Building

Abstract

A building according to the present invention is provided with: a lattice section formed with a plurality of first framework members and a plurality of second framework members; and a plurality of panels held in the lattice section. One or more of the panels are capable of transmitting visible light. One or more of the light transmissive panels are illuminating devices. The illuminating devices are each provided with a light source and a light guide unit that has a light guide plate for guiding light emitted from the light source and that is transparent with respect to visible light. The light guide plate comprises: a light incident end face which is disposed so as to face the light source and through which the light emitted from the light source enters; a first main surface which is disposed inside the building and from which the light guided through the light guide plate is emitted; and a second main surface which is disposed outside the building so as to face the first main surface.

Description

Technical Field

[0001] The present invention relates to a building.

Background Art

[0002] In order to make the appearance of a building more attractive, attempts have been widely made to incorporate lighting members such as LED lights into building materials such as panel units, partition walls, and fixtures.

[0003] For example, a building is disclosed in which a lighting device having a lens for controlling light from a light source in a specific direction is provided on a curtain wall constituting an outer wall (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the building equipped with the lighting device of Patent Document 1 irradiates light from the lighting device in a specific direction such as the outer wall or the interior to perform various lighting effects, and it is only described that the lighting device is used for lighting effects, and it is not described that it is used as lighting for illuminating the entire interior space.

[0006] When applying a lighting device to a building, it is required that in a bright time zone such as daytime, one side inside and outside the building can be visually recognized without being obstructed by the lighting device from the other side, and in a dark time zone such as nighttime, the lighting device can function as lighting for illuminating the interior of the building, and the design of the appearance of the building is not impaired.

[0007] One aspect of the present invention aims to provide a building that can function as lighting for illuminating the interior of the building while enabling good visibility from one of the interior and exterior of the building to the other, and can maintain high design quality.

Means for Solving the Problems

[0008] One aspect of the building according to the present invention includes a lattice portion formed by a plurality of first frame members erected at predetermined intervals and a plurality of second frame members connecting adjacent first frame members, and a plurality of transparent panels held by the lattice portion. One or more of the transparent panels are lighting devices, and the lighting device includes a light source and a light guide plate that guides the light emitted from the light source. The light guide plate faces the light source and has a light incident end face on which the light emitted from the light source is incident, a first main face on the inner side of the building from which the light guided through the light guide plate exits, and a second main face on the outer side of the building that faces the first main face.

Effects of the Invention

[0009] One aspect of the building according to the present invention can function as lighting for illuminating the interior of the building while enabling good visibility from one of the interior and exterior of the building to the other, and can maintain high design quality.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail. For ease of understanding of the description, the same reference numerals are given to the same components in each drawing, and duplicate descriptions are omitted. In addition, the scales of the respective members in the drawings may be different from the actual ones. In this specification, a tilde "~" indicating a numerical range means including the numerical values described before and after it as a lower limit value and an upper limit value unless otherwise specified.

[0012] [First Embodiment] A building according to the first embodiment of the present invention will be described. FIG. 1 is a perspective view showing the building according to this embodiment. As shown in FIG. 1, the building 1 according to this embodiment includes a lattice portion 10 and a plurality of panels 20 held by the lattice portion 10.

[0013] In this specification, a three-dimensional orthogonal coordinate system in three axial directions (X-axis direction, Y-axis direction, Z-axis direction) is used, the width direction of the building is defined as the X-axis direction, the length direction is defined as the Y-axis direction, and the height direction is defined as the Z-axis direction. The direction from the bottom to the top of the building is defined as the +Z-axis direction, and the opposite direction is defined as the -Z-axis direction. In the following description, the +Z-axis direction is referred to as up or upward, and the -Z-axis direction is referred to as down or downward.

[0014] [Lattice Portion] The lattice portion 10 is formed of a plurality of first skeletal members 11 and a plurality of second skeletal members 12.

[0015] Figure 2 is a partial side view of the building shown in Figure 1 as seen from the X-axis direction. As shown in Figure 2, a plurality of first frame members 11 are erected at predetermined intervals in the Y-axis direction. The first frame member 11 is formed in an H shape when viewed in the longitudinal axis direction. The first frame member 11 is configured to have a size such that the panel 20 can be inserted into and removed from the gap between its inner surfaces. By combining a plurality of the first frame members 11 in the longitudinal axis direction thereof, as shown in Figure 1, the lattice portion 10 is formed in an arch shape when viewed in the longitudinal direction of the building (viewed in the Y-axis direction). Note that by appropriately designing the shape of the first frame member 11, the lattice portion 10 may be formed in other shapes such as a polygon (including a rectangle) when viewed in the longitudinal direction of the building (viewed in the Y-axis direction).

[0016] As shown in Figure 2, a plurality of second frame members 12 are provided at predetermined intervals in the Z-axis direction, and connect adjacent first frame members 11 to each other. The second frame member 12 is formed in an H shape when viewed in the longitudinal axis direction, similar to the first frame member 11. The second frame member 12 is configured to be able to sandwich and fit the panel 20 into the gap between its inner surfaces, similar to the first frame member 11.

[0017] The lattice portion 10 can be held by inserting the panel 20 into the gap between the inner surfaces of the first frame member 11 and sandwiching and fitting the panel 20 into the gap between the inner surfaces of the second frame member 12. Note that the lattice portion 10 may be held by inserting the panel 20 into the gap between the inner surfaces of the second frame member 12 and sandwiching and fitting the panel 20 into the gap between the inner surfaces of the first frame member 11, or by sandwiching and fitting the panel 20 into the gap between the inner surfaces of the first frame member 11 and the gap between the inner surfaces of the second frame member 12.

[0018] As the material of the first frame member 11 and the second frame member 12, metals such as aluminum and stainless steel can be used.

[0019] <Panel> The plurality of panels 20 are each held in a state of being fitted into the lattice part 10. Among the plurality of panels 20, one or more panels 20 have transmissivity (light transmissivity) with respect to visible light. One or more panels 20 having transmissivity with respect to visible light are constituted by the lighting device 30A. Note that the panel 20 having transmissivity with respect to visible light may include other members in addition to the lighting device 30A. Also, among the plurality of panels 20, all the panels 20 having transmissivity with respect to visible light may be constituted by the lighting device 30A, or some of the panels 20 having transmissivity with respect to visible light may be constituted by the lighting device 30A.

[0020] Note that having light transmissivity means having transmissivity that allows visible light (light with a wavelength of 380 nm to 780 nm) to pass through the inside of the panel 20 when irradiated from the outside of the panel 20. The transmittance of visible light of the panel 20 is preferably 60% or more, more preferably 75% or more, and still more preferably 90% or more. The transmittance of visible light can be specified as the average value of the transmittances at each wavelength when measured at wavelengths of 380 nm to 780 nm using a spectrophotometer.

[0021] When the panel 20 having transmissivity with respect to visible light is not the lighting device 30A, its material is not particularly limited. For example, a material similar to the light guide plate 33 described later can be used.

[0022] (Lighting device) The lighting device 30A will be described. In this embodiment, for convenience of explanation, a case where a plate-shaped panel 20 installed vertically is constituted by the lighting device 30A will be described as an example.

[0023] FIG. 3 is a view of the state in which the panel 20 is fitted into the lattice portion 10 as seen from the Y-axis direction. As shown in FIG. 3, the lighting device 30A includes a light source 31 and a light guide portion 32A. The light guide portion 32A is formed in a plate shape and is held by a pair of holding members 41 provided on the inner surfaces of the upper and lower ends of the light guide portion 32A on the inner surface of the first skeleton member 11, and is provided so as to have a predetermined interval from the light source 31 located below the light guide portion 32A. In the lighting device 30A, the light that guides through the inside of the light guide portion 32A and exits from the light guide portion 32A is irradiated to the indoor side.

[0024] The light source 31 is disposed in the gap between the inner surfaces of the second skeleton members 12. Note that the light source 31 may be disposed in the gap between the inner surfaces of the first skeleton members 11, or may be disposed in the gap between the inner surfaces of both the first skeleton members 11 and the second skeleton members 12.

[0025] The light source 31 is installed on a substrate 42 provided inside the second skeleton member 12. For the substrate 42, a metallic material having conductivity such as aluminum can be used. The substrate 42 is fixed on the heat dissipation portion 43 by a double-sided adhesive tape 44, and the heat generated by the light source 31 is dissipated to the heat dissipation portion 43. The heat dissipation portion 43 can be formed of a heat dissipation layer that releases heat to the outside. As the heat dissipation portion 43, for example, a material having a high thermal conductivity such as carbon, copper, or aluminum can be used. Note that since the substrate 42 only needs to be fixed on the heat dissipation portion 43, an adhesive or the like may be used instead of the double-sided adhesive tape 44.

[0026] As the light source 31, a known light source such as a light-emitting diode (LED), a linear light source such as a fluorescent lamp or a cold cathode tube, or a bundle of a plurality of optical fibers in a line shape can be used.

[0027] FIG. 4 is a view of the panel 20 as seen from the X-axis direction. As shown in FIG. 4, a plurality of light sources 31 are arranged linearly along the Y-axis direction on a substrate 42 provided inside the second skeletal member 12. By applying a driving voltage from a driving circuit (not shown), each light source 31 emits light. Thereby, the linearly-shaped light extending in the Y-axis direction formed by the light emitted from each light source 31 can be emitted in the +Z-axis direction. As the light emitted by the light source 31, white light such as incandescent color, cool white, daylight color, or monochromatic light can be used for illumination.

[0028] The light guide portion 32A has a function of guiding the light emitted from the light source 31 and is transmissive to visible light. The light guide portion 32A includes a light guide plate 33 that guides the light emitted from the light source 31.

[0029] The light guide plate 33 is formed in a rectangular shape. Note that the light guide plate 33 can also be formed to have a curved main surface according to the shape of the lattice portion 10.

[0030] As shown in FIG. 4, the light guide plate 33 can be sandwiched by the second skeletal member 12 via the holding member 41 near the end faces of its upper and lower surfaces. FIG. 5 is a view of the state where the transparent panel is fitted in the lattice portion 10 as seen from the Z-axis direction without the second skeletal member 12. As shown in FIG. 5, the light guide plate 33 is held in a state where its vicinity of the side surface (vicinity of the end face in the Y-axis direction) is disposed in the gap of the inner surface of the first skeletal member 11 of the lattice portion 10. Therefore, by fitting the vicinity of the upper and lower ends of the light guide plate 33 by a pair of holding members 41 provided on the inner surface of the second skeletal member 12 of the lattice portion 10, the light guide plate 33 can be supported in a state of holding a predetermined position and posture with respect to the light source 31 within the lattice portion 10.

[0031] The light guide plate 33 has light transmissivity.

[0032] The light guide plate 33 can be manufactured by molding a material having light transmissibility. Examples of the material include olefin resins such as polyethylene (PE), polypropylene (PP), cycloolefin polymer (COP), and cycloolefin copolymer (COC); acrylic resins such as polymethyl methacrylate (PMMA); styrene resins such as polystyrene (PS), acrylonitrile-styrene resin, and acrylonitrile-butadiene-styrene (ABS) resin; vinyl resins such as polyvinyl chloride (PVC) resin, vinylidene chloride resin, polyacrylonitrile, polyvinyl acetate, acrylic acid copolymer, and polyvinyl alcohol; fluorine resins such as polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinyl fluoride resin, and polyvinylidene fluoride; engineering plastics such as polycarbonate (PC) resin, polyacetal (POM) resin, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethyl terephthalate, polyphenylene oxide, nylon 6, nylon 66, and aromatic polyamide; super engineering plastics such as polyphenylene sulfide (PPS) resin, polysulfone (PSF) resin, polyethersulfone (PES), polyetheretherketone (PEEK), polyarylate resin, aromatic polyester resin, polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, and aramid resin; thermosetting resins such as epoxy resin, silicone resin, phenol resin, unsaturated polyester resin, and polyurethane resin; and glass. The materials may be used alone or in combination of two or more. Among these, PMMA can be preferably used.

[0033] Depending on the type of material, the refractive index, strength, moisture resistance, etc. of the light guide plate 33 are different. Therefore, it is preferable to appropriately select the material according to the usage conditions and usage environment of the building 1. Note that the light guide plate 33 may be made of a colored material as long as it has transmissibility to visible light.

[0034] The light guide plate 33 can be formed into a desired shape using known molding methods such as compression molding, injection molding, and transfer molding. When using these molding methods, a mold corresponding to the shape of the light guide plate 33 is used. Also, the light guide plate 33 may be formed by press working or the like, or may be formed by processing with a laser or the like.

[0035] As shown in FIG. 3, the light guide plate 33 has a light incident end face 331 that receives the light emitted from the light source 31, a first main face 332 that is inside the building 1 and from which the light guided inside the light guide plate 33 exits, and a second main face 333 that is outside the building 1 and faces the first main face 332. Note that the first main face 332 is the main face located on the indoor side of the building 1, and the second main face 333 is the main face located on the outdoor side of the building 1.

[0036] The light guide plate 33 has a light extraction portion 50A inside the light guide plate 33 that causes the light guided inside the light guide plate 33 to exit from the first main face 332. The light extraction portion 50A is provided near the first main face 332 inside the light guide plate 33.

[0037] The light extraction portion 50A can be composed of a void portion 51. The void portion 51 can have a plurality of voids (also referred to as cavities) 511. The plurality of voids 511 can totally reflect the light propagating through the light guide plate 33 and cause it to exit from the first main face 332. In the region of the first main face 332, the region through which the light exiting from the light guide plate 33 passes due to the light extraction portion 50A is defined as the first light emission portion 332A.

[0038] The plurality of voids 511 may be regularly provided in at least one of the width direction (Y-axis direction) and the height direction (Z-axis direction) of the light guide plate 33 inside the light guide plate 33, or may be provided randomly.

[0039] The voids 511 are filled with air. Note that instead of air, a material having a refractive index lower than that of the light guide plate 33 may be filled in the voids 511.

[0040] The size of the gap 511 can be appropriately designed according to the range where it can be installed in the light guide plate 33 and the like. The interval between adjacent gaps 511 can be appropriately selected within the range that can be formed on the light guide plate 33.

[0041] The angle of the interface between the light guide plate 33 and the gap 511 is preferably designed to be an angle suitable for irradiating the interior of the building 1.

[0042] As shown in FIG. 4, the light guide plate 33 can be manufactured by a lamination method such as microwave surface treatment to bond a first light guide plate 33-1 without a pattern and a second light guide plate 33-2 with a desired concave fine pattern formed thereon, or by an adhesive such as a pressure-sensitive adhesive to bond the first light guide plate 33-1 and the second light guide plate 33-2. In order to suppress the interface reflection between the first light guide plate 33-1 and the second light guide plate 33-2, it is preferable that the refractive indexes of the first light guide plate 33-1 and the second light guide plate 33-2 are substantially equal. Also, when the first light guide plate 33-1 and the second light guide plate 33-2 are bonded by an adhesive, it is preferable that the refractive index of the adhesive is substantially equal to those of the first light guide plate 33-1 and the second light guide plate 33-2. In the present embodiment, a concave fine pattern may be formed on the first light guide plate 33-1 and no pattern may be formed on the second light guide plate 33-2, or concave fine patterns may be formed on both the first light guide plate 33-1 and the second light guide plate 33-2.

[0043] For forming the fine pattern on the second light guide plate 33-2, laser patterning, direct laser imaging, laser drilling, laser or electron beam irradiation are used. Also, individual characteristics may be imparted by inkjet printing, screen printing, etc. to change the material and refractive index value. Micro / nano dispensing, dosing, laser sintering, micro-discharge machining, micromachining, microforming, imprinting, embossing, etc. can also be used.

[0044] In the lighting device 30A, the light emitted from the light source 31 in the +Z axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z axis direction within the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333.

[0045] Among the light guided in the +Z axis direction within the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333, a part of the light is reflected, scattered, or diffracted at the gap 511 of the light extraction portion 50A as shown in FIG. 6, guided to the first main surface 332, and emitted from the light guide plate 33 through the first light emission portion 332A. The light emitted from the first light emission portion 332A irradiates the interior of the building 1.

[0046] Note that the amount of light emitted from the first main surface 332 can be measured, for example, by a total luminous flux measurement system (manufactured by Otsuka Electronics Co., Ltd.). The adjustment of the emission amount of the light emitted from the first main surface 332 can be performed, for example, by adjusting the light amount of the light source 31, the area of the first light emission portion 332A, etc.

[0047] As described above, the building 1 according to the present embodiment includes the lattice portion 10 and a plurality of panels 20, and the lighting device 30A is used for one or more panels 20. The lighting device 30A includes the light source 31 and the light guide plate 33, and the light guide plate 33 has a light incident end face 331, a first main surface 332, and a second main surface 333. The lighting device 30A can cause the light emitted from the light source 31 to enter the light guide plate 33 from the light incident end face 331, and cause the light guided within the light guide plate 33 to be emitted into the room from the first main surface 332 of the light guide plate 33.

[0048] In addition, since the light guide plate 33 constituting the lighting device 30A of the building 1 can have light transmissivity, it is possible to make it easy to visually recognize from one of the inside and outside of the building 1 without being obstructed by the lighting device 30A during bright time zones such as daytime. Furthermore, the building 1 causes the light from the light source 31 to enter the light incident end face 331 with the lighting device 30A, and causes the light guided within the light guide plate 33 to be emitted from the first main surface 332 of the light guide plate 33, so that the lighting device 30A can function as lighting for illuminating the inside of the building 1 during dark time zones such as nighttime.

[0049] In addition, the building 1 can arrange the light source 31 of the lighting device 30A on at least one of the first skeletal member 11 and the second skeletal member 12 that constitute the lattice portion 10 so that it cannot be visually recognized from the outside. Therefore, the building 1 can maintain its appearance so as not to impair its design.

[0050] Therefore, the building 1 according to the present embodiment can function as lighting for illuminating the inside of the building with the lighting device 30A while improving the visibility from one of the inside and the outside of the building 1 to the other, and can maintain high design. Therefore, the building 1 can provide a building that is practical and has high design.

[0051] In addition, since the lighting device 30A of the building 1 includes the light extraction portion 50A, the light guided in the light guide plate 33 can be emitted from the first main surface 332. Therefore, the building 1 can effectively function as lighting for illuminating the inside of the building with the lighting device 30A while maintaining good visibility from one of the inside and the outside of the building 1 to the other, and can maintain its design.

[0052] Furthermore, the building 1 provides the void portion 51 as the light extraction portion 50A inside the light guide plate 33 and configures the void portion 51 with a plurality of voids 511, so that the light propagating through the light guide plate 33 in the voids 511 is totally reflected and the light is emitted from the first main surface 332. Therefore, since the building 1 can emit the light guided into the light guide plate 33 from the light source 31 into the room, the lighting device 30A can function more effectively as lighting for illuminating the inside of the building.

[0053] In addition, the light guide plate 33 of the building 1 can have light transmissivity. Since the light guide plate 33 has light transmissivity, a person inside or outside the building 1 can visually recognize from one of the inside and the outside of the building 1 to the other through the light guide plate 33. Therefore, it is possible to surely suppress a decrease in visibility when looking from one of the inside and the outside of the building to the other.

[0054] As described above, since the building 1 according to this embodiment can have practicality and high design quality, it can be suitably used for the roof of a building, a passage with a roof, a greenhouse for plant cultivation, etc. In particular, if the building 1 is used as a greenhouse for plant cultivation, the wall surface of the greenhouse for plant cultivation can be made transparent and emit light, so that an environment can be created in which plants can be actively irradiated with light of an efficient color, and thus it can be effectively used for a greenhouse for cultivating plants and the like.

[0055] In this embodiment, as shown in FIG. 7, the light extraction part 50A may have light scattering particles 52 in the light guide plate 33 instead of the void part 51. The light scattering particles 52 have a refractive index difference with respect to the material constituting the light guide plate 33. The light scattering particles 52 are particles having an average particle diameter of 0.3 μm to 5 μm, and can function as a light scatterer that scatters the light guided in the light guide plate 33. The light scattering particles 52 can scatter the light propagating through the light guide plate 33 and emit it from the first main surface 332. Here, the average particle diameter is the volume average particle diameter, and can be measured using a known particle size distribution measuring device such as an ultracentrifugal automatic particle size distribution measuring device, for example.

[0056] The light guided in the light guide plate 33 is reflected, scattered or diffracted by the light scattering particles 52 of the light extraction part 50A and guided to the first main surface 332, and is emitted from the light guide plate 33 through the first light emitting part 332A. The light emitted from the first light emitting part 332A irradiates the interior of the building 1.

[0057] [Second Embodiment] A building according to the second embodiment of the present invention will be described. The building according to this embodiment is provided with a first optical function layer outside the first main surface 332 of the light guide plate 33 provided in the building 1 according to the above-described first embodiment, and the light extraction part 50A is provided inside the first optical function layer.

[0058] FIG. 8 is a side view of the lighting device provided in the building according to the present embodiment, as viewed from the Y-axis direction, with the lighting device fitted into the lattice portion. As shown in FIG. 8, the lighting device 30B provided in the building according to the present embodiment is the lighting device 30A of the building 1 according to the above-described first embodiment, and includes a light guide portion 32B having a light guide plate 33 and a first optical function layer 34A provided outside the first main surface 332 of the light guide plate 33, and instead of the light extraction portion 50A provided in the light guide plate 33, it includes a light extraction portion 50B inside the first optical function layer 34A.

[0059] The light guide portion 32B includes a light guide plate 33 and a first optical function layer 34A provided on the first main surface 332 of the light guide plate 33.

[0060] The first optical function layer 34A refers to a layer that exhibits an optical function. The first optical function layer 34A can emit the light incident from the incident surface 34a facing the first main surface 332 from the opposite emission surface 34b.

[0061] The first optical function layer 34A is a layer formed using a material such as resin. The first optical function layer 34A can be formed using the same material as the light guide plate 33. The first optical function layer 34A can be provided on the first main surface 332, for example, by using a method of attaching a layered member including the first optical function layer 34A by a lamination method such as microwave surface treatment, or a method of adhering with an adhesive such as a pressure-sensitive adhesive.

[0062] Note that a cover layer or a layer having other functions may be provided between the first optical function layer 34A and the light guide plate 33, or on the surface opposite to the light guide plate 33.

[0063] The material of the first optical function layer 34A and the material of the adhesive that adheres the first optical function layer 34A to the light guide plate 33 are preferably those having a refractive index close to that of the light guide plate 33 in order to suppress refraction and reflection of light at the interface with the light guide plate 33.

[0064] The light extraction unit 50B has a void portion 51 composed of a plurality of voids 511 inside the first optical functional layer 34A. The first optical functional layer 34A can emit the light incident from the incident surface 34a from the emission surface 34b due to the void portion 51. Since the void portion 51 is provided inside the first optical functional layer 34A, the region of the first optical functional layer 34A where the void portion 51 is provided can function as the first light emission unit 332A from which light is emitted to the outside.

[0065] Since the void portion 51 can have the same configuration as the void portion 51 of the light guide plate 33 of the lighting device 30A provided in the building 1 according to the above-described first embodiment, details of the void portion 51 are omitted. The angle of the interface between the first optical functional layer 34A and the void 511 is preferably designed to be an angle suitable for irradiating the interior of the building 1.

[0066] As the first optical functional layer 34A containing the void portion 51 therein, for example, the optical functional layers disclosed in International Publication No. WO2011 / 124765, International Publication No. WO2011 / 127187, International Publication No. WO2019 / 087118, International Publication No. WO2019 / 182091, etc. can be used. These contents are incorporated herein by reference.

[0067] The void portion 51 of the first optical functional layer 34A can be formed in the same manner as the void portion 51 of the light guide plate 33 of the building 1 according to the above-described first embodiment. That is, for example, a method of laminating a first film 34-1 on which no pattern is formed and a second film 34-2 on which a desired fine pattern is formed by a lamination method, a method of bonding with an adhesive such as a pressure-sensitive adhesive, etc., can be used to produce the void portion 51 inside the first optical functional layer 34A.

[0068] For forming the fine pattern on the second film 34-2, the same method as that for forming the fine pattern on the second film 34-2 of the light guide plate 33 of the building 1 according to the above-described first embodiment can be applied.

[0069] In the lighting device 30B, the light emitted from the light source 31 in the +Z axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z axis direction within the light guide plate 33 while repeating total reflection at the first main face 332 and the second main face 333.

[0070] Then, the light guided within the light guide plate 33 passes through the interface between the light guide plate 33 and the first optical functional layer 34A or is refracted at the interface and enters the first optical functional layer 34A. And a part of the light guided within the first optical functional layer 34A is reflected at the interface between the first optical functional layer 34A and the air gap 511, and is guided toward the first light emitting portion 332A of the first main face 332. Among this reflected light, the light incident on the first main face 332 at an angle exceeding the critical angle exits from the first optical functional layer 34A to the outside.

[0071] The light not reflected at the interface between the first optical functional layer 34A and the air gap 511 is guided in the +Z axis direction while repeating total reflection at the interface between the first optical functional layer 34A and the outside air. A part of this light is reflected at the interface between the air gap 511 and the first optical functional layer 34A, and exits from the light guide plate 33 to the outside.

[0072] Therefore, the lighting device 30B can emit light in the +X axis direction from the first optical functional layer 34A by the light extraction portion 50B.

[0073] Thus, the building according to the present embodiment includes the lattice portion 10 and a plurality of panels 20, and the lighting device 30B is used for one or more panels 20. The lighting device 30B includes a light source 31 and a light guide plate 33, similar to the lighting device 30A of the building 1 according to the above-described first embodiment, and the light guide plate 33 has a light incident end face 331, a first main face 332, and a second main face 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to the present embodiment can function as lighting for illuminating the inside of the building while improving the visibility from one of the inside and the outside of the building to the other, and can maintain high design quality.

[0074] In addition, in the building according to the present embodiment, the lighting device 30B has a light guide portion 32B provided with a first optical function layer 34A on the first main surface 332 of the light guide plate 33, and has a light extraction portion 50B inside the first optical function layer 34A. Thereby, the light guided in the light guide plate 33 can be surely emitted from the first optical function layer 34A into the room through the voids 511 included in the first optical function layer 34A from the first main surface 332 of the light guide plate 33.

[0075] Furthermore, since the first optical function layer 34A has transparency to visible light like the light guide plate 33, a person either inside or outside the building can see from one side to the other side through the light guide plate 33. Therefore, it is possible to suppress a decrease in visibility when looking from one side to the other side inside and outside the building.

[0076] In the present embodiment, as shown in FIG. 9, the light extraction portion 50B may have light scattering particles 52 inside the first optical function layer 34A instead of the void portion 51. The light scattering particles 52 have a refractive index difference with respect to the material constituting the first optical function layer 34A, are particles having an average particle diameter of 0.3 μm to 5 μm, and can function as a light scatterer that scatters the light propagating through the first optical function layer 34A. A plurality of light scattering particles 52 can scatter the light propagating through the first optical function layer 34A and emit it from an emission surface located on the side opposite to the first main surface 332. The optical function layer containing light scattering particles inside is not particularly limited, but for example, the optical function layer disclosed in JP-A-2013-195811 can be used. These contents are incorporated herein by reference.

[0077] In the lighting device 30B shown in FIG. 9, the light guided in the light guide plate 33 enters the first optical function layer 34A by passing through or refracting at the interface between the light guide plate 33 and the first optical function layer 34A. Then, a part of the light guided in the first optical function layer 34A is scattered at the interface between the first optical function layer 34A and the light scattering particles 52, is guided toward the first main surface 332, and is emitted from the first optical function layer 34A to the outside. Note that the portion where light is emitted within the first main surface 332 corresponds to the first light emission portion 332A.

[0078] The light that is not scattered at the interface between the first optical functional layer 34A and the light scattering particles 52 is guided in the +Z-axis direction while repeating total reflection at the interface between the first optical functional layer 34A and the external air. A part of the light is scattered at the interface between the light scattering particles 52 and the first optical functional layer 34A and is emitted to the outside from within the first optical functional layer 34A. The above-described scattering occurs at each of the plurality of light scattering particles 52 provided in the first optical functional layer 34A.

[0079] In this way, the light extraction unit 50B can emit light in the +X-axis direction side from the entire first light emission unit 332A along the plane of the first main surface 332.

[0080] [Third Embodiment] A building according to the third embodiment of the present invention will be described. The building according to the present embodiment is provided with a first optical functional layer outside the first main surface 332 of the light guide plate 33 included in the building 1 according to the above-described first embodiment, and the light extraction unit 50A is provided inside the first optical functional layer.

[0081] FIG. 10 is a side view of the lighting device included in the building according to the present embodiment as viewed from the Y-axis direction. As shown in FIG. 10, the lighting device 30C included in the building according to the present embodiment is the lighting device 30A of the building 1 according to the above-described first embodiment, and instead of the light guide portion 32A, it includes a light guide plate 33 and a first optical functional layer 34B provided outside the first main surface 332 of the light guide plate 33. The light guide portion 32C, and instead of the light extraction unit 50A provided in the light guide plate 33, the light extraction unit 50C is provided on the emission surface located on the side opposite to the first main surface 332 of the first optical functional layer 34B.

[0082] The light guide portion 32C includes a light guide plate 33 and a first optical functional layer 34B provided on the first main surface 332 of the light guide plate 33.

[0083] The first optical functional layer 34B can emit the light incident from the incident surface 34a facing the first main surface 332 through the prism portion 53A from the emission surface 34b.

[0084] The first optical function layer 34B is a layer formed using a material such as resin, and can be formed using the same material as the light guide plate 33. The first optical function layer 34B is preferably composed of a material having a refractive index close to that of the light guide plate 33 in order to suppress refraction and reflection of light at the interface between the light guide plate 33 and the first optical function layer 34B.

[0085] The light extraction portion 50C has a prism portion 53A on the surface of the first optical function layer 34B.

[0086] The formation of the prism portion 53A on the first optical function layer 34B can be applied in the same manner as the formation of the fine pattern on the second film 34-2 of the light guide plate 33 of the building 1 according to the above-described first embodiment.

[0087] The plurality of prism portions 53A can be provided regularly or randomly on the surface of the first optical function layer 34B. The size and adjacent intervals of the prism portions 53A can be appropriately selected within the range that can be formed on the first optical function layer 34B.

[0088] The prism portion 53A includes a fine inclined surface capable of deflecting light. Since the prism portion 53A is provided on the surface of the first optical function layer 34B, the region where the first optical function layer 34B is provided on the first main surface 332 can function as the first light emitting portion 332A. In addition, since the prism portion 53A can increase the amount of light reflected by surfaces other than the inclined surface such as the surface 5211 substantially parallel to the X-axis direction, it is preferable to design the prism portion 53A so that light is incident on surfaces other than the inclined surface such as the surface 5211.

[0089] In the lighting device 30C, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end surface 331, and is guided in the +Z-axis direction within the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333.

[0090] The light guided within the light guide plate 33 passes through the interface between the light guide plate 33 and the first optical functional layer 34B or is refracted at the interface and enters the first optical functional layer 34B. Then, the light guided within the first optical functional layer 34B is scattered at the interface between the prism portion 53A and the air, and light can be emitted from the prism portion 53A to the outside (the indoor side).

[0091] As described above, the building according to this embodiment includes the lattice portion 10 and the plurality of panels 20, and the lighting device 30C is used for one or more of the panels 20. The lighting device 30C includes a light source 31 and a light guide plate 33, similar to the lighting device 30A of the building 1 according to the above-described first embodiment. The light guide plate 33 has a light incident end face 331, a first main face 332, and a second main face 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to this embodiment can function as lighting for illuminating the interior of the building while improving the visibility from one side to the other side between the inside and the outside of the building 1, and can maintain high design quality.

[0092] In addition, in the building according to this embodiment, the lighting device 30C has a light guide portion 32C provided with the first optical functional layer 34B on the first main face 332 of the light guide plate 33, and has a light extraction portion 50C on the surface of the first optical functional layer 34B. Thereby, the light guided within the light guide plate 33 can be surely emitted from the prism portion 53A into the room through the first optical functional layer 34B provided in the light extraction portion 50C from the first main face 332 of the light guide plate 33.

[0093] Furthermore, since the first optical functional layer 34B has permeability to visible light similar to the light guide plate 33, a person on either the inside or the outside of the building can see from one side to the other side through the light guide plate 33. Therefore, it is possible to suppress a decrease in visibility when looking from one side to the other side between the inside and the outside of the building.

[0094] In addition, in this embodiment, as shown in FIG. 11, the light extraction unit 50C may have concavo-convex portions 54A instead of the prism portion 53A. The concavo-convex portions 54A have a plurality of concave and convex portions with a width and height of 1 μm to 50 μm. By being irregularly formed on the surface of the first optical functional layer 34B, the concavo-convex portions 54A can scatter the light guided within the first optical functional layer 34B toward the interior of the room.

[0095] The formation of the concavo-convex portions 54A on the first optical functional layer 34B can apply the same method as the formation of the fine pattern on the second film 34-2 of the light guide plate 33 of the building 1 according to the above-described first embodiment. Also, since the concavo-convex portions 54A may be an irregular rough surface, blasting or the like can also be applied.

[0096] In the lighting device 30C shown in FIG. 11, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z-axis direction within the light guide plate 33 while repeating total reflection at the first main face 332 and the second main face 333. Then, the light guided within the light guide plate 33 enters the interior of the first optical functional layer 34B by passing through the interface between the light guide plate 33 and the first optical functional layer 34B or refracting at the interface. Then, a part of the light guided within the first optical functional layer 34B scatters at the interface between the concavo-convex portions 54A and the air, and exits from the first optical functional layer 34B to the outside. Therefore, even when the light extraction unit 50C has the concavo-convex portions 54A, the lighting device 30C shown in FIG. 11 can emit light from the concavo-convex portions 54A of the first optical functional layer 34B to the interior of the room by the light extraction unit 50C.

[0097] [Fourth Embodiment] A building according to a fourth embodiment of the present invention will be described. The building according to this embodiment is the one in which the light extraction unit 50A provided in the lighting device 30A of the building 1 according to the above-described first embodiment is provided on the first main face 332 of the light guide plate 33.

[0098] FIG. 12 is a view of the lighting device provided in the building according to the present embodiment, as viewed from the Y-axis direction, with the lighting device fitted into the grid portion. As shown in FIG. 12, in the lighting device 30D of the building according to the present embodiment, in the lighting device 30A of the building 1 according to the above-described first embodiment, the light extraction portion 50A provided in the light guide plate 33 is changed to the light extraction portion 50D provided on the first main surface 332 of the light guide plate 33, and the light guiding portion 32A is changed to the light guiding portion 32D provided with the light extraction portion 50D on the first main surface 332 of the light guide plate 33.

[0099] The light extraction portion 50D has concavo-convex portions 54A formed in a concavo-convex shape on the first main surface 332 of the light guide plate 33. Since the concavo-convex portions 54A are provided on the first main surface 332 of the light guide plate 33, the region where the concavo-convex portions 54A are provided on the first main surface 332 can function as the first light emitting portion 332A.

[0100] The concavo-convex portions 54A have a plurality of concave portions and convex portions having a width and height of 1 μm to 50 μm. The concavo-convex portions 54A are irregularly formed on the first main surface 332, and can scatter the light guided in the light guide plate 33 toward the interior of the room.

[0101] For forming the concavo-convex portions 54A on the light guide plate 33, the same method as for forming the fine pattern on the second film 34-2 of the light guide plate 33 of the building 1 according to the above-described first embodiment can be applied. Also, since the concavo-convex portions 54A may be a random rough surface, blasting or the like can also be applied.

[0102] In the lighting device 30D, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end surface 331, and is guided in the +Z-axis direction in the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333. A part of the light guided in the light guide plate 33 is scattered at the interface between the concavo-convex portions 54A and the air, and the light can be emitted from the concavo-convex portions 54A to the outside (indoor side).

[0103] Thus, the building according to this embodiment includes a lattice portion 10 and a plurality of panels 20, and the lighting device 30C is used for one or more panels 20. Similar to the lighting device 30A of the building 1 according to the above-described first embodiment, the lighting device 30C includes a light source 31 and a light guide plate 33. The light guide plate 33 has a light incident end face 331, a first main face 332, and a second main face 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to this embodiment can function as lighting for illuminating the interior of the building while improving the visibility from one of the inside and outside of the building to the other, and can maintain high design quality.

[0104] Further, in the building according to this embodiment, the lighting device 30D includes a light extraction portion 50D on the first main face 332 of the light guide plate 33, and the light extraction portion 50D has uneven portions 54A on the first main face 332, so that the light guided in the light guide plate 33 can be surely emitted into the room from the uneven portions 54A.

[0105] In this embodiment, as shown in FIG. 13, the light extraction portion 50D may have a prism portion 53A instead of the uneven portions 54A. The prism portion 53A can have the same configuration as the prism portion 53A of the lighting device 30C included in the building according to the above-described third embodiment. Therefore, details of the prism portion 53A are omitted. The prism portion 53A can be formed by the same method as the formation of the uneven portions 54A.

[0106] In the lighting device 30D shown in FIG. 13, the light emitted from the light source 31 in the +Z axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the light guide plate 33 in the +Z axis direction while repeatedly undergoing total reflection at the first main face 332 and the second main face 333. Then, a part of the light guided in the light guide plate 33 is scattered at the interface between the prism portion 53A and air, and the light can be emitted from the prism portion 53A to the outside (indoor side). Therefore, even when the light extraction portion 50D has the prism portion 53A, the lighting device 30D shown in FIG. 13 can emit light from the prism portion 53A into the room by the light extraction portion 50D.

[0107] [Embodiment 5] A building according to a fifth embodiment of the present invention will be described. The building according to this embodiment is provided with a second optical function layer outside the second main surface 333 of the light guide plate 33 provided in the building 1 according to the above-described first embodiment, and the light extraction portion 50A is provided inside the second optical function layer.

[0108] FIG. 14 is a view seen from the Y-axis direction of a state in which the lighting device included in the building according to this embodiment is fitted into the lattice portion. As shown in FIG. 14, the lighting device 30E included in the building according to this embodiment is the lighting device 30A of the building 1 according to the above-described first embodiment, and instead of the light guide portion 32A, it includes a light guide plate 33 and a second optical function layer 34C provided outside the second main surface 333 of the light guide plate 33. And instead of the light extraction portion 50A provided in the light guide plate 33, the light extraction portion 50E is provided inside the second optical function layer 34C.

[0109] The light guide portion 32E includes a light guide plate 33 and a second optical function layer 34C provided on the second main surface 333 of the light guide plate 33.

[0110] The second optical function layer 34C is provided on the second main surface 333 of the light guide plate 33. The second optical function layer 34C can emit the light incident from the incident surface 34a facing the second main surface 333 in the direction of the first main surface 332 of the light guide plate 33.

[0111] The light extraction portion 50E has a void portion 51 composed of a plurality of voids 511 inside the second optical function layer 34C. The void portion 51 has a plurality of voids 511 that emit the light incident from the incident surface 34a of the second optical function layer 34C in the direction of the first main surface of the light guide plate 33.

[0112] In the lighting device 30E, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z-axis direction inside the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333.

[0113] The light guided within the light guide plate 33 passes through the interface between the light guide plate 33 and the second optical functional layer 34C or is refracted at the interface and enters the second optical functional layer 34C. Then, a part of the light guided within the second optical functional layer 34C is reflected at the interface between the second optical functional layer 34C and the gap 511. A part of this reflected light is reflected toward the first main surface 332 side and passes through the second optical functional layer 34C and the light guide plate 33. The light guided through the second optical functional layer 34C and the light guide plate 33 can be emitted from the first main surface 332 toward the +X-axis direction side.

[0114] Thus, the building according to the present embodiment includes a lattice portion 10 and a plurality of panels 20, and uses a lighting device 30E for one or more panels 20. The lighting device 30E includes a light source 31 and a light guide plate 33, similar to the lighting device 30A of the building 1 according to the above-described first embodiment. The light guide plate 33 has a light incident end surface 331, a first main surface 332, and a second main surface 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to the present embodiment can function as lighting for illuminating the inside of the building while improving the visibility from one of the inside and the outside of the building to the other, and can maintain high design quality.

[0115] Also, in the building according to the present embodiment, the lighting device 30E has a light guide portion 32E provided with a second optical functional layer 34C on the second main surface 333 of the light guide plate 33, and a light extraction portion 50E having a gap portion 51 is provided inside the first optical functional layer 34A. Thereby, the light guided within the second optical functional layer 34C can be reflected toward the first main surface 332 side at the gap portion 51. Therefore, in the building according to the present embodiment, the light reflected within the light guide plate 33 can be emitted from the first main surface 332 of the light guide plate 33.

[0116] Furthermore, since the second optical functional layer 34C has permeability to visible light, similar to the light guide plate 33, a person on either the inside or the outside of the building can see from one side to the other through the light guide plate 33. Therefore, it is possible to suppress a decrease in visibility when looking from one of the inside and the outside of the building to the other.

[0117] In addition, in the present embodiment, as shown in FIG. 15, the light extraction unit 50E may have light scattering particles 52 in the second optical functional layer 34C instead of the void portion 51. The light scattering particles 52 have a refractive index difference with respect to the material constituting the second optical functional layer 34C, are particles having an average particle diameter of 0.3 μm to 5 μm, and can function as a light scatterer that scatters light propagating through the second optical functional layer 34C. A plurality of light scattering particles 52 can scatter the light propagating through the second optical functional layer 34C and emit it toward the first main surface 332 side. The optical functional layer containing light scattering particles inside is not particularly limited, but for example, the optical functional layer disclosed in JP-A-2013-195811 can be used. These contents are incorporated herein by reference.

[0118] In the illumination device 30E shown in FIG. 15, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z-axis direction in the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333. Then, the light guided in the light guide plate 33 enters the second optical functional layer 34C by passing through the interface between the light guide plate 33 and the second optical functional layer 34C or refracting at the interface. Then, a part of the light guided in the second optical functional layer 34C is scattered at the interface between the second optical functional layer 34C and the light scattering particles 52, and passes through the second optical functional layer 34C and the light guide plate 33. Among the scattered light generated at the interface between the second optical functional layer 34C and the light scattering particles 52, the light incident on the first main surface 332 at an angle not exceeding the critical angle can be emitted from the light guide plate 33 to the outside to irradiate the interior of the building 1. Note that the portion where the light is emitted within the first main surface 332 corresponds to the first light emission unit 332A.

[0119] The light that is not scattered at the interface between the second optical functional layer 34C and the light scattering particles 52 is guided in the +Z-axis direction while repeating total reflection at the interface between the second optical functional layer 34C and the external air. A part of the light is scattered at the interface between the light scattering particles 52 and the second optical functional layer 34C and is emitted from the second optical functional layer 34C to the outside. The above scattering is performed by each of the plurality of light scattering particles 52 provided in the second optical functional layer 34C.

[0120] In this way, the light extraction unit 50E can emit light from the entire first light emitting unit 332A along the plane of the first main surface 332 in the +X-axis direction side.

[0121] [Sixth Embodiment] A building according to the sixth embodiment of the present invention will be described. The building according to this embodiment is provided with a second optical function layer outside the second main surface 333 of the light guide plate 33 included in the building 1 according to the above-described first embodiment, and the light extraction unit 50A is provided inside the second optical function layer.

[0122] FIG. 16 is a view seen from the Y-axis direction of a state where the lighting device included in the building according to this embodiment is fitted in the lattice portion. As shown in FIG. 16, the lighting device 30F included in the building according to this embodiment is the lighting device 30A of the building 1 according to the above-described first embodiment, and instead of the light guide portion 32A, it includes a light guide portion 32F having a light guide plate 33 and a second optical function layer 34D provided outside the second main surface 333 of the light guide plate 33, and instead of the light extraction unit 50A provided in the light guide plate 33, it includes a light extraction unit 50F on the emission surface located on the side opposite to the second main surface 333 of the second optical function layer 34D.

[0123] The light guide portion 32F includes a light guide plate 33 and a second optical function layer 34D provided on the second main surface 333 of the light guide plate 33.

[0124] The second optical function layer 34D can emit the light incident from the incident surface 34a facing the second main surface 333 in the direction of the first main surface 332 of the light guide plate 33.

[0125] The light extraction unit 50F has a prism portion 53B on the outer (-X-axis direction) surface of the second optical function layer 34D. Since the prism portion 53B is the same as the prism portion 53A provided in the lighting device 30C of the building according to the above-described third embodiment, details thereof are omitted. Note that the angle of the inclined surface in the prism portion 53B is preferably set to an angle suitable for irradiating the interior of the building. The formation of the prism portion 53B on the second optical function layer 34D can be applied by the same method as the formation of the fine pattern on the uneven portion 54A on the first optical function layer 34B provided on the light guide plate 33 of the lighting device 30B provided in the building according to the above-described second embodiment. The second optical function layer 34D can emit the light incident from the incident surface 34a facing the second main surface 333 in the direction of the first main surface 332 of the light guide plate 33 by the prism portion 53B.

[0126] In the lighting device 30F, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331 and is guided in the +Z-axis direction in the light guide plate 33 while repeating total reflection at the first main surface 332 and the second main surface 333.

[0127] The light guided in the light guide plate 33 passes through the interface between the light guide plate 33 and the second optical function layer 34D or is refracted at the interface and enters the second optical function layer 34D. Then, a part of the light guided in the second optical function layer 34D is reflected at the interface between the prism portion 53B and the air. A part of this reflected light is reflected toward the first main surface 332 side and passes through the second optical function layer 34C and the light guide plate 33. The light guided in the second optical function layer 34D and the light guide plate 33 can be emitted from the first main surface 332 in the +X-axis direction side.

[0128] Thus, the building according to this embodiment includes a lattice portion 10 and a plurality of panels 20, and a lighting device 30F is used for one or more of the panels 20. The lighting device 30F includes a light source 31 and a light guide plate 33, similar to the lighting device 30A of the building 1 according to the above-described first embodiment. The light guide plate 33 has a light incident end face 331, a first main face 332, and a second main face 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to this embodiment can function as lighting for illuminating the inside of the building while improving the visibility from one of the inside and the outside of the building to the other, and can maintain high design quality.

[0129] Further, in the building according to this embodiment, the lighting device 30F has a light guide portion 32F provided with a second optical function layer 34D on the second main face 333 of the light guide plate 33, and a light extraction portion 50F is provided on the surface of the second optical function layer 34D. Thereby, the light guided in the second optical function layer 34D can be reflected to the first main face 332 side by the prism portion 53B. Therefore, in the building according to this embodiment, the light reflected in the light guide plate 33 can be emitted from the first main face 332 of the light guide plate 33.

[0130] Furthermore, since the second optical function layer 34D has transparency with respect to visible light, similar to the light guide plate 33, a person either inside or outside the building can see from one side to the other through the light guide plate 33. Therefore, it is possible to suppress a decrease in visibility when looking from one of the inside and the outside of the building to the other.

[0131] Note that in this embodiment, as shown in FIG. 17, the light extraction portion 50F may have uneven portions 54B instead of the prism portion 53B. The uneven portions 54B can have the same configuration as the uneven portions 54B of the lighting device 30C included in the building according to the above-described third embodiment. Therefore, details of the uneven portions 54B are omitted.

[0132] In the lighting device 30F shown in Fig. 17, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z-axis direction within the light guide plate 33 while repeating total reflection at the first main face 332 and the second main face 333. Then, the light guided within the light guide plate 33 passes through the interface between the light guide plate 33 and the second optical function layer 34D or is refracted at the interface and enters the second optical function layer 34D. Then, the light guided within the second optical function layer 34D is reflected toward the first main face 332 at the uneven portion 54B and passes through the second optical function layer 34D and the light guide plate 33. The light guided through the second optical function layer 34D and the light guide plate 33 is emitted from the first main face 332 toward the +X-axis direction side. Therefore, even when the light extraction portion 50F of the lighting device 30F shown in Fig. 17 has the uneven portion 54B, the light extraction portion 50F can emit light into the room from the uneven portion 54B of the second optical function layer 34D.

[0133] [Seventh Embodiment] A building according to the seventh embodiment of the present invention will be described. The building according to this embodiment is obtained by providing the light extraction portion 50A provided in the lighting device 30A of the building 1 according to the above-described first embodiment on the second main face 333 of the light guide plate 33.

[0134] Fig. 18 is a view seen from the Y-axis direction of a state where the lighting device provided in the building according to this embodiment is fitted in the lattice portion. As shown in Fig. 18, the lighting device 30G provided in the building according to this embodiment is obtained by changing the light extraction portion 50A provided within the light guide plate 33 in the lighting device 30A of the building 1 according to the above-described first embodiment to the light extraction portion 50G provided on the second main face 333 of the light guide plate 33, and changing the light guide portion 32A to the light guide portion 32G in which the light extraction portion 50G is provided on the second main face 333 of the light guide plate 33.

[0135] The light extraction part 50G is composed of the uneven part 54B formed in an uneven shape on the second main surface 333 of the light guide plate 33. Note that the light extraction part 50G may have other configurations in addition to the uneven part 54B. Since the uneven part 54B is the same as the uneven part 54A provided in the lighting device 30C of the building according to the above-described third embodiment, the details are omitted. The formation of the uneven part 54B on the second main surface 333 can use the same method as the formation of the uneven part 54A on the first optical functional layer 34B provided on the light guide plate 33 of the lighting device 30B provided in the building according to the above-described second embodiment.

[0136] In the lighting device 30G, the light emitted from the light source 31 in the +Z axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z axis direction in the light guide plate 33 while repeating total reflection on the first main surface 332 and the second main surface 333. The light guided in the light guide plate 33 is reflected toward the first main surface 332 side at the interface between the uneven part 54B and the air, and the light guided in the light guide plate 33 can be emitted from the first main surface 332 into the room.

[0137] In this way, the building according to the present embodiment includes the lattice part 10 and a plurality of panels 20, and the lighting device 30G is used for one or more panels 20. The lighting device 30G includes a light source 31 and a light guide plate 33, similar to the lighting device 30A of the building 1 according to the above-described first embodiment, and the light guide plate 33 has a light incident end face 331, a first main surface 332, and a second main surface 333. Therefore, similar to the building 1 according to the above-described first embodiment, the building according to the present embodiment can function as lighting for illuminating the interior of the building while improving the visibility from one of the inside and outside of the building to the other, and can maintain high design quality.

[0138] Further, in the building according to the present embodiment, the lighting device 30G provides the light extraction part 50G on the second main surface 333 of the light guide plate 33, and by configuring the light extraction part 50G with the prism part 53B, the light guided in the light guide plate 33 can be reflected toward the first main surface 332 side by the prism part 53B. Therefore, the building according to the present embodiment can surely emit the light reflected in the light guide plate 33 from the first main surface 332 of the light guide plate 33.

[0139] Furthermore, since the second optical function layer 34D, like the light guide plate 33, has transparency to visible light, a person either inside or outside the building can see from one side to the other through the light guide plate 33. Therefore, it is possible to suppress a decrease in visibility when looking from one side to the other between the inside and the outside of the building.

[0140] In addition, in the present embodiment, as shown in FIG. 19, the light extraction part 50G may have a prism part 53B instead of the uneven part 54B. The prism part 53B can have the same configuration as the prism part 53A of the lighting device 30C provided in the building according to the above-described third embodiment. Therefore, details of the prism part 53B are omitted.

[0141] In the lighting device 30G shown in FIG. 19, the light emitted from the light source 31 in the +Z-axis direction enters the light guide plate 33 through the light incident end face 331, and is guided in the +Z-axis direction in the light guide plate 33 while repeating total reflection at the first main face 332 and the second main face 333. Then, the light guided in the light guide plate 33 is reflected to the first main face 332 side at the interface between the prism part 53B and air, and the light guided in the light guide plate 33 is emitted from the first main face 332 into the room. Therefore, even when the light extraction part 50G has the prism part 53B, the lighting device 30G shown in FIG. 19 can emit light from the prism part 53B into the room by the light extraction part 50G.

[0142] [Eighth Embodiment] A building according to the eighth embodiment of the present invention will be described. The building according to the present embodiment is obtained by providing a low refractive index layer on the second main face 333 side of the light guide plate 33 of the lighting device 30A provided in the building 1 according to the above-described first embodiment.

[0143] FIG. 20 is a view of the lighting device included in the building according to the present embodiment fitted into the grid portion as seen from the Y-axis direction. As shown in FIG. 20, the lighting device 30H included in the building according to the present embodiment has a low refractive index layer 61 and a cover layer 62 laminated in this order on the second main surface 333 of the light guide plate 33 of the lighting device 30A provided in the building 1 according to the above-described first embodiment. Note that a layer having other functions may be included between the surface of the light guide plate 33 and the low refractive index layer 61. Further, the low refractive index layer 61 may be adhered to the light guide plate 33 via an adhesive such as a pressure-sensitive adhesive.

[0144] The low refractive index layer 61 is a layer having a refractive index lower than that of the light guide plate 33. For example, when the light guide plate 33 is mainly composed of PMMA, the refractive index n1 of the light guide plate 33 is around 1.49. In this case, the refractive index n2 of the low refractive index layer 61 is preferably 1.30 or less, and more preferably 1.20 or less.

[0145] The low refractive index layer 61 only needs to have a refractive index lower than that of the light guide plate 33. For example, a low refractive index layer having voids disclosed in International Publication No. 2019 / 146628 can be used. This content is incorporated herein by reference.

[0146] When the incident angle of the light guided by the light guide plate 33 to the low refractive index layer 61 is larger than the critical angle (when incident at a shallow angle) among the light guided by the light guide plate 33, the total reflection condition is satisfied, and the light is totally reflected at the interface between the light guide plate 33 and the low refractive index layer 61. Here, the critical angle θc is represented by the following formula (1). θc = θi = arcsin(n2 / n1) ···(1) Note that θi in formula (1) is the incident angle (angle from the normal line).

[0147] The cover layer 62 is for protecting the light guide plate 33 and preferably has high transmittance for visible light. The cover layer 62 can be manufactured using the same material as the light guide plate 33. Further, the cover layer 62 may have an ultraviolet absorption effect. From the viewpoint of a protective layer, the cover layer 62 preferably has high strength, but may be thin and flexible.

[0148] In the building according to this embodiment, since the lighting device 30H includes the low refractive index layer 61 on the second main surface 333 of the light guide plate 33, it is possible to reduce the loss of light guided in the light guide plate 33 due to scratches, dirt, fingerprints, etc., so that the utilization efficiency of the light emitted from the light source 31 can be improved.

[0149] Also, in the building according to this embodiment, by providing the low refractive index layer 61 between the cover layer 62 and the light guide plate 33 in the lighting device 30H, it is possible to reduce the light guided in the light guide plate 33 from reaching the foreign matter C adhering to the surface of the cover layer 62.

[0150] For example, as shown in FIG. 21, when the cover layer 62 is provided on the surface of the light guide plate 33 and the low refractive index layer 61 is not provided, if foreign matters such as scratches, dirt, fingerprints, sweat, and dust adhere to the surface of the cover layer 62, among the light guided in the light guide plate 33, the light directed toward the cover layer 62 side may be scattered by the foreign matters and leak out of the light guide plate 33 to the outside, resulting in light loss. In the building according to this embodiment, as shown in FIG. 22 for example, the lighting device 30H provides the low refractive index layer 61 between the cover layer 62 and the light guide plate 33, so that even if foreign matters adhere to the surface of the cover layer 62, it is possible to reduce the light guided in the light guide plate 33 from reaching the foreign matters adhering to the surface of the cover layer 62, and thus reduce the loss of the light emitted from the light source 31.

[0151] Therefore, the building according to this embodiment can further function more effectively as lighting for illuminating the interior of the building by including the lighting device 30H.

[0152] In addition, in the present embodiment, the low refractive index layer 61 may be provided on at least a part of the second main surface 333.

[0153] In the present embodiment, the low refractive index layer 61 only needs to be provided on at least one of the first main surface 332 side and the second main surface 333 side of the light guide plate 33. For example, as shown in FIG. 23, the low refractive index layer 61 may be provided on both the first main surface 332 and the second main surface 333 of the light guide plate 33, or as shown in FIG. 24, the low refractive index layer 61 may be provided on the first main surface 332 of the light guide plate 33.

[0154] In the present embodiment, when the first optical function layer 34A is provided on the first main surface 332 of the light guide plate 33 as in the lighting device 30B of the building according to the above-described second embodiment, the low refractive index layer 61 may be provided on at least a part of the first optical function layers 34A and 34B provided on at least one of the first main surface 332 and the second main surface 333, and the second optical function layers 34C and 34D.

[0155] As described above, the embodiments have been described. However, the above embodiments are presented as examples, and the present invention is not limited by the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

[0156] This application claims priority based on Japanese Patent Application No. 2020-127350 filed with the Japan Patent Office on July 28, 2020, and incorporates the entire contents of Japanese Patent Application No. 2020-127350 into this application.

Description of Reference Numerals

[0157] 1 Building 10 Lattice part 11 First skeletal member 12 Second skeletal member 20 Panel 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H Lighting device 31 Light source 32A, 32B, 32C, 32D, 32E, 32F, 32G Light guide part 33 Light guide plate 331 Light incident end face 332 First main surface 333 Second main surface 34A, 34B First optical function layer 34C, 34D Second optical function layer 50A, 50B, 50C, 50D, 50E, 50F, 50G Light extraction part 51 Gap part 511 Gap 52 Light scattering particles 53A, 53B Prism part 54A, 54B Concavo-convex part 61 Low refractive index layer

Claims

1. A lattice part formed by a plurality of first skeleton members erected at a predetermined interval and a plurality of second skeleton members connecting the adjacent first skeleton members, A plurality of panels held by the lattice part, A building comprising: One or more of the panels are transparent to visible light, One or more of the panels that are transparent to visible light are lighting devices that irradiate toward the inside of the building, The lighting device, A light source, A light guide plate that guides the light emitted from the light source and has a light guide part that is transparent to visible light, and comprises, The light guide plate, A light incident end face that faces the light source and into which the light emitted from the light source is incident, A first main face that is inside the building and from which the light guided inside the light guide plate is emitted, A second main face that is outside the building and faces the first main face, A building having.

2. The building according to claim 1, wherein the light guide part has a light extraction part that emits the light guided inside the light guide plate from the first main face.

3. The building according to claim 2, wherein the light extraction part has an air gap part formed of a plurality of air gaps that totally reflect the light propagating through the light guide plate and emit it from the first main face or a plurality of light scattering particles that scatter the light propagating through the light guide plate and emit it from the first main face.

4. The light guide part is provided on the first main face side of the light guide plate and comprises a first optical function layer that emits the light incident from the first main face from an emission face located on the side opposite to the first main face, The building according to claim 2, wherein the light extraction part has an air gap part formed of a plurality of air gaps or light scattering particles inside the first optical function layer.

5. The light guide part is provided on the first main face side of the light guide plate and comprises a first optical function layer that emits the light incident from the first main face from an emission face located on the side opposite to the first main face, The building according to claim 2, wherein the light extraction part has a prism part on the emission face of the first optical function layer.

6. The building according to claim 2, wherein the light extraction part has a concavo-convex part formed in a concavo-convex shape on the first main face or the second main face.

7. The light guide part is provided on the second main face side of the light guide plate and comprises a second optical function layer that emits the light incident from the second main face in the direction of the first main face of the light guide plate, The building according to claim 2, wherein the light extraction part has an air gap part formed of a plurality of air gaps or light scattering particles inside the second optical function layer.

8. The light guide part is provided on the second main surface side of the light guide plate, and includes a second optical function layer that emits the light incident from the second main surface in the direction of the first main surface of the light guide plate. The building according to claim 2, wherein the light extraction part has a prism part on a surface of the second optical function layer that is located on the side opposite to the second main surface. **Claim 9** The building according to any one of claims 1 to 8, wherein the light guide part includes a low refractive index layer having a lower refractive index than the light guide plate on at least one of the first main surface side and the second main surface side. **Claim 10** The building according to any one of claims 1 to 9, wherein the building is a greenhouse for plant cultivation.

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