Lighting device

Abstract

To provide a lighting device capable of more efficiently using light from a light source as illumination light and light for power generation by solar cells.SOLUTION: A lighting device 1 includes light sources 2, a straight-tube cover member 6 that has optical transparency and houses the light sources 2, a reflective member 4 that has optical reflectivity and is provided inside the cover member 6 so as to face an inner circumferential surface 6s of the cover member 6, solar cells 3 that are housed inside the cover member 6 and can generate electric power by irradiation light, and a storage battery 5 that is electrically connected to each of the light sources 2 and the solar cells 3, stores electric power from the solar cells 3, and supplies the stored electric power to the light sources 2. A diffusing surface 6t is provided on the inner circumferential surface 6s at least in a range irradiated with the direct light L1 emitted from the light source 2, for diffusing and reflecting the direct light L1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] There are known lighting devices that use power generated by solar cells. For example, the lighting device described in Patent Document 1 includes an illumination light source, a solar cell that generates power by receiving sunlight and light from the illumination light source, and a storage battery that stores the power generated by the solar cell and supplies it to the illumination light source.

[0003] In the lighting device described in Patent Document 1, the solar cell can generate electricity using light irradiated from the illumination light source even at night when there is no sunlight, etc. Therefore, power shortages are less likely to occur compared to lighting devices that use power generated only by sunlight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-229298 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned lighting device, the solar cell is installed outside the cover member that covers the LED lamp, which is the light source, so the distance from the light source to the solar cell is likely to be large. If this distance is large, the solar cell may not receive light efficiently, and sufficient power generation may not be achieved. On the other hand, if the solar cell is installed so that the distance from the light source to the light source is small, some of the light from the light source may be blocked by the solar cell, resulting in insufficient illumination light. Therefore, it is necessary to more efficiently use the light from the light source as illumination light and light for power generation by the solar cell.

[0006] An object of the present invention is to provide a lighting device that can more efficiently use light from a light source as illumination light and light for generating electricity using a solar cell. [Means for solving the problem]

[0007] The lighting device of the present invention comprises a light source, a straight-tube-type cover member that is optically transparent and houses the light source, a reflective member that is optically reflective and is provided inside the cover member so as to face the inner surface of the cover member, a solar cell that is housed inside the cover member and is capable of generating electricity from irradiated light, and a storage battery that is electrically connected to each of the light source and the solar cell, stores power from the solar cell, and supplies the stored power to the light source, and a diffusion surface that diffuses and reflects the direct light irradiated from the light source is provided on at least the area of ​​the inner surface that is irradiated with the direct light. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an illumination device that can more efficiently use light from a light source as illumination light and light for generating electricity using a solar cell. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an illumination device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing an illumination device according to a second embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same or corresponding elements will be designated by the same reference numerals, and duplicate descriptions will be omitted. For convenience of explanation, the terms "upper" and "lower" will be used to indicate the vertically upper and lower sides, respectively, based on the installation state of the lighting device.

[0011] [First embodiment] The configuration of the lighting device according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing a schematic view of the lighting device according to the first embodiment. In this embodiment, the lighting device 1 will be described by taking as an example a cold cathode fluorescent lamp installed on a mounting wall such as a ceiling. Note that the mounting wall and fixtures for installation are not shown in Fig. 1.

[0012] 1 illuminates from above an indoor space R that extends downward as an illumination target area. The illumination device 1 includes a light source 2, a solar cell 3, a reflecting member 4, a storage battery 5, and a straight-tube cover member 6 that houses these components.

[0013] The light source 2 includes a light-emitting element that emits light toward the entire inner circumferential surface 6s of the cover member 6. In this embodiment, the light source 2 is configured by a pair of cold cathode lamps 21 as light-emitting elements. The pair of cold cathode lamps 21 is disposed between the interior space R and the solar cell 3. Each cold cathode lamp 21 irradiates both the interior space R and the solar cell 3 with direct light L1. Specifically, the direct light L1 extending downward from the cold cathode lamp 21 irradiates the interior space R, and the direct light L1 extending upward from the cold cathode lamp 21 irradiates the solar cell 3. Here, the direct light L1 extending downward from the cold cathode lamp 21 functions as illumination light. In other words, the direct light L1 from the cold cathode lamp 21 that is not used as illumination light irradiates the solar cell 3. The cold cathode lamp 21 also irradiates the reflecting member 4 and the inner circumferential surface 6s with direct light L1. The pair of cold cathode lamps 21 face each other and are disposed along the longitudinal direction of the cover member 6.

[0014] As an example, the cold cathode lamp 21 is a straight-type cold cathode lamp. The tube diameter of the cold cathode lamp 21 may be 2.0 mm or more and 12.0 mm or less, 2.0 mm or more and 6.0 mm or less, or 2.0 mm or more and 4.0 mm or less. In this embodiment, the tube diameter of the cold cathode lamp 21 is 4.0 mm. The rated lamp power of the cold cathode lamp 21 is, for example, 6.0 W or more and 8.0 W or less. The rated life of the cold cathode lamp 21 is, for example, 50,000 hours or more, and in this embodiment, it is 80,000 hours.

[0015] The light source 2 may include only one cold cathode lamp 21, or may include three or more cold cathode lamps 21. The light source 2 may include a light-emitting element other than the cold cathode lamp 21 as a light-emitting element. For example, the light source 2 may include a light-emitting diode element that emits light toward the entire circumference of the inner circumferential surface 6s as a light-emitting element. Specifically, the light source 2 may include, as a light-emitting element, a plurality of light-emitting diode elements that are radially arranged so as to be toward the entire circumference of the inner circumferential surface 6s. In this case, the light source 2 does not need to include a cold cathode lamp 21 as a light-emitting element.

[0016] The solar cell 3 is capable of generating electricity using irradiated light. Specifically, the solar cell 3 converts light irradiated onto the solar cell 3 into energy. In this embodiment, the solar cell 3 includes a plurality of (e.g., 30) rectangular plate-shaped power generation panels 31. The solar cell 3 is disposed above the light source 2. The plurality of power generation panels 31 are arranged in two rows along the longitudinal direction of the cover member 6 so as to face the pair of cold cathode lamps 21 in the up-down direction. In this embodiment, each power generation panel 31 is capable of generating electricity using direct light L1 irradiated by the cold cathode lamp 21 and indirect light that arrives when the direct light L1 passes through another object. Each power generation panel 31 may also be capable of generating electricity using other light, such as external light.

[0017] As an example, the length of each side of one power generation panel 31 is 5 mm. The thickness of the power generation panel 31 is, for example, 1.0 mm or less, and in this embodiment, it is 0.6 mm. As an example, the maximum output current of one power generation panel 31 is 0.06 mA. Therefore, the maximum output current of 30 power generation panels 31 is 0.184 mA. The number and dimensions of the power generation panels 31 can be changed as appropriate depending on the desired output.

[0018] The reflecting member 4 has light reflectivity. For example, the reflecting member 4 is made of a shiny metal plate-like member. The reflecting member 4 is provided inside the cover member 6 so as to face the inner peripheral surface 6s of the cover member 6. In this embodiment, the reflecting member 4 is arranged next to the plurality of power generation panels 31 on the opposite side of the pair of cold cathode lamps 21 as viewed from the indoor space R. Specifically, the reflecting member 4 is arranged above the pair of cold cathode lamps 21 so as to be sandwiched between the plurality of power generation panels 31 stacked in two rows along the longitudinal direction of the cover member 6. In this embodiment, the reflecting member 4 extends along the longitudinal direction of the cover member 6 and is formed in a V-shape protruding toward the indoor space R in a cross section perpendicular to the longitudinal direction of the cover member 6. The reflecting member 4 reflects light incident on a reflective surface 4s formed by a combination of flat surfaces.

[0019] The reflective surface 4s faces the inner circumferential surface 6s and downward. In other words, the reflective surface 4s faces the pair of cold cathode lamps 21 and the indoor space R. The reflective surface 4s is irradiated with direct light L1 from the pair of cold cathode lamps 21 and indirect light that arrives when the direct light L1 passes through other objects. The reflective surface 4s may also be irradiated with other light, such as external light. The reflective member 4 reflects light incident on the reflective surface 4s and emits reflected light L2. In this embodiment, the reflective member 4 irradiates the power generation panel 31 with a portion of the reflected light L2, which is obtained by reflecting the incident light.

[0020] The reflective member 4 may be formed in a U-shape in a cross section perpendicular to the longitudinal direction of the cover member 6, bending toward the interior space R and then turning back. For example, from the viewpoint of making the emitted light give a soft impression, the reflective surface 4s may be formed of a curved surface.

[0021] The storage battery 5 is electrically connected to each of the pair of cold cathode lamps 21 and the solar cell 3 via wiring (not shown) or the like. The storage battery 5 stores the power generated by the solar cell 3. The storage battery 5 also supplies the stored power to each cold cathode lamp 21. For example, the storage battery 5 supplies power to each cold cathode lamp 21 via an inverter circuit 51 or the like that has a plurality of capacitors provided therein. Each cold cathode lamp 21 is further supplied with power from a system power supply (not shown) via the inverter circuit 51. The storage battery 5 may be housed inside the cover member 6 in communication with the inverter circuit 51, or may be attached to the outside of the cover member 6 (for example, on the cover member 6).

[0022] The cover member 6 is optically transparent. The cover member 6 is made of an optically transparent or translucent straight-tube hollow member. Examples of materials for forming the cover member 6 include synthetic resin and glass. In this embodiment, the cover member 6 is made of a plate-shaped polycarbonate resin processed into a straight-tube shape. The outer diameter of the cover member 6 may be, for example, 30 mm or more and 40 mm or less, or 32 mm or more and 38 mm or less.

[0023] The cover member 6 accommodates a pair of cold cathode lamps 21, a solar cell 3, a reflecting member 4, and a storage battery 5 inside. The cover member 6 is hung from a mounting wall (not shown) such as a ceiling, and is installed so as to extend horizontally above the approximate center of the interior space R. For example, the cover member 6 holds each cold cathode lamp 21 at its longitudinal end. In this embodiment, a holding member 61 that holds the solar cell 3, the reflecting member 4, and the storage battery 5 is provided inside the cover member 6.

[0024] As an example, the holding member 61 extends over the entire length of the cover member 6 in the longitudinal direction. The holding member 61 is made of a plate-like member provided inside the cover member 6 so as to cover the pair of cold cathode lamps 21 from above. The holding member 61 holds the solar cell 3 and the reflecting member 4 from above, and also holds the storage battery 5 from below. The solar cell 3, the reflecting member 4, and the storage battery 5 may each be adhesively fixed to the holding member 61.

[0025] A diffusing surface 6t that diffusely reflects (also referred to as "scattered reflection") the direct light L1 is provided on at least the area of ​​the inner circumferential surface 6s of the cover member 6 that is irradiated with the direct light L1. In this embodiment, the diffusing surface 6t is provided on the entire inner circumferential surface 6s. The diffusing surface 6t is irradiated with the direct light L1 from the pair of cold cathode lamps 21 and indirect light that arrives when the direct light L1 passes through another object. The diffusing surface 6t may also be irradiated with other light, such as external light. The cover member 6 diffusely reflects the light that has entered the diffusing surface 6t, and emits diffused light L3.

[0026] In this embodiment, the indirect light that arrives when the direct light L1 passes through another object includes reflected light L2 and diffused light L3. That is, in this embodiment, the reflected light L2 refers to light that is formed by the reflecting surface 4s reflecting at least one of the direct light L1 and the diffused light L3, and the diffused light L3 refers to light that is formed by the diffusing surface 6t diffusing and reflecting at least a portion of the direct light L1, reflected light L2, and diffused light L3.

[0027] For example, the diffusion surface 6t is an uneven or rough surface. In this embodiment, the diffusion surface 6t is formed by a fine uneven structure provided on the entire inner circumferential surface 6s.

[0028] In this embodiment, the range irradiated with the direct light L1 corresponds to the portion of the inner circumferential surface 6s below the holding member 61. The diffusing surface 6t may be provided only on the portion of the inner circumferential surface 6s below the holding member 61. The diffusing surface 6t may be a flat surface configured to be capable of diffusively reflecting light. The diffusing surface 6t may be formed by painting a liquid containing fine particles on the inner circumferential surface 6s, or by attaching a film containing fine particles to the inner circumferential surface 6s.

[0029] [Action and effect] In the lighting device 1 according to the first embodiment, the cover member 6 houses the light source 2 and the solar cell 3. This prevents the distance between the light source 2 and the solar cell 3 from becoming too large. Furthermore, in this lighting device 1, direct light L1 is diffusely reflected by the diffusion surface 6t of the cover member 6, and the diffused light L3 emitted from the diffusion surface 6t is reflected by the reflecting member 4. Therefore, the direct light L1, diffused light L3, and reflected light L2 are added together to form illumination light, allowing lighting to be achieved by efficiently utilizing the direct light L1 and indirect light from the light source 2.

[0030] The light source 2 is disposed between the indoor space R as a predetermined illumination target area and the solar cell 3, and includes a cold cathode lamp 21 as a light-emitting element that emits light toward the entire circumference of the inner circumferential surface 6t. The reflecting member 4 is disposed alongside the solar cell 3 on the opposite side of the cold cathode lamp 21 as viewed from the indoor space R, and irradiates the solar cell 3 with reflected light L2, which is at least one of direct light L1 and diffused light L3 irradiated from the diffusing surface 6t. With this configuration, the solar cell 3 is irradiated with reflected light L2 in addition to direct light L1 and diffused light L3, so that the direct light L1 and indirect light from the light source 2 can be used more efficiently as light for power generation by the solar cell 3.

[0031] The light source 2 includes a cold cathode lamp 21 as a light emitting element. With this configuration, the lighting device 1 can provide light that gives a soft impression as illumination light.

[0032] The reflective member 4 is formed in a V-shape in a cross section perpendicular to the longitudinal direction of the cover member 6, protruding toward the indoor space R. With this configuration, the reflected light L2 is reflected by the reflective surfaces 4s that form the V-shape of the reflective member 4, improving the directivity of the reflected light L2 and enabling it to be irradiated over a relatively long distance.

[0033] The diffusing surface 6t is formed by a fine uneven structure provided on the entire inner circumferential surface 6s. This configuration makes it possible to diffuse and reflect the direct light L1 from the light source 2 without leakage.

[0034] [Second embodiment] The configuration of a lighting device according to a second embodiment will be described with reference to Figs. 2 and 3. Fig. 2 is a cross-sectional view schematically showing the lighting device according to the second embodiment. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. The lighting device 10 according to this embodiment will be described using a straight tube LED lamp installed on a mounting wall such as a ceiling. Note that the mounting wall and the fixture for installation are not shown in Figs. 2 and 3.

[0035] 2 and 3, like the lighting device 1, illuminates from above an indoor space R that extends downward as an illumination target area. In the following description of the lighting device 10, differences from the lighting device 1 according to the first embodiment will be mainly described, and descriptions of commonalities may be omitted. The lighting device 10 differs from the lighting device 1 in that it includes a light source 20 instead of the light source 2, a solar cell 30 instead of the solar cell 3, and a reflecting member 40 instead of the reflecting member 4.

[0036] The light source 20 includes a light-emitting diode element 22 that emits light toward the interior space R. The light-emitting diode element 22 emits light that spreads downward. In this embodiment, the light source 20 is composed of a plurality of light-emitting diode elements 22. The plurality of light-emitting diode elements 22 are stacked along the longitudinal direction of the cover member 6. Each of the plurality of light-emitting diode elements 22 emits light that spreads downward, so that the light source 20 as a whole illuminates a wide range of the interior space R. As an example, the light source 20 can obtain an illuminance of 1200 lux to 1300 lux with a power consumption of 6 W to 8 W. Note that the light source 20 may be composed of only one light-emitting diode element 22.

[0037] Each light-emitting diode element 22 irradiates direct light L11 onto an area excluding the solar cell 30, a lower portion of the inner circumferential surface 6s, and a portion of the interior space R. The area excluding a portion of the interior space R is an area excluding the portion that overlaps with the solar cell 30 as viewed from the light-emitting diode element 22. In other words, in the area where the light-emitting diode element 22 and the solar cell 30 overlap as viewed from above the light-emitting diode element 22, the interior space R is not irradiated with direct light L11. In other words, the direct light L11 is blocked by the solar cell 30.

[0038] Like the solar cell 3, the solar cell 30 can generate power using irradiated light. That is, the solar cell 30 converts light irradiated onto the solar cell 30 into energy. In this embodiment, the solar cell 30 includes a plurality of (e.g., 25) rectangular plate-shaped power generation panels 32. The solar cell 30 is disposed between the interior space R and the light source 20 so as to face the light source 20. The plurality of power generation panels 32 are disposed along the longitudinal direction of the cover member 6 so as to face the stacked plurality of light-emitting diode elements 22 in the vertical direction. In this embodiment, each power generation panel 32 can generate power using direct light L11 irradiated by the light-emitting diode elements 22 and indirect light that arrives when the direct light L11 passes through another object. Each power generation panel 32 may also be capable of generating power using other light, such as external light. The same components as those of the power generation panel 31 may be used for the power generation panels 32.

[0039] The reflective member 40, like the reflective member 4, has light reflectivity. For example, the reflective member 40 is made of a shiny metal plate-like member. The reflective member 40 is provided inside the cover member 6 so as to face the inner circumferential surface 6s of the cover member 6. In this embodiment, the reflective member 40 is disposed between the indoor space R and the solar cells 30. Specifically, the reflective member 40 is disposed below the multiple power generation panels 32 and along the longitudinal direction of the cover member 6. The length of the reflective member 40 along the longitudinal direction of the cover member 6 is equal to or greater than the length of the solar cells 30 along the longitudinal direction of the cover member 6. Like the reflective member 4, the reflective member 40 extends along the longitudinal direction of the cover member 6 and is formed in a V-shape protruding toward the indoor space R in a cross section perpendicular to the longitudinal direction of the cover member 6. The reflective member 40 reflects light incident on a reflective surface 40s formed by a combination of flat surfaces.

[0040] The reflective surface 40s faces the inner circumferential surface 6s and downward. In other words, the reflective surface 40s faces the indoor space R. The reflective surface 40s is irradiated with direct light L11 from the plurality of light-emitting diode elements 22 and indirect light that arrives when the direct light L11 passes through other objects. The reflective surface 40s may also be irradiated with other light, such as external light. The reflective member 40 reflects light incident on the reflective surface 40s and emits reflected light L12. In this embodiment, the reflective member 40 irradiates the indoor space R with reflected light L12, which is the diffused light L3 that is diffused from the diffusing surface 6t of the cover member 6. The reflective member 40 particularly irradiates the reflected light L12 to an area of ​​the indoor space R that is not irradiated with the direct light L11. The area of ​​the indoor space R that is not irradiated with the direct light L11 is an area where the direct light L11 is blocked by the solar cell 30.

[0041] Similar to the reflecting member 4, the reflecting member 40 may be formed in a U-shape that is bent toward the interior space R and then folded back in a cross section perpendicular to the longitudinal direction of the cover member 6. For example, from the viewpoint of making the emitted light appear soft, the reflecting surface 40s may be formed of a curved surface.

[0042] In this embodiment, the cover member 6 accommodates therein the light source 20 composed of a plurality of light-emitting diode elements 22, the solar cell 30, the reflecting member 40, and the storage battery 5. For example, the cover member 6 holds the plurality of light-emitting diode elements 22 stacked at an end in the longitudinal direction. In this embodiment, the holding member 61 holds the plurality of stacked light-emitting diode elements 22 and the storage battery 5. The holding member 61 holds the plurality of light-emitting diode elements 22 from above and holds the storage battery 5 from below. The plurality of light-emitting diode elements 22 and the storage battery 5 may each be adhesively fixed to the holding member 61.

[0043] In this embodiment, a holding member 62 is further provided inside the cover member 6. The holding member 62 extends along the longitudinal direction of the cover member 6. The holding member 62 is provided below the holding member 61 so as to face the holding member 61 in the vertical direction. The holding member 62 holds the solar cells 30 from below and holds the reflecting member 40 from above. The solar cells 30 and the reflecting member 40 may each be adhesively fixed to the holding member 62.

[0044] The holding member 62 is optically transparent. The holding member 62 is made of an optically transparent or translucent plate-like member. Examples of materials that can be used to form the holding member 62 include synthetic resin and glass. In this embodiment, the holding member 62 is made of a plate-like polycarbonate resin. The direct light L11 can pass through the holding member 62.

[0045] In this embodiment, the diffusing surface 6t is irradiated with direct light L11 from the plurality of light-emitting diode elements 22 and indirect light that is the direct light L11 that reaches the diffusing surface 6t after passing through another object. In this embodiment, the indirect light that is the direct light L11 that reaches the diffusing surface 6t after passing through another object includes reflected light L12 and diffused light L3. In this embodiment, the reflected light L12 refers to light that is the diffused light L3 that is reflected, and the diffused light L3 refers to light that is at least a portion of the direct light L11, reflected light L12, and diffused light L3 that is diffusely reflected by the diffusing surface 6t.

[0046] [Action and effect] The lighting device 10 according to the second embodiment has the same configuration as the lighting device 1 according to the first embodiment, and therefore provides the same effects as the lighting device 1. In the lighting device 10 as well, the cover member 6 houses the light source 20 and the solar cell 30. This prevents the distance between the light source 20 and the solar cell 30 from becoming too large. In the lighting device 10 as well, direct light L11 is diffusely reflected by the diffusion surface 6t of the cover member 6, and the diffused light L3 emitted from the diffusion surface 6t is reflected by the reflecting member 40. Therefore, the direct light L11, the diffused light L3, and the reflected light L12 are added together to form illumination light, allowing lighting to be achieved by efficiently utilizing the direct light L11 and indirect light from the light source 20.

[0047] In the lighting device 10 according to the second embodiment, the light source 20 includes a light-emitting diode element 22 that emits light toward the indoor space R. The solar cell 30 is disposed between the indoor space R and the light source 20 so as to face the light source 20. The reflective member 40 is disposed between the indoor space R and the solar cell 30, and reflects diffused light L3 emitted from the diffusing surface 6t, thereby irradiating reflected light L12 onto an area of ​​the indoor space R that is not irradiated with direct light L11. Because the light source 20 includes the light-emitting diode element 22, the illuminance can be increased compared to other light sources. Furthermore, because the solar cell 30 is more likely to receive direct light L11, the power generated can be increased. On the other hand, even in a configuration in which the direct light L11 is blocked by the solar cell 30 in a portion of the indoor space R, resulting in a shortage of illumination light, the reflected light L12 and diffused light L3 are irradiated as illumination light in addition to the direct light L11, thereby preventing a shortage of illumination light. Furthermore, since the reflective member 40 is disposed between the interior space R and the solar cell 30, the reflected light L12 from the reflective member 40 can prevent the shadow of the solar cell 30 from being visible from the interior space R.

[0048] Although the present invention has been described above with reference to various embodiments, it is not limited to these specific embodiments, and various modifications and variations are possible within the spirit and scope of the present invention as defined in the claims. For example, the configuration of each embodiment may be appropriately added or deleted, and the configuration of one embodiment may be applied to the configuration of another embodiment. Furthermore, the effects of each embodiment are merely illustrative examples of the effects resulting from the present invention. In other words, the present invention may also provide additional effects.

[0049] For example, in the above embodiments, the lighting device 1 and the lighting device 10 are described as being installed on a mounting wall such as a ceiling, but the present invention may also be applied to lighting devices placed on a floor, etc. In this case, the lighting device illuminates from below an indoor space extending above the lighting device as a target illumination area.

[0050] 3, in the second embodiment, an example has been described in which the solar cells 30, the reflecting member 40, and the holding member 62 extend over the entire longitudinal length of the cover member 6, but the solar cells 30, the reflecting member 40, and the holding member 62 do not have to extend over the entire longitudinal length of the cover member 6. The solar cells 30, the reflecting member 40, and the holding member 62 may be arranged in only one location along a portion of the longitudinal length of the cover member 6, or multiple units each composed of the solar cells 30, the reflecting member 40, and the holding member 62 may be arranged side by side at intervals in the longitudinal direction of the cover member 6. [Explanation of symbols]

[0051] 1, 10: Lighting equipment 2, 20: Light source 3, 30: Solar cell 4, 40: Reflective material 4s, 40s: Reflective surface 5: Storage battery 6: Cover material 6s: Inner surface 6t: Diffused surface 21: Cold cathode lamp (light emitting element) 22: Light-emitting diode element 31, 32: Power generation panels 51: Inverter circuit 61, 62: holding members L1, L11: Direct light L2, L12: Reflected light L3: Diffused light R: Indoor space (lighting target area)

Claims

1. A light source and a straight tube-type cover member that is optically transparent and accommodates the light source; a reflective member having light reflectivity and provided inside the cover member so as to face an inner circumferential surface of the cover member; a solar cell housed inside the cover member and capable of generating electricity by irradiating light; a storage battery electrically connected to each of the light source and the solar cell, storing power from the solar cell and supplying the stored power to the light source; The lighting device further comprises a diffusing surface that diffuses and reflects the direct light emitted from the light source, at least in an area of ​​the inner circumferential surface that is irradiated with the direct light.

2. the light source includes a light-emitting element that is disposed between a predetermined illumination target area and the solar cell and emits light toward the entire periphery of the inner circumferential surface, 2. The lighting device according to claim 1, wherein the reflective member is arranged alongside the solar cell on the opposite side of the light-emitting element from the illumination target area, and irradiates the solar cell with reflected light that reflects at least one of the direct light and the diffused light irradiated from the diffusing surface.

3. The lighting device according to claim 2 , wherein the light source includes a cold cathode lamp as the light emitting element.

4. the light source includes a light emitting diode element that emits light toward a predetermined illumination target area; the solar cell is disposed between the illumination target area and the light source so as to face the light source, 2. The lighting device according to claim 1, wherein the reflective member is disposed between the illumination target area and the solar cell, and reflects diffused light irradiated from the diffusing surface to irradiate an area of ​​the illumination target area that is not irradiated by the direct light.

5. The lighting device according to claim 2 , wherein the reflective member is formed in a V-shape protruding toward the target illumination area in a cross section perpendicular to a longitudinal direction of the cover member.

6. The lighting device according to claim 1 , wherein the diffusing surface is formed by a fine uneven structure provided on the entire inner circumferential surface.

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