JP2016100219A - Daylighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a daylighting system capable of suppressing the decay of light brought thereinto.SOLUTION: A daylighting system 1 includes a daylighting part 3 through which light is brought thereinto, and a bent part 5 for guiding the light brought through the daylighting part into a predetermined space, the bent part having a curved-surface reflecting portion for changing the moving direction of the light brought through the daylighting part, the curved-surface reflecting portion having an elliptical arc face or a plurality of polygonal faces each having an end located on the elliptical arc face. An angle formed between the long-axis direction of the elliptical arc face and the normal direction of the emission end face of the bent part is smaller than an angle formed between the light incidence direction into the bent part and the normal direction of the emission end face of the bent part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a daylighting system that actively uses natural light for daylighting.

Attention has been focused on technology for reducing energy consumption by actively using natural light for daylighting to reduce the amount of carbon dioxide generated.
As one of the techniques, an optical duct that guides external light to a predetermined indoor space is known. The optical duct has a problem in that the amount of light gradually attenuates when light propagates through a light propagation path provided indoors. Therefore, in Patent Document 1, the shape of the bent portion of the optical duct is devised to reduce the number of times of light reflection on the inner surface of the optical duct, thereby suppressing light attenuation.

Japanese Unexamined Patent Publication No. 4-271303

  However, the bent portion of the optical duct of Patent Document 1 has a planar shape, and most of the light reflected by the bent portion is further reflected by the inner surface of the optical duct, and the amount of light is attenuated at that time. Resulting in.

  That is, the optical duct of Patent Document 1 can reduce the number of reflections of light propagating in the optical duct, but is highly likely to cause multiple reflections on the inner surface of the optical duct, and can suppress light attenuation. Not necessarily.

  The problem to be solved by the present invention is to provide a daylighting system capable of suppressing attenuation of light taken in.

In order to solve the above problems, in one aspect of the present invention, a daylighting unit that takes in light;
A bending portion that guides the light taken in by the daylighting portion to a predetermined space,
The bent portion has a curved reflecting portion that changes the traveling direction of the light taken in by the daylighting portion,
The curved reflecting portion has an elliptical arc surface, or a plurality of bent surfaces with respective end portions located on the elliptical arc surface,
The angle formed by the major axis direction of the elliptical arc surface and the normal direction of the exit end face of the bent portion is smaller than the angle formed by the light incident direction to the bent portion and the normal direction of the exit end face of the bent portion. A daylighting system is provided.

A first light guide for propagating the light taken in by the daylighting unit in a predetermined direction,
The bent portion changes the traveling direction of the light emitted from the emission end face of the first light guide portion,
The angle formed between the major axis direction of the elliptical arc surface and the normal direction of the exit end surface of the bent portion is the normal direction of the exit end surface of the first light guide portion and the normal direction of the exit end surface of the bent portion. It may be smaller than the angle made.

  Of the first focal point and the second focal point on the major axis of the elliptical arc surface, the first focal point closer to the elliptical arc surface may be located inside the first light guide unit or the bent portion.

  The first focal point may be located on an emission end surface of the first light guide unit.

  The second focal point may be arranged behind the light exit direction of the bent portion in the light traveling direction.

The elliptical arc surface has an area of ¼ from the major axis to the minor axis of the ellipsoidal surface,
The exit end surface of the bent portion may be a region in contact with the minor axis of the ellipsoid.

  The ratio of the major axis to the minor axis of the elliptical arc surface may be √2 or more.

In another aspect of the present invention, a daylighting unit that takes in light,
A bending portion that guides the light taken in by the daylighting portion to a predetermined space,
The bent portion has a curved reflecting portion that changes the traveling direction of the light taken in by the daylighting portion,
The curved reflecting portion has a parabolic surface, or a plurality of bent surfaces with respective end portions located on the parabolic surface,
The angle formed by the axial direction of the paraboloid and the normal direction of the exit end face of the bent portion is smaller than the angle formed by the light incident direction to the bent portion and the normal direction of the exit end face of the bent portion. A daylighting system is provided.

A first light guide for propagating light taken by the daylighting unit in a predetermined direction;
The bent portion changes the traveling direction of the light emitted from the emission end face of the first light guide portion,
The angle formed between the axial direction of the paraboloid and the normal direction of the exit end face of the bent portion is the normal direction of the exit end face of the first light guide portion and the normal direction of the exit end face of the bent portion. It may be smaller than the angle made.

  The focal point of the paraboloid may be located inside the first light guide part or the bent part.

  The focal point of the paraboloid may be located on the emission end face of the first light guide.

  You may provide the 2nd light guide part which guides the light radiate | emitted from the output end surface of the said bending part to a predetermined direction.

The daylighting unit has an incident surface for taking in light,
The curved reflecting portion may be provided inside the surface on the incident surface side in the bent portion.

  According to the present invention, it is possible to efficiently suppress the attenuation of light taken in.

The longitudinal cross-sectional view which shows typically the building where the lighting system was attached. Sectional drawing which shows the principal part of the lighting system of FIG. The longitudinal cross-sectional view which shows typically the building provided with the lighting system which provided the 2nd light guide part. The figure which shows the example which has an elliptical arc surface of 1/4 length of an elliptical surface. Sectional drawing which shows an example of the internal structure of a lighting panel. Sectional drawing which shows another example of the internal structure of a lighting panel. The figure which shows the cross-sectional shape of the bending part by 2nd Embodiment. The figure which shows the lighting system 1 of the comparative example which made the curved surface reflection part of the bending part the inclined surface which hardly curves. (A)-(d) is a figure which shows a simulation result.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product. FIGS. 1-9 is a figure for demonstrating one Embodiment by this invention. Among these, FIG. 1 is a longitudinal sectional view schematically showing a building 2 to which a daylighting system 1 is attached.

  In the present specification, terms such as “panel”, “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in names. Therefore, for example, a “panel” is a concept including members that can also be called plates, sheets, and films. As a specific example, the “lighting panel” includes members called “lighting plate”, “lighting sheet”, “lighting film”, and the like.

  The daylighting system 1 in FIG. 1 is attached at the time of construction of a building 2 or after construction, and is for taking in light and guiding it to a predetermined space, for example, a room in the building 2.

  The daylighting system 1 in FIG. 1 includes a daylighting unit 3 that takes in light, a first light guide unit 4 that propagates light emitted from the daylighting unit 3 in a predetermined direction, and light emitted from the first light guide unit 4. And a bent portion 5 that changes the traveling direction of. In the example of FIG. 1, the daylighting unit 3 and the first light guide unit 4 are arranged along the outer wall of the building 2, and the bent portion 5 is connected to the emission end face of the first light guide unit 4. The end surface 5a is joined to the outer wall of the building 2 with or without the diffusion member 6 interposed therebetween. Then, the light collected by the daylighting unit 3 is guided to, for example, a room in the building 2 via the first light guide unit 4 and the bent portion 5.

  The daylighting system 1 in FIG. 1 can use the light collected by the daylighting unit 3 as, for example, room illumination light. That is, by using the daylighting system 1 of FIG. 1, energy saving can be achieved and it can contribute to the reduction of carbon dioxide.

  FIG. 2 is a cross-sectional view showing a main part of the daylighting system 1 of FIG. 1, and shows a cross-sectional structure along the light propagation direction of the first light guide part 4 and the bent part 5. The first light guide 4 and the bent portion 5 are both hollow cylindrical members, and light propagates through the hollow portions of the first light guide 4 and the bent portion 5. The inner surfaces of the first light guide portion 4 and the bent portion 5 are made of a highly reflective material so that the light is not excessively attenuated during light propagation. The cross-sectional shapes of the hollow portions of the first light guide portion 4 and the bent portion 5 are not particularly limited, and may be rectangular or circular, for example, or other shapes.

  The daylighting unit 3 is provided to stably take in light whose incident direction varies depending on the season and time zone. The daylighting unit 3 has a daylighting panel 21 for taking in light, particularly outside light. The light taken in by the daylighting panel 21 is light including a plurality of components belonging to different wavelength bands, and is typically natural light represented by sunlight. The first light guide portion 4 and the bent portion 5 constitute a hollow optical duct, and the emission end face 5 a side of the bent portion 5 is joined to a hole provided in the outer wall of the building 2 without a gap. In addition, you may arrange | position the output end surface 5a of the bending part 5 to the inner wall face of the building 2, and may provide in an indoor side rather than an inner wall face. In this case, a part of the optical duct is arranged indoors.

  In the example of FIG. 2, the diffusing member 6 is disposed on the exit end surface 5a of the bent portion 5 to diffuse the light emitted from the exit end surface 5a of the bent portion 5, but the diffusing member 6 is an essential configuration. Instead, the light emitted from the emission end face of the first light guide 4 may be emitted directly into the room, or the light may be emitted into the room via an optical member other than the diffusion member 6. However, if the emission end face 5a of the bent portion 5 is exposed, foreign matters such as airborne substances may enter the bent portion 5 and cause lighting performance to deteriorate. Therefore, it is desirable to seal the emission end surface 5a of the bent portion 5 with the diffusion member 6 or a transparent base material.

  The exit end face 5a of the bent portion 5 in the daylighting system 1 according to the present embodiment can be attached not only to the outer wall of the building 1 but also to a window. Thereby, external light can be guide | induced to the indoor predetermined direction through a part of window. In particular, in the case of the north side window, sunlight is not directly incident, and the amount of outside light that can be taken in is limited. Therefore, by providing the daylighting system 1 according to the present embodiment in the north side window, a larger amount of light can be taken in. It becomes like this.

  1 and 2 show an example in which light from the first light guide 4 is incident on the bent portion 5, the first light guide 4 and the bent portion 5 may be integrally formed. . That is, the daylighting unit 3 side of the bent portion 5 may extend in one direction and be connected to the daylighting unit 3. As described above, the term “first light guide unit 4” is functionally expressed, and the first light guide unit 4 and the daylighting unit 3 are not necessarily arranged separately.

  One of the features of the daylighting system 1 in FIG. 2 is the structure of the bent portion 5. The bent portion 5 has a curved reflecting portion 7 inside the surface of the daylighting unit 3 on the daylighting panel 21 side. That is, the curved reflecting portion 7 is provided on the inner surface of the curved surface of the bent portion 5 far from the building 2. The curved reflecting portion 7 has an elliptical arc surface or a plurality of bent surfaces each having an end portion located on the elliptical arc surface. The curved surface reflection unit 7 is a surface that regularly reflects, that is, specularly reflects light from the daylighting unit 3. Even when this surface is formed by a plurality of bent surfaces, since it can be approximately regarded as an elliptical arc surface, hereinafter, it is generically called an elliptical arc surface or an elliptical arc mirror surface.

  FIG. 2 illustrates an ellipse 10 obtained by cutting the ellipsoid along a plane passing through the major axis 8 and the minor axis 9. The cross section of the elliptical arc surface of the bent portion 5 is a part of the ellipse 10 shown by a broken line in FIG. 2 (for example, an elliptical arc 10a that is 1/4 of the ellipse 10). The ellipse 10 has two focal points located on the major axis 8 as shown in FIG. Hereinafter, these focal points are referred to as a first focal point 11 and a second focal point 12.

  As indicated by an arrow line in FIG. 2, the light passing through the first focal point 11 of the ellipse 10 is reflected on the elliptical arc 10 a and passes through the second focal point 12. Therefore, if the ellipticity represented by the ratio of the major axis 8 to the minor axis 9 of the ellipse 10 is made sufficiently long, the light passing through the first focal point 11 and reflected on the elliptical arc 10a is regarded as almost parallel light. be able to. That is, in FIG. 2, the arrow lines y1 to y3 are not parallel light, but if the ellipticity is sufficiently large, the arrow lines y1 to y3 become substantially parallel light.

  In the present embodiment, the cross section of the curved reflecting portion 7 of the bent portion 5 is approximated to the elliptical arc 10a or the elliptical arc 10a so that the light emitted from the emission end surface 5a of the bent portion 5 approaches parallel light. The shape approximated to the elliptical arc 10a is a shape in which the cross section of the bent portion 5 is formed by connecting a plurality of broken lines so that the corners of each bent line are positioned in the shape of the elliptical arc 10a.

  In addition, the whole curved surface reflection part 7 does not need to be an elliptical arc surface, and only a part of the curved surface reflection part 7 may be an elliptical arc surface. However, in the following, for the sake of simplification of explanation, an example in which the entire curved surface reflection portion 7 is in the shape of an elliptic arc 10a will be described.

  As shown in FIG. 2, the light passing through the first focal point 11 and reflected by the elliptical arc 10 a passes through the second focal point 12, but the light passing through the second focal point 12 is not completely parallel light. Therefore, in the present embodiment, the angle between the direction of the major axis 8 of the elliptical arc 10a and the normal direction of the exit end surface 5a of the bent portion 5 is the normal direction of the exit end surface of the first light guide portion 4 and the bent portion 5. The condition that the angle is smaller than the angle formed with the normal direction of the emission end face 5a is satisfied. If this condition is satisfied, the light reflected by the elliptical arc 10a propagates in a direction closer to parallel light and is emitted from the emission end face 5a of the bent portion 5.

  In the present embodiment, the first focal point 11 is provided inside the first light guide part 4 or the bent part 5. In this case, if the curved reflection portion 7 of the bent portion 5 is an ideal elliptical arc surface, the light that has passed through the first focal point 11 is reflected by the elliptical arc surface and passes through the second focal point 12. Therefore, if the ratio of the major axis 8 to the minor axis 9 of the elliptical arc 10a is sufficiently large, the light emitted from the emission end face 5a of the bent portion 5 becomes substantially parallel light. Thereby, when the output end surface 5a of the bent portion 5 is provided on the outer wall or window of the building, it is possible to allow outside light to reach the back of the room. In addition, by directing the normal direction of the emission end face 5a in a predetermined direction, it is possible to selectively illuminate the indoor target direction with outside light.

  The fact that the light reflected by the elliptical arc surface of the bent portion 5 becomes substantially parallel light means that the light reflected by the elliptical arc surface of the bent portion 5 is likely to be emitted from the bent portion 5 without being further reflected. Means. For example, in FIG. 2, if the second focal point 12 is ahead of the exit end face 5 a of the bent portion 5, the light reflected by the elliptical arc surface travels toward the second focal point 12, and thus the bent portion 5. The light is emitted from the bent portion 5 without being reflected on the inner surface. Thereby, according to the bending part 5 by this embodiment, the frequency | count of reflection of light can be reduced, and attenuation of the light by reflection in the inner surface of the bending part 5 can be suppressed to the minimum.

  The light emitted from the emission end face of the first light guide 4 does not necessarily pass through the first focal point 11. The light that has reached the elliptical arc surface without passing through the first focal point 11 will not pass through the second focal point 12, which may be a factor that hinders parallelization of the light emitted from the bent portion 5. However, if the first focal point 11 is set inside the first light guide part 4 or the bent part 5, the light emitted from the emission end face of the first light guide part 4 is slightly different. Also passes in the vicinity of the first focal point 11, passes through the vicinity of the second focal point 12 after being reflected by the elliptical arc surface. Therefore, the light emitted from the bent portion 5 is almost parallel light.

  On the other hand, the second focal point 12 may be provided inside the bent portion 5, or may be provided behind the emission end surface 5 a of the bent portion 5 in the light traveling direction. The farther the second focus 12 is from the first focus 11, the more parallel the light emitted from the bent portion 5 can be. However, since the size of the elliptical arc surface increases, What is necessary is just to set the position of the 2nd focus 12 by the trade-off with the need of how much the light radiate | emitted from the part 5 needs to be made parallel, and the size of an elliptical arc surface.

  As described above, the curved reflecting portion 7 is provided inside the surface of the bent portion 5 on the daylighting panel 21 side. The inner surface of the bent portion 5 disposed to face the curved reflecting portion 7 is a curved reflecting surface. The elliptical arc surface of the curved reflecting portion 7 and the reflecting surface arranged opposite to each other are directly connected to each other through another reflecting surface to form the inner surface of the bent portion 5. More specifically, when the cross-sectional shape when the bent portion 5 is cut in a direction orthogonal to the traveling direction of light is a rectangle, the surface connected to the daylighting panel 21 is an elliptical arc surface, and the other three surfaces have some shape. It is a reflective surface. In addition, when the cross-sectional shape when the bent portion 5 is cut in a direction orthogonal to the traveling direction of light is circular, the elliptical arc surface and the reflective surface arranged opposite to each other are continuously connected. The boundary is no longer clear. As described above, the boundary line of the curved reflection portion 7 does not always exist. In the present embodiment, the inner surface of the bent portion 5 on the daylighting panel 21 side is the curved reflecting portion 7, but any curved surface shape other than the curved reflecting portion 7 of the bent portion 5 is arbitrary. It is.

  The inner surface of the bent portion 5 including the curved reflecting portion 7 and the inner surface of the first light guide portion 4 are made of, for example, a high reflectivity material such as silver, aluminum, or a dielectric multilayer film, and the first light guide portion 4 and the bent portion. It is formed by coating the inner surface of the cylindrical base material of the part 5. For example, when the cross section of the bent portion 5 in the direction orthogonal to the light propagation direction is rectangular, prepare four thin plate substrates made of resin, metal material, etc. A reflectance material is coated, and one of the thin plate base materials is deformed into an elliptical arc surface by pressing or the like to form a thin plate base material having an elliptical arc surface. Similarly, a thin plate base material having a reflective surface is also formed, and the bent end portions 5 are formed by welding the longitudinal end surfaces of the four thin plate base materials.

  In FIG. 1, the exit end surface 5 a of the bent portion 5 is used as the exit port of the daylighting system 1. However, as shown in the daylighting system 1 of FIG. 3, the second light guide portion 13 connected to the exit end surface 5 a of the bent portion 5. And the exit end face of the second light guide unit 13 may be used as the exit port of the daylighting system 1.

  3 extends along the normal direction of the exit end surface 5a of the bent portion 5, and the normal direction of the exit end surface of the second light guide portion 13 and the exit end surface 5a of the bent portion 5. It is parallel to the normal direction. Thereby, the light emitted from the emission end face 5 a of the bent portion 5 propagates through the second light guide portion 13 and is emitted from the second light guide portion 13 while maintaining a substantially parallel state.

  When providing the 2nd light guide part 13 like FIG. 3, the 2nd focus 12 in the elliptical arc surface of the bending part 5 is provided in the inside of the 2nd light guide part 13, for example. For example, when the second light guide unit 13 indicated by a broken line in FIG. 2 exists, the second focal point 12 is provided at a predetermined position on the upper surface of the second light guide unit 13. In this case, as shown by the arrow line in FIG. 2, the light passing through the first focal point 11 and reflected by the elliptical arc surface of the bent portion 5 passes through the second focal point 12. If the second focal point 12 is provided deep inside the second light guide part 13 beyond the emission end face 5a of the bent part 5, the distance from the elliptical arc surface is increased. It can be made more parallel. Thereby, the frequency | count of reflection of the light in the 2nd light guide part 13 can be decreased, and attenuation of the light during passing through the 2nd light guide part 13 can be suppressed.

  FIG. 2 shows an example in which the second focal point 12 is provided on the inner surface on the upper surface side of the second light guide unit 13, but the second focal point 12 is provided in the vicinity of the radial center of the second light guide unit 13. For example, the light can be emitted from the second light guide unit 13 without reflecting the light on the inner surface of the second light guide unit 13.

  Next, when the cross section of the elliptical arc surface in the curved reflecting portion 7 of the bent portion 5 is an ideal elliptical arc 10a, the major axis a which is the length of the major axis 8 of the elliptical arc 10a is changed to the minor axis which is the length of the minor axis 9. The range of the ellipticity a / b that is a value divided by b will be described. In FIG. 4, the second light guide unit 13 is connected to the emission end surface 5 a of the bent part 5, and the cross section of the elliptical arc surface of the bent part 5 is a part of an ideal elliptical surface. The example which is the elliptical arc surface of 1/4 length is shown. The exit end surface 5a of the bent portion 5 is an end portion of an elliptical arc surface that is ¼ of the length of the elliptical surface, and the direction of the incident end surface of the second light guide portion 13 coincides with the direction of the minor axis 9 of the elliptical surface. Yes.

  Assuming that the elliptical surface is regularly reflected, the light that has passed through the first focal point 11 of the elliptical surface passes through the second focal point 12 after being reflected by the elliptical surface. As described above, in the present embodiment, the light beam reflected by the ellipsoid and incident on the second light guide unit 13 is closer to the direction parallel to the normal direction of the incident surface of the second light guide unit 13. Is desirable. In order to approach parallelism, it is desirable that the angle range (θ in FIG. 4) of the light passing through the second focal point 12 after being reflected by the ellipsoid is as small as possible. As described above, there is actually light that does not pass through the first focal point 11 and reaches the ellipsoidal surface, but these light also pass through the vicinity of the first focal point 11, and as a result, Since the light passes through the vicinity of the second focal point 12 after being reflected by the ellipsoidal surface, only light passing through the first focal point 11 is considered here.

  The angle range θ in FIG. 4 is maximized when light rays are incident on the position of the exit end face 5 a of the bent portion 5. The angle in this case is θmax. The angle θmax is an angle with respect to the longitudinal direction of the second light guide portion 13 of the light that is reflected by the emission end surface 5a of the bent portion 5 and travels toward the second focal point 12.

  The angle θmax decreases as the ellipticity a / b increases, that is, as the ellipse 10 becomes elongated along the major axis 8. If the angle θmax is 45 ° or less, it can be said that the light reflected by the elliptical arc surface of the bent portion 5 travels in a direction close to parallel, if not parallel. Therefore, in defining the ellipticity of the elliptical arc surface of the bent portion 5, the angle θmax is set to 45 ° or less.

The condition for the angle θmax = 45 ° is when the distance k from the center of the ellipse 10 which is a cross section of the ellipsoid to the focal point is equal to the minor axis b, and is expressed by the following equation (1).

When this equation (1) is transformed,
Therefore, to make the angle θmax ≦ 45 °,
It is necessary to.

  Next, the configuration of the daylighting unit 3 will be described. As shown in FIG. 2, the daylighting unit 3 includes a daylighting panel 21 on which light is incident, and a counter panel 31 disposed to face the daylighting panel 21. The distance S between the reflection surface of the opposing panel 31 and the light output side surface of the daylighting panel 21 gradually increases according to the position along the uniaxial direction d1.

  Side panels are respectively provided on both sides of the daylighting panel 21 and the opposing panel 31. Each side panel is connected to the edges of the daylighting panel 21 and the opposing panel 31 along the direction orthogonal to both the uniaxial direction d1 and the normal direction of the daylighting panel 21, that is, the depth direction of the paper surface in FIG. . A reflective surface is formed on the inner surface of the side panel in the same manner as the opposing panel 31.

  The daylighting panel 21, the opposing panel 31, and the both side panels form an opening on one side in the uniaxial direction d1, and this opening is the emission end surface 3a of the daylighting unit 3, and the first light guide portion is formed on the emission end surface 3a. 4 is connected.

  FIG. 5 is a cross-sectional view showing an example of the internal structure of the daylighting panel 21. The daylighting panel 21 of FIG. 5 has a light incident surface in which first and second surfaces that are non-parallel to each other are alternately arranged. The first surface 22 a is inclined with respect to the vertical direction that coincides with the light output side surface 23 of the daylighting panel 21. The first surface 22a is inclined with respect to the vertical direction so as to face upward. On the other hand, each second surface 22 b is inclined to the opposite side to the first surface 22 a with respect to the light output side surface 23 or is orthogonal to the light output side surface 23. In the illustrated example, the second surface 22b is inclined with respect to the vertical direction so as to face downward.

  Accordingly, as shown in FIG. 3, most of the light L31 and L32 from above in the vertical direction is incident on the first surface 22a of the light incident side surface 22 and refracted, and then is emitted in parallel with the vertical direction. The light is further refracted by the side surface 23 and enters the daylighting unit 3. Thereby, the light transmitted through the daylighting panel 21 from the upper side to the lower side in the vertical direction is deflected in the traveling direction so that the inclination angle with respect to the vertical direction becomes small, and propagates in the direction of the first light guide unit 4. .

  The internal structure of the daylighting panel 21 is not limited to that shown in FIG. For example, FIG. 6 is a cross-sectional view showing another example of the internal structure of the daylighting panel 21. The daylighting panel 21 in FIG. 6 has a support plate 22, a bonding layer 23, a light-transmitting light-transmitting base material 24, and a molding base material 26, which are sequentially stacked from the light incident side toward the light-emitting side. Structure. As the support plate 22, for example, a glass plate or an acrylic plate can be used. As the bonding layer 23, a bonding material known per se can be used. In addition, the shaping | molding base material 26 is a base material required in order to manufacture the lighting panel 21, as mentioned later.

  In the translucent substrate 24, a plurality of reflectors 25 arranged along a uniaxial direction d1 extending in a plane parallel to the first surface 24a are provided. Each reflector 25 is inclined downward in the vertical direction d1 with respect to the horizontal direction nd from the first surface 24a side to the second surface 24b side. The angle θ at which the reflecting material 25 is inclined downward with respect to the normal direction nd is determined according to the incident directions of the lights P1 and P2 intended to change the traveling direction. For example, the traveling direction of the light P1 from the sun having a relatively low altitude such as the time zone of winter or morning or evening is changed so as to be directed further downward by the reflector 25, so that the time zone of the daytime in summer is changed. It is intended to transmit such light P2 from the sun having a relatively high altitude while maintaining the traveling direction.

  The internal structure of the daylighting panel 21 is not limited to that shown in FIG. 5 or FIG. Any structure may be used as long as the light incident on the daylighting unit 3 can be efficiently propagated to the light guide unit.

  Thus, in the first embodiment, the curved reflection portion 7 of the bent portion 5 provided on the daylighting panel 21 side of the daylighting portion 3 is an elliptical arc surface, the direction of the major axis 8 of the elliptical arc surface and the emission end surface of the bent portion 5 In order to make the angle made by the normal direction of 5a smaller than the angle made by the normal direction of the outgoing end face of the first light guide part 4 and the normal direction of the outgoing end face 5a of the bent part 5, The light reflected by the elliptical arc surface can be collimated. Thereby, the frequency | count that the light after reflecting by the elliptical arc surface of the bending part 5 is reflected by the inner surface of the bending part 5 can be reduced, and attenuation | damping of the light radiate | emitted from the output end surface 5a of the bending part 5 can be suppressed. . Therefore, the light incident on the daylighting system 1 can be efficiently guided to a predetermined space, and illumination using the natural light effectively is possible. Therefore, the amount of carbon dioxide emission can be reduced and energy saving can be achieved. In particular, according to the present embodiment, since the light emitted from the emission end face 5a of the bent portion 5 can be collimated, it is possible to allow outside light to reach the interior of the interior and to aim indoors. It is also possible to selectively illuminate the direction with external light.

(Second Embodiment)
In the second embodiment, at least a part of the curved reflecting portion 7 of the bent portion 5 is a paraboloid. Other than this, the configuration is the same as in the first embodiment, and therefore, the following description will focus on differences from the first embodiment.

  FIG. 7 is a diagram showing a cross-sectional shape of the bent portion 5 according to the second embodiment. The curved surface reflecting portion 7 of the bent portion 5 according to the second embodiment has a parabolic surface or a plurality of bent surfaces each having its end positioned on the parabolic surface. The paraboloid having a paraboloid or a plurality of bent surfaces is a surface that specularly reflects, that is, specularly reflects light from the first light guide unit 4.

  A paraboloid is obtained by rotating a parabola around the axis of a parabola composed of quadratic functions. In this specification, the axis of the parabola used to generate the paraboloid is called the axis of the paraboloid. The paraboloid may have a shape generated by sweeping a parabola in the normal direction.

  The axis of the paraboloid extends parallel to the normal direction of the emission end face 5a of the bent portion 5. Although FIG. 7 shows an example in which the second light guide unit 13 is connected to the emission end surface 5a of the bent portion 5, the second light guide unit 13 may be omitted. When the second light guide unit 13 is not provided, another optical member such as the diffusing member 6 may be disposed on the exit end surface 5a of the bent portion 5, or the exit end surface 5a of the bent portion 5 may be used as the exit port of the daylighting system 1. It is good.

  A parabolic focal point 14 is provided on the axis 15. The light passing through the focal point 14 is reflected on the paraboloid and travels in a direction substantially parallel to the axis of symmetry. Therefore, if the normal direction of the exit end face 5a of the bent portion 5 is arranged in a direction parallel to the axis 15 of the paraboloid, the light reflected by the curved reflecting portion 7 made of a paraboloid will be emitted from the exit end face of the bent portion 5. It proceeds in the normal direction of 5a. As a result, at least light that has passed through the focal point 14 is reflected by the paraboloid, and then is emitted from the bent portion 5 without being reflected by the inner surface of the bent portion 5, thereby suppressing attenuation due to light reflection.

  When at least a part of the curved reflecting portion 7 of the bent portion 5 is a paraboloid, the focal point 14 of the paraboloid is provided inside the daylighting portion 3 or the bent portion 5. In this case, not all the light emitted from the emission end face of the first light guide portion 4 passes through the focal point 14, but since all the light passes near the focal point 14, after being reflected by the paraboloid. The light propagates in a direction close to the direction of the axis of symmetry, and light close to parallel is emitted from the exit end face 5a of the bent portion 5.

  In order to make the light emitted from the emission end face 5a of the bent part 5 closer to parallel, in addition to making at least a part of the curved reflection part 7 of the bent part 5 a paraboloid, the axial direction of the paraboloid The condition that the angle formed between the normal direction of the exit end surface 5a of the bent portion 5 is smaller than the angle formed between the normal direction of the exit end surface of the daylighting portion 3 and the normal direction of the exit end surface 5a of the bent portion 5 is satisfied. There is a need. By satisfying this condition, the light reflected by the paraboloid propagates in a direction close to the normal direction of the emission end face 5a of the bent portion 5.

  In addition, you may implement combining 1st Embodiment and 2nd Embodiment. That is, a part of the curved reflection part 7 of the bent part 5 may be an elliptical arc surface, and at least a part of the remaining part may be a paraboloid. For example, the side close to the daylighting unit 3 may be a paraboloid, and the side close to the emission end surface 5a of the bent portion 5 may be an elliptical arc surface. The paraboloid has the effect of collimating the reflected light on the paraboloid, so the paraboloid is superior to the elliptical arc surface in terms of collimating the rays, but away from the symmetry axis. However, since the distance from the symmetry axis is not constant and the connecting portion with the second light guide portion 13 does not have a smooth shape, the vicinity of the emission end face 5a of the bent portion 5 is preferably an elliptical arc surface.

  As described above, in the second embodiment, at least a part of the curved reflection portion 7 of the bent portion 5 is formed into a parabolic surface or a plurality of bent surface shapes each having its end positioned on the parabolic surface, and The angle between the major axis 8 direction of the paraboloid and the normal direction of the exit end face 5a of the bent portion 5 is the normal direction of the exit end face of the daylighting portion 3 and the normal direction of the exit end face 5a of the bent portion 5. Since the angle is smaller than the formed angle, the light reflected by the elliptical arc surface of the bent portion 5 can be collimated. Thereby, as in the first embodiment, attenuation of light emitted from the emission end face 5a of the bent portion 5 can be suppressed, and light incident on the daylighting system 1 can be efficiently guided to a predetermined space. This enables illumination using natural light effectively. Therefore, the amount of carbon dioxide emission can be reduced and energy saving can be achieved.

  As in the first embodiment, the present inventor has a daylighting system 1 according to an example in which the curved reflecting portion 7 of the bent portion 5 is an elliptical arc surface, and the curved reflecting portion of the bent portion 5 as shown in FIG. About the lighting system 1 of the comparative example which made 7 the inclined surface which hardly bends, the propagation direction of light was schematized by simulation.

  One example and one comparative example were compared in the case where the propagation angle of light propagating through the first light guide unit 4 is relatively large and the case where the propagation angle is relatively small.

  FIG. 9 is a diagram showing simulation results. FIG. 9A and FIG. 9B respectively show the simulation results of one example and one comparative example when the light propagation angle is large. FIG. 9C and FIG. 9D show simulation results of an example and a comparative example, respectively, when the light propagation angle is small.

  Compared to FIG. 9B, the light transmission efficiency is improved by about 2% in FIG. 9A, and in FIG. 9C, the light transmission efficiency is improved by about 18% compared to FIG. 9D. did. At the same time, the emitted light was closer to the parallel light in FIG. 9A than in FIG. 9B, and in FIG. 9C from FIG. 9D.

  Thus, it was confirmed that the light transmission efficiency was improved by making the curved reflection portion 7 of the bent portion 5 an elliptical arc surface as in the present embodiment.

  The aspect of the present invention is not limited to the individual embodiments described above, and includes various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

    DESCRIPTION OF SYMBOLS 1 Daylighting system, 2 Building, 3 Daylighting part, 4 1st light guide part, 5 Bending part, 6 Diffusing member, 7 Curved reflection part, 8 Long axis, 9 Short axis, 10 Ellipse, 10a Elliptical arc, 11 1st focus, 12 second focus, 13 second light guide, 21 daylighting panel, 31 counter panel

Claims (13)

A daylighting section that incorporates light;
A bending portion that guides the light taken in by the daylighting portion to a predetermined space,
The bent portion has a curved reflecting portion that changes the traveling direction of the light taken in by the daylighting portion,
The curved reflecting portion has an elliptical arc surface, or a plurality of bent surfaces with respective end portions located on the elliptical arc surface,
The angle formed by the major axis direction of the elliptical arc surface and the normal direction of the exit end face of the bent portion is smaller than the angle formed by the light incident direction to the bent portion and the normal direction of the exit end face of the bent portion. Daylighting system. A first light guide for propagating light taken by the daylighting unit in a predetermined direction;
The bent portion changes the traveling direction of the light emitted from the emission end face of the first light guide portion,
The angle formed between the major axis direction of the elliptical arc surface and the normal direction of the exit end surface of the bent portion is the normal direction of the exit end surface of the first light guide portion and the normal direction of the exit end surface of the bent portion. The daylighting system according to claim 1, wherein the daylighting system is smaller than an angle formed.   The first focal point closer to the elliptical arc surface among the first focal point and the second focal point on the major axis of the elliptical arc surface is located inside the first light guide part or the bent part. Daylighting system.   The daylighting system according to claim 3, wherein the first focal point is located on an emission end face of the first light guide unit.   5. The daylighting system according to claim 3, wherein the second focal point is disposed rearward in the light traveling direction from the emission end surface of the bent portion. The elliptical arc surface has an area of ¼ from the major axis to the minor axis of the ellipsoidal surface,
The daylighting system according to any one of claims 1 to 5, wherein the exit end surface of the bent portion is a region in contact with the minor axis of the elliptical surface.   The daylighting system according to any one of claims 1 to 6, wherein a ratio of a major axis to a minor axis of the elliptical arc surface is √2. A daylighting section that incorporates light;
A bending portion that guides the light taken in by the daylighting portion to a predetermined space,
The bent portion has a curved reflecting portion that changes the traveling direction of the light taken in by the daylighting portion,
The curved reflecting portion has a parabolic surface, or a plurality of bent surfaces with respective end portions located on the parabolic surface,
The angle formed by the axial direction of the paraboloid and the normal direction of the exit end face of the bent portion is smaller than the angle formed by the light incident direction to the bent portion and the normal direction of the exit end face of the bent portion. Daylighting system. A first light guide for propagating light taken by the daylighting unit in a predetermined direction;
The bent portion changes the traveling direction of the light emitted from the emission end face of the first light guide portion,
The angle formed between the axial direction of the paraboloid and the normal direction of the exit end face of the bent portion is the normal direction of the exit end face of the first light guide portion and the normal direction of the exit end face of the bent portion. The daylighting system according to claim 8, wherein the daylighting system is smaller than an angle formed.   The daylighting system according to claim 9, wherein a focal point of the paraboloid is located inside the first light guide portion or the bent portion.   The daylighting system according to claim 10, wherein a focal point of the paraboloid is located on an emission end face of the first light guide unit.   The daylighting system according to any one of claims 1 to 11, further comprising: a second light guide unit configured to guide light emitted from an output end surface of the bent portion in a predetermined direction. The daylighting unit has an incident surface for taking in light,
The daylighting system according to any one of claims 1 to 12, wherein the curved reflecting portion is provided inside a surface on the incident surface side in the bent portion.