WO2019181450A1

WO2019181450A1 - Daylighting member

Info

Publication number: WO2019181450A1
Application number: PCT/JP2019/008331
Authority: WO
Inventors: 佑輔藤井; 栄二新倉
Original assignee: 三菱電機株式会社
Priority date: 2018-03-20
Filing date: 2019-03-04
Publication date: 2019-09-26

Abstract

A daylighting member (1) has a substrate (10) and a projecting part (13) which protrudes in a first direction from the substrate (10) and extends in a second direction. The projecting part (13) includes an incidence surface (14) on which light is incident, and a reflecting surface (15) for reflecting light incident on the incidence surface (14). In a plane orthogonal to the second direction, the expression φ = ((π/2) – θ₁ + θ₂)/2 is satisfied with respect to at least a portion of a light ray (L1) incident on the incidence surface (14), where θ₁ is the refracting angle of a light ray (L₁) incident on the incidence surface (14), θ₂ is the angle formed by the incidence surface (14) and a light ray (L₂) reflected by the reflecting surface (15), and φ is the angle formed by the incidence surface (14) and a tangential plane (TP) at the point (Pt) at which the light ray (L₂) is reflected by the reflecting surface (15).

Description

Daylighting member

The present invention relates to a daylighting member.

Generally, a window having a prism surface is known (for example, Patent Document 1). For example, the window described in Patent Document 1 includes a transparent window plate that covers a prism sheet having a surface subjected to minute prism processing, and a window frame that supports the window plate. In this window, the angle between the slope of the prism and the window plate is 40 °. As a result, when the altitude of the sun is low, the sunlight is guided toward the ceiling of the room and the whole room is brightened by diffusing the sunlight. Even when the altitude of the sun is high, the sunlight that has entered only the window is directed deeper into the room.

JP-A-11-280350

However, in the window having the prism surface described in Patent Document 1, it is difficult to suppress the change in the emission angle of the light emitted from the prism when the incident angle of the light incident on the prism changes.

An object of the present invention is to suppress a change in the emission angle of the emitted light from the daylighting member even when the incident angle of the incident light on the daylighting member changes.

A daylighting member according to one aspect of the present invention includes:
A base material that transmits light, has a thickness in a first direction, and extends in a second direction orthogonal to the first direction;
Projecting from the base material in the first direction and extending in the second direction; and
The protrusion includes an incident surface on which light is incident and a reflecting surface that reflects the light incident on the incident surface,
The incident surface extends from the substrate in the first direction;
The reflective surface has a curved surface curved in a direction away from the incident surface,
In a plane orthogonal to the second direction, the refraction angle of the light beam incident on the incident surface is θ ₁ , the angle formed by the light beam reflected by the reflection surface and the incident surface is θ ₂ , and the light beam is When the angle between the tangential plane at the point reflected by the reflecting surface and the incident surface is φ, at least a part of the light incident on the incident surface,
φ = ((π / 2) −θ ₁ + θ ₂ ) / 2
Meet.

According to the daylighting member according to the present invention, even when the incident angle of the incident light to the daylighting member changes, it is possible to suppress the change in the outgoing angle of the outgoing light from the daylighting member.

2 is a perspective view showing a schematic configuration of a daylighting member according to Embodiment 1. FIG. 3 is a cross-sectional view illustrating a schematic configuration of a daylighting member according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view illustrating a configuration of a protrusion of the lighting member according to Embodiment 1. It is a schematic diagram which shows the definition of the inclination of the reflective surface of a projection part. It is a schematic diagram which shows the behavior of the light ray in a projection part. It is a schematic diagram which shows the definition of the angle of the incident light with respect to a lighting member, and the angle of an emitted light. It is a schematic diagram which shows the definition of the coordinate on the reflective surface in a projection part. It is a figure which shows the advancing direction in the lighting member of the light ray which passes the focus at the time of a solar height change, and the emitted direction from a lighting member. It is a figure which shows the simulation result of the angular intensity distribution of the emitted light in the lighting member which concerns on Embodiment 1. FIG. FIG. 6 is a cross-sectional view of a modified example of a protrusion in the lighting member according to Embodiment 1. FIG. 6 is a cross-sectional view of a modified example of a protrusion in the lighting member according to Embodiment 1. FIG. 6 is a cross-sectional view of a modified example of a protrusion in the lighting member according to Embodiment 1. It is a schematic diagram which shows the behavior of the light ray which passes except a focus in a projection part. 6 is a schematic diagram showing the behavior of light rays in a daylighting member according to Embodiment 2. FIG. 6 is a schematic diagram showing an example of a daylighting member according to Embodiment 2. FIG. It is a figure which shows the simulation result of the angular intensity distribution of the emitted light in the lighting member which concerns on Embodiment 2. FIG.

The daylighting member described below is installed in, for example, a window. And a lighting member takes in sunlight indoors. The daylighting member is, for example, a daylighting sheet. It is desired that the daylighting sheet realizes a stable amount of light and an irradiation range throughout the year. However, as the solar altitude changes, the incident angle of the light incident on the projection (prism) of the daylighting member changes. The daylighting member according to the present invention suppresses the change in the emission angle of the light emitted from the protrusion with respect to the change in the incident angle of the incident light. This makes it possible to obtain a stable irradiation range throughout the year.

<Explanation of coordinates in the figure>
In the following embodiments, for ease of explanation, the coordinate axes of the xyz orthogonal coordinate system are shown in each drawing.
In the xyz orthogonal coordinate system, the x-axis direction is the first direction, the y-axis direction is the second direction, and the z-axis direction is the third direction. The x-axis direction is a direction orthogonal to the y-axis direction and the z-axis direction, the y-axis direction is a direction orthogonal to the x-axis direction and the z-axis direction, and the z-axis direction is the x-axis direction and the y-axis direction. It is a direction orthogonal to.

The zx plane shown in each figure is a plane orthogonal to the y-axis direction.

The x-axis direction is a direction perpendicular to the surface 11 of the base material 10 of the daylighting member 1. The x-axis direction is the thickness direction of the plate-shaped daylighting member 1. The + x-axis direction is the direction on the surface 11 side of the substrate 10. The −x-axis direction is the direction on the surface 12 side of the substrate 10. For example, external light (for example, sunlight) enters the daylighting member 1 from the + x-axis direction side. For example, the light emitted from the daylighting member 1 travels indoors on the −x axis direction side.

The y-axis direction is a direction that does not have the curvature of the reflection surface 15 of the cylindrical projection 13. The + y-axis direction is the right side when the daylighting member 1 is installed from the protrusion 13 side when the daylighting member 1 is installed with the y-axis direction horizontal. The −y-axis direction is the left side when the daylighting member 1 is viewed from the protrusion 13 side when the daylighting member 1 is installed with the y-axis direction horizontal. “Looking at the daylighting member 1 from the protrusion 13 side” means looking at the −x axis side from the + x axis side.

The z-axis direction is a direction perpendicular to the xy plane. The + z-axis direction is a direction in which the incident surface 14 is disposed in one protrusion 13. The −z-axis direction is a direction in which the reflecting surface 15 is disposed in one protrusion 13.

Embodiment 1 FIG.
The first embodiment will be described below with reference to FIGS. In each drawing, the scale of a dimension may differ with components.

FIG. 1 is a perspective view showing a schematic configuration of a daylighting member 1 according to Embodiment 1. FIG.
FIG. 2 is a cross-sectional view showing a schematic configuration of the daylighting member 1 according to the first embodiment.
FIG. 3 is a cross-sectional view showing the configuration of the protrusion 13 of the daylighting member 1 according to the first embodiment.
FIG. 4 is a schematic diagram illustrating the definition of the inclination of the reflection surface 15 of the protrusion 13.
FIG. 5 is a schematic diagram showing the behavior of light rays at the protrusion 13.
Figure 6 is a schematic diagram showing the definition of the angle theta _OUT angle theta _IN and the outgoing light _{L OUT} of the incident light _{L IN} for lighting member 1.
FIG. 7 is a schematic diagram showing the definition of coordinates on the reflecting surface 15 in the protrusion 13.
FIG. 8 is a diagram showing the traveling direction of the light beam passing through the focal point f when the solar altitude changes in the lighting member 1 and the emitting direction from the lighting member 1.
FIG. 9 is a diagram illustrating a simulation result of the angular intensity distribution of the outgoing light L _OUT in the daylighting member 1 according to the first embodiment.
10 to 12 are cross-sectional views of modifications of the protrusion 13 in the daylighting member 1 according to the first embodiment.

<Configuration of Daylighting Member 1> The configuration of the daylighting member 1 will be described below with reference to FIGS.

As shown in FIG. 1, the daylighting member 1 includes a base material 10 and at least one protrusion 13. “At least one protrusion 13” includes a plurality of protrusions 13. In the present embodiment, a plurality of protrusions 13 are provided on the surface 11 (for example, the first surface) of the base material 10.

The protrusion 13 extends in the y-axis direction. That is, the bottom surface of the protrusion 13 is a surface on the zx plane. Here, the y-axis direction is a direction corresponding to the height direction of the columnar shape. That is, the protrusion 13 has a column shape extending in the y-axis direction. The protrusion 13 protrudes from the base material 10 in the x-axis direction. Specifically, the tip of the protrusion 13 protrudes in the + x axis direction. The protrusion 13 is formed on the surface 11. Specifically, the protrusion 13 is disposed on the surface 11 of the substrate 10. Specifically, the plurality of protrusions 13 are arranged in the z-axis direction on the surface 11 of the substrate 10.

≪Base material 10≫
Below, the structure of the base material 10 is demonstrated with reference to FIG.

The base material 10 has a plate shape. The plate shape includes a sheet shape and a film shape. The base material 10 includes a surface 11 and a surface 12 that is opposite to the surface 11 in the x-axis direction. The surface 11 is disposed on the + x axis direction side of the daylighting member 1. The surface 12 is disposed on the −x axis direction side of the daylighting member 1. The surface 11 is a flat surface, for example. The surface 12 is a flat surface, for example. The surface 11 and the surface 12 are opposed to each other. For example, the surface 11 and the surface 12 are arranged in parallel.

The base material 10 has a thickness in the x-axis direction and extends in the y-axis direction and the z-axis direction. The substrate 10 is formed of a material that transmits light. Therefore, the base material 10 transmits light.

The base material 10 may be formed of a resin film using, for example, a thermoplastic polymer, a thermosetting resin, a photopolymerizable resin, or the like. As the resin film, acrylic polymer, olefin polymer, vinyl polymer, cellulose polymer, amide polymer, fluorine polymer, urethane polymer, silicone polymer, imide polymer, or the like can be used.

In Embodiment 1, polymethyl methacrylate (PMMA) is used as an example of the material of the base material 10.

<< Protrusion 13 >> Hereinafter, the protrusion 13 will be described with reference to FIGS.

The following description of the protrusion 13 will be made on the zx plane for the sake of simplicity. Therefore, for example, a portion where two surfaces intersect is described as a “point” such as “a point where the incident surface 14 and the reflecting surface 15 virtually intersect”. However, even in the case described above, in the actual three-dimensional shape, this “point” is a line extending in the y-axis direction.

The protrusion 13 includes an incident surface 14 and a reflecting surface 15 that reflects light incident on the incident surface 14. The tip portion P of the protrusion 13 is a portion where the incident surface 14 and the reflecting surface 15 intersect. However, the boundary between the incident surface 14 and the reflecting surface 15 may be a curved surface. The tip portion P is a point where the incident surface 14 and the reflecting surface 15 virtually intersect in the zx plane.

The protrusion 13 further includes a valley V ₁ and a valley V ₂ . The valley portion V ₁ of the protrusion 13 is an end portion of the incident surface 14 on the base material 10 side. Valleys V ₂ of the protruding portion 13 is an end portion of the base material 10 side of the reflecting surface 15.

The incident surface 14 is a surface on which light is incident. Light enters the protrusion 13 from the incident surface 14. The light beam L ₁ incident on the incident surface 14 reaches the reflecting surface 15. The light beam L _{1 that} has reached the reflecting surface 15 is reflected by the reflecting surface 15. For example, the light beam L _{1 that} has reached the reflecting surface 15 is totally reflected by the reflecting surface 15. As shown in FIG. 4, the light beam L ₂ reflected by the reflecting surface 15 reaches the surface 11. As shown in FIGS. 5 and 6, the light beam L _{2 that} has reached the surface 11 travels in the substrate 10. The light beam L _{2 that} has traveled through the substrate 10 reaches the surface 12. The light beam L ₂ that has reached the surface 12 is emitted from the surface 12. As shown in FIG. 6, the light emitted from the surface 12 is light L _OUT . The light L _OUT is also called a light ray L _OUT or an outgoing light L _OUT .

The incident surface 14 extends from the base material 10 in the x-axis direction (specifically, the + x-axis direction). The incident surface 14 is an optical surface. The optical surface is a surface that suppresses wavefront disturbance and scattering because light is reflected, refracted, or transmitted. Specifically, the optical surface is a smooth surface. Thereby, the light incident on the incident surface 14 does not become scattered light.

The protrusion 13 has a focal point. Specifically, the point f (also referred to as the first point) is the focal point of the protrusion 13. As shown in FIG. 5, for example, the arrival point of the light beam L _IN1 to reach the point f as the incident surface 14 and the point I _1. The point f is a point on a plane that is parallel to the plane including the valley portion V ₁ and the valley portion V ₂ and includes the tip portion P. In other words, the point f is a focal point where the light beam from the base material 10 is reflected by the reflecting surface 15 and the reflected light beam from the reflecting surface 15 is collected. In this case, light from the substrate 10 is a light ray incident from the substrate 10 to the projection 13, light rays incident on the projecting portion 13, parallel rays (e.g., rays parallel to the beam L ₂ in FIG. 5) It is. The goal of the reflecting surface 15 of the light beam _{L IN1} and the point _{R 1.} Similarly, the arrival point of the light beam _{L IN2} to reach the point f as the incident surface 14 and the point _{I 2.} The goal of the reflecting surface 15 of the light beam _{L IN2} to the point _{R 2.} When the distance from the end E ₁ to the point I _{1 in} the x-axis direction (specifically, the + x-axis direction) of the incident surface 14 is shorter than the distance from the end E ₁ to the point I ₂ , the reflecting surface The distance from the end E ₂ to the point R _{1 in} 15 x-axis directions (specifically, the + x-axis direction) is shorter than the distance from the end E ₂ to the point R ₂ .

On the zx plane, the distance on the incident surface 14 from the end E ₁ to the incident position of the light beam L _{1 on} the incident surface 14 (that is, the point I ₁ ) is the distance D _in (also referred to as a first distance). A distance on the reflection surface 15 from the end E ₂ to the reflection position of the light beam L ₁ (that is, the point R ₁ ) is a distance D _ref (also referred to as a second distance). When the distance D _in changes continuously, the distance D _ref changes continuously with the distance D _in on a one-to-one basis. The distance D _in and the distance D _ref have the same increase / decrease direction. In other words, the distance _{D in} is increased the distance _{D ref} with increasing distance _{D in} the distance _{D ref} decreases as decreases. Since the end E ₁ and the end E ₂ coincide with the tip end P on the zx plane, the relationship between the distance D _in and the distance D _ref described above is the end E ₁ and the end E _2. Even if is replaced with the tip portion P, it is established.

Thus, for example, when the shape of the incident surface 14 from the end E ₁ to the valley V ₁ is set, the reflection surface 15 from the end E ₂ to the valley V ₂ using the formula (1) described later. Can be set.

The incident surface 14 is, for example, a flat surface. However, the incident surface 14 may be, for example, a cylindrical shape having a curvature in the x-axis direction (that is, a direction perpendicular to the surface 11). In addition, the sign of curvature is not ask | required. That is, the incident surface 14 may be other than a plane. For example, the incident surface 14 may have a cylindrical shape that is convex with respect to the reflecting surface 15, that is, a cylindrical shape that has a bulge in the + z direction. Further, the incident surface 14 may have a cylindrical shape that is concave with respect to the reflecting surface 15, that is, a cylindrical shape that has a bulge in the −z direction.

The reflection surface 15 has a curved surface that is curved away from the incident surface 14. In other words, the reflecting surface 15 has a curved surface protruding in a direction away from the incident surface 14. Specifically, the reflecting surface 15 has a curvature in the x-axis direction (that is, the direction perpendicular to the surface 11). The reflective surface 15 does not have a curvature in the y-axis direction. That is, the reflecting surface 15 has a cylindrical shape. A “cylindrical shape” has a curvature in one direction (eg, the first direction) and a curvature in a direction (eg, the second direction) perpendicular to that direction (ie, the first direction). There is no surface shape. The cylindrical shape is not limited to a cylindrical shape. In the present embodiment, the reflecting surface 15 has a cylindrical shape that is convex with respect to the incident surface 14, that is, a cylindrical shape that has a bulge in the −z direction.

The protrusion 13 can be made of, for example, a material such as acrylic resin, epoxy resin, or silicone resin. That is, the protrusion 13 can be formed of a material including an acrylic resin, an epoxy resin, or a silicone resin. These materials are organic materials having a property of transmitting light and photosensitivity. “Photosensitivity” is a property in which a substance undergoes a chemical change when irradiated with light. Moreover, what mixed the polymerization initiator, the coupling agent, the monomer, the organic solvent, etc. can be used for these organic materials. Furthermore, the polymerization initiator may contain various additive components. The various additive components are, for example, a stabilizer, an inhibitor, a plasticizer, an optical brightener, a release agent, a chain transfer agent, or other photopolymerizable monomer.

In the first embodiment, polymethyl methacrylate (PMMA) is used as an example of the protrusion 13.

The protruding portion 13 may be formed integrally with the base material 10. In this case, the surface 11 is, for example, a plane passing through the valley _{V 1} and valleys _{V 2.} Further, the protrusion 13 may be formed separately from the base material 10 and then integrated with the base material 10. However, it is desirable that the protrusion 13 is formed of the same material as the base material 10. Thereby, unnecessary refraction and reflection at the interface between the protrusion 13 and the substrate 10 can be avoided.

In the example shown in FIG. 5, the point f is parallel to the plane including the valley part V ₁ and the valley part V ₂ and is on the plane including the tip part P. In other words, the point f is a point on a line that is located on the opposite side of the reflecting surface 15 with respect to the incident surface 14 and is parallel to the y-axis direction. Specifically, the point f is a straight line passing through the tip P in the x-axis direction (specifically, the + x-axis direction) of the protrusion 13 and parallel to the z-axis direction in the zx plane. Located on the top. Here, the plane including the valley portion V ₁ and the valley portion V ₂ is, for example, the surface 11 of the base material 10. At least a portion of the light beam L ₁ incident on the incident surface 14, passes through the point f. A light ray that has entered the protrusion 13 from the incident surface 14 through the point f is defined as a light ray L ₁ (for example, a first light ray). The light beam L ₁ reflected by the reflecting surface 15 is referred to as a light beam L ₂ (for example, a second light beam).

As shown in FIG. 4, in the zx plane, the refraction angle of the light ray L ₁ incident on the incident surface 14 is an angle θ _1, and the angle formed by the light ray L ₂ reflected by the reflective surface 15 and the incident surface 14 is an angle. and θ _2. Light L ₁ is the angle φ formed by the tangent plane TP and the incident surface 14 of the Pt point of intersection with the reflecting surface 15 is defined by the following equation (1). The point Pt is a point where the light beam L ₁ is reflected by the reflecting surface 15. The tangent plane TP is a plane in contact with the curved surface of the reflecting surface 15. Note that the angle θ ₁ , the angle θ _2, and the angle φ are angles on the zx plane. The zx plane is a plane perpendicular to the direction in which the reflecting surface 15 has no curvature (that is, the y-axis direction).
φ = ((π / 2) −θ ₁ + θ ₂ ) / 2 (1)
All the light rays incident on the incident surface 14 do not have to satisfy the above formula (1). That is, the above equation (1) may be established for at least a part of the light rays incident on the incident surface 14. In this case, at least some of the light incident on the incident surface 14, for example, a light L ₁ described above.

The refraction angle θ ₁ of the light beam L _{1 on} the incident surface 14 is a variable. An angle θ ₂ formed by the light ray L ₂ with respect to the incident surface 14 is set. Here, the angle θ ₂ is an angle of the light beam L ₂ traveling indoors. When the angle φ is set based on the equation (1), the reflecting surface 15 that reflects the light beam L ₁ at the angle θ ₂ can be designed.

The angle θ ₂ formed by the light beam L ₂ may be set to be constant with respect to the angle θ ₁ . The angle θ ₁ is a variable. For example, the angle θ ₂ is a constant (that is, a constant value). The reflecting surface 15 designed based on the expression (1) reflects the light beam L ₁ at a constant angle θ ₂ regardless of the angle θ ₁ .

The angle θ ₂ may be set so as to change with respect to the angle θ ₁ . Further, the angle θ ₂ may be set so as to change with respect to the angle range of the angle θ ₁ .

Further, the relationship between the angle φ and the angle θ ₁ defined by the equation (1) is shown in the equation (2). When the angle φ and the angle θ ₁ satisfy the relationship of the expression (2), the reflection on the reflection surface 15 is total reflection. The angle θ _T represents a critical angle at the interface between the protrusion 13 and air. That is, when the total reflection occurs at the reflective surface 15, the critical angle of the light beam reflected by the reflecting surface 15 and theta _T. The “critical angle” is the smallest incident angle at which total reflection occurs when light travels from a high refractive index to a small one.
φ + θ ₁ ≧ θ _T (2)

This eliminates the need for the reflecting surface 15 to be a mirror surface. The mirror surface is formed, for example, by coating the reflective surface 15 with a metal film or a dielectric film. These films reduce the transmission of light that does not satisfy the total reflection condition on the reflection surface 15.

In the first embodiment, the angle θ ₂ formed by the light beam L ₂ is set to be constant with respect to the angle range of the angle θ ₁ . For example, the angle θ ₂ formed by each of the plurality of light beams L _{2 with} respect to the incident surface 14 is the same. Thus, in the example shown in FIG. 5, a plurality of light beams L ₂ are parallel to each other. Here, for example, the angle θ _IN shown in FIG. 5 is in the range of 20 ° ≦ θ _IN ≦ 90 °. The angle θ ₁ has a one-to-one correspondence with the angle θ _IN . In FIG. 5, the angle θ ₂ is expressed by Expression (3).
θ ₂ = β−α (3)

For example, assuming that the refractive index of the protrusion 13 is n and the inclination angle of the incident surface 14 with respect to the x axis is α degrees in the zx plane, the angle θ ₁ and the angle θ _IN are related by the following formula (*). Attached.
θ ₁ = arcsin [1 / n {sin (90 ° −θ _IN −α)}] (*)
That is, the angle θ ₁ changes according to the incident angle θ _IN of the light beam L ₁ incident on the protrusion 13 to the protrusion 13.

When the angle θ ₂ formed by the light beam L ₂ becomes constant with respect to the angle θ _{1 in} a certain angle range, the point f behaves as the focal point of the protrusion 13. Therefore, in this case, the point f is also referred to as the focal point f of the protrusion 13 or simply as the focal point f. The focal point f of the protrusion 13 is located on the opposite side of the reflecting surface 15 with respect to the incident surface 14. The focal point f is a point on a line parallel to the y axis. The y axis is parallel to the direction in which the reflecting surface 15 has no curvature.

In some angular range of the angle theta ₁ of the angular range, the angle theta ₂ may be constant. However, in all the angular range of the angle theta ₁ of the angular range, the angle theta ₂ may be constant. If in some angular range of the angle theta ₁ of the angular range angle theta ₂ is constant, the angle theta ₁ of the angular range, determined to cover a range of solar altitude at the installation location of the lighting member 1 Also good. In this case, the angle range of the angle theta _IN, is set to correspond to the maximum value from the minimum value of the solar altitude at the installation location of the lighting member 1. For example, when the solar south-middle altitude of the winter solstice in Japan is 31 ° and the solar south-middle altitude of the summer solstice is 77 °, the angle range of the angle θ _IN corresponds to the minimum value of the solar altitude. 31 ° ≦ θ _IN ≦ 77 °. The range of the angle θ _IN may be determined as 30 ° ≦ θ _IN ≦ 80 ° by rounding off the decimal place of the minimum value 31 ° and the maximum value 77 ° of the solar altitude. As described above, the angle θ ₁ is calculated from the above formula (*), and the obtained angle θ ₁ , that is, the angle θ ₂ is constant in the angle range of the angle θ ₁ corresponding to the minimum value to the maximum value of the solar altitude. You may make it become. It is also possible to further reduce the lower limit of the angle theta _IN considering the like glare from the ground.

In the example shown in FIG. 5, the focal point f is a straight line passing through the tip portion P in the x-axis direction (specifically, the + x-axis direction) of the protrusion 13 in the zx plane, and is parallel to the z-axis direction. Located on a straight line. As shown in FIG. 5, light L _IN reaches the incident surface 14 of the projection 13 of the lighting member 1 through the focal point f. The light _{L IN,} also referred to as the incident light _{L IN.} The light beam L _IN reaches the incident surface 14 at an angle θ _IN , for example. Light L _IN reaching the entrance surface 14 is refracted at the interface between air and the incident surface 14.

As shown in FIG. 6, the angle θ _IN of the light incident on the protrusion 13 is defined by the inclination of the light ray L _IN with respect to the x axis on the zx plane. Angle theta _IN is + a x-axis direction is 0 °, + direction of rotation from the x-axis direction to the + z-axis direction is positive (+), negative direction of rotation of the -z axis direction from the + x-axis direction (-) to .

The light beam L ₁ refracted by the incident surface 14 enters the protrusion 13. The light ray L ₁ travels toward the reflecting surface 15.

As shown in FIGS. 5 and 6, the light beam L _{1 that} has reached the reflecting surface 15 is reflected by the reflecting surface 15. The reflection at the reflection surface 15 is total reflection at the interface between the protrusion 13 and air, for example. The light beam L ₂ reflected by the reflecting surface 15 travels toward the surface 11. The angle between the ray L ₂ and the x-axis and the angle beta.

As shown in FIG. 5, the incident surface 14 is inclined at an inclination angle α in the positive direction with respect to the x-axis. The range of the inclination angle α of the incident surface 14 is determined by the following equation (4). Α ≧ β (4)

Further, the inclination angle α of the incident surface 14 is preferably within the range of the following formula (5). Β ≦ α ≦ 60 ° (5)

The inclination angle α of the incident surface 14, light rays L ₂ reflected by the reflecting surface 15 is provided in order to avoid reaching the entrance surface 14 again. That is, when the angle β of the light beam L ₂ reflected by the reflecting surface 15 is larger than the inclination angle α, a part of the light beam L ₂ reflected by the reflecting surface 15 is reflected by the incident surface 14. Therefore, the light beam L ₂ reflected by the incident surface 14 is not emitted from the lighting member 1 at the emission angle θ _OUT . By satisfying the condition of Expression (4), the directivity of the light L _OUT emitted from the daylighting member 1 can be improved.

The material of the lighting member 1 is, for example, PMMA. When the incident angle of light from air to PMMA exceeds 60 degrees, the reflectance of light on the surface of PMMA exceeds 10%. Therefore, in order to suppress a decrease in light utilization efficiency on the incident surface 14, the incident angle of light on the incident surface 14 is desirably 60 degrees or less.

When the angle α is large, the incident angle of the light ray L _IN having a large angle θ _IN becomes large. When the angle θ _IN is the largest, it is 90 degrees. When the angle θ _IN is 90 degrees, the incident angle to the incident surface 14 is the angle α. By setting the angle α to 60 degrees or less, it is possible to suppress a decrease in light utilization efficiency on the incident surface 14.

When the angle α is small, the incident angle of the light ray L _IN having a small angle θ _IN is large. When the angle θ _IN is the smallest, it is 20 degrees. When the angle θ _IN is 20 degrees, the incident angle to the incident surface 14 is (70 degrees−α). The angle β is also related to the size of the room where the external light is incident. For example, the angle β is set in a range of 5 degrees to 10 degrees. From equation (4), the angle α is set to be equal to or greater than the angle β, and therefore the angle α is a value of 5 degrees to 10 degrees or more. Even when the angle α and the angle β are the same, the incident angle of the light on the incident surface 14 is a value close to 60 degrees. In addition, by setting the angle β to 10 degrees or more, the incident angle of light on the incident surface 14 is 60 degrees or less. Therefore, it is possible to suppress a decrease in light utilization efficiency at the incident surface 14.

In Embodiment 1, both the base material 10 and the protrusion 13 are formed of PMMA. For this reason, as shown in FIG. 5, the light beam L < _b > ₂ goes straight at the interface between the protruding portion 13 and the base material 10.

As shown in FIG. 6, the light beam L _{2 that} has traveled straight through the interface between the protrusion 13 and the substrate 10 reaches the surface 12. The light beam L ₂ that has reached the surface 12 is emitted from the surface 12 in the −x-axis direction. Here, the light beam emitted from the surface 12 is the light beam L _OUT . Ray _{L 2} is a light ray _{L OUT} is refracted by the surface 12. Ray L ₂ is refracted at the interface between the surface 12 and the air. The exit angle of the light beam L _OUT is the exit angle θ _OUT . The light beam L _OUT from the daylighting member 1 travels indoors, for example.

Here, the angle θ _OUT of the light emitted from the lighting member 1 is defined by the inclination of the light ray L _OUT with respect to the x axis on the zx plane. The angle θ _OUT is 0 ° in the −x-axis direction, the rotation direction from the −x-axis direction to the + z-axis direction is positive (+), and the rotation direction from the −x-axis direction to the −z-axis direction is negative (− ).

The definition of the coordinates of an arbitrary point on the reflection surface 15 of the protrusion 13 will be described with reference to FIG.

FIG. 7 will be described using x′y ′ coordinates. In the x′y ′ coordinate shown in FIG. 7, the focal point f is the origin in the x′y ′ coordinate. The x ′ axis corresponds to the x axis of the xyz coordinates shown in other figures. The + x′-axis direction corresponds to the −x-axis direction of the xyz coordinate. The y ′ axis corresponds to the z axis of the xyz coordinate. The + y′-axis direction corresponds to the + z-axis direction of the xyz coordinate.

As shown in FIG. 7, the intersection (origin) of the x ′ axis and the y ′ axis is the focal point f. The angle between the light beam _LIN and the y ′ axis is the angle θ _i . The angle between the ray L ₂ and x 'axis, an angle beta _i. The angle formed by the incident surface 14 and the x ′ axis is an angle α.

Based on the x′y ′ coordinate system, the shape of the reflecting surface 15 in the protrusion 13 will be described.

The light ray L _θi is emitted at an angle θ _i from the origin of the x′y ′ coordinate system (that is, the focal point f). The light L _IN from the origin (the focus f) emitted at an angle theta _i and beam L _.theta.i. The coordinates of the intersection of the light beam L _θi and the incident surface 14 are (Δx ′ _i , Δy ′ _i ).

The angle θ _i−1 is an angle smaller than the angle θ _i . The light _{L IN} emitted from the origin (the focus f) at an angle theta _i-1 and light beam _{L θi-1.}

The light beam L _θ′i is a light beam that is refracted at the incident surface 14 and is incident on the protrusion 13. The angle formed between the light beam L _θ′i and the y ′ axis is an angle θ ′ _i . The coordinates of the intersection of the light ray _Lθ′i and the reflecting surface 15 are (x ′ _i , y ′ _i ). Rays L _Shita'i reflected by the reflecting surface 15 is a ray L _.beta.i.

The light beam L _θ′i−1 is a light beam that is refracted at the incident surface 14 and is incident on the protrusion 13. The angle formed between the light beam L _θ′i−1 and the y ′ axis is an angle θ ′ _i−1 . The coordinates of the intersection of the light beam L _θ′i−1 and the reflecting surface 15 are (x ′ _i−1 , y ′ _i−1 ). Light _{L θ'i-1} reflected by the reflection surface 15 is a ray _{L βi-1.}

The angle between the tangent line of the reflecting surface 15 at the point (x ′ _i−1 , y ′ _i−1 ) and the x ′ axis is defined as an inclination angle γ _i−1 .

At this time, the point (x ′ _i , y ′ _i ) on the reflecting surface 15 where the light beam L _θi emitted from the origin (focal point f) at the angle θ _i reaches is expressed by the following equations (6a) and (6b): This is the solution of the simultaneous equations. y ′ _i = y ′ _i−1 + (x ′ _i −x ′ _i−1 ) × tan (γ _i−1 ) (6a) y ′ _i = Δy ′ _i + (x ′ _i −Δx ′) _i ) × tan (90−θ ′ _i ) (6b)

At this time, γ _i-1 is expressed as a solution of simultaneous equations of the following equations (7), (8a), and (8b). 0 = sin (θ ′ _i−1 + γ _i−1 ) −sin ((90−β _i−1 ) + γ _i−1 ) (7)

However, the angles θ ′ _i−1 and θ ′ _i are expressed by the following equations. θ ′ _i−1 = arcsin (sin (θ _i−1 ) / n) + α (8a) θ ′ _i = arcsin (sin (θ _i ) / n) + α (8b)

At this time, n is the refractive index of the protrusion 13.

Δx ′ _i and Δy ′ _i are expressed by the following equations (9a) and (9b). Δx ′ _i = y ′ ₀ × tan (θ _i ) / (1 + tan (α) × tan (θ _i )) (9a) Δy ′ _i = y ′ ₀ −Δx ′ _i × tan (α)・ (9b)

However, the initial value y ′ ₀ of y ′ _i is an arbitrary value, and the scale of the protrusion can be changed according to y ′ ₀ .

The reflection surface 15 is a curve formed by changing the point (x ′ _i , y ′ _i ) in the range of 0 ° ≦ θ _i ≦ 70 °, which is defined by the above equations (9a) and (9b).

When the step size θ _i −θ _i−1 of the angle θ _i is as close to 0 (zero) as possible, the reflecting surface 15 becomes a curved surface. When the step size θ _i −θ _i−1 of the angle θ _i is increased, the reflecting surface 15 becomes a polyhedron.

As described above, the reflecting surface 15 is a surface that converts the light beam L _.theta.i emitted at an angle theta _i from the origin of the x'y 'coordinate system on the ray L _.beta.i output angle beta _i. At this time, the origin of the x′y ′ coordinate system is the focal point f of the protrusion 13. Therefore, light that passes through the focal point f of the projection 13 enters the projection 13 (ray L _.theta.i) is reflected at an angle β in the reflecting surface 15 irrespective of the angle theta _IN.

However, the angle theta _IN satisfies a relation of the following formula as the angle θ _i (10).
θ _IN = 90−θ _i [°] (10)

Therefore, in the angle range 0 ° ≦ θ _i ≦ 70 °, the incident angle θ _IN satisfies the following formula (11). 20 ° ≦ θ _IN ≦ 90 ° (11)

The light beam L ₂ reflected at the reflection surface 15 at the angle β is refracted by the surface 12 and is emitted from the daylighting member 1 at the angle θ _OUT .

Here, the angle θ _OUT is expressed by the following formula (12) using the angle β and the refractive index n of the protrusion 13.
θ _OUT = arcsin (n × sin (β)) (12)

For example, as shown in FIG. 8, when the incident light _LIN is sunlight, the solar altitude range S is a range of the angle θ _IN represented by Expression (11). By using the lighting member 1, regardless of the altitude of the sun, the light passing through the focal point f (beam L _.theta.i), as shown in FIG. 6, is emitted from the lighting member 1 at the exit angle theta _OUT.

By reducing the change in the emission angle θ _OUT , a certain percentage of light is taken into the room regardless of the change in solar altitude. In other words, a certain proportion of light is taken into the room regardless of seasonal changes and time changes. The light taken into the room is irradiated to the ceiling, for example. The light taken into the room may be taken into a lighting device or the like in the room, for example. In other words, the daylighting member 1 can be used to supplement the power of the light source in an instrument such as a lighting device, and can also be used as a substitute for the light source in an instrument such as a lighting device. The daylighting member 1 shown in Embodiment 1 enables stable daylight throughout the year.

In the example shown in FIG. 10, the tip of the protrusion 13 is cut. That is, as shown in FIG. 10, the tip end portion P of the protruding portion 13 is cut. In this case, the tip P is an intersection of the extension lines of the incident surface 14 and the reflecting surface 15 on the zx plane. In FIG. 10, the distal end portion P is cut, for example, in parallel to the yz plane. Note that the protrusion 13 cannot capture light having a smaller incident angle when entering the incident surface 14 than light entering from the end E ₁ on the distal end portion P side of the incident surface 14 through the focal point f. That is, the lighting efficiency is reduced. The end portion E ₂ is an end portion of the distal portion P side of the reflecting surface 15.

Further, the focal point f can be arranged on a cutting plane parallel to the yz plane. In other words, it is also possible to place the focal point f on a plane parallel to the y-z plane includes an end portion E _1. In this case, for example, the reflection surface 15 of the protrusion 13 shown in FIG. 5 is moved in the −z-axis direction so that the shape of the reflection surface 15 is adjusted to match the incident light. In this case, light parallel to the z-axis can be incident. For this reason, the reduction of the lighting efficiency as described above does not occur.

As shown in FIG. 5, when the incident surface 14 and the reflecting surface 15 extend to the tip portion P, the end portion E ₁ coincides with the tip portion P.

In the example shown in FIG. 11, the focal point f is located in the −x-axis direction with respect to the tip portion P in the x-axis direction. That is, the focal point f is located closer to the base material 10 than the front end portion P in the thickness direction of the base material 10. Note that the amount of light incident on the focal point f from the −x-axis direction side of the focal point f is small due to the situation where the daylighting member 1 is disposed. That is, the amount of light incident on the focal point f from the base material 10 side is smaller than the focal point f in the thickness direction of the base material 10. Therefore, the effect of the daylighting is small in the portion of the protrusion 13 that is located on the + x axis direction side from the plane that includes the focal point f and is parallel to the yz plane.

In the example shown in FIG. 12, the focal point f is located in the + x-axis direction with respect to the tip portion P in the x-axis direction. That is, the focal point f is located on the opposite side of the base material 10 with respect to the distal end portion P in the thickness direction of the base material 10. Note that the protrusion 13 cannot capture light having a smaller incident angle when entering the incident surface 14 than light entering the tip P through the focal point f.

From the above, for example, when the daylighting member 1 is attached to a vertically arranged glass window, the projection 13 shown in FIG. 5 can take in external light most efficiently. The focal point f of the protrusion 13 shown in FIG. 5 is located on a plane that includes the tip P and is parallel to the surface 11 of the substrate 10.

As shown in FIG. 2, the relationship between the distance D between the tip portions P of the protrusions 13 adjacent to each other and the width W on the incident surface 14 irradiated with the incident light _LIN is expressed by the following equation (13). The The distance D is the length on the zx plane between the tips P of the protrusions 13 adjacent to each other. Width W is the length of the z-x plane of the incident surface 14 of the incident light L _IN is irradiated. In other words, the width W is irradiated by the width of the incident light L _IN at the incident surface 14.
W = D / (cos (α) × tan (θ _IN )) (13)

From equation (13), the smaller the distance D, the smaller the width W. As a result, the width of the incident light _LIN irradiated on the reflecting surface 15 is also reduced. In other words, the distance D the amount of incident light L _IN entering the projection 13 without passing through the smaller the focal point f is suppressed. Therefore, variation in the angle θ _OUT of the light L _OUT emitted from the daylighting member 1 is also suppressed. That is, the directivity of the light L _OUT emitted from the daylighting member 1 is improved.

Note that even if the shape of the daylighting member 1 is uniformly enlarged or reduced on the zx plane, the directivity of the light L _OUT emitted from the daylighting member 1 does not change. Note that “equally” indicates that the ratio of enlargement and reduction is the same in the x and z directions.

The directivity of the light L _OUT emitted from the daylighting member 1 is improved by arranging the protrusions 13 densely rather than arranging the protrusions 13 in the z-axis direction with a large interval. That is, the directivity of the light L _OUT emitted from the daylighting member 1 is improved by arranging the projections 13 densely, rather than arranging the projections 13 with a wide interval in the z-axis direction.

The most projecting portion 13 but closely lined shape, a shape in which the valley portion V ₂ of the protruding portion 13 is connected adjacent to the valleys V ₁ of the protrusion 13 with. In other words, the most protruding part 13 is arranged closely the shape, a shape in which the valley portion V ₁ of the certain projection 13 and the valleys V ₂ of the adjacent protrusions 13 coincide in the z-axis direction. That is, the “closely arranged shape” is a shape in which the protrusions 13 are continuously arranged. The “closely arranged shape” indicates a shape in which the surface 11 of the base material 10 does not appear between the protruding portions 13 arranged. Therefore, the “closely arranged shape” includes, for example, a shape in which the valleys V ₁ and V ₂ of the adjacent protrusions 13 are connected by curved surfaces in consideration of formability and the like. Further, “continuous” means to continue without a break.

<< Effect of Daylighting by the Daylighting Member 1 >> FIG. 9 is a diagram showing a simulation result of the intensity distribution of the outgoing light with respect to the angle _θOUT of the outgoing light. In FIG. 9, the intensity distribution of the emitted light within the range of the distance I from the daylighting member 1 is shown. FIG. 9 shows the case where direct light at noon (θ _IN = 56 °) in spring equinox, noon on the summer solstice (θ _IN = 77 °) and noon on the winter solstice (θ _IN = 31 °) is incident on the daylighting member 1. Yes.

Here, direct light means sunlight that does not contain diffuse light, and is generally direct sunlight. Sunlight includes direct light and scattered light. Direct light is light received directly from the sun. Scattered light is light reflected, refracted or scattered by something sunlight.

Here, direct light is treated as parallel light.

Light whose angle θ _OUT is greater than zero (θ _OUT > 0) becomes light that travels toward the ceiling. For this reason, the ratio of the energy emitted in the range where the angle θ _OUT is larger than zero (θ _OUT > 0) is high. For example, the daylighting member 1 is desired to emit light toward the ceiling.

In addition, light having an angle θ _OUT smaller than zero (θ _OUT <0) is light directed toward the floor. The light toward the floor becomes glare light that makes a person in the room feel dazzling. For this reason, it is desirable to suppress the light which goes to a floor direction.

As shown in FIG. 9, the ratio of the energy toward the ceiling side (θ _OUT > 0) out of the total energy of the emitted light (light ray L _OUT ) is as follows. In the equinox (θ _IN = 56 °), the ratio of energy toward the ceiling is 79%. In the summer solstice (θ _IN = 77 °), the ratio of energy toward the ceiling is 93%. In the winter solstice (θ _IN = 31 °), the ratio of energy toward the ceiling is 73%. It can be seen that a relatively large amount of light is applied to the ceiling regardless of the season (solar altitude).

Of the incident light (light ray L _IN ), the light passing through the focal point f is emitted at a constant angle θ _OUT regardless of the angle θ _IN . However, there is also light that enters the protrusion 13 without passing through the focal point f. For this reason, as shown in FIG. 9, the emitted light (that is, the light beam L _OUT ) has an angular distribution.

The outgoing angle θ _{P at} which the intensity of the outgoing light (that is, the light beam L _OUT ) is maximum is as follows. In spring equinox, the emission angle θ _P is 23.5 °. In the summer solstice, the emission angle θ _P is 19.5 °. In the winter solstice, the emission angle θ _P is 10.5 °. The change in the angle of the outgoing light (that is, the light beam L _OUT ) is suppressed to be smaller than the change in the angle of the incident light (that is, the light beam L _IN ) due to the seasonal change.

As described above, according to the lighting member 1, even if the incident angle of the incident light L _IN to the incident surface 14 is changed, suppressing the change of the emission angle theta _OUT of the output light L _OUT from the lighting member 1 Can do.

Embodiment 2. FIG. Hereinafter, Embodiment 2 will be described with reference to FIGS. In each drawing, the scale of a dimension may differ with components.

In Embodiment 2, the light that is irradiated onto the floor is reduced by using the light shielding portion 21.

FIG. 13 shows the behavior of light rays when incident lights having different angles θ _IN (that is, light rays L _IN ) are reflected at the same location on the reflecting surface 15. The angles β, β ′, and β ″ are angles with respect to the x axis.

When the light is reflected at the same place on the reflecting surface 15 in the zx plane, the angle β _IN of the reflected light (ie, light ray L ₂ ) increases as the angle θ _IN of the incident light (ie, light ray L _IN ) increases. Becomes bigger. On the other hand, the smaller the angle θ _{IN of} the incident light (ie, the light beam L ₂ ), the smaller the angle β of the reflected light (ie, the light beam L ₂ ).

First, a case where the angle θ ′ _IN is larger than the angle θ _IN is shown. A light ray passing through the focal point f is a light ray L. A light ray that does not pass through the focal point f is defined as a light ray L ′. The angle at which the light beam L is incident is defined as an angle θ _IN . The angle at which the light beam L ′ is incident is defined as an angle θ ′ _IN . The angle of the reflected light of the light beam L is defined as an angle β. The angle of the reflected light of the light ray L ′ is defined as an angle β ′. Light L incident on the projection 13 of the focal point f in street angle theta _IN is a point R the point on the reflecting surface 15 to reach. When the light ray L ′ is reflected at the point R, if the angle θ ′ _IN is larger than the angle θ _IN , the angle β ′ becomes larger than the angle β. The angle β usually has a value larger than 0 (zero). For this reason, the angle β ′ is also larger than 0 (zero). Then, the reflected light of the light beam L ′ is applied to the ceiling, for example.

Next, "the light that does not pass through the _IN indicates smaller than the angle theta _IN. Focal f beam L" angle theta to. The angle at which the light beam L ″ is incident is defined as an angle θ ″ _IN . The angle of the reflected light of the light beam L ″ is defined as an angle β ″. When ray L ″ is reflected at point R, if angle θ ″ _IN is smaller than angle θ _IN , angle β ″ is smaller than angle β. If angle β ″ is greater than 0 (zero). For example, the light beam L ″ is applied to the ceiling. If the angle β ″ is smaller than 0 (zero), for example, the light beam L ″ is applied to the floor. .

As shown in the first embodiment, in the daylighting member 1, light with an angle β ″ smaller than 0 (zero) is suppressed. However, the light with the angle β ″ smaller than 0 (zero) is better.

When the angle θ ′ _IN is larger than the angle θ _IN , the light ray L ′ passes through the point located on the + z-axis direction side with respect to the focal point f on the plane including the focal point f and the tip P, and enters the incident surface 14. Incident.

On the other hand, the angle theta "If _IN is less than the angle theta _IN is light L" passes through the point located -z axis direction side than the focal point f on the plane including the focal point f and the tip portion P incident Incident on the surface 14.

That is, as shown in FIG. 14, light that passes through the plane including the focal point f and the tip portion P and enters from the incident surface 14 is blocked by the light blocking portion 21. The light shielding unit 21 is provided in the light shielding member 20, for example. Thereby, the occurrence of glare can be suppressed.

The daylighting member 2 according to the second embodiment includes a light shielding member 20 in addition to the base material 10 and the protrusions 13 described in the first embodiment. The light shielding member 20 includes at least one light shielding portion 21 and a base material 22. The light shielding portion 21 is provided on the surface or inside of the base material 22 on the −x axis direction side.

The base material 22 is formed of a material that transmits light.

The base material 22 may be formed from a resin film using, for example, a thermoplastic polymer, a thermosetting resin, a photopolymerizable resin, or the like. As the resin film, an acrylic polymer, an olefin polymer, a vinyl polymer, a cellulose polymer, an amide polymer, a fluorine polymer, a urethane polymer, a silicone polymer, an imide polymer, or the like can be used.

In the second embodiment, polymethyl methacrylate (PMMA) is used as an example of the material of the base material 22.

As shown in FIG. 14, the light shielding unit 21 adjusts the incident range of light on the incident surface 14. The light shielding part 21 is formed on a surface including the focal point f and the tip part P, for example. The light shielding portion 21 extends in the z-axis direction from the tip portion P in the x-axis direction (specifically, the + x-axis direction) of the incident surface 14. In other words, the light shielding part 21 is formed in the range from the focal point f to the tip part P. That is, the light shielding part 21 is formed in a band shape. A plurality of light shielding portions 21 are formed on the base material 22. The plurality of light shielding portions 21 are arranged in parallel to each other on the base material 22. The interval between the adjacent light shielding portions 21 is equal to the interval between the tip portions P of the adjacent protruding portions 13.

However, the light shielding portion 21 may be arranged so that light passing through the focal point f is incident on the incident surface 14. In this case, the effect of the daylighting member 1 described in the first embodiment is also obtained.

The light shielding part 21 is a film formed of, for example, a black pigment. For example, the light shielding portion 21 is a black pigment printing film. The light shielding part 21 may be a film formed of a white pigment. In this case, the light shielding unit 21 may be, for example, a white pigment printing film. In the second embodiment, for example, the light shielding portion 21 is a black pigment printing film.

As shown in FIG. 15, a cutting surface 24 is formed by cutting the vicinity of the tip portion P of the protruding portion 13 along a plane parallel to the yz plane, and the light shielding member 20 is formed on the protruding portion 13 by the cutting surface 24. It may be fixed.

In FIG. 16, the intensity distribution of the emitted light within the range of the distance I from the daylighting member 2 is shown. As shown in FIG. 16, the ratio of the energy toward the ceiling side (θ _OUT > 0) in the total energy of the emitted light is as follows: equinox (θ _IN = 56 °), summer solstice (θ _IN = 77 °), and winter solstice ( All of θ _IN = 31 °) is 100%. And all the emitted light is irradiated to a ceiling irrespective of a season (namely, solar altitude). And the light which goes to the floor side ((theta) _OUT <= 0) which causes a glare is suppressed.

The outgoing angle θ _{P at} which the intensity of the outgoing light is maximum is as follows. In spring equinox, the emission angle θ _P is 23.5 °. In the summer solstice, the emission angle θ _P is 19.5 °. In the winter solstice, the emission angle θ _P is 10.5 °. The change in the angle of the outgoing light is suppressed to be smaller than the change in the angle of the incident light due to the seasonal change.

As described above, the embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and the components can be modified and embodied without departing from the scope of the invention in the implementation stage. The features in the embodiments described above and the features in the modifications can be appropriately combined with each other.

In each of the above-described embodiments, there are cases where terms such as “parallel” or “vertical” indicating the positional relationship between parts or the shape of the part are used. These represent that a range that takes into account manufacturing tolerances and assembly variations is included. For this reason, when the description showing the positional relationship between the parts or the shape of the part is included in the scope of claims, it indicates that the range including a manufacturing tolerance or a variation in assembling is included.

Based on the above embodiments, the contents of the invention will be described as supplementary notes (1) and supplementary notes (2) below. The supplementary note (1) and the supplementary note (2) are each independently labeled. Therefore, for example, “Appendix 1” exists in both appendices (1) and (2).

Also, the feature of supplementary note (1) and the feature of supplementary note (2) can be combined.

<Appendix (1)>
<Appendix 1>
A base material that transmits light, has a thickness in a first direction, and extends in a second direction orthogonal to the first direction;
Projecting from the base material in the first direction and including at least one protrusion extending in the second direction;
The at least one protrusion includes an incident surface on which light is incident and a reflecting surface that reflects the light incident on the incident surface;
The incident surface extends from the substrate in the first direction;
The reflective surface has a curved surface curved in a direction away from the incident surface,
In a plane perpendicular to the second direction, the refraction angle of the light beam incident on the incident surface is θ ₁ , the angle formed by the light beam reflected by the reflection surface and the incident surface is θ ₂ , and the light beam is When the angle between the tangent plane at the point reflected by the reflecting surface and the incident surface is φ,
φ = ((π / 2) −θ ₁ + θ ₂ ) / 2
A daylighting member that meets the requirements.

<Appendix 2>
The daylighting member according to claim 1, wherein the incident surface is a flat surface.

<Appendix 3>
The daylighting member according to

appendix

1 or 2, wherein a focal point of the at least one protrusion is located at a position facing the incident surface.

<Appendix 4>
The focal point is a straight line passing through a tip portion of the at least one protrusion in the first direction on a plane orthogonal to the second direction, and is orthogonal to the first direction and the second direction. The daylighting member according to attachment 3, which is located on a straight line parallel to the third direction.

<Appendix 5>
When the total reflection occurs at said reflecting surface, when the critical angle of the light beam reflected by the reflecting surface and theta _T,
φ + θ1 ≧ θ _T
The lighting member according to any one of supplementary notes 1 to 4, which satisfies:

<Appendix 6>
The at least one protrusion includes a plurality of protrusions;
The daylighting member according to any one of supplementary notes 1 to 5, wherein the plurality of protrusions are arranged in a third direction orthogonal to the first direction and the second direction.

<Appendix 7>
In a plane orthogonal to the second direction, the distance from the end of the incident surface in the first direction to the incident position of the light beam on the incident surface is D _in, and the first surface of the reflective surface is said distance as when the distance from the end to the reflection position of the light beam at said reflecting surface and D _ref in the direction, the distance the distance D _ref increases as D _in increases, the distance D _in is reduced The lighting member according to any one of supplementary notes 1 to 6, wherein D _ref decreases.

<Appendix 8>
The daylighting member according to any one of appendices 1 to 7, wherein the base material has a plate shape.

<Appendix 9>
The said base material is a lighting member as described in any one of the additional remarks 1-8 currently formed with the resin film.

<Appendix 10>
The daylighting member according to any one of appendices 1 to 9, wherein the at least one protrusion is formed of a material including an acrylic resin, an epoxy resin, or a silicone resin.

<Appendix 11>
A light-shielding part that adjusts an incident range of light on the incident surface;
The light shielding portion extends from a tip portion of the incident surface in the first direction in a third direction orthogonal to the first direction and the second direction. The daylighting member of description.

<Appendix 12>
The daylighting member according to supplementary note 11, wherein the light shielding portion is a film formed of a black pigment.

<Appendix 13>
The daylighting member according to supplementary note 11, wherein the light shielding portion is a film formed of a white pigment.

<Appendix (2)>
<Appendix 1>
A plate-shaped substrate that transmits light;
A protrusion formed so as to protrude from one surface of the base material,
The protrusion includes a light incident surface and a reflective surface that reflects the incident light.
The incident surface is arranged extending from the surface,
The reflective surface is arranged extending from the surface and has a cylindrical shape having a curvature in a first direction perpendicular to the surface;
The direction having no cylindrical curvature is the second direction, the first direction and the direction perpendicular to the second direction is the third direction,
A point on a line parallel to the second direction that is located on the opposite side of the reflecting surface with respect to the incident surface is defined as a first point, and a light ray that has entered the incident surface through the first point is defined as a first point. And the first light beam reflected by the reflecting surface is the second light beam,
The plane perpendicular to the second direction is the first plane,
The angle on the first plane of the refraction angle of the first light beam at the incident surface and the angle theta _1, the angle the angle on the first plane of the angle of the second light flux to the incident surface θ ₂
When the end of the incident surface opposite to the surface is the first end, and the end of the reflecting surface opposite to the surface is the second end,
On the first plane, the length on the incident surface from the first end to the incident position of the first light beam is a first length, and the first end is the first length from the second end. When the length on the reflecting surface to the reflection position of the light beam is the second length,
When the first length continuously changes, the second length continuously changes 1: 1 with the first length, and the first length and the second length Has the same direction of increase and decrease,
The angle φ on the first plane of the angle formed by the tangent plane of the reflective surface at the second point where the first light ray intersects the reflective surface and the incident surface is:
φ = ((π / 2) −θ ₁ + θ ₂ ) / 2
A daylighting member that meets the requirements.

<Appendix 2>
When the angle on the first plane of the critical angle with respect to the reflecting surface of the first light beam and the angle theta _T,
The angle φ and the angle θ ₁ are
φ + θ ₁ ≧ θ _T
The daylighting member according to Supplementary Note 1, wherein

<Appendix 3>
A light-shielding portion that prevents light incident on the side opposite to the incident surface with respect to the second point by the reflective surface by shielding light incident from the incident surface;
The daylighting member according to

supplementary note

1 or 2, wherein the light-shielding portion is arranged from the end portion toward the side opposite to the reflecting surface.

<Appendix 4>
Two surfaces parallel to a straight line connecting the first and second ends and a thickness in a direction opposite to a direction from the second end toward one surface of the base material, the first end The lighting member according to

appendix

1 or 2, further comprising a light-shielding portion extending in a direction parallel to a straight line connecting the first end portion and the third end portion.

<Appendix 5>
The daylighting member according to any one of supplementary notes 3 to 4, wherein the light shielding portion includes a light shielding portion on one surface of the protrusion portion.

<Appendix 6>
The light-shielding portion has a width that passes through the second end portion and the second end portion of the protrusion, and is parallel to one surface of the base material. The lighting member according to any one of supplementary notes 3 to 5, which is equal in length to a straight line connecting a point located on the opposite side.

<Appendix 7>
The light-shielding portion has a width that passes through the second end portion and the second end portion of the protrusion, and is parallel to one surface of the base material. The lighting member according to any one of supplementary notes 3 to 6, which is equal to a length of a straight line connecting a point located on the opposite side.

<Appendix 8>
The daylighting member according to any one of appendices 3 to 7, wherein the daylighting member and the light-shielding portion are bonded together by filling a part of the plurality of protrusions included in the daylighting member with an adhesive layer.

<Appendix 9>
The said lighting member and the said light-shielding part were bonded by the cut surface which cut | disconnected the said 2nd edge part vicinity of the several projection part with which the said lighting member is equipped with the surface parallel to one surface of the said base material. The lighting member according to any one of appendices 3 to 8.

<Appendix 10>
The daylighting member according to any one of supplementary notes 1 to 9, wherein the protrusion is arranged side by side in the third direction.

<Appendix 11>
The daylighting member according to any one of supplementary notes 1 to 10, wherein the protrusion is continuously arranged in the third direction.

<Appendix 12>
The daylighting member according to any one of appendices 1 to 11, wherein the reflecting surface has a concave shape with respect to the first light beam.

<Appendix (3)>
<Appendix 1>
A base material that transmits light, has a thickness in a first direction, and extends in a second direction orthogonal to the first direction;
Projecting from the base material in the first direction and extending in the second direction; and
The protrusion includes an incident surface on which light is incident and a reflecting surface that reflects the light incident on the incident surface,
The incident surface extends from the substrate in the first direction;
The reflective surface has a curved surface curved in a direction away from the incident surface,
In a plane orthogonal to the second direction, the refraction angle of the light beam incident on the incident surface is θ ₁ , the angle formed by the light beam reflected by the reflection surface and the incident surface is θ ₂ , and the light beam is When the angle between the tangential plane at the point reflected by the reflecting surface and the incident surface is φ, at least a part of the light incident on the incident surface,
φ = ((π / 2) −θ ₁ + θ ₂ ) / 2
A daylighting member that meets the requirements.

<Appendix 3>
The reflective surface is a cylindrical shape having a curvature in the first direction;
At least a part of the light beam incident on the incident surface passes through a first point which is a point on a line parallel to the second direction and located on the opposite side of the reflecting surface with respect to the incident surface. The daylighting member according to 2.

<Appendix 4>
The protrusion has a focal point;
The focal point of the protrusion is a focal point where the light beam from the base material is reflected by the reflective surface and the reflected light beam from the reflective surface is collected,
The light beam from the base material is a light beam incident on the protrusion from the base material,
The daylighting member according to any one of appendices 1 to 3, wherein the light beam incident on the protrusion is a parallel light beam.

<Appendix 5>
The refraction angle θ ₁ changes according to the incident angle θ _IN of the light beam incident on the protrusion to the protrusion,
The daylighting member according to

Supplementary Note

3 or 4, wherein the incident angle θ _IN satisfies 20 ° ≦ θ _IN ≦ 90 °.

<Appendix 6>
The refraction angle θ ₁ changes according to the incident angle θ _IN of the light beam incident on the protrusion to the protrusion,
The angular range of the incident angle theta _IN is lighting member according to

Appendix

3 or 4 corresponds to the maximum value from the minimum value of the solar altitude at the installation location of the lighting member.

<Appendix 7>
Some of the angular range, the lighting member according to any one of the angle theta ₂ is constant Appendix 3 to 6 of the angular range of the refraction angle theta _1.

<Appendix 8>
All the angular range, the lighting member according to any one of the angle theta ₂ is constant Appendix 3 to 6 of the angular range of the refraction angle theta _1.

<Appendix 9>
The focal point of the protrusion is a straight line passing through the tip of the protrusion in the first direction on a plane orthogonal to the second direction, and orthogonal to the first direction and the second direction. The lighting member according to any one of supplementary notes 4 to 8, which is located on a straight line parallel to the third direction.

<Appendix 10>
In the plane orthogonal to the second direction, the distance on the incident surface from the tip of the protrusion to the incident position of the light beam incident on the incident surface is defined as a first distance. When the distance on the reflection surface from the tip of the projection to the reflection position of the light beam incident on the incident surface is a second distance,
The daylighting member according to any one of appendices 3 to 9, wherein the second distance increases as the first distance increases, and the second distance decreases as the first distance decreases.

<Appendix 11>
When the critical angle of the light beam reflected by the reflecting surface and theta _T,
φ + θ ₁ ≧ θ _T
The lighting member according to any one of supplementary notes 1 to 10, wherein:

<Appendix 12>
A plurality of the protrusions;
The lighting member according to any one of supplementary notes 1 to 11, wherein the plurality of protrusions are arranged in a third direction orthogonal to the first direction and the second direction.

<Appendix 13>
The daylighting member according to any one of appendices 1 to 12, wherein the base material has a plate shape.

<Appendix 14>
A light-shielding part that adjusts an incident range of light on the incident surface;
The said light-shielding part extends in the 3rd direction orthogonal to the said 1st direction and the said 2nd direction from the front-end | tip part in the said 1st direction of the said incident surface. The daylighting member of description.

1, 2 Daylighting Member, 10 Base Material, 11, 12 Plane, 13 Projection, 14 Incident Surface, 15 Reflecting Surface, P Tip, V1, V2 Valley, L ₁ , L ₂ , L _IN , L _OUT , L _{_{_θi,}} L _θ'i, L _βi, _{_{rays, θ 1, θ 2, φ}} , θ IN, θ OUT, α, β angle, f focal, 20 light shielding member, 21 light-shielding portion, 22 substrate, 24 cut surface.

Claims

A base material that transmits light, has a thickness in a first direction, and extends in a second direction orthogonal to the first direction;
Projecting from the base material in the first direction and extending in the second direction; and
The protrusion includes an incident surface on which light is incident and a reflecting surface that reflects the light incident on the incident surface,
The incident surface extends from the substrate in the first direction;
The reflective surface has a curved surface curved in a direction away from the incident surface,
In a plane orthogonal to the second direction, the refraction angle of the light beam incident on the incident surface is θ 1 , the angle formed by the light beam reflected by the reflection surface and the incident surface is θ 2 , and the light beam is When the angle between the tangential plane at the point reflected by the reflecting surface and the incident surface is φ, at least a part of the light incident on the incident surface,
φ = ((π / 2) −θ 1 + θ 2 ) / 2
A daylighting member that meets the requirements.
The daylighting member according to claim 1, wherein the incident surface is a flat surface.
The reflective surface is a cylindrical shape having a curvature in the first direction;
The at least part of the light beam incident on the incident surface passes through a first point that is a point on a line parallel to the second direction and located on the opposite side of the reflecting surface with respect to the incident surface. Or the lighting member of 2.
The protrusion has a focal point;
The focal point of the protrusion is a focal point where the light beam from the base material is reflected by the reflective surface and the reflected light beam from the reflective surface is collected,
The light beam from the base material is a light beam incident on the protrusion from the base material,
The daylighting member according to any one of claims 1 to 3, wherein a light beam incident on the protrusion is a parallel light beam.
The refraction angle θ 1 changes according to the incident angle θ IN of the light beam incident on the protrusion to the protrusion,
The daylighting member according to claim 3, wherein the incident angle θ IN satisfies 20 ° ≦ θ IN ≦ 90 °.
The refraction angle θ 1 changes according to the incident angle θ IN of the light beam incident on the protrusion to the protrusion,
The angular range of the incident angle theta IN is lighting member according to claim 3 or 4 corresponds to the maximum value from the minimum value of the solar altitude at the installation location of the lighting member.
Some of the angular range, the lighting member according to any one of claims 3 to 6 wherein the angle theta 2 is constant among the angle range of the refraction angle theta 1.
All the angular range, the lighting member according to any one of claims 3 to 6 wherein the angle theta 2 is constant among the angle range of the refraction angle theta 1.
The focal point of the protrusion is a straight line passing through the tip of the protrusion in the first direction on a plane orthogonal to the second direction, and orthogonal to the first direction and the second direction. The daylighting member according to any one of claims 4 to 8, which is located on a straight line parallel to the third direction.
In the plane orthogonal to the second direction, the distance on the incident surface from the tip of the protrusion to the incident position of the light beam incident on the incident surface is defined as a first distance. When the distance on the reflection surface from the tip of the projection to the reflection position of the light beam incident on the incident surface is a second distance,
The daylighting member according to any one of claims 3 to 9, wherein the second distance increases as the first distance increases, and the second distance decreases as the first distance decreases. .
When the critical angle of the light beam reflected by the reflecting surface and theta T,
φ + θ 1 ≧ θ T
The daylighting member according to any one of claims 1 to 10, wherein:
A plurality of the protrusions;
The daylighting member according to any one of claims 1 to 11, wherein the plurality of protrusions are arranged in a third direction orthogonal to the first direction and the second direction.
The daylighting member according to any one of claims 1 to 12, wherein the base material has a plate shape.
A light-shielding part that adjusts an incident range of light on the incident surface;
The said light-shielding part extends in the 3rd direction orthogonal to the said 1st direction and the said 2nd direction from the front-end | tip part in the said 1st direction of the said incident surface. A daylighting member according to claim 1.