JP6519154B2 - Daylighting system - Google Patents

Description

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

Technologies that aim to save energy by reducing the amount of carbon dioxide generated by actively using natural light for daylighting are drawing attention.
As one of the techniques, an optical duct for guiding external light to a predetermined space indoors is known. The light duct has a problem that the amount of light gradually attenuates when the light propagates in the light propagation path provided indoors. So, in patent document 1, the frequency | count of reflection of the light in the inner surface of an optical duct is reduced by devising the shape of the bending part of an optical duct, and attenuation of light is suppressed.

JP-A-4-271303

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

  That is, although the light duct of Patent Document 1 can reduce the number of reflections of light propagating in the light duct, there is a high possibility that a plurality of reflections may occur on the inner surface of the light 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 the attenuation of the introduced light.

In order to solve the above-described problems, in one aspect of the present invention, a light receiving unit for introducing light, a first light guide unit for propagating the light introduced by the light receiving unit in a predetermined direction, and the light receiving unit And a bent portion for guiding the light into the predetermined space, wherein the bent portion has a curved reflecting portion for changing the traveling direction of the light taken in by the light collecting portion, and the curved reflecting portion has an elliptical arc surface Or a plurality of broken surfaces whose ends are located on an elliptical arc surface, and the first light guide has an elliptical arc surface, or a plurality of broken surfaces where each end is located on an elliptical arc surface The curved surface reflection portion is not provided, and a long axis direction of the elliptical arc surface and a normal direction of an emission end face which is a cross section of a light passing region at an end on the light emission side of the bent portion angle, said first light guide portion, the light passage area of the light at the end of the side to be emitted Face a is rather smaller than the angle formed between the normal direction of the normal direction and the exit end face of the bent portion of the exit end face, of the first focal point and second focal point on the long axis of the elliptical arc surface, said elliptical arc surface The first focal point closer to the light source is located inside the first light guiding portion or the bending portion, and the second focal point is disposed behind the light emitting facet of the bending portion with respect to the light traveling direction A system is provided.

The first light guiding unit may be provided to propagate the light introduced by the light collecting unit in a predetermined direction,
The bending portion changes the traveling direction of light emitted from the emission end surface of the first light guide portion,
The angle between the major axis direction of the elliptical arc surface 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 to be made.

  The first focal point closer to the elliptical arc surface among the first focal point and the second focal point on the long axis of the elliptical arc surface may be located inside the first light guiding portion or the bending portion.

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

  The second focal point may be disposed rearward of the light emitting surface with respect to the light emitting end surface of the bending portion.

The elliptical arc surface has an area of 1⁄4 from the major axis to the minor axis of the ellipsoid,
The output end face of the bent portion may be a region in contact with the minor axis of the elliptical surface.

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

According to another aspect of the present invention, there is provided a light collecting unit for introducing light, and a bending unit for guiding the light collected by the light collecting unit to a predetermined space, and the light collecting unit is provided on the light incident side. A light receiving panel having a light incident side surface provided and a light emitting side surface provided on a side from which light is emitted, wherein the light incident side surface is a first surface when the light incident panel is viewed in cross section The curved surface is formed by alternately arranging the first surface and the non-parallel second surface, and the bent portion has a curved surface reflecting portion for changing the traveling direction of light taken in by the light collecting portion, and the curved surface The reflecting portion has a paraboloid surface or a plurality of bent surfaces on which the respective end portions are located on the paraboloid surface, and an end of the axis direction of the paraboloid surface and the bent portion on the side where light is emitted. the angle formed between the normal direction of the exit end face is a cross-section of the passing area of light in, it parabolic or paraboloidal on Is a boundary surface between the bent portion and having no region reflecting portion having a plurality of segmental surfaces which the end of the record is located, the light of the bent portion of the cross section of the passage area of the light at the end of the side incident A daylighting system is provided that is smaller than the angle between the normal direction and the normal direction of the exit end face of the bend. Further, according to another aspect of the present invention, there is provided a light collecting unit for taking in light, and a bending unit for guiding the light taken in at the light collecting unit to a predetermined space, and the light collecting unit has light transparency. A lighting panel comprising: a translucent substrate; and a plurality of reflectors provided in the translucent substrate, wherein the plurality of reflectors are translucent when the daylighting panel is viewed in cross section Are arranged along a uniaxial direction extending in a plane parallel to the side surface of the light emitting substrate from which light is emitted, and each is inclined in a direction different from the uniaxial direction, and the bent portion is The curved surface reflecting portion has a curved surface reflecting portion for changing the traveling direction of light taken in by the light collecting portion, and the curved surface reflecting portion has a plurality of bending surfaces in which each end is located on a paraboloid or paraboloid. The axial direction of the paraboloid and the cross section of the light passage area at the end of the bending portion on the side where the light is emitted The angle between the light emitting end face and the normal direction of the light emitting end face is a paraboloid or an interface between a region without a reflecting portion having a plurality of broken surfaces on which respective ends are located and the bent portion. A light collecting system is provided which is smaller than the angle between the normal direction of the cross section of the light passage region at the end of the side where the light of the bent portion is incident and the normal direction of the light emitting end face of the bent portion. .

It has a first light guiding portion for propagating the light introduced by the light collecting portion in a predetermined direction,
The bending portion changes the traveling direction of light emitted from the emission end surface of the first light guide portion,
The angle 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 to be made.

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

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

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

The lighting unit has an entrance surface for taking in light,
The curved surface reflection portion may be provided inside a surface on the incident surface side in the bending portion.

  According to the present invention, attenuation of introduced light can be efficiently suppressed.

The longitudinal cross-sectional view which shows typically the building to which the daylighting 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 daylighting panel. Sectional drawing which shows another example of the internal structure of a daylighting panel. The figure which shows the cross-sectional shape of the bending part by 2nd Embodiment. The figure which shows the daylighting system 1 of one comparative example which made the curved surface reflection part of a bending part the inclined surface which hardly bends. (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 easy illustration and understanding, the scale, the dimensional ratio in the vertical and horizontal directions, etc. are appropriately changed from those of the actual one and exaggerated. 1 to 9 are diagrams for explaining an embodiment according to the present invention. Among these, FIG. 1 is a longitudinal cross-sectional view which shows typically the building 2 to which the daylighting system 1 was attached.

  In the present specification, the terms "panel", "plate", "sheet", "film" and the like are not distinguished from each other based on only the difference in designation. Thus, for example, "panel" is a concept including members such as plates, sheets, and films. As one specific example, the “light collecting panel” includes members called “light collecting plate”, “light collecting sheet”, “light collecting film” and the like.

  The lighting system 1 of FIG. 1 is attached at the time of construction of the 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 of FIG. 1 includes a daylighting unit 3 for taking in light, a first light guiding unit 4 for propagating light emitted from the daylighting unit 3 in a predetermined direction, and light emitted from the first light guiding unit 4 And a bending portion 5 for changing the traveling direction of In the example of FIG. 1, the daylighting unit 3 and the first light guiding unit 4 are disposed along the outer wall of the building 2, the bending unit 5 is connected to the light emitting end surface of the first light guiding unit 4, and the light emission of the bending unit 5 The end face 5 a is joined to the outer wall of the building 2 with or without the diffusion member 6. The light collected by the light collecting unit 3 is guided to, for example, a room in the building 2 through the first light guide 4 and the bending portion 5.

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

  FIG. 2 is a cross-sectional view showing the main part of the light collecting system 1 of FIG. 1, and shows a cross-sectional structure along the light propagation direction of the first light guiding part 4 and the bending part 5. Each of the first light guide 4 and the bending portion 5 is a hollow cylindrical member, and light is allowed to propagate through the hollow portions of the first light guiding portion 4 and the bending portion 5. The inner surfaces of the first light guide portion 4 and the bending portion 5 are formed of a material having a high reflectance so that light is not excessively attenuated during propagation of the light. The cross-sectional shape of the hollow portion of the first light guide 4 and the bending portion 5 is not particularly limited, and may be, for example, rectangular or circular, or another shape.

  The daylighting unit 3 is provided to stably take in light whose incident direction changes according to the season or time zone. The daylighting unit 3 has a daylighting panel 21 for taking in light, particularly ambient 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 guiding portion 4 and the bending portion 5 constitute a hollow light duct, and the emission end face 5 a side of the bending portion 5 is joined to the hole provided in the outer wall of the building 2 without a gap. The emission end face 5 a of the bending portion 5 may be flush with the inner wall surface of the building 2 or may be provided indoors more than the inner wall surface. In this case, a part of the light duct will be disposed in the room.

  In the example of FIG. 2, the diffusion member 6 is disposed at the emission end face 5 a of the bending portion 5 so as to diffuse the light emitted from the emission end face 5 a of the bending portion 5. Instead, the light emitted from the emission end face of the first light guide 4 may be directly emitted into the room, or the light may be emitted into the room via an optical member other than the diffusion member 6. However, when the emitting end face 5a of the bending portion 5 is exposed, foreign matter such as floating matter in the air may enter the inside of the bending portion 5 and cause deterioration of the light collecting performance. Therefore, it is desirable to seal the emitting end face 5 a of the bending portion 5 by the diffusion member 6 or the transparent base material.

  It is also possible to attach not only the outer wall of the building 1 but also the window to the output end face 5a of the bending portion 5 in the light collecting system 1 according to the present embodiment. Thus, ambient light can be guided in a predetermined direction in the room through a part of the window. In particular, in the case of the window on the north side, sunlight is not directly incident, and the amount capable of taking in external light is limited. Therefore, providing the daylighting system 1 according to this embodiment to the window on the north side can capture more light. It will be.

  Although the example from which the light from the 1st light guide part 4 injects into the bending part 5 is shown in FIG. 1 and FIG. 2, the 1st light guide part 4 and the bending part 5 may be shape | molded integrally. . That is, the light receiving portion 3 side of the bending portion 5 may extend in one direction and be connected to the light receiving portion 3. As described above, the term first light guide 4 is functionally expressed, and the first light guide 4 and the light collecting unit 3 may not necessarily be separately provided.

  One of the features of the lighting system 1 of FIG. 2 is the structure of the bending portion 5. The bending portion 5 has a curved surface reflection portion 7 on the inside of the surface of the light collection portion 3 on the light collection panel 21 side. That is, the curved surface reflection part 7 is provided in the surface inside the curved surface of the bending part 5 of the side far from the building 2. The curved reflecting portion 7 has an elliptical arc surface or a plurality of broken surfaces whose ends are located on the elliptical arc surface. The curved surface reflection unit 7 is a surface that specularly reflects the light from the light reception unit 3. Even when this surface is formed of a plurality of broken surfaces, it can be regarded as an approximately elliptical arc surface, so hereinafter, it will be generically called an elliptical arc surface or an elliptical arc mirror surface.

  FIG. 2 illustrates an ellipse 10 obtained by cutting an ellipsoid with a plane passing through the major axis 8 and the minor axis 9. The cross section of the elliptical arc of the bending portion 5 is a part of the ellipse 10 shown by a broken line in FIG. 2 (e.g., an elliptic arc 10a of 1⁄4 of the ellipse 10). The ellipse 10 has two foci located on the major axis 8 as shown in FIG. Hereinafter, these foci are referred to as a first foci 11 and a second foci 12.

  As indicated by arrow lines in FIG. 2, light passing through the first focal point 11 of the ellipse 10 has the property of being reflected on the elliptic arc 10 a and passing 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 substantially 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 surface reflection portion 7 of the bending portion 5 is shaped to approximate the elliptical arc 10 a or the elliptic arc 10 a so that the light emitted from the emission end face 5 a of the bending portion 5 approaches parallel light. The shape approximate to the elliptic arc 10a is a shape in which the cross section of the bending portion 5 is formed by connecting a plurality of broken lines, and the corner of each broken line is positioned in the shape of the elliptic 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 curved surface reflection part 7 may be an elliptical arc surface. However, in the following, in order to simplify the description, an example in which the entire curved surface reflection portion 7 has an elliptical arc 10a shape will be described.

  As shown in FIG. 2, the light passing through the first focal point 11 and reflected by the elliptic arc 10a passes through the second focal point 12, but the light passing through the second focal point 12 is not a perfect parallel beam. 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 emitting end face 5a of the bending portion 5 is the normal direction of the emitting end face of the first light guide 4 and the bending portion 5 It satisfies the condition of being smaller than the angle made with the normal direction of the emitting end face 5a. If this condition is satisfied, the light reflected by the elliptic arc 10a propagates in a direction closer to parallel light and is emitted from the emission end face 5a of the bending portion 5.

  In the present embodiment, the first focal point 11 is provided inside the first light guiding portion 4 or the bending portion 5. In this case, if the curved surface reflection portion 7 of the bending portion 5 is an ideal elliptical arc surface, the light passing 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 elliptic arc 10a is sufficiently large, the light emitted from the emission end face 5a of the bending portion 5 becomes substantially parallel light. Thereby, when the outgoing end face 5a of the bending part 5 is provided in the outer wall or window of a building, external light can be made to reach the back of indoors. In addition, by directing the normal direction of the emission end face 5a to a predetermined direction, it is possible to selectively illuminate the indoor target direction with the outside light.

  The fact that the light reflected by the elliptical arc of the bending portion 5 is substantially parallel light means that the light reflected by the elliptical arc of the bending portion 5 is likely to be emitted from the bending 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 bending portion 5, the light reflected by the elliptical arc surface travels toward the second focal point 12. The light is emitted from the bending 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 the reflection in the inner surface of the bending part 5 can be minimized.

  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 and may be a factor that hinders the collimation of the light emitted from the bending portion 5. However, if the first focal point 11 is set inside the first light guiding portion 4 or the bending portion 5, there is a slight difference in all the light emitted from the light emitting end face of the first light guiding portion 4. Also pass near the first focal point 11 and pass near the second focal point 12 after being reflected by the elliptical arc surface. Therefore, the light emitted from the bending portion 5 is substantially parallel light.

  On the other hand, the second focal point 12 may be provided inside the bending portion 5 or may be provided on the rear side in the traveling direction of light from the output end face 5 a of the bending portion 5. As the second focal point 12 is farther from the first focal point 11, the light emitted from the bending portion 5 can be made more parallel, but on the other hand, the size of the elliptical arc increases, so The position of the second focal point 12 may be set by the trade-off between the size of the elliptical arc surface and the need for how much the light emitted from the unit 5 needs to be collimated.

  As described above, the curved reflecting portion 7 is provided inside the surface of the bending portion 5 on the side of the daylighting panel 21. The inner surface of the bending 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 oppositely disposed reflecting surface are in direct contact with each other or are connected via another reflecting surface to form the inner surface of the bending portion 5. More specifically, in the case where the cross-sectional shape in the case where the bending portion 5 is cut in the direction orthogonal to the traveling direction of light is rectangular, 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. When the cross-sectional shape of the bent portion 5 is cut in a direction perpendicular to the traveling direction of light is circular, the elliptical arc surface and the reflecting surface disposed opposite to each other are continuously connected, and therefore the elliptical arc surface and the reflecting surface The boundaries of are no longer clear. Thus, the boundary of the curved reflecting portion 7 does not necessarily exist. In the present embodiment, the inner surface of the surface on the lighting panel 21 side of the bending portion 5 is the curved surface reflection portion 7, but any surface shape other than the curved surface reflection portion 7 of the bending portion 5 is arbitrary. It is.

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

  In FIG. 1, although the output end face 5a of the bending part 5 is used as the output port of the light collecting system 1, as shown in the light collecting system 1 of FIG. 3, the second light guide part 13 connected to the output end face 5a of the bending part 5 The light emission end face of the second light guide 13 may be used as the light emission port of the lighting system 1.

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

  When the second light guide 13 is provided as shown in FIG. 3, the second focal point 12 in the elliptical arc plane of the bending portion 5 is provided, for example, inside the second light guide 13. For example, in the case where the second light guiding portion 13 indicated by the broken line in FIG. 2 is present, the second focal point 12 is provided at a predetermined position on the upper surface of the second light guiding portion 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 bending portion 5 passes through the second focal point 12. If the second focal point 12 is provided deep beyond the emission end face 5a of the bending portion 5 and deep inside the second light guide portion 13, the light reflected by the elliptical arc surface is separated because the distance with the elliptical arc surface is separated. 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 | damping of the light while passing the 2nd light guide part 13 can be suppressed.

  Although 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 guiding part 13, the second focal point 12 is provided near the center of the second light guiding part 13 in the radial direction. For example, the light can be emitted from the second light guide 13 without the light being reflected by the inner surface of the second light guide 13.

  Next, when the section of the elliptic arc in the curved surface reflection part 7 of the bending part 5 is the ideal elliptic arc 10a, the major axis a which is the length of the major axis 8 of the elliptical arc 10a is the minor axis which is the length of the minor axis 9 The range of the ellipticity a / b which is a value divided by b will be described. In FIG. 4, the second light guide portion 13 is connected to the emission end face 5 a of the bending portion 5, and the cross section of the elliptic arc surface of the bending portion 5 is a part of an ideal elliptical surface. An example is shown which is an elliptical arc surface of 1/4 length of. The emission end face 5a of the bending portion 5 is an end of an elliptical arc having a length of 1⁄4 of the elliptic face, and the direction of the incident end face of the second light guide portion 13 coincides with the minor axis 9 direction of the elliptic face There is.

  Assuming that the ellipsoidal surface is specularly reflected, the light passing through the first focal point 11 of the ellipsoidal surface passes through the second focal point 12 after being reflected by the ellipsoidal surface. As described above, in the present embodiment, the light beam reflected by the elliptical surface and incident on the second light guide portion 13 is close to parallel to the normal direction of the incident surface of the second light guide portion 13 Is desirable. In order to approach parallel, it is desirable that the angular range (θ in FIG. 4) of light passing through the second focal point 12 after being reflected by the ellipsoidal surface be as small as possible. As described above, in fact, there are also lights that reach the elliptical surface without passing through the first focus 11, but these lights also pass near the first focus 11, and as a result, In order to pass through the vicinity of the second focal point 12 after being reflected by the ellipsoidal plane, only light passing through the first focal point 11 is considered here.

  The angle range θ in FIG. 4 is maximized when the light beam is incident on the position of the output end face 5 a of the bending portion 5. The angle in this case is assumed to be θmax. The angle θmax is an angle with respect to the longitudinal direction of the second light guide portion 13 of the light reflected by the output end face 5 a of the bending portion 5 and directed to the second focal point 12.

  The angle θmax decreases as the ellipticity a / b increases, that is, as the ellipse 10 narrows along the major axis 8. If the angle θmax is 45 ° or less, it can be said that the light reflected by the elliptic arc surface of the bending portion 5 travels in a direction close to parallel, even if not parallel. Therefore, in defining the ellipticity of the elliptic arc surface of the bending 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 the cross section of the ellipsoid to the focal point becomes 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 °,
You need to

  Next, the configuration of the daylighting unit 3 will be described. As illustrated in FIG. 2, the light collecting unit 3 includes a light collecting panel 21 on which light is incident, and an opposing panel 31 disposed to face the light collecting panel 21. The distance S between the reflective surface of the opposing panel 31 and the light emitting side surface of the light collecting panel 21 gradually widens in accordance with the position along the uniaxial direction d1.

  Side panels are respectively provided on both sides of the daylighting panel 21 and the facing panel 31. Each side panel is connected to an edge of the daylighting panel 21 and the opposite panel 31 along a 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. . The inner surface of the side panel is formed with a reflective surface, like the opposite panel 31.

  The daylighting panel 21, the facing panel 31 and both side panels form an opening on one side in the uniaxial direction d 1, and this opening is the emitting end face 3 a of the daylighting part 3, and the light emitting end face 3 a is the first light guiding part 4 are connected.

  FIG. 5 is a cross-sectional view showing an example of the internal structure of the daylighting panel 21. As shown in FIG. The daylighting panel 21 of FIG. 5 has a light entrance surface in which first and second surfaces, which are not 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 emitting side surface 23 of the light collecting panel 21. The first surface 22 a is inclined with respect to the vertical direction to face upward. On the other hand, each second surface 22 b is inclined to the side opposite 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 relative to the vertical direction to face downward.

  Therefore, 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 22 and is refracted, and then the light output extending parallel to the vertical direction The light is further refracted at the side surface 23 and enters the inside of the light collecting unit 3. Thereby, the light transmitted through the daylighting panel 21 in the vertical direction from the upper side to the lower side is deflected in the traveling direction so that the inclination angle with respect to the vertical direction becomes smaller, and propagates in the direction of the first light guide 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. As shown in FIG. In the daylighting panel 21 of FIG. 6, the support plate 22, the bonding layer 23, the light transmitting base material 24 having light transmittance, and the molding base material 26 are laminated in order from the light entrance side to the light exit side. It is a structure. For example, a glass plate or an acrylic plate can be used as the support plate 22. As the bonding layer 23, a bonding material known per se can be used. The molding base 26 is a base required to manufacture the daylighting panel 21 as described later.

  In the translucent base material 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 of the reflective members 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 reflective material 25 inclines downward with respect to the normal direction nd is determined according to the incident direction of the light P1, P2 intended to change the traveling direction. For example, the traveling direction of light P1 from a relatively low altitude sun, such as winter, morning, and evening hours, is changed downward by the reflector 25, and It is intended to transmit light P2 from such a relatively high altitude sun while maintaining its traveling direction.

  In addition, the internal structure of the daylighting panel 21 is not limited to what was shown in FIG. 5 or FIG. Any structure may be used as long as the light incident on the light collecting unit 3 can be efficiently transmitted to the light guiding unit.

  As described above, in the first embodiment, the curved surface reflection portion 7 of the bending portion 5 provided on the light collecting panel 21 side of the lighting portion 3 is an elliptical arc surface, and the direction of the major axis 8 of the elliptic arc surface and the emission end surface of the bending portion 5 In order to make the angle with the normal direction of 5 a be smaller than the angle between the normal direction of the emitting end face of the first light guide 4 and the normal direction of the emitting end face 5 a of the bending portion 5, The light reflected by the elliptical arc can be collimated. Thereby, it is possible to reduce the number of times light reflected by the elliptical arc surface of the bending portion 5 is reflected by the inner surface of the bending portion 5 and to suppress attenuation of light emitted from the emission end face 5 a of the bending portion 5 . Therefore, the light which injected into the daylighting system 1 can be efficiently guide | induced to predetermined space, and the illumination which used natural light effectively is attained. Therefore, the emission of carbon dioxide can be reduced and energy saving can be achieved. In particular, according to the present embodiment, the light emitted from the output end face 5a of the bending portion 5 can be collimated, so that it is possible to let outside light reach the interior of the room and aim at the interior of the room. It is also possible to selectively illuminate the direction with ambient light.

Second Embodiment
In the second embodiment, at least a part of the curved reflecting portion 7 of the bending portion 5 is a paraboloid. Except for this point, the configuration is the same as that of the first embodiment, and therefore, differences from the first embodiment will be mainly described below.

  FIG. 7 is a view showing the cross-sectional shape of the bending portion 5 according to the second embodiment. The curved reflecting portion 7 of the bending portion 5 according to the second embodiment has a paraboloid or a plurality of bending surfaces on which respective ends are located on the paraboloid. A paraboloid or a paraboloid having a plurality of broken surfaces is a surface that specularly reflects, ie, specularly reflects the light from the first light guide 4.

  The paraboloid is obtained by rotating the parabola about the axis of the parabola which is a quadratic function. The axis of the parabola used to generate the paraboloid is referred to herein as the axis of the paraboloid. Also, the paraboloid may have a shape generated by sweeping a parabola in the direction of its normal.

  The axis of the paraboloid extends parallel to the normal direction of the output end face 5 a of the bending portion 5. Although FIG. 7 shows an example in which the second light guide portion 13 is connected to the emission end face 5 a of the bending portion 5, the second light guide portion 13 may be omitted. When the second light guide portion 13 is not provided, another optical member such as the diffusion member 6 may be disposed on the output end face 5a of the bending portion 5, and the output end face 5a of the bending portion 5 It may be

  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 symmetry axis. Therefore, if the normal direction of the emitting end face 5a of the bending portion 5 is arranged in the direction parallel to the axis 15 of the paraboloid, the light reflected by the curved reflecting portion 7 consisting of the paraboloid is the emitting end face of the bending portion 5 It will advance in the normal direction of 5a. As a result, at least the light that has passed through the focal point 14 is reflected by the paraboloid, is not reflected by the inner surface of the bending portion 5, and is emitted from the bending portion 5, thereby suppressing attenuation of the light due to reflection.

  When at least a part of the curved surface reflection portion 7 of the bending portion 5 is a paraboloid, the focal point 14 of the paraboloid is provided inside the light collecting portion 3 or the bending portion 5. In this case, not all the light emitted from the output end face of the first light guide 4 passes through the focal point 14, but any light also passes in the vicinity of the focal point 14, so after being reflected by the paraboloid The light propagates in a direction close to the direction of the symmetry axis, and light close to parallel light is emitted from the emission end face 5 a of the bending portion 5.

  In order to make the light emitted from the emission end face 5a of the bending portion 5 closer to parallel, in addition to making at least a part of the curved surface reflection portion 7 of the bending portion 5 a paraboloid, the axial direction of the paraboloid and The condition that the angle between the bending portion 5 and the normal direction of the light emitting end face 5a is smaller than the angle between the normal direction of the light emitting end face of the light collecting portion 3 and the normal direction of the light emitting end surface 5a of the bending 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 emitting end face 5 a of the bending portion 5.

  The first embodiment and the second embodiment may be implemented in combination. That is, a part of the curved surface reflection part 7 of the bending part 5 may be an elliptical arc surface, and at least a part of the remaining part may be a paraboloid surface. For example, the side closer to the light collecting unit 3 may be a paraboloid, and the side closer to the output end face 5 a of the bending unit 5 may be an elliptical arc surface. Since the paraboloid acts to collimate the light reflected on the paraboloid, it is far from the symmetry axis while the paraboloid is superior to the elliptic arc surface in terms of collimation of light rays. However, since the distance from the symmetry axis is not constant and the connection portion with the second light guide 13 does not have a smooth shape, an elliptical arc surface is preferable in the vicinity of the emission end face 5 a of the bending portion 5.

  As described above, in the second embodiment, at least a part of the curved surface reflection portion 7 of the bending portion 5 is formed into a paraboloid or a plurality of bent surfaces in which respective end portions are positioned on the paraboloid, and The angle between the long axis 8 direction of the paraboloid and the normal direction of the emitting end face 5a of the bending portion 5 is the normal direction of the emitting end face of the light collecting portion 3 and the normal direction of the emitting end face 5a of the bending portion 5 In order to make it smaller than the angle to be made, the light reflected by the elliptic arc surface of the bending portion 5 can be collimated. Thus, similarly to the first embodiment, the attenuation of the light emitted from the output end face 5a of the bending portion 5 can be suppressed, and the light incident on the light collection system 1 can be efficiently guided to a predetermined space. It is possible to do lighting that effectively uses natural light. Therefore, the emission of carbon dioxide can be reduced and energy saving can be achieved.

  As shown in FIG. 8, the inventor of the present invention has, as in the first embodiment, a daylighting system 1 according to an embodiment in which the curved reflecting portion 7 of the bending portion 5 has an elliptical arc surface, and the curved reflecting portion of the bending portion 5. The propagation direction of the light was schematically illustrated by simulation for the daylighting system 1 of a comparative example in which 7 was an inclined surface with few bends.

  One example and one comparative example were compared about the case where the propagation angle of the light which propagates the 1st light guide part 4 is relatively large, and the case where it is relatively small.

  FIG. 9 is a diagram showing simulation results. FIGS. 9A and 9B respectively show simulation results of an example and a comparative example in the case where the light propagation angle is large. Moreover, FIG.9 (c) and FIG.9 (d) have respectively shown the simulation result of one Example and one comparative example in case the propagation angle of light is small.

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

  Thereby, it was confirmed that the light transmission efficiency is improved by making the curved surface reflecting portion 7 of the bending portion 5 an elliptical arc as in the present embodiment.

  The aspects of the present invention are not limited to the above-described individual embodiments, but include various modifications that those skilled in the art can conceive, 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 conceptual idea and spirit of the present invention derived from the contents defined in the claims and the equivalents thereof.

    DESCRIPTION OF SYMBOLS 1 Daylighting system, 2 buildings, 3 Daylighting parts, 4 1st light guide part, 5 bending parts, 6 diffusion members, 7 curved surface reflecting parts, 8 major axes, 9 minor axes, 10 ellipses, 10a elliptical arcs, 11 first focus, 12 2nd focus, 13 2nd light guide part, 21 Daylighting panel, 31 Opposite panel

Claims (9)

The daylighting section that takes in light,
A first light guide portion for propagating the light introduced by the light collecting portion in a predetermined direction;
And a bent portion for guiding the light introduced by the light receiving portion to a predetermined space,
The bent portion has a curved surface reflecting portion that changes the traveling direction of light taken in by the light collecting portion,
The curved reflecting portion has an elliptical arc surface or a plurality of broken surfaces whose ends are located on the elliptical arc surface,
The first light guiding portion does not have the curved surface reflecting portion having an elliptical arc surface or a plurality of bending surfaces on which the respective end portions are positioned on the elliptical arc surface,
The angle between the major axis direction of the elliptical arc surface and the normal direction of the light emitting end face, which is a cross section of the light passing area at the end of the light emitting side of the bent portion, is The angle between the normal direction of the output end face, which is the cross section of the light passage area at the end where light is output, and the normal direction of the output end face of the bent portion,
The first focal point closer to the elliptical arc surface among the first focal point and the second focal point on the long axis of the elliptical arc surface is located inside the first light guiding portion or the bending portion, and the second focal point is A light collecting system, wherein a focal point is disposed behind the light emitting end surface of the bending portion in the light traveling direction. The elliptical arc surface has an area of 1⁄4 from the major axis to the minor axis of the ellipsoid,
The lighting system according to claim 1, wherein the output end face of the bent portion is a region in contact with the minor axis of the elliptical surface.   The lighting system according to claim 1, wherein a ratio of a major axis to a minor axis of the elliptical arc surface is √2 or more. The daylighting section that takes in light,
And a bent portion for guiding the light introduced by the light receiving portion to a predetermined space,
The light collecting unit includes a light collecting panel having a light transmitting base material having a light transmitting property, and a plurality of reflectors provided in the light transmitting base material.
When the daylighting panel is viewed in cross section, the plurality of reflectors are arranged along a uniaxial direction extending in a plane parallel to the side surface of the light-transmissive substrate on which the light is emitted, and It is inclined in a direction different from the uniaxial direction,
The bent portion has a curved surface reflecting portion that changes the traveling direction of light taken in by the light collecting portion,
The curved reflecting portion has a paraboloid, or a plurality of folds whose ends are located on the paraboloid,
The angle between the axial direction of the paraboloid and the normal direction of the light emitting end face, which is a cross section of the light passing region at the end of the light emitting side of the bent portion, is a paraboloid or a paraboloid A light passing region at the end of the bent portion on which light is incident, which is a boundary surface between the bent portion and a region having no reflecting portion having a plurality of bent surfaces on which the respective end portions are positioned A daylighting system smaller than an angle between a normal direction of a cross section and a normal direction of an output end face of the bent portion. It has a first light guiding portion for propagating the light introduced by the light collecting portion in a predetermined direction,
The bending portion changes the traveling direction of light emitted from the emission end surface of the first light guide portion,
The angle 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 lighting system according to claim 4, which is smaller than the angle to be made. The lighting system according to claim 5 , wherein the focal point of the paraboloid is located inside the first light guide or the bending portion. The light collecting system according to claim 6 , wherein the focal point of the paraboloid is located on the output end face of the first light guide. The light collecting system according to any one of claims 1 to 7, further comprising a second light guide unit configured to guide light emitted from the output end surface of the bent portion in a predetermined direction. The lighting unit has an entrance surface for taking in light,
The curved reflection portion is a light emission side provided on the side from which light of the light collection portion is emitted, or a flat surface extending the side provided on the side from which light of the light collection portion is emitted, and the bending portion The lighting system according to any one of claims 1 to 8 , wherein the lighting system is provided so as to include the closest point of the distance.