devices (20a to 20c) and one or more second lighting devices (20d to 20f) other than the one or more first lighting devices (20a to 20c). The one or more first lighting devices (20a to 20c) are associated with the first environment sensor (41). The one or more second lighting devices (20d to 20f) are associated with the second environment sensor (42). The control device (30) controls the one or more first lighting fixtures (20a-20c) based on the environmental information from the first environmental sensor (41), and controls the one or more second lighting fixtures (20d-20f) based on the environmental information from the second environmental sensor (42). According to this aspect, the lighting fixtures (20; 20A) can be independently controlled according to the surrounding environment of the entrance (120) and the exit (130) of the tunnel (100).

The seventh aspect is a lighting system (10) based on any one of the third to sixth aspects. In the seventh aspect, the environmental information includes at least one of brightness information, chromaticity information, and weather information. The brightness information is information about the brightness around the tunnel (100). The chromaticity information is information about the chromaticity around the tunnel (100). The weather information is information about the weather around the tunnel (100). According to this aspect, it is possible to control the lighting fixtures (20; 20A) according to the environment around the tunnel (100).

The eighth aspect is a lighting system (10) based on the seventh aspect. In the eighth aspect, the control device (30) controls the plurality of lighting devices (20; 20A) by adjusting the output of at least one of the first light source (231) and the one or more second light sources (232, 232a, 232b) of the light source unit (23) based on the environmental information. According to this aspect, the lighting devices (20; 20A) can be easily controlled.

The ninth aspect is a lighting system (10) based on the seventh or eighth aspect. In the ninth aspect, the control device (30) controls the plurality of lighting devices (20; 20A) based on the environmental information so that at least one of the brightness and chromaticity of the interior (110) of the tunnel (100) changes from the post mouth (120, 130) of the tunnel (100) toward the center. According to this aspect, the interior (110) of the tunnel (100) can be made to be in a state that corresponds to the environment around the tunnel (100).

The tenth aspect is a lighting system (10) based on the ninth aspect. In the tenth aspect, the control device (30) controls the plurality of lighting devices (20; 20A) so as to improve visibility at the pile mouths (120, 130) of the tunnel (100). According to this aspect, it is possible to reduce the decrease in visibility of people moving inside and outside the tunnel (100).

The eleventh aspect is a lighting system (10) based on any one of the first to tenth aspects. In the eleventh aspect, the light source unit (23) is installed in the tunnel (100) so as not to be exposed to the interior (110) of the tunnel (100). According to this aspect, the maintainability of the light source unit (23) can be improved.

A twelfth aspect is a lighting system (10) based on any one of the first to eleventh aspects. In the twelfth aspect, at least one of the plurality of lighting devices (20; 20A) includes the light source unit (23), a plurality of the optical fibers (24; 24A to 24F), and a plurality of light irradiation units (22; 22a to 22d). The plurality of light irradiation units (22; 22a to 22d) illuminate the interior (110) of the tunnel (100) with light from the plurality of optical fibers (24; 24A to 24F). According to this aspect, a plurality of lights can be irradiated from one light source unit (23) to the interior (110) of the tunnel (100).

A thirteenth aspect is a lighting system (10) based on the twelfth aspect. In the thirteenth aspect, a ratio of the amount of light received by the light irradiation unit (22; 22a to 22d) to the total amount of light from the plurality of optical fibers (24; 24A to 24F) is set for each of the plurality of light irradiation units (22; 22a to 22d). The plurality of light irradiation units (22; 22a to 22d) includes two or more light irradiation units (22; 22a to 22d) having different ratios. According to this aspect, it is easy to set the brightness of the light irradiation units (22; 22a to 22d).

The fourteenth aspect is a lighting system (10) based on the thirteenth aspect. In the fourteenth aspect, the ratio is determined by the ratio of the numbers of the plurality of optical fibers (24; 24A to 24F). According to this aspect, it becomes easy to set the brightness of the light irradiation unit (22; 22a to 22d).

The fifteenth aspect is a lighting system (10) that is installed in a tunnel (100) and includes a plurality of lighting fixtures (20; 20A) that illuminate the interior (110) of the tunnel (100), and a control device (30) that controls the plurality of lighting fixtures (20; 20A). At least one of the plurality of lighting fixtures (20; 20A) includes a light source unit (23) and an optical fiber (24; 24A to 24F). The optical fiber (24; 24A to 24F) has a wavelength conversion unit (24c) that includes a wavelength conversion element that converts the wavelength of at least a portion of the light incident on the optical fiber (24; 24A to 24F). The light source unit (23) includes a first light source (231) and one or more second light sources (232, 232a, 232b). The first light source (231) causes a first light (P1) to enter the optical fiber (24). The one or more second light sources (232, 232a, 232b) emit second light (P2, P21, P22) having a wavelength different from that of the first light (P1) into the optical fiber (24; 24A to 24F). This aspect makes it possible to reduce the weight of the lighting device (20; 20A) and improve maintainability.

The sixteenth aspect is a lighting system (10) based on the fifteenth aspect. In the sixteenth aspect, the optical fiber (24; 24A to 24F) is configured such that the wavelength conversion element is excited by excitation light (P1) to generate spontaneous emission light having a longer wavelength than the excitation light (P1), and is also excited by amplified spontaneous emission light. The first light (P1) is the excitation light. The second light (P2, P21, P22) is a seed light for generating stimulated emission light from the wavelength conversion element excited by the excitation light (P1) or the amplified spontaneous emission light. According to this aspect, the weight of the lighting fixture (20; 20A) can be reduced and the maintainability can be improved.

Note that aspects 2 to 14 can also be modified and applied to aspect 15 as appropriate.

10 Lighting system 20, 20A Lighting fixture 22, 22a to 22d Light irradiation unit 23 Light source unit 231 First light source 232, 232a, 232b Second light source 24, 24A to 24F Optical fiber 24c Wavelength conversion unit 31 Light adjustment unit 32 Color adjustment unit 40 Environment detection unit 41 First environment sensor 42 Second environment sensor 100 Tunnel 110 Inside 120 Entrance 130 Exit P1 Excitation light (first light)
P2, P21, P22 Seed light (second light)

Claims (15)

A plurality of lighting fixtures installed in a tunnel to illuminate the interior of the tunnel;
A control device that controls the plurality of lighting devices;
Equipped with
At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber,
the optical fiber has a wavelength converting section including a wavelength converting element that is excited by pumping light to generate spontaneous emission light having a longer wavelength than the pumping light and that can be excited by amplified spontaneous emission light;
The light source unit includes:
A first light source that causes the excitation light to enter the optical fiber;
one or more second light sources that input seed light into the optical fiber to generate stimulated emission light from the wavelength conversion element excited by the excitation light or the amplified spontaneous emission light;
having
At least one of the plurality of lighting fixtures is
The light source unit,
A plurality of the optical fibers;
a plurality of light irradiation units that illuminate the inside of the tunnel with light from the plurality of optical fibers;
Including,
a ratio of an amount of light received by the light irradiation unit to a total amount of light from the optical fibers is set for each of the light irradiation units;
The plurality of light irradiation units include two or more light irradiation units having different ratios.
Lighting system. A plurality of lighting fixtures installed in a tunnel to illuminate the interior of the tunnel;
A control device that controls the plurality of lighting devices;
Equipped with
At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber,
The optical fiber has a wavelength converting portion including a wavelength converting element that converts the wavelength of at least a part of the light incident on the optical fiber,
The light source unit includes:
A first light source that causes a first light to enter the optical fiber;
one or more second light sources that emit second light having a wavelength different from that of the first light into the optical fiber;
having
At least one of the plurality of lighting fixtures is
The light source unit,
A plurality of the optical fibers;
a plurality of light irradiation units that illuminate the inside of the tunnel with light from the plurality of optical fibers;
Including,
a ratio of an amount of light received by the light irradiation unit to a total amount of light from the optical fibers is set for each of the light irradiation units;
The plurality of light irradiation units include two or more light irradiation units having different ratios.
Lighting system. A plurality of lighting fixtures installed in a tunnel to illuminate the interior of the tunnel;
A control device that controls the plurality of lighting devices;
Equipped with
At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber,
the optical fiber has a wavelength converting section including a wavelength converting element that is excited by pumping light to generate spontaneous emission light having a longer wavelength than the pumping light and that can be excited by amplified spontaneous emission light;
The light source unit includes:
A first light source that causes the excitation light to enter the optical fiber;
one or more second light sources that input seed light into the optical fiber to generate stimulated emission light from the wavelength conversion element excited by the excitation light or the amplified spontaneous emission light;
having
The control device controls the plurality of lighting devices based on environmental information regarding an environment around the tunnel;
The environmental information includes brightness information related to the brightness of the surroundings of the tunnel, chromaticity information related to the chromaticity of the surroundings of the tunnel, and meteorological information related to the weather around the tunnel.
Lighting system. The control device includes:
A light control unit that controls the intensity of light output from the plurality of lighting devices;
A color adjustment unit that controls the color of light output from the plurality of lighting devices;
At least one of
4. The lighting system of claim 3. The environmental information is obtained from an environmental detection unit including one or more environmental sensors that detect the environment around the tunnel.
5. The lighting system of claim 3 or 4. The environment detection unit is
A first environment sensor installed outside the tunnel to detect an environment around an entrance of the tunnel;
A second environmental sensor is installed outside the tunnel to detect the surrounding environment of the exit of the tunnel;
At least one of
6. The lighting system of claim 5. the environment detection unit includes the first environment sensor and the second environment sensor,
The plurality of lighting fixtures include:
one or more first lighting fixtures associated with the first environmental sensor;
one or more second lighting fixtures other than the one or more first lighting fixtures associated with the second environmental sensor;
Including,
The control device includes:
controlling the one or more first lighting fixtures based on the environmental information from the first environmental sensor;
controlling the one or more second lighting devices based on the environmental information from the second environmental sensor.
7. The lighting system of claim 6. The control device controls the plurality of lighting devices by adjusting an output of at least one of the first light source and the one or more second light sources of the light source unit based on the environmental information.
8. A lighting system according to claim 3. The control device controls the plurality of lighting devices based on the environmental information so that at least one of brightness and chromaticity inside the tunnel changes from the tunnel mouth toward the center.
9. A lighting system according to any one of claims 3 to 8. The control device controls the plurality of lighting devices so as to improve visibility at the tunnel post mouth.
10. The lighting system of claim 9. The light source unit is installed in the tunnel so as not to be exposed inside the tunnel.
11. A lighting system according to any one of claims 3 to 10. At least one of the plurality of lighting fixtures is
The light source unit,
A plurality of the optical fibers;
a plurality of light irradiation units that illuminate the inside of the tunnel with light from the plurality of optical fibers;
including,
12. A lighting system according to any one of claims 3 to 11. a ratio of an amount of light received by the light irradiation unit to a total amount of light from the optical fibers is set for each of the light irradiation units;
The plurality of light irradiation units include two or more light irradiation units having different ratios.
13. The lighting system of claim 12. The ratio is determined by a ratio of the numbers of the optical fibers of the plurality of optical fibers.
14. The lighting system of claim 1 or claim 13. A plurality of lighting fixtures installed in a tunnel to illuminate the interior of the tunnel;
A control device that controls the plurality of lighting devices;
Equipped with
At least one of the plurality of lighting fixtures includes a light source unit and an optical fiber,
The optical fiber has a wavelength converting portion including a wavelength converting element that converts the wavelength of at least a part of the light incident on the optical fiber,
The light source unit includes:
A first light source that causes a first light to enter the optical fiber;
one or more second light sources that emit second light having a wavelength different from that of the first light into the optical fiber;
having
The control device controls the plurality of lighting devices based on environmental information regarding an environment around the tunnel;
The environmental information includes brightness information related to the brightness of the surroundings of the tunnel, chromaticity information related to the chromaticity of the surroundings of the tunnel, and meteorological information related to the weather around the tunnel.
Lighting system.