JPWO2020115855A1 - Daylighting device - Google Patents

Abstract

The daylighting device (100) includes an optical component (1). The optical component (1) has a plate shape, and a lens surface of a cylindrical concave lens is formed on one surface, and a planar shape is formed on the other surface. The lens surface includes a Fresnel shape formed by a plurality of prisms. The surface corresponding to the lens surface is a prism surface (1 c _L ), and the other surface is a prism surface (1 c _F ). The plurality of prisms includes a first prism and a second prism. The first prism is located closer to the optical axis (C) of the cylindrical concave lens than the second prism. In the region (1c) where a light ray (Lc) parallel to the optical axis (C) incident from the plane side is reflected by the _{prism surface (1c L} ) and then refracted by the _{prism surface (1c F) and emitted, the prism} By changing the arrangement, the incident angle (E ₁ ) at which the light ray (Lc) parallel to the optical axis (C) is _{incident on the prism surface (1c L} ) is higher in the first prism than in the second prism. large.

Description

The present invention relates to a daylighting apparatus.

Patent Document 1 describes an optical transport device including a primary reflector, a secondary reflector, and an optical duct. Since the primary reflector directly receives sunlight while changing its direction according to the position of the sun, it can receive sunlight stably during the day. The light reflected by the primary reflector is parallel light and does not diffuse. Therefore, it is possible to directly receive light from the secondary reflector without using an optical duct. The parallel light reflected by the secondary reflector is emitted to the daylighting port of the light duct.

JP-A-2007-115417 (paragraphs 0013, 0014, FIG. 1)

However, the light carrier described in Patent Document 1 changes the direction of the primary reflector according to the position of the sun.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to collect sunlight without tracking the movement of the sun.

The light collector has a plate shape including a first surface, a second surface facing the first surface, and a side surface, and a lens surface of a cylindrical concave lens is formed on the first surface, and the second surface is formed. The lens surface includes an optical component in which a plane is formed in a region of the surface facing the lens surface, the lens surface includes a Frenel shape formed by a plurality of prisms, and the surface of the prism corresponding to the lens surface is first. The other surface of the prism is a second prism surface, the plurality of prisms include a first prism and a second prism, and the first prism is more than the second prism. Assuming that the lens is located on the optical axis side of the cylindrical concave lens, a light beam parallel to the optical axis incident from the side of the second surface is reflected by the first prism surface and then the second prism surface. By changing the arrangement of the plurality of prisms in the first region that is refracted and emitted by, the incident angle at which a light beam parallel to the optical axis is incident on the first prism surface is the second The first prism is larger than the prism.

According to the present invention, sunlight can be collected without tracking the movement of the sun.

It is a schematic diagram explaining daylighting of a sun ray. It is a block diagram which shows the structure of the daylighting apparatus 100 which concerns on Embodiment 1. FIG. It is a ray tracing diagram of an optical component 1. It is a ray tracing diagram of an optical component 1. An example of the result of ray tracing of the optical component 12 is shown. An example of the result of ray tracing of the optical component 12 is shown. An example of the result of ray tracing of the optical component 12 is shown. An example of the result of ray tracing of the region 12c of the optical component 12 is shown. An example of the result of ray tracing of the region 1c of the optical component 1 is shown. It is a schematic diagram which shows the altitude θ and the direction φ of the sun. It is a schematic diagram which shows an example of a building in the case of adopting window lighting. It is explanatory drawing explaining the simulation condition. It is a figure which shows the simulation result of the optical component 1. It is a figure which shows the simulation result of the optical component 12. It is a block diagram which shows the structure of the daylighting apparatus 200 which concerns on modification 1. FIG. It is a schematic diagram which shows an example of a building in the case of adopting daylighting in a stairwell. It is explanatory drawing explaining the simulation condition. It is a figure which shows the simulation result. It is a figure which shows the simulation result. It is a block diagram which shows the structure of the daylighting apparatus 300 which concerns on modification 2. FIG. 5 is a ray tracing diagram of the optical component 10. FIG. 5 is a ray tracing diagram of the optical component 10. An example of the result of ray tracing of the optical component 11 is shown. An example of the result of ray tracing of the optical component 11 is shown. It is a figure which shows the simulation result. It is a block diagram which shows the structure of the optical component 13 which concerns on modification 3. FIG. It is a ray tracing diagram of the boundary part 10bc, 13bc. It is a ray tracing diagram of the boundary part 10cd, 13cd. It is a figure which shows the simulation result.

In the embodiment shown below, sunlight is collected by using a concave lens including a Fresnel shape.

However, when the concave lens is formed of a Fresnel lens, light that is focused in a part of the region is generated by total reflection and refraction. Then, when the collected light is condensed in the light guide portion, the light guide portion may be damaged. Examples of the light guide portion for light include a stairwell in a building. In addition, when sunlight is taken in from a window, the collected light may be condensed on the ceiling or the like, and the building may be damaged. The "atrium" is a space in which the ceiling of the lower floor and the floor of the upper floor are not provided so that the vertical direction of the building is continuous.

In the embodiment shown below, the light collection generated in a part of the Fresnel-shaped concave lens is reduced. By changing the prism shape of the concave lens formed by the Fresnel lens, the light condensing when daylight is taken is reduced. The Fresnel shape is formed by a plurality of prisms. In the region where condensing occurs, the focused light is changed to diverging light by reversing the arrangement of the prisms. In particular, the embodiments shown below reduce the concentration of light when the sun is in the south. At mid-south of the sun, the intensity of light is highest.

<Coordinate setting>
For ease of explanation, XYZ coordinates are used in the figures shown below. The XYZ coordinates are the coordinates when the daylighting device is installed. The X-axis is an axis parallel to the north-south direction. The + X-axis direction is south (S) and the -X-axis direction is north (N). The Y-axis is an axis parallel to the east-west direction. The + Y-axis direction is east (E) and the -Y-axis direction is west (W). The Z axis is an axis parallel to the vertical direction. The sun during the day is located in the + Z axis direction. That is, the + Z axis direction is the direction of the sky (zenith).

The "zenith" refers to a point on the celestial sphere that is directly above the observer. In other words, it is a point where the altitude is a pole of +90 degrees in horizontal coordinates. The direction from the ground to the zenith is the vertical direction of the observation point. That is, the zenith direction is the direction of gravity at the observation point. The zenith direction is the vertical direction of the observation point.

In FIG. 2, the daylighting device 100 is installed in a window provided on the wall. Therefore, the X-axis direction is the direction in which the light beam is incident on the lighting device 100. Daylight is incident on the daylighting device 100 from the + X-axis direction to the −X-axis direction. The Y-axis direction is the direction in which the prisms of the Fresnel lens of the optical component 1 are arranged. The Z-axis direction is the direction in which the prism of the Fresnel lens of the optical component 1 extends. The Fresnel lens of the optical component 1 extends linearly.

In FIG. 15, the daylighting device 200 is installed in a window provided on the ceiling. Therefore, the Z-axis direction is the direction in which the light beam is incident on the daylighting device. Daylight is incident from the + Z-axis direction to the −Z-axis direction. The X-axis direction is the direction in which the prisms of the Fresnel lens of the _{optical component 1 NS are arranged.} The Y-axis direction is the direction in which the prism of the Fresnel lens of the _{optical component 1 NS extends.} The Y-axis direction is the direction in which the prisms of the Fresnel lens of the _{optical component 1 EW are arranged.} The X-axis direction is the direction in which the prism of the Fresnel lens of the _{optical component 1 EW extends.} The Fresnel lens of the optical component 1 _NS , 1 _{EW extends linearly.}

Looking at the + X-axis direction from the −X-axis direction side, the X-axis is the central axis, the clockwise direction is the + RX direction, and the counterclockwise direction is the −RX direction. Further, when looking at the + Y-axis direction from the −Y-axis direction side, the Y-axis is the central axis, the clockwise direction is the + RY direction, and the counterclockwise direction is the −RY direction. Further, when the + Z axis direction is viewed from the −Z axis direction side, the Z axis is the central axis, the clockwise direction is the + RZ direction, and the counterclockwise direction is the −RZ direction. Unless otherwise explained, the positive direction of the angle is the + RX direction, the + RY direction, or the + RZ direction.

<Fresnel lens>
A Fresnel lens replaces the curved surface of an optical lens with a series of grooves. These grooves act individually as refracting surfaces, for example, bending the optical path of parallel rays to collect light at the focal position. Hereinafter, the shape of the mountain formed by this groove is referred to as a prism. The surface on which the prism is formed is also referred to as a prism surface.

The prism includes a prism surface on the optical axis side of the Fresnel lens and a prism surface on the peripheral side of the Fresnel lens. That is, the prism is formed by two surfaces. The surface of the prism on the optical axis side is the surface of the prism on the side close to the optical axis. The surface on the peripheral side of the prism is the surface of the prism far from the optical axis. By acting as a small bent surface, each prism surface functions as one large lens as a whole.

In the case of a convex lens, the surface on the peripheral side with respect to the optical axis of the convex lens corresponds to the lens surface of the convex lens. The surface of the convex lens on the optical axis side is usually a surface parallel to the optical axis. In the case of a concave lens, the surface of the concave lens on the optical axis side corresponds to the lens surface of the concave lens. Further, the surface on the peripheral side of the concave lens with respect to the optical axis of the concave lens is usually a surface parallel to the optical axis. The plane parallel to the optical axis is, for example, a plane. The surface parallel to the optical axis has, for example, a planar shape. Further, the surface parallel to the optical axis may be inclined with respect to the optical axis, for example, due to manufacturing reasons.

The prism shown in the following embodiment includes a shape in which a prism surface having a lens shape is replaced with a surface parallel to a plane in contact with the prism surface of the lens shape. That is, the prism of the Fresnel lens includes a prism in which both the prism surface on the optical axis side and the prism surface on the peripheral side are formed in a plane. The prism of a Fresnel lens includes a prism having a planar shape on two surfaces.

<Sunlighting>
The daylighting device will be described by taking daylight as an example. Daylight is the daylight of sunlight. Daylight includes direct and indirect light from the sun. The sun moves from east to west within a day. Also, the altitude changes within a day. In addition, sunlight can be treated as parallel light. That is, daylight can be treated as parallel light.

The daylighting apparatus shown in the embodiment can suppress a change in the emission direction of the light emitted from the daylighting apparatus when the incident direction of the parallel light incident on the daylighting apparatus changes.

FIG. 1 is a schematic diagram illustrating daylighting of the sun's rays. 1 (A) is a diagram that lighting sunlight _{L A,} L B, the _{L C} using a concave lens 81. Figure 1 (B) is a diagram that lighting sunlight _{L A,} L B, the _{L C} using a lens 82 of a convex shape. Sun _{9 A} emits the sunlight _{L A.} Sun _{9 B} emits the sunlight _{L B.} Sun _{9 C} emits the sunlight _{L C.}

The sun 9 moves, for example, from the sun 9 _A to the sun 9 _B. Also, the sun 9 moves from, for example, the sun 9 _B to the sun 9 _C. In FIG. 1, for example, the Y-axis direction is the moving direction of the sun 9. The + Y-axis direction is the east direction, and the -Y-axis direction is the west direction. The + X-axis direction is the south direction, and the -X-axis direction is the north direction. The zenith is located in the + Z axis direction. Note that FIG. 1 is shown in the case of the Northern Hemisphere.

The lens 81 shown in FIG. 1 (A) is a concave lens. The lens 81 includes eight regions in the Y-axis direction about the optical axis C of the lens 81. Toward the optical axis C in the + Y-axis direction, the area of the lens 81, the region 81a _p, region 81b _p, are arranged in order of region 81c _p and region 81d _p. Toward the optical axis C in the -Y-axis direction, the area of the lens 81, the region 81a _m, area 81b _m, are arranged in order of region 81c _m and area 81d _m.

The lens 82 shown in FIG. 1 (B) is a convex lens. The lens 82 includes eight regions in the Y-axis direction about the optical axis C of the lens 82. Toward the optical axis C in the + Y-axis direction, the area of the lens 82, the region 82a _p, region 82b _p, are arranged in order of region 82c _p and region 82d _p. Toward the optical axis C in the -Y-axis direction, the area of the lens 82, the region 82a _m, area 82b _m, are arranged in order of region 82c _m and area 82d _m.

The angle of incidence of the light rays _{L A} incident from the sun _{9 A} lens 81 of FIG. 1 (A) is equal to the incident angle of the light beam _{L A} is incident on the lens 82 from the sun _{9 A} in FIG. 1 (B). Similarly, the angle of incidence of the light rays _{L B} entering the lens 81 from the sun _{9 B} in FIG. 1 (A) is equal to the incident angle of the light beam _{L B} is incident on the lens 82 from the sun _{9 B} in FIG. 1 (B). The angle of incidence of the light rays _{L C} incident from the sun _{9 C} to the lens 81 of FIG. 1 (A) is equal to the incident angle of the light beam _{L C} incident on the lens 82 from the sun _{9 C} in FIG. 1 (B).

The focal point F ₈₁ of the lens 81 is located on the exit surface side of the lens 81. The focal point F ₈₂ of the lens 82 is located on the incident surface side of the lens 82.

Light _{L A} emitted from the sun _{9 A} in FIG. 1 (A), traveling toward the focal point _{F 81} of the lens 81. Light _{L A} is emitted from region 81d _p of the lens 81. Light _{L B} emitted from the sun _{9 B} in FIG. 1 (A), traveling toward the focal point _{F 81} of the lens 81. Light _{L B} is emitted from between the region 81a _p and the region 81a _m of the lens 81. Between the regions 81a _p and the region 81a _m is the position of the optical axis C of the lens 81. Light _{L C} emitted from the sun _{9 C} in FIG. 1 (A), traveling toward the focal point _{F 81} of the lens 81. Light _{L C} is emitted from region 81d _m of the lens 81.

Light incident on the lens 81 _{L A,} L B, _{L C} is emitted as parallel light rays to the optical axis C of the lens 81.

Light _{L A} emitted from the sun _{9 A} in FIG. 1 (B), traveling toward the focal point _{F 82} of the lens 82. Light _{L A} is emitted from the region 82d _m of the lens 82. Light _{L B} emitted from the sun _{9 B} in FIG. 1 (B), traveling toward the focal point _{F 82} of the lens 82. Light _{L B} is emitted from between the region 82a _p and the region 82a _m of the lens 82. Between the regions 82a _p and the region 82a _m is the position of the optical axis C of the lens 82. Light _{L C} emitted from the sun _{9 C} in FIG. 1 (B), traveling toward the focal point _{F 82} of the lens 82. Light _{L C} is emitted from region 82d _p of the lens 82.

Light incident on the lens 82 _{L A,} L B, _{L C} is emitted as parallel light rays to the optical axis C of the lens 82.

As described above, by using the lens 81, it can be converted into a parallel light beam _L A from the mobile solar _9, L B, the _{L C} to the optical axis C of the lens 81. Thus, lighting apparatus, it is possible to suppress the light L _A, L _B, a change in emission direction of L _C from the mobile solar 9.

Further, for example, when parallel light is incident on the concave lens, the light emitted from the concave lens becomes divergent light. Then, even when the position of the sun 9 changes, the divergent light includes light rays parallel to the optical axis C. Therefore, the concave lens can suppress the change in the emission direction of the divergent light emitted from the concave lens with respect to the change in the position of the sun 9.

Light _{L A, L B, L C} from the sun 9 is incident on the lens 81 as parallel light rays. Therefore, for example, it is possible to replace the region 81d _p of the lens 81 and the region 82d _m of the lens 82. The lens 81 is a concave lens. The lens 82 is a convex lens. That is, + region 81d _p of Y-axis side is replaced with a region 82d _m of -Y axis side.

Similarly, for example, it is possible to replace the region 81d _m of the lens 81 and the region 82d _p of the lens 82. In other words, the region 81d _m of -Y axis side is replaced with a region 82d _p of + Y axis side.

That is, light rays L _A of the same angle of _incidence, L _B, if an area for conversion into light parallel to L _C with respect to the optical axis C, a region of the lens 82 in the region and the convex shape of the concave lens 81 The same effect can be obtained by replacing.

Embodiment 1.
FIG. 2 is a diagram showing the configuration of the daylighting device 100 according to the first embodiment. FIG. 2A is a configuration diagram of the daylighting device 100 viewed from the + Z axis direction side. FIG. 2B is a configuration diagram of the daylighting device 100 viewed from the −Y axis direction side.

FIG. 3 is a diagram showing an example of the result of ray tracing of the optical component 1 of the daylighting device 100. FIG. 3 is a diagram showing the behavior of a light ray when a parallel light ray (light ray L) is incident from the plane portion 1e side of the optical component 1. The parallel ray (ray L) is parallel to the optical axis C of the optical component 1. Partial detailed views are attached to the regions 1b, 1c and 1d.

FIG. 4 is a diagram showing the behavior of a light ray when a parallel light ray (light ray L) is incident from the optical surface portion 1f side of the optical component 1. The parallel ray (ray L) is parallel to the optical axis C of the optical component 1. In FIGS. 2, 3 and 4, the parallel light beam (light ray L) is incident on the optical component 1 from the + X axis direction side.

The daylighting device 100 includes an optical component 1. The daylighting device 100 can include a light deflection component 2. The light deflection component 2 can be integrally provided on the surface of the optical component 1 on the flat surface portion 1e side. In this case, the light deflection component 2 becomes a light deflection unit.

The daylighting device 100 will be described as, for example, a device installed on a window to guide sunlight indoors. The light deflection component 2 has a function of suppressing a change in the incident angle of light incident indoors in response to a change in the altitude of the sun. The light deflection component 2 emits sunlight, for example, toward the ceiling indoors. The light deflection component 2 suppresses a change in the distance from the window to the position of the ceiling where the sunlight is irradiated even when the altitude of the sun changes. As a result, the movement of the position of the sunlight shining on the ceiling is suppressed regardless of the altitude. Then, the sunlight reflected by the ceiling is used as indoor lighting.

For example, the light deflecting component 2 reduces the change in distance from the window in the area where sunlight is applied to the ceiling. However, the sun moves from east to west within a day. Along with this, the area where sunlight is applied to the ceiling also moves from west to east. The optical component 1 can diverge incident sunlight including light directed in one direction. Here, one direction is, for example, a direction perpendicular to the window. One direction is, for example, a direction perpendicular to the optical component 1. Here, the optical component 1 has a plate shape. That is, the optical component 1 reduces the movement of the position where the sunlight is applied to the ceiling in the direction parallel to the window. The daylighting device 100 can reduce the movement of the position where the sunlight is irradiated even when the position of the sun moves.

<Configuration of daylighting device 100>
≪Optical parts 1≫
The optical component 1 includes a lens surface of a cylindrical lens. The lens surface of the cylindrical lens includes a Fresnel-shaped lens surface. Cylindrical lenses include Fresnel-shaped regions.

The optical component 1 has, for example, a plate shape. The plate shape is a shape in which two opposing surfaces are connected by side surfaces. The optical component 1 has a cylindrical lens formed on one surface (optical surface portion 1f). The optical component 1 has a flat surface (flat surface portion 1e) formed on the other surface. The other surface of the optical component 1 includes a planar shape. The plane of the other surface (plane portion 1e) is formed in a region facing the cylindrical lens. The region facing the cylindrical lens has a planar shape.

One side of the optical component 1 is a flat surface. The plane side surface is called a flat surface portion 1e. One surface of the optical component 1 is a surface on which a cylindrical lens is formed. The surface on the side where the cylindrical lens is formed is called an optical surface portion 1f. In FIG. 2, the surface of the optical component 1 on the + X axis direction is, for example, a flat surface portion 1e. The surface of the optical component 1 on the −X axis direction side is, for example, the optical surface portion 1f. The optical surface portion 1f faces the flat surface portion 1e.

The optical component 1 includes regions 1a, 1b, 1c, and 1d of a Fresnel lens. The optical component 1 includes regions 1a, 1b, 1c, and 1d of a Fresnel lens on the optical surface portion 1f. Regions 1a, 1b, 1c, and 1d of the cylindrical lens are formed on the optical surface portion 1f. The optical surface portion 1f is a surface on which regions 1a, 1b, 1c, and 1d of the cylindrical lens of the optical component 1 are formed.

In the following description, the optical component 1 will be described as a Fresnel lens. That is, the optical surface portion 1f will be described as a surface on which a Fresnel lens is formed. Usually, the prism of a Fresnel lens is formed by a lens surface having one surface formed by a curved surface. However, the lens surface of the prism of the Fresnel lens can be a plane parallel to the plane in contact with the lens surface. Further, a part of the optical surface portion 1f can be formed as a prism formed by the lens surface, and the other region can be formed as a prism formed by two planes.

For example, the region 1a can be a prism formed on the lens surface, and the regions 1b, 1c, 1d can be a prism formed on two planes. The region 1a is a region at the center of the lens shape of the optical component 1. The regions 1b, 1c, and 1d are regions of the peripheral portion of the lens shape of the optical component 1.

As shown in FIG. 2, the direction having the curvature of the optical component 1 is the Y-axis direction. The optical component 1 is symmetrical with respect to the optical axis C. Therefore, the light ray tracing of the optical component 1 on the + Y-axis direction side with respect to the optical axis C will be described, and the description on the −Y-axis direction side with respect to the optical axis C will be omitted.

The light ray L is a light ray incident on the optical component 1. The light ray L is a parallel light ray parallel to the optical axis C. The light ray L includes light rays La, Lb, Lc, and Ld. The light ray La is a light ray L incident on the region 1a. The light ray Lb is a light ray L incident on the region 1b. The light ray Lc is a light ray L incident on the region 1c. The light ray Ld is a light ray L incident on the region 1d.

<Optical component 12 of Fresnel-shaped concave lens>
Next, the optical component 12 on which the Fresnel-shaped cylindrical concave lens is formed will be described. That is, the optical component 12 is a normal Fresnel-shaped cylindrical concave lens. The optical component 12 is a Fresnel-shaped concave lens. The optical component 12 is formed of, for example, only a recess.

FIG. 5 shows an example of the result of ray tracing of the optical component 12. FIG. 5 is a diagram showing the behavior of a light ray when a parallel light ray (light ray L) is incident from the side of the flat surface portion 12e of the optical component 12. The parallel ray (ray L) is parallel to _{the optical axis C 12 of the optical component 12.} A partial detailed view is attached to the region 12c.

6 and 7 are diagrams showing the behavior of light rays when a parallel light ray (light ray L) is incident from the side of the optical surface portion 12f of the optical component 12. The parallel ray (ray L) is parallel to _{the optical axis C 12 of the optical component 12.} The positions of the incident light rays in the Y-axis direction are different between FIGS. 6 and 7. Therefore, the actual light beam behaves in a state where FIG. 6 and FIG. 7 are overlapped.

<< Flat surface portion 12e and optical surface portion 12f >>
In the optical component 12 shown in FIG. 5, one surface is a flat surface (flat surface portion 12e) and a Fresnel-shaped cylindrical concave lens is formed on the other surface (optical surface portion 12f). One surface of the optical component 12 is a flat surface. One surface of the optical component 12 includes a planar shape. The plane side surface is called a flat surface portion 12e. The other surface of the optical component 12 is a surface on which a cylindrical lens is formed. The surface on the side where the cylindrical lens is formed is called an optical surface portion 12f. The optical surface portion 12f faces the flat surface portion 12e. The region facing the cylindrical lens has a planar shape.

The optical surface portion 12f includes, for example, the shape of a cylindrical concave lens surface. The cylindrical concave lens surface includes a Fresnel shape. The optical surface portion 12f includes, for example, regions 12a, 12b, 12c, and 12d of four cylindrical concave lens surfaces. The prisms in each region 12a, 12b, 12c, 12d are prisms 12a _P , 12b _P , 12c _P , 12d _P.

《Prism shape》
The surfaces corresponding to the lens surfaces of each prism are surfaces 12a _L , 12b _L , 12c _L , and 12d _L. The surfaces 12a _L , 12b _L , 12c _L , and 12d _L of each prism are inclined with respect to the optical axis C _12. The inclined surfaces 12a _L , 12b _L , 12c _L , and 12d _L of each groove are lens surfaces.

The other surfaces of each prism are surfaces 12a _F , 12b _F , 12c _F , 12d _F. The other surfaces 12a _F , 12b _F , 12c _F , and 12d _F of each prism are planes perpendicular to the flat surface portion 12e for the sake of simplicity. The surfaces 12a _F , 12b _F , 12c _F , 12d _F are, for example, flat surfaces. Further, the surfaces 12a _F , 12b _F , 12c _F , and 12d _F may be inclined within a draft range in consideration of productivity at the time of molding, for example.

The optical component 12 is a concave lens. Therefore, the surface of the optical axis _{C 12} side of each prism surface _{12a L, 12b L, 12c L} , a 12d _L. The peripheral surfaces of each prism are surfaces 12a _F , 12b _F , 12c _F , and 12d _F.

The regions of the optical component 12 are arranged in the order of region 12a, region 12b, region 12c, and region 12d from the optical axis C _{12 toward the + Y axis direction.} The optical component 12, in the Y-axis direction, since the optical axis _{C 12} is symmetrical, the optical axis _{C 12} of the -Y-axis direction explanation is omitted.

<< Area 12a >>
The region 12a is a region including _{the optical axis C 12 of the cylindrical concave lens.} Region 12a is a region in contact with the optical axis _{C 12} of the cylindrical concave lens.

As shown in FIG. 5, in the region 12a, the light ray La incident from the flat surface portion 12e is emitted by one refraction. In the region 12a, the light ray La incident from the flat surface portion 12e is refracted by the _{surface 12a L and emitted.} The light emitted from the region 12a is diverged light. The light emitted from the region 12a is divergent light. The divergent light emitted from the region 12a travels to the peripheral side of the optical component 12.

As shown in FIGS. 6 and 7, in the region 12a, the light ray La incident from the optical surface portion 12f is emitted by one refraction. In the region 12a, the light beam La incident from the optical surface portion 12f is refracted by the _{surface 12a L and emitted.} The light emitted from the region 12a is divergent light. The divergent light emitted from the region 12a travels to the peripheral side of the optical component 12.

<< Area 12b >>
The region 12b is a region located on the peripheral side of the _{optical axis C 12 with respect to the region 12a.}

As shown in FIG. 5, in the region 12b, the light beam Lb incident from the flat surface portion 12e is emitted in the + Y-axis direction by one reflection. In the region 12b, the light beam Lb incident from the flat surface portion 12e is reflected by the _{surface 12b L and emitted from the surface 12b F in the} + Y axis direction. The reflection here is, for example, total internal reflection. The light beam Lb emitted from the surface 12b _F is incident on the prism on the peripheral side. Therefore, the light is not used in the daylighting device 100.

As shown in FIGS. 6 and 7, in the region 12b, the light beam Lb incident from the optical surface portion 12f is emitted by one refraction. In the region 12b, the light beam Lb incident from the optical surface portion 12f is refracted by the _{surface 12b L and emitted.} The light emitted from the region 12b is divergent light. The divergent light emitted from the region 12b travels to the peripheral side of the optical component 12.

<< Area 12c >>
The region 12c is a region located on the peripheral side of the _{optical axis C 12 with respect to the region 12b.}

As shown in FIG. 5, in the region 12c, the light ray Lc incident from the flat surface portion 12e is reflected once and then emitted by one refraction. In the region 12c, the light beam Lc incident from the flat surface portion 12e is reflected by the _{surface 12c L} and then refracted by the _{surface 12c F and emitted.} The reflection here is, for example, total internal reflection. The light emitted from the region 12c is the focused light. The focused light is called condensed light. The light emitted from the region 12c is focused on the focusing _{point A 12c.} The focusing point A _12c is located on the peripheral side of the optical component 12 with respect to the region 12c. The focusing point A _12c is located on the peripheral side of the region 12c.

As shown in FIG. 6, in the region 12c, the light ray Lc incident from the optical surface portion 12f is emitted by one refraction. In the region 12c, the light beam Lc incident from the optical surface portion 12f is refracted by the _{surface 12c L and emitted.} The light emitted from the region 12c is divergent light. The divergent light emitted from the region 12c travels to the peripheral side of the optical component 12.

As shown in FIG. 7, in the region 12c, the light ray Lc incident from the optical surface portion 12f is refracted once and then reflected once and emitted. The reflection here is, for example, total internal reflection. In the region 12c, the light beam Lc incident from the optical surface portion 12f is refracted by the _{surface 12c L} and then reflected by the _{surface 12c F and emitted.} The light emitted from the region 12c is condensed light. The light emitted from the region 12c is focused on the focusing _{point A 12d.} The focusing point A _12d is located on the optical axis C _12.

As shown in FIGS. 6 and 7, in the region 12c, the light rays incident from the optical surface portion 12f are converted into divergent light and condensed light. That is, the actual light beam behaves in a state where the divergent light and the condensed light are overlapped.

<< Area 12d >>
The region 12d is a region located on the peripheral side of the _{optical axis C 12 with respect to the region 12c.}

As shown in FIG. 5, in the region 12d, the light ray Ld incident from the flat surface portion 12e is reflected twice and then emitted by one refraction. The reflection here is, for example, total internal reflection. In the region 12d, the light beam Ld incident from the flat surface portion 12e is _{reflected by the surface 12d L} , reflected by the surface 12d _F , and then refracted by the surface 12d _{L and emitted.} The light emitted from the region 12d is divergent light. Divergent light emitted from region 12d proceeds to the optical axis _{C 12} side of the optical component 12.

As shown in FIG. 6, in the region 12d, the light ray Ld incident from the optical surface portion 12f is emitted by one refraction. In the region 12d, the light beam Ld incident from the optical surface portion 12f is refracted by the _{surface 12d L and emitted.} The light emitted from the region 12d is divergent light. The divergent light emitted from the region 12d travels to the peripheral side of the optical component 12.

As shown in FIG. 7, in the region 12d, the light ray Ld incident from the optical surface portion 12f is refracted once and then emitted by one reflection. The reflection here is, for example, total internal reflection. In the region 12d, the light beam Ld incident from the optical surface portion 12f is refracted by the _{surface 12d L} and then reflected by the _{surface 12d F and emitted.} The light emitted from the region 12d is condensed light. The light emitted from the region 12d is focused on the focusing _{point A 12d.}

As shown in FIGS. 6 and 7, in the region 12d, the light rays incident from the optical surface portion 12f are converted into divergent light and condensed light. That is, the actual light beam behaves in a state where the divergent light and the condensed light are overlapped.

<Structure of optical component 1>
The configuration of the optical component 1 will be described with reference to FIG.

≪Area 1a≫
The region 1a is the same as the region 12a of the optical component 12. The prisms 1a _P , 1b _P , 1c _P , 1d _P correspond to the prisms 12a _P , 12b _P , 12c _P , 12d _P. The surface 1a _L corresponds to the surface 12a _L. The surface 1a _F corresponds to the surface 12a _F. The optical axis C corresponds to the _{optical axis C 12.} Regarding the configuration of the region 1a and the behavior of the light beam La in the region 1a, the description of the optical component 12 will be substituted.

In the optical component 1, for example, the region 1a is a Fresnel lens. However, the region 1a does not have to be a Fresnel lens. The region 1a may be a normal concave lens.

<< Area 1b >>
The region 1b is the same as the region 12b of the optical component 12. The surface 1b _L corresponds to the surface 12b _L. The surface 1b _F corresponds to the surface 12b _F. The optical axis C corresponds to the _{optical axis C 12.} Regarding the configuration of the region 1b and the behavior of the light beam Lb in the region 1b, the description of the optical component 12 will be substituted.

In the first embodiment, for example, the region 1b is a Fresnel lens. However, the region 1b does not have to be a Fresnel lens. The region 1b may be a normal concave lens. By using the region 1b as a normal concave lens, it is possible to prevent the light ray Lb from becoming unnecessary light.

In the case of a light ray that is inclined and incident on the optical axis C of the optical component 1, the light ray Lb may be effective light. Ray entering inclined with respect to the optical axis C is, for example, a light beam L _A, L _C shown in FIG.

≪Area 1c≫
FIG. 8 is a diagram showing the behavior of light when light Lc is incident on the region 12c of the optical component 12 from the flat surface portion 12e. FIG. 9 is a diagram showing the behavior of light when light Lc is incident on the region 1c of the optical component 1 from the flat surface portion 1e.

In FIGS. 8 and 9, the reference numeral of the prism in the region 12c is 12c _P. Further, the _{two surfaces of the prism 12c P} are referred to as a surface 12c _L and a surface 12c _F.

_{The prism 1c P} of the region 1c of the optical component 1 is arranged in the order of the _{prism 1c 1P} , the prism 1c _2P , the prism 1c _3P , the prism 1c _4P, and the prism 1c _5P from the optical axis C side.

In addition, in order _{to make the arrangement of the prisms 12c P easy to understand, the reference numerals 12c 1P} , 12c _2P , 12c _3P , 12c _4P , and 12c _5P of FIG. 8 are also used in FIG. 9 showing the prism of the optical component 1. In FIG. 9, the prism 12c _5P corresponds to the prism 1c _{1P of the optical component 1.} The prism 12c _4P corresponds to the prism 1c _{2P of the optical component 1.} The prism 12c _3P corresponds to the prism 1c _{3P of the optical component 1.} The prism 12c _2P corresponds to the prism 1c _{4P of the optical component 1.} The prism 12c _1P corresponds to the prism 1c _{5P of the optical component 1.}

The surface of the prism 12c _{1p on} the optical axis C ₁₂ side is a surface 12c _1L , and the surface on the peripheral side with respect to the optical axis C _{12 is a surface 12c 1F} . The surface of the prism 12c _{2P on} the optical axis C ₁₂ side is a surface 12c _2L , and the surface on the peripheral side with respect to the optical axis C _{12 is a surface 12c 2F} . The surface of the prism 12c _{3P on} the optical axis C ₁₂ side is a surface 12c _3L , and the surface on the peripheral side with respect to the optical axis C _{12 is a surface 12c 3F} . The surface of the prism 12c _{4P on} the optical axis C ₁₂ side is a surface 12c _4L , and the surface on the peripheral side with respect to the optical axis C _{12 is a surface 12c 4F} . The surface of the prism 12c _{5P on} the optical axis C ₁₂ side is a surface 12c _5L , and the surface on the peripheral side with respect to the optical axis C _{12 is a surface 12c 5F} . Here, the surfaces 12c _1L , 12c _2L , 12c _3L , 12c _4L , and 12c _5L are lens surfaces.

First, the region 12c shown in FIG. 8 will be described. The light Lc is light parallel to the _{optical axis C 12.} In the region 12c, the cylindrical concave lens has a Fresnel shape. The prisms 12c _{P in the} region 12c are arranged in the order of the prism 12c _1P , the prism 12c _2P , the prism 12c _3P , the prism 12c _4P, and the prism 12c _5P from the optical axis C _{12 side.}

Next, the region 1c shown in FIG. 9 will be described. The light Lc is light parallel to the optical axis C. The prism of the region 1c reverses the arrangement of _{the prisms 12c 1P} , 12c _2P , 12c _3P , 12c _4P , 12c _{5P of the region 12c shown in FIG.} The prisms in the region 1c are arranged in the order of the _{prism 12c 5P} , the prism 12c _4P , the prism 12c _3P , the prism 12c _2P, and the prism 12c _{1P from the optical axis C side.}

As an example, one _{prism 12c P} in FIG. 8 shows _{an incident angle E 1} , an exit angle E _2, and an exit angle E ₃ . The incident angle E ₁ is an incident angle when the light ray Lc is _{incident on the surface 12 c L.} The emission angle E ₂ is an emission angle when the light ray Lc reflected by the surface 12c _{L is emitted from the surface 12c F.} The reflection here is, for example, total internal reflection. The emission angle E ₃ is an emission angle when the light ray Lc is emitted from the optical component 12. That is, the emission angle E ₃ is an inclination angle of the light ray Lc emitted from the optical component 12 with respect to the optical axis C _12. The emission angle E ₃ is an angle formed by the light ray Lc emitted from the optical component 12 on the XY plane and the optical axis C _12. The angle here is an acute angle.

_{The incident angle E 12} of the light ray Lc incident on the surface 12c _2L is larger than _{the incident angle E 11} of the light ray Lc incident on the surface 12c _{1L. The incident angle E 13} of the light ray Lc incident on the surface 12c _3L is larger than _{the incident angle E 12} of the light ray Lc incident on the surface 12c _{2L. The incident angle E 14} of the light ray Lc incident on the surface 12c _4L is larger than _{the incident angle E 13} of the light ray Lc incident on the surface 12c _{3L. The incident angle E 15} of the light ray Lc incident on the surface 12c _5L is larger than _{the incident angle E 14} of the light ray Lc incident on the surface 12c _4L.

As the incident angle E ₁ increases, the exit angle E ₂ increases. As the exit angle E ₂ increases, the exit angle E ₃ decreases. That is, as the incident angle E ₁ increases, the exit angle E ₃ decreases. For example, _{the incident angle E 15} of the light ray Lc incident on the _{prism 12c 5P} is larger than _{the incident angle E 11} of the light ray Lc incident on the prism 12c _{1P. Therefore, the emission angle E 35} of the light ray Lc emitted from the prism 12c _5P is smaller than _{the emission angle E 31 of the} light ray Lc emitted from the prism 12c _1P.

As shown in FIG. 8, when the prism 12c _5P is arranged on the outer peripheral side of the prism 12c _{1P, the} light beam Lc emitted from the optical component 12 is focused. That is, the condensing point A _12c is generated. As shown in FIG. 9, when the prism 12c _5P is arranged on the optical axis C side of the prism 12c _1P , the light ray Lc emitted from the optical component 1 is diverged.

It is assumed that a plurality of prisms include a first prism and a second prism. Then, the first prism is located on the optical axis C ₁₂ side of the cylindrical concave lens than the second prism.

In the region 12c shown in FIG. 8, the incident angle _{E 1} of light Lc parallel to the optical axis _{C 12} is incident on the surface 12c _L is than the second prisms toward the first prism small. Therefore, emission angle E ₃ of the light beam Lc emitted from the first prism is greater than the emission angle E ₃ of the light beam Lc emitted from the second prism.

In the region 1c shown in FIG. 9, _{the incident angle at which the light ray Lc parallel to the optical axis C is incident on the surface 1c L} is larger in the first prism than in the second prism. Therefore, emission angle E ₃ of the light beam Lc emitted from the first prism is smaller than the output angle E ₃ of the light beam Lc emitted from the second prism.

In the region 12c shown in FIG. 8, the optical axis C ₁₂ side of the emission angle E ₃ of the optical prism is greater than the emission angle E ₃ of the light near the side of the prism. That is, the deflection amount of light of the optical axis C ₁₂ side prism is greater than the amount of deflection of light near the side of the prism. The amount of deflection of the light of the prism is an acute angle formed by the incident light Lc and the emitted light. Therefore, the light emitted from the region 12c has a condensing point A _12c .

On the other hand, in the region 1c shown in FIG. 9, emission angle E ₃ of the prism optical optical axis C side is smaller than the output angle E ₃ of the light near the side of the prism. That is, the amount of light deflection of the prism on the optical axis C side is smaller than the amount of light deflection of the prism on the peripheral side. Therefore, the light emitted from the region 1c is diverged, and the light emitted from the region 1c does not have a focusing point corresponding to _{the focusing point A 12c of the region 12c.}

<< Area 1d >>
The region 1d is the same as the region 12d of the optical component 12. The surface 1d _L corresponds to the surface 12d _L. The surface 1d _F corresponds to the surface 12d _F. The optical axis C corresponds to the _{optical axis C 12.} Regarding the configuration of the region 1d and the behavior of the light beam Ld in the region 1d, the description of the optical component 12 will be substituted.

<Behavior of the sun>
FIG. 10 is a diagram showing an example of the altitude θ and the direction φ of the sun. Table 1 shows the value of altitude θ and the value of azimuth φ in Tokyo. The 0 degree of the azimuth φ corresponds to the north. 90 degrees of azimuth φ corresponds to the east. 180 degrees of azimuth φ corresponds to the south. The 270 degree azimuth φ corresponds to the west.

Tables 1 and 2 are shown below. The unit is degrees. In Tables 1 and 2, the values of the spring equinox, the summer solstice, the autumn equinox, and the winter solstice are shown as the seasons. In addition, the values of 10 o'clock, 12 o'clock and 14 o'clock are shown as the time.

Table 1 shows the altitude θ and the direction φ of the sun. In Table 1, for example, the values from 10:00 to 14:00 are shown. This time zone is an effective time zone when considering the intake of sunlight (daylight) into the interior of the building. In particular, when the solar zenith angle θ is low, the energy per unit area that can be taken into the building becomes small. Therefore, for example, from 10:00 to 14:00 is appropriate.

Table 2 shows the values obtained by projecting the incident angles of the light from the sun 9 located at the altitude θ and the azimuth φ shown in Table 1 onto the YZ plane and the ZX plane. The angle V is the incident angle of light when the altitude θ and the direction φ of the sun 9 in Table 1 are projected on the YZ plane. The angle of incidence on the YZ plane is the angle V. The positive direction of the angle V is the + RX direction. The angle H is the incident angle of light when the altitude θ and the direction φ of the sun 9 in Table 1 are projected on the ZX plane. The angle of incidence on the ZX plane is the angle H. The positive direction of the angle H is the −RY direction.

The YZ plane is a plane perpendicular to the horizontal plane including straight lines parallel to the east-west direction. The ZX plane is a plane perpendicular to the horizontal plane including straight lines parallel to the north-south direction. The XY plane is a plane parallel to the horizontal plane. A plane perpendicular to a horizontal plane is, for example, a plane containing a straight line parallel to the direction of gravity.

The incident angle is the angle formed by the incident direction when the light beam is incident and the normal of the boundary surface. Here, the interface corresponds to the XY plane. The normal of the interface corresponds to the Z axis. Therefore, the + Z axis direction is 0 degrees.

On the YZ plane, 0 degree of the angle V is the + Z axis direction (empty direction). On the YZ plane, −90 degrees of the angle V is in the + Y axis direction (eastward direction). On the YZ plane, +90 degrees of the angle V is the −Y axis direction (westward direction). On the ZX plane, 0 degree of the angle H is the + Z axis direction (empty direction). On the ZX plane, −90 degrees of the angle H is in the + X axis direction (south direction).

The component of the angle V of the light incident on the daylighting device 100 of FIG. 2 is a component deflected by the optical component 1. The component of the angle H of the light incident on the daylighting device 100 is a component deflected by the light deflection component 2.

From Table 2, it is preferable that the optical component 1 can capture light in the range of −41 degrees to +54.4 degrees at an angle V. Further, it is confirmed that the change in the angle H in one day is small. The angle H is adjusted with a blind or the like according to the season. Then, the light reflected by the blind or the like is incident on the optical component 1.

Further, the prism sheet (light deflection component 2) for window lighting emits incident light in the + Z axis direction. Here, the + Z-axis direction is the direction of the indoor ceiling. Then, regardless of the season, the optical component 1 incidents light deflected in the + Z axis direction. In addition, sunlight is treated as, for example, parallel light.

Blinds are usually covers for windows that are placed inside the windows. Blinds connect elongated boards called slats with threads. Then, the angle of the slats is adjusted by the tilt pole (rod) or the cord (string). Slats are also called louvers. The slats are made of metal or plastic. Here, the slats reflect the light from the sun 9 towards the ceiling indoors.

<Installation example of daylighting device 100>
FIG. 11 is a diagram showing an example in which daylight is taken from the window of the building 400 by using the daylighting device 100. Daylight is a ray L. The building 400 is, for example, 7 stories high. The daylighting device 100 is installed in a window facing the + X-axis side (south side) of the building 400. The daylighting device 100 is installed, for example, on the upper side (+ Z axis side) of the window.

The daylighting device 100 diverges the incident daylight in the Y-axis direction (east-west direction). In addition, the daylighting device 100 suppresses the generation of condensing points. By diverging daylight, for example, glare can be reduced. Glare is the "glare" that causes discomfort and obscurity. The daylighting device 100 can reduce the reflection glare. Reflective glare occurs, for example, when strong light from the sun 9 is reflected on the ceiling.

<Simulation conditions for optical component 1>
FIG. 12 is a diagram showing conditions for simulating the optical component 1.

The optical component 1 has, for example, a square plate shape. The optical component 1 is arranged parallel to the YZ plane. The length Wo of one side of the optical component 1 is, for example, 100 mm. Further, the distance D from the incident surface of the optical component 1 to the evaluation surface P is 21 m. Here, the incident surface of the optical component 1 is a flat surface portion 1e. The material of the optical component 1 is PMMA (Polymethyl acrylic). The material of the optical component 1 may be polycarbonate (PC). In that case, the index of refraction of polycarbonate is different from the index of refraction of PMMA. Therefore, the lens shape in the case of polycarbonate is different from the lens shape in the case of PMMA.

The cylindrical lens of the optical component 1 has a curvature in the Y-axis direction. The focal length of the optical component 1 is 35 mm excluding the region 1c. In the region 1c, the arrangement of the prisms is reversed with respect to the arrangement of the concave lenses. Therefore, the focal length of the region 1c is not 35 mm. Regions 1a, 1b, and 1d of the optical component 1 are Fresnel lenses having even-order aspherical prisms. The optical component 1 is designed to capture light rays having an incident angle of −55 degrees to +55 degrees. The absolute values of the curvature, the cornic constant, and the aspherical coefficient are equal for the shapes of the regions 1a, 1b, and 1d.

The evaluation surface P has, for example, a square shape. The evaluation surface P is arranged parallel to the YZ plane. The length Wp of one side of the evaluation surface P is, for example, 35.24 m. The size of the evaluation surface P was determined so that the angle β was 40 degrees. The angle β is represented by the following equation (1). The positive direction of the angle β is the −RZ direction. In addition, "/" represents division.
β = arctan ((Wp / 2) / D) ・ ・ ・ (1)

The light source S emits parallel rays. A rectangular parallel ray is incident on the optical component 1. The size of the light source S is changed according to the incident angle α when the parallel light beam is incident on the optical component 1.

The incident angle α is an angle on the XY plane. The positive direction of the incident angle α is the + RZ direction. The incident angle α takes a positive value counterclockwise with respect to the + X axis direction when viewed from the + Z axis direction side. For example, when the incident angle α is 0 degrees, the parallel rays are parallel to the X axis. Then, the parallel light beam is incident on the optical component 1 from the + X-axis direction. For example, when the incident angle α is 90 degrees, the parallel rays are parallel to the Y axis. Then, the parallel light rays enter the optical component 1 from the + Y-axis direction.

For example, when the incident angle α is 0 degrees, the light source S has a square shape. The length Ws of one side of the light source S is, for example, 99 mm. When the incident angle α is 30 degrees, the light source S has a rectangular shape. _{The length Ws 1} of the short side of the light source S is, for example, 86 mm (99 mm × cos ((30 ° × π) / 180 °) ≈86 mm). _{The length Ws 1} of the short side is the length of the light source S in the Y direction on the YZ plane. _{The length Ws 2} of the long side of the light source S is, for example, 99 mm. _{The length Ws 2} of the long side is the length of the light source S in the Z direction on the YZ plane. In addition, "x" represents multiplication. "°" represents the unit of angle "degree". Further, "≈" indicates that they are approximately equal.

In the simulation, the light intensity distribution in the Y-axis direction on the evaluation surface P is obtained. The conditions of the incident angle α are 0 degree, 15 degree, 30 degree, 45 degree and 55 degree.

<Simulation result of optical component 1>
FIG. 13 is a diagram showing a simulation result of the optical component 1. The vertical axis is the relative light intensity normalized by the maximum light intensity when the incident angle α is changed [a. u. ]. The horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. The horizontal axis is centered on the intersection of the evaluation surface P and the optical axis C.

In FIG. 13A, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 15 degrees is shown by a broken line. The case where the incident angle α is 30 degrees is shown by the dotted line.

In FIG. 13B, the case where the incident angle α is 45 degrees is shown by a solid line. The case where the incident angle α is 55 degrees is shown by a broken line.

As shown in FIG. 13A, when the incident angle α is 30 degrees (dotted line), the light intensity on the + Y axis direction side is reduced. Further, as shown in FIG. 13B, when the incident angle α is 55 degrees (broken line), the light intensity on the −Y axis direction side is reduced. Regardless of the change in the incident angle α, the portion having strong light intensity is located near the center of the evaluation surface P.

Glare is reduced by the divergence of light. Then, the optical component 1 can obtain a light intensity distribution in which the dependence of the incident angle α is reduced.

<Comparison with optical component 12>

FIG. 14 is a diagram showing a simulation result of the optical component 12. The conditions of the simulation are the same as the conditions of the optical component 1 shown in FIG. The optical component 12 is a Fresnel-shaped concave lens. The absolute values of the curvature, the cornic constant, and the aspherical coefficient of the optical component 12 are equal to the values of the shapes of the regions 1a, 1b, and 1d of the optical component 1 in FIG.

The vertical axis is the relative light intensity normalized by the maximum light intensity when the incident angle α is changed [a. u. ]. The horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. The horizontal axis is centered on the intersection of the evaluation surface P and the optical axis C _12.

In FIG. 14A, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 15 degrees is shown by a broken line. The case where the incident angle α is 30 degrees is shown by the dotted line.

In FIG. 14B, the case where the incident angle α is 45 degrees is shown by a solid line. The case where the incident angle α is 55 degrees is shown by a broken line.

When the incident angles α are 0 degrees, 15 degrees, and 30 degrees, the result of the optical component 1 shown in FIG. 13 is substantially the same as the result of the optical component 12. Similarly, when the incident angles α are 45 degrees and 55 degrees, the result of the optical component 1 shown in FIG. 13 is substantially the same as the result of the optical component 12. Therefore, the optical component 1 has the same divergence effect as the optical component 12.

<Modification example 1>
FIG. 15 is a configuration diagram showing the configuration of the daylighting device 200 according to the first modification. The daylighting device 200 includes two optical components 1. Further, the daylighting device 200 does not include the light deflection component 2. The daylighting device 200 differs from the daylighting device 100 in these respects. The description of the optical component 1 will be replaced by the description of the lighting device 100. In order to distinguish between the two optical components 1, they will be described as the optical component 1 _NS and the optical component 1 _EW .

The plate-shaped optical component 1 _NS and the optical component 1 _EW are arranged parallel to the XY plane. The flat surface portion 1e of the optical component 1 _{NS and} the flat surface portion 1e of the optical component 1 _EW are parallel to the XY plane. The optical component 1 _NS is arranged on the + Z axis direction side with respect to the optical component 1 _EW. The optical component 1 _NS and the optical component 1 _EW are arranged so as to be overlapped in the Z-axis direction. The flat surface portion 1e of the optical component 1 _{NS and} the flat surface portion 1e of the optical component 1 _EW are located on the + Z axis direction side. The sun during the day is located on the + Z axis direction. That is, the + Z axis direction side is the direction of the sky (zenith). Therefore, the light is incident on the _{optical components 1 NS} and 1 _EW from the flat surface portion 1e side.

The optical components 1 _NS and 1 _EW have a shape symmetrical with respect to the optical axis C in the direction having the curvature of the cylindrical lens. The optical component 1 _NS and the optical component 1 _EW are arranged so that the directions having curvatures are orthogonal to each other. In FIG. 15, the _{direction having the curvature of the optical component 1 NS} is parallel to the X axis (north-south direction). The direction having the curvature of the optical component 1 _EW is parallel to the Y axis (east-west direction).

≪Example of lighting of a building using atrium 40≫
FIG. 16 is a configuration diagram showing a configuration in which the daylighting device 200 is installed. The daylighting device 200 is installed on the roof of the building 410, for example. The daylighting device 200 collects daylight through, for example, the atrium 40 of the building 410.

The building 410 is, for example, 7 stories high. The height Ha of one floor of the building 410 is, for example, 3 m. The height Hb of the building 410 is, for example, 22.5 m.

The cross section of the atrium 40 has, for example, a square shape. The cross section of the atrium 40 is a cross section parallel to the XY plane. The length Wc of one side of the atrium 40 is, for example, 4 m. From the heights Ha and Hb and the length Wc, the divergence angle γ ₁ of the daylight taken in is expressed by the following equation (2). The divergence angle γ ₁ is half-width.
γ ₁ = arctan ((Wc / 2) / (Hb-7 × Ha)) ... (2)

From the equation (2), when the light is guided from the upper floor to the lower floor of the building 410, the divergence angle γ _{1 of the} light emitted from the daylighting device 200 is about 53 degrees. The divergence angle of the light emitted from the daylighting device 200 is about 106 degrees in full width.

Further, it is easy to allow the light to reach the upper floors of the building 410 by providing a structure for diverging the light on the exit surface of the daylighting device 200. Therefore, even when the light divergence angle γ ₁ is made narrower than about 53 degrees, daylight can reach from the upper floors to the lower floors.

In order for the light to reach each floor of the building 410, it is preferable that the light reaching from the top floor to the first floor of the building 410 exists. The light that reaches the floor surface of the first floor of the building 410 is the light emitted by _{the divergence angle γ 2 of the following equation (3).} The divergence angle γ ₂ is half-width.
γ ₂ = arctan ((Wc / 2) / Hb) ... (3)

Substituting the value of the building 410 into equation (3), the divergence angle γ ₂ is about 5 degrees. Therefore, when daylighting is performed on the first floor of the building 410, it is preferable that light having _{a divergence angle γ 2 having a half-width of 5 degrees or more is present.}

The daylighting device 200 shown in FIG. 15 is applied to the building 410 of FIG. This makes it possible to guide daylight to the inside of the building 410. Further, the daylighting device 200 does not require, for example, a driving unit for tracking the movement of the sun 9. Further, for example, in order to guide the daylight into the room, a film for window lighting or the like can be attached to the window surface facing the atrium 40.

The film for window lighting is, for example, a light deflection component 2. The light deflection component 2 provided on the window of each floor can reduce the difference in the angle of incidence of the light incident on each floor from the atrium 40 and guide the sunlight indoors. This makes it possible to guide daylight indoors. The amount of lighting depends largely on the length Wc of one side of the atrium 40.

Modification 1 shows a case where the lighting device 200 is installed in the atrium 40. However, the lighting device 200 does not have to be installed in the atrium 40. A daylighting device 200 may be installed between adjacent buildings to reduce dark areas between the buildings.

<< Installation example of daylighting device 200 >>
Details of the case where the daylighting device 200 is installed in the building 410 will be described. FIG. 15 is a configuration diagram of the daylighting device 200. Here, when the daylighting device 200 is installed in the building 410, the + Y-axis direction shown in FIG. 15 is east. The −Y axis direction is west. The + X-axis direction is south. -The X-axis direction is north. That is, the direction having the curvature of the optical component 1 _NS is the north-south direction (X-axis direction). The direction having the curvature of the optical component 1 _EW is the east-west direction (Y-axis direction).

Optical component 1 _NS receives light from the + Z axis direction. Here, the incident light is outdoor daylight. Optical component 1 _NS emits light in the −Z axis direction. The optical component 1 _NS emits light toward the optical component 1 _EW. Optical component 1 _NS diverges light in the north-south direction (X-axis direction).

Optical component 1 _EW incidents light from the + Z axis direction. Here, the incident light is the light emitted by the _{optical component 1 NS.} Optical component 1 _EW emits light in the −Z axis direction. The optical component 1 _EW emits light toward the atrium 40, for example. Optical component 1 _EW radiates light in the east-west direction (Y-axis direction).

The daylighting device 200 includes two optical components 1 including an optical component 1 _NS and an optical component 1 _EW . Then, the daylighting device 200 radiates light in the north-south direction and the east-west direction. The light emitted by the daylighting device 200 includes light rays traveling in the −Z axis direction. The daylighting device 200 emits divergent light including light rays traveling in the −Z axis direction even when the sun 9 moves. As a result, the daylighting device 200 can collect daylight from the rooftop and guide the light to each floor of the building 410 without tracking the sun. When the daylighting device 200 is installed in the building 410 shown in FIG. 16, it is possible to guide the daylight to each floor facing the atrium 40.

The distribution of light intensity with respect to the incident angle α of parallel light rays (daylight) is the same as the distribution of light intensity shown in FIG. As shown in FIG. 15A, the incident angle on the YZ plane is the incident angle α _EW . As shown in FIG. 15B, the incident angle on the ZX plane is the incident angle α _NS . The positive direction of the incident angle α _EW is the + RX direction. The positive direction of the incident angle α _NS is the + RY direction. The light emitted from the optical components 1 _NS and 1 _EW is diverged at an angle of ± 40 degrees with respect to the −Z axis direction, for example.

In Japan in the Northern Hemisphere, the sun is never located on the north side. _{Therefore, the portion of the optical component 1 NS on} the −X axis side with respect to the optical axis C can be deleted. _{Then, two portions of the optical component 1 NS on} the + X axis side can be arranged side by side with respect to the optical axis C. In the Southern Hemisphere, the + X-axis side portion of the _{optical component 1 NS} with respect to the optical axis C can be deleted. _{Then, two portions of the optical component 1 NS on} the −X axis side can be arranged side by side with respect to the optical axis C.

<< Simulation conditions for daylighting device 200 >>
FIG. 17 is a diagram showing the simulation conditions of the daylighting apparatus 200. The arrangement of the optical components 1 _NS and 1 _EW shown in FIG. 17 is the same as that in FIG. 15 (B).

The optical component 1 _NS and the optical component 1 _EW have, for example, a square plate shape. The optical components 1 _NS and 1 _EW are arranged parallel to the XY plane. The length Wo of one side of the optical component 1 _NS , 1 _{EW is, for example, 100 mm.} The optical component 1 _NS is arranged in the + Z axis direction of the optical component 1 _EW. The distance between the optical component 1 _NS and the optical component 1 _EW in the Z direction is 1 mm. The distance D from the incident surface of the optical component 1 _{NS to the evaluation surface P is 21 m.} Here, the incident surface of the optical components 1 _NS and 1 _EW is the flat surface portion 1 e. The material of the optical components 1 _NS and 1 _{EW is PMMA.} The material of the optical component 1 may be polycarbonate (PC). In that case, the index of refraction of polycarbonate is different from the index of refraction of PMMA. Therefore, the lens shape in the case of polycarbonate is different from the lens shape in the case of PMMA.

Optical component 1 The _NS cylindrical lens has a curvature in the X-axis direction. Optical component 1 The _EW cylindrical lens has a curvature in the Y-axis direction. The focal length of the optical component 1 _NS , 1 _EW is 35 mm excluding the region 1c. The regions 1a, 1b, and 1d of the optical component 1 _NS , 1 _{EW are Fresnel lenses having even-order aspherical prisms.} The optical components 1 _NS , 1 _EW are designed to capture light rays with an incident angle of -55 degrees to +55 degrees. The absolute values of the curvature, the cornic constant, and the aspherical coefficient are equal for the shapes of the regions 1a, 1b, and 1d.

The evaluation surface P has, for example, a square shape. The evaluation surface P is arranged parallel to the XY plane. The length Wp of one side of the evaluation surface P is, for example, 35.24 m. The size of the evaluation surface P is determined so that the angle β is 40 degrees. The angle β is represented by the equation (1). The positive direction of the angle β is the + RY direction.

The light source S emits parallel rays. A rectangular parallel ray is incident on the _{optical component 1 NS.} The size of the light source S is changed according to the incident angle α when the _{parallel light beam is incident on the optical component 1 NS.}

The incident angle α is an angle on the ZX plane. The + X-axis direction is the south direction. The positive direction of the incident angle α is the + RY direction. The incident angle α takes a positive value counterclockwise with respect to the + Z axis direction when viewed from the + Y axis direction side. For example, when the incident angle α is 0 degrees, the parallel rays are parallel to the Z axis. Then, the parallel light beam is incident on the _{optical component 1 NS from the + Z axis direction.} For example, when the incident angle α is 90 degrees, the parallel rays are parallel to the X axis. Then, the parallel light is incident on the _{optical component 1 NS from the + X axis direction.} The magnitude of the light source S with respect to the incident angle α is the same as the description of FIG. 12, although the coordinates are different.

<< Simulation result of daylighting device 200 >>
FIG. 18 is a diagram showing a simulation result of the configuration shown in FIG.

FIG. 19 is a diagram showing _{a simulation result when the arrangement of the optical component 1 NS} and the optical component 1 _EW in the Z-axis direction is reversed in the configuration shown in FIG. That is, the optical component 1 _EW is arranged on the + Z axis side of the optical component 1 _NS. In FIG. 17, the optical component 1 _NS is arranged on the + Z axis side of the optical component 1 _EW.

The vertical axis is the relative light intensity normalized by the maximum light intensity when the incident angle α is changed [a. u. ]. The horizontal axis is the position [mm] of the evaluation surface P in the X-axis direction or the Y-axis direction. The horizontal axis is centered on the intersection of the evaluation surface P and the optical axis C.

In FIG. 18A, the horizontal axis is the position [mm] of the evaluation surface P in the X-axis direction. Further, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 30 degrees is shown by a broken line. The case where the incident angle α is 55 degrees is shown by the dotted line.

In FIG. 18B, the horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. Further, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 30 degrees is shown by a broken line. The case where the incident angle α is 55 degrees is shown by the dotted line.

As shown in FIG. 18A, when the incident angle α is 30 degrees (broken line), the light intensity on the + X axis direction side is reduced. Further, when the incident angle α is 55 degrees (dotted line), the light intensity on the −X axis direction side is reduced. Regardless of the change in the incident angle α, the portion having strong light intensity is located near the center of the evaluation surface P.

As shown in FIG. 18B, at the position of the evaluation surface P in the Y-axis direction, the emitted light is uniformly diverged regardless of the change in the incident angle α. It can be confirmed that the tendency of each incident angle α of 0 degree, 30 degree and 55 degree is the same.

In FIG. 19A, the horizontal axis is the position [mm] of the evaluation surface P in the X-axis direction. Further, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 30 degrees is shown by a broken line. The case where the incident angle α is 55 degrees is shown by the dotted line.

In FIG. 19B, the horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. Further, the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 30 degrees is shown by a broken line. The case where the incident angle α is 55 degrees is shown by the dotted line.

As shown in FIG. 19A, when the incident angle α is 30 degrees (broken line), the light intensity on the + X axis direction side is reduced. Further, when the incident angle α is 55 degrees (dotted line), the light intensity on the −X axis direction side is reduced. Regardless of the change in the incident angle α, the portion having strong light intensity is located near the center of the evaluation surface P. FIG. 19 (A) shows the same tendency as that of FIG. 18 (A).

As shown in FIG. 19B, at the position of the evaluation surface P in the Y-axis direction, when the incident angle α is 55 degrees (dotted line), 1.55 × 10 ⁴ [mm] from the center of the Y-axis. Little light reaches the area outside. That is, the relative light intensity is 0.01 [a. u. ] It is as follows. The regions where the light hardly reaches are generated on the positive side and the negative side in the Y-axis direction.

In the daylighting device 200, it is preferable to diverge the light in the X-axis direction and the Y-axis direction. In FIG. 19B, the divergence width in the Y-axis direction is narrow. The configuration of FIG. 19 is inferior to the configuration of FIG. 18 in that the width of light divergence is narrow.

The optical component 1 _EW has a shape in which a groove of a prism extends in the X-axis direction. Therefore, as shown in FIG. 17, when the parallel ray L having an angle in the X-axis direction is incident, it is different from the case where the incident angle α of the parallel ray L is 0 degree. In FIG. 17, the parallel light beam L is inclined on the ZX plane and is incident on the _{optical component 1 NS.}

For example, linear light is incident on the optical component 1. The linear light is parallel to the direction having the curvature of the optical component 1. For example, in the optical component 1 _{NS of} FIG. 17, linear light extending in the X-axis direction is incident on the _{optical component 1 NS.} When the linear light is incident perpendicular to the optical component 1, the light emitted from the optical component 1 is diverged. Then, the linear shape of the light emitted from the optical component 1 is maintained. That is, the light on the evaluation surface P is linear.

However, when the linear light is inclined in a direction perpendicular to the direction having the curvature of the optical component 1 and is incident, the light emitted from the optical component 1 is diverged. Here, "the linear light is inclined and incident" means that the linear light vertically incident on the optical component 1 is rotated about an axis parallel to the direction having the curvature of the optical component 1. It is incident in the state. _{In the example of the optical component 1 NS} of FIG. 17 described above, the linear light is incident on the _{optical component 1 NS} in a state of being inclined in the RX direction. Then, the linear shape of the light emitted from the optical component 1 is distorted. That is, the light on the evaluation surface P is distorted. "Distortion" is distortion.

Further, the degree of distortion is large in the peripheral portion of the concave surface shape centered on the optical axis C. That is, the emission angle of the light in the peripheral portion of the optical component 1 is larger than the emission angle in the vicinity of the optical axis C. _{In the example of the optical component 1 NS in} FIG. 17, the linear light intersecting the optical axis C and parallel to the X axis is incident on the _{optical component 1 NS in a state of being inclined in the RX direction.} In this case, the light on the XY plane (evaluation plane P) has a convex shape in the −Y axis direction and a shape symmetrically bent in the Y axis direction.

It is desirable that the light incident on the optical component 1 is parallel light. Further, as described above, when the daylighting device is designed by daylighting from 10:00 to 14:00 in a day, the maximum value of the incident angle in the east-west direction is about 54 degrees at 14:00 on the winter solstice. On the other hand, the angle of incidence in the north-south direction at mid-south throughout the year is about 10 degrees at the summer solstice and about 60 degrees at the winter solstice. The maximum value of the incident angle in the north-south direction is about 65 degrees at 14:00 on the winter solstice. Therefore, the degree of distortion of the light emitted from the optical component 1 is greater in the north-south direction than in the east-west direction.

For example, _{when sunlight L is incident on the optical component 1 NS} and then is incident on the optical component 1 _{EW , the optical component 1 NS} is incident with light having an incident angle of 60 degrees at the time of the winter solstice. Then, the light emitted from the optical component 1 _NS is converted into divergent light including a light ray parallel to the optical axis C. Then, the optical component 1 _EW incidents divergent light including a light ray parallel to the optical axis C. Therefore, the influence of light having an incident angle of 60 degrees can be mitigated. Then, it is reduced that the region where the emitted light reaches on the evaluation surface P becomes narrow.

On the other hand, _{when the sunlight L is incident on the optical component 1 EW} and then is incident on the optical component 1 _{NS , the optical component 1 EW} is incident with light having an incident angle of 60 degrees at the time of the winter solstice. Then, the light emitted from the optical component 1 _EW becomes distorted light. That is, the parallelism of the light emitted from the optical component 1 _{EW is reduced.} Therefore, the influence of light having an incident angle of 60 degrees cannot be mitigated. Then, the region where the emitted light reaches on the evaluation surface P becomes narrow.

In FIG. 15, the optical component 1 _NS is arranged on the + Z axis side of the optical component 1 _EW. The daylighting device 200 receives sunlight from the + Z axis side. The sunlight is incident from the + Z axis side of the daylighting device 200. Optical component 1 _NS diverges the incident light in the X-axis direction (north-south direction). Optical component 1 _EW diverges the incident light in the Y-axis direction (east-west direction). The daylighting device 200 shown in FIG. 15 reduces the narrowing of the area where the emitted light reaches.
<Modification 2>
FIG. 20 is a configuration diagram showing the configuration of the daylighting device 300 according to the second modification. FIG. 20A is a configuration diagram of the daylighting device 300 as viewed from the + Z axis direction side. FIG. 20B is a configuration diagram of the daylighting device 300 viewed from the −Y axis direction side.

FIG. 21 is a diagram showing an example of the result of ray tracing of the optical component 10 of the daylighting device 300. FIG. 21 is a diagram showing the behavior of a light ray when a parallel light ray (light ray L) is incident from the plane portion 1e side of the optical component 10. Partial detailed views are attached to the boundary portion 10bc, the region 10c, and the region 10d.

FIG. 22 is a diagram showing the behavior of light rays when parallel light rays (light rays L) are incident from the optical surface portion 10f side of the optical component 10. In FIGS. 20, 21 and 22, the parallel light beam (light ray L) is incident on the optical component 10 from the + X axis direction side.

The optical component 10 differs from the optical component 1 in that the region 10c is replaced with a Fresnel-shaped cylindrical convex lens. Regarding other points, the description of the optical component 1 substitutes the description of the optical component 10.

<Optical component 11 of Fresnel-shaped convex lens>
First, the optical component 11 on which the Fresnel-shaped cylindrical convex lens is formed will be described. That is, the optical component 11 is a normal Fresnel-shaped cylindrical convex lens. The optical component 11 is a Fresnel-shaped convex lens. The optical component 11 is formed of, for example, only a convex portion.

23 and 24 show an example of the result of ray tracing of the optical component 11. FIG. 23 is a diagram showing the behavior of light rays when parallel light L is incident from the side of the flat surface portion 11e of the optical component 11. FIG. 24 is a diagram showing the behavior of light rays when parallel light L is incident from the side of the optical surface portion 11f of the optical component 11.

<< Flat surface portion 11e and optical surface portion 11f >>
In the optical component 11 shown in FIG. 23, one surface is a flat surface (flat surface portion 11e) and a Fresnel-shaped cylindrical convex lens is formed on the other surface (optical surface portion 11f). One surface of the optical component 11 is a flat surface. One surface of the optical component 11 includes a planar shape. The plane side surface is called a flat surface portion 11e. The other surface of the optical component 11 is a surface on which a cylindrical lens is formed. The surface on the side where the cylindrical lens is formed is called an optical surface portion 11f. The optical surface portion 11f faces the flat surface portion 11e. The region facing the cylindrical lens has a planar shape.

The optical surface portion 11f includes, for example, the shape of a cylindrical convex lens surface. The cylindrical convex lens surface includes a Fresnel shape. The optical surface portion 11f includes, for example, regions 11a, 11b, 11c, and 11d of four cylindrical convex lens surfaces. The prisms in the regions 11a, 11b, 11c, and 11d are prisms 11a _P , 11b _P , 11c _P , and 11d _P.

《Prism shape》
The surfaces corresponding to the lens surfaces of each prism are surfaces 11a _L , 11b _L , 11c _L , and 11d _L. The surfaces 11a _L , 11b _L , 11c _L , and 11d _L of each prism are inclined with respect to the optical axis C _11. The inclined surfaces 11a _L , 11b _L , 11c _L , and 11d _L of each groove are lens surfaces.

The other surfaces of each prism are surfaces 11a _F , 11b _F , 11c _F , 11d _F. The other surfaces 11a _F , 11b _F , 11c _F , and 11d _F of each prism are planes perpendicular to the flat surface portion 11e for the sake of simplicity. The surfaces 11a _F , 11b _F , 11c _F , 11d _F are, for example, flat surfaces. Further, the surfaces 11a _F , 11b _F , 11c _F , and 11d _F may be inclined within a draft range in consideration of productivity at the time of molding, for example.

The optical component 11 is a convex lens. Therefore, the surface of the optical axis _{C 11} side of each prism surface _{11a F, 11b F, 11c F} , a 11d _F. The peripheral surfaces of each prism are surfaces 11a _L , 11b _L , 11c _L , and 11d _L.

The regions of the optical component 11 are arranged in the order of region 11a, region 11b, region 11c, and region 11d from the optical axis C _{11 toward the + Y axis direction.} The optical component 11 is in the Y-axis direction, since the optical axis _{C 11} is symmetrical, the optical axis _{C 11} of the -Y-axis direction explanation is omitted.

<< Area 11a >>
The region 11a is a region including _{the optical axis C 11 of the cylindrical convex lens.} The region 11a is a region in contact with _{the optical axis C 11 of the cylindrical convex lens.}

As shown in FIG. 23, in the region 11a, the light ray La incident from the flat surface portion 11e is emitted by one refraction. In the region 11a, the light beam La incident from the flat surface portion 11e is refracted by the _{surface 11a L and emitted.} The light emitted from the region 11a is condensed light. The light emitted from the region 11a is focused on the focusing _{point A 11a.} The focusing point A _11a is located on the optical axis C _11.

As shown in FIG. 24, in the region 11a, the light ray La incident from the optical surface portion 11f is emitted by one refraction. In the region 11a, the light beam La incident from the optical surface portion 11f is refracted by the _{surface 11a L and emitted.} The light emitted from the region 11a is condensed light. Light emitted from region 11a is focused on the focal point _{F 11.}

<< Area 11b >>
The region 11b is a region located on the peripheral side of the _{optical axis C 11 with respect to the region 11a.}

As shown in FIG. 23, in the region 11b, the light beam Lb incident from the flat surface portion 11e is emitted in the −Y axis direction with one reflection. In the region 11b, the light beam Lb incident from the flat surface portion 11e is reflected by the _{surface 11b L and emitted from the surface 11b F in the} −Y axis direction. The reflection here is, for example, total internal reflection. Light Lb emitted from the surface 11b _F is incident to the optical axis _{C 11} side of the prism. Therefore, the light is not used in the daylighting device 100.

As shown in FIG. 24, in the region 11b, the light beam Lb incident from the optical surface portion 11f is emitted by one refraction. In the region 11b, the light beam Lb incident from the optical surface portion 11f is refracted by the _{surface 11b L and emitted.} The light emitted from the region 11b is condensed light. Light emitted from region 11b is focused on the focal point _{F 11.}

<< Area 11c >>
The region 11c is a region located on the peripheral side of the _{optical axis C 11 with respect to the region 11b.}

As shown in FIG. 23, in the region 11c, the light ray Lc incident from the flat surface portion 11e is reflected once and then emitted by one refraction. In the region 11c, the light beam Lc incident from the flat surface portion 11e is reflected by the _{surface 11c L} and then refracted by the _{surface 11c F and emitted.} The reflection here is, for example, total internal reflection. The light emitted from the region 11c is divergent light. The divergent light is called divergent light. Divergent light emitted from region 11c proceeds to the optical axis _{C 11} side of the optical component 11.

As shown in FIG. 24, in the region 11c, the light ray Lc incident from the optical surface portion 11f is emitted by one refraction. In the region 11c, the light beam Lc incident from the optical surface portion 11f is refracted by the _{surface 11c L and emitted.} The light emitted from the region 11c is condensed light. Light emitted from region 11c is converged on the focal point _{F 11.}

<< Area 11d >>
The region 11d is a region located on the peripheral side of the _{optical axis C 11 with respect to the region 11c.}

As shown in FIG. 23, in the region 11d, the light ray Ld incident from the flat surface portion 11e is reflected twice and then emitted by one refraction. In the region 11d, the light beam Ld incident from the flat surface portion 11e is _{reflected by the surface 11d L} , reflected by the surface 11d _F , and then refracted by the surface 11d _{L and emitted.} The reflection here is, for example, total internal reflection. The light emitted from the region 11d is condensed light. The light emitted from the region 11d is focused on the focusing _{point A 11d.} The focusing point A _11d is located on the peripheral side of the optical component 11. The focusing point A _11d is located on the peripheral side of the region 11d.

As shown in FIG. 24, in the region 11d, the light ray Ld incident from the optical surface portion 11f is emitted by one refraction. In the region 11d, the light beam Ld incident from the optical surface portion 11f is refracted by the _{surface 11d L and emitted.} The light emitted from the region 11d is condensed light. Light emitted from region 11d is focused on the focal point _{F 11.}

The absolute values of the radius of curvature, the aspherical coefficient, and the conic constant of the convex lens surface of the optical component 11 and the concave lens surface of the optical component 12 are made equal. When the groove depth of the prisms of the optical components 11 and 12 is made constant, it is necessary to increase the thickness of the convex lens surface of the optical components 11. In particular, it is necessary to increase the thickness of the convex lens surface of the optical component 11 with the prism in the peripheral portion. The prisms in the peripheral portion are, for example, the prisms in the regions 11c and 11d. The region 11c and the region 11d are regions of the peripheral portion of the optical component 11.

However, the focal length of the optical component 11 and the focal length of the optical component 12 differ due to the difference in the thickness of the optical components 11 and 12. That is, the focal length differs between the optical component 11 and the optical component 12. Therefore, the focal length of the region 11c and the focal length of the region 12c are different.

In the optical component 10, the prism shape of the region 12c of the optical component 12 is changed to the prism shape of the region 11c of the optical component 11. The prism shapes of the regions 10a, 10b and 10d are the same as the prism shapes of the regions 12a, 12b and 12d. The prism shape of the region 10c is the same as the prism shape of the region 11c. Therefore, in the optical component 10, the focal lengths of the regions 10a, 10b, and 10d other than the region 10c are different from the focal lengths of the regions 10c.

It is also possible to make the depth of the prism groove different in order to match the focal length. However, in manufacturing the optical component 10, it is preferable that the depth of the prism groove in the regions 10a, 10b, and 10d is the same as the depth of the prism groove in the region 10c. The angle of incidence of the light beam Lc emitted from the optical component 10 as light parallel to the optical axis C on the optical component 10 differs depending on the focal length of the optical component 10. However, the difference in the incident angle of the light beam Lc due to the difference in the focal length between the region 11c and the region 12c is, for example, about 0.1 degree in the peripheral region. Therefore, there is no problem in actually using it.

Here, for the incident angle difference Δα of 0.1 degrees, the dimension W in the Y direction of the optical component is 100 [mm], the focal length Fd is 35 [mm], and the amount of change in the thickness T ΔT It was calculated using the following formula (4) as 0.12 [mm].
Δα = arctan ((Wo / 2) / Fd) -arctan ((Wo / 2) / (Fd + ΔT)) ... (4)

<Structure of optical component 10>
<< Areas 10a, 10b, 10d >>
The regions 10a, 10b, and 10d are the same as the regions 1a, 1b, and 1d of the optical component 1. That is, the regions 10a, 10b, 10d are the same as the regions 12a, 12b, 12d of the optical component 12. Regarding the configuration of the regions 10a, 10b, 10d and the behavior of the light rays La in the regions 10a, 10b, 10d, the description of the optical component 1 and the optical component 12 will be substituted.

≪Area 10c≫
The region 10c can be replaced with the region 11c of the optical component 11. The region 10c shown in FIG. 21 is replaced with the region 11c on the same side of _{the optical axis C 11 of the optical component 11.} Therefore, the outer peripheral surface of the prism in the region 10c is a surface 10c _L. The surface 10c _L is a lens surface.

As described in FIG. 1, for example, regions 81d _p concave lens 81 is replaced with a region 82d _m convex lens 82. The region 81d _m concave lens 81 is replaced with a region 82d _p convex lens 82. That is, the region 10c on the + Y-axis side is replaced with the region 11c on the −Y-axis side. Further, the region 10c on the −Y axis side is replaced with the region 11c on the + Y axis side.

In the second modification, the optical component 10 has a symmetrical shape _{about the optical axis C 10.} Therefore, the region 10c on the + Y-axis side is replaced with the region 11c on the + Y-axis side. Further, the region 10c on the −Y axis side is replaced with the region 11c on the −Y axis side.

However, area 10c is replaced with the region 11c of the opposite side with respect to the optical axis _{C 11} of the optical component 11. That is, when the region 10c is a region on the + Y-axis side, the corresponding region 11c is a region on the −Y-axis side. When the region 10c is a region on the −Y axis side, the corresponding region 11c is a region on the + Y axis side. The surface 10c _L corresponds to the surface 11c _L. The surface 10c _F corresponds to the surface 11c _F. The optical axis C corresponds to the _{optical axis C 11.} Regarding the configuration of the region 10c and the behavior of the light beam Lc in the region 10c, the description of the optical component 11 will be substituted.

In the description of "+ Y-axis side" and "-Y-axis side", it is assumed that the optical axes C ₁₀ and C ₁₁ are located on the X-axis.

≪Light deflection component 2≫
The light deflection component 2 of the daylighting device 300 is the same as the light deflection component 2 of the daylighting device 100. The description of the light deflection component 2 of the daylighting device 300 will be substituted by the description of the light deflection component 2 of the daylighting device 100.

<Simulation result of optical component 10>
FIG. 25 is a diagram showing a simulation result of the optical component 10. The vertical axis is the relative light intensity normalized by the maximum light intensity when the incident angle α is changed [a. u. ]. The horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. The horizontal axis is centered on the intersection of the evaluation surface P and the optical axis C. Further, FIG. 12 is used as a substitute for a diagram showing conditions for performing a simulation for explaining the operation of the optical component 10.

In FIG. 25 (A), the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 15 degrees is shown by a broken line. The case where the incident angle α is 30 degrees is shown by the dotted line.

In FIG. 25B, the case where the incident angle α is 45 degrees is shown by a solid line. The case where the incident angle α is 55 degrees is shown by a broken line.

As shown in FIG. 25 (A), when the incident angle α is 30 degrees (dotted line), the light intensity on the + Y axis direction side is reduced. Further, as shown in FIG. 25 (B), when the incident angle α is 55 degrees (broken line), the light intensity on the −Y axis direction side is reduced. Regardless of the change in the incident angle α, the portion having strong light intensity is located near the center of the evaluation surface P.

Glare is reduced by the divergence of light. Then, the optical component 10 can obtain a light intensity distribution in which the dependence of the incident angle α is reduced. When the incident angle α is 55 degrees (broken line in FIG. 25 (B)), locations with strong light intensity (regions Pa and Pb) are locally generated. The cause of the strong light intensity is a light ray passing through the boundary portion 10bc between the region 10b and the region 10c of the optical component 10 and a light ray passing through the boundary portion 10cd between the region 10c and the region 10d.

When the incident angles α are 0 degrees, 15 degrees, and 30 degrees, the results of the optical component 10 shown in FIG. 25 are substantially the same as the results of the optical component 1 and the optical component 12. Further, when the incident angles α are 45 degrees and 55 degrees, the result of the optical component 12 has a smoother curve of the light intensity distribution as compared with the result of the optical component 10. However, the optical component 10 has the same divergence effect as the optical component 1 and the optical component 12.

<Modification example 3>
As shown in FIG. 25, when a parallel ray having an incident angle α of 55 degrees (broken line in FIG. 25 (B)) is incident, a portion having a strong light intensity is locally generated in the optical component 10. .. Therefore, the boundary portion 10bc between the region 10b and the region 10c of the optical component 10 is formed into a devised shape. Further, the boundary portion 10cd between the region 10c and the region 10d has a devised shape. With these, it is possible to locally suppress the generation of a portion having a strong light intensity.

FIG. 26 is a configuration diagram showing the configuration of the optical component 13 according to the modified example 3. FIG. 26 is a diagram showing the behavior of light rays when parallel light L is incident from the flat surface portion 13e side of the optical component 13. The light ray Lbc is a light ray incident on the boundary portion 13bc between the region 13b and the region 13c of the optical component 13. The ray Lbc is shown by a dotted line in FIG. The light ray Lcd is a light ray that is incident on the boundary portion 13cd between the region 13c and the region 13d of the optical component 13. The ray Lcd is indicated by a chain double-dashed line in FIG. Light Lbc, Lcd is parallel to the optical axis _{C 13.}

The regions 13a, 13b, 13c, and 13d have the same shape as the regions 10a, 10b, 10c, and 10d of the optical component 10. The light transmitted through the regions 13a, 13b, 13c, 13d exhibits the same behavior as that of the optical component 10. Therefore, the description thereof will be omitted.

≪Boundary part 13bc≫
At the boundary portion 10bc between the region 10b and the region 10c of the optical component 10, there is one vertex. As shown in the partial detailed view of FIG. 21 (a boundary portion 10bc), the boundary portion 10bc, prisms formed by a surface 10b _L and the surface 10c _L comprises one of the vertices _{V 10bc.} That is, the boundary portion 10 bc includes one vertex V _{10 bc} .

On the other hand, the boundary portion 13bc between the region 13b and the region 13c of the optical component 13 has two vertices. As shown in the partial detailed view (boundary portion 13bc) of FIG. 26, at the boundary portion 13bc, the _{prism formed by the surface 13b L} and the surface 13b _F has a vertex V _{13bc 1} . Further, at the boundary portion 13bc, the _{prism formed by the surface 13c L} and the surface 13c _F has an apex V _{13bc 2} . That is, the boundary portion 13bc includes two vertices V _{13bc 1} and V ₁₃ bc 2.

Further, the height of the prism at the boundary portion 13bc is lower than the height of the prism in the regions 13b and 13c. That is, in the X-axis direction, the prism vertices V _13bc1 and V _13bc2 at the boundary portion 13bc are located on the + X-axis side of _{the prism vertices V 13b} and V _{13c in} the regions 13b and 13c.

_{This is because the inclination of the surface 13b L and} the inclination of the surface 13c _L at the boundary portion 13bc are maintained in the same manner as in the regions 13b and 13c. _{The inclination of the surface 13b L} at the boundary portion 13bc is, for example, equal to the inclination _{of the surface 13b L at the region 13b. Further, the inclination of the surface 13c L} at the boundary portion 13bc is equal to, for example, the inclination of the surface 13c _{L at the region 13c.}

At the boundary portion 13bc of the optical component 13, the light beam Lbc reflected by the _{surface 13b L is refracted by the surface 13b F} and emitted from the optical component 13. Similarly, the light beam Lbc reflected by the _{surface 13c L is refracted by the surface 13c F} and emitted from the optical component 13. The light emitted from the boundary portion 13bc of the optical component 13 is used.

On the other hand, at the boundary portion 10bc of the optical component 10, the incident light ray Lbc is unnecessary light. That is, the amount of light used is reduced at the boundary portion 10bc of the optical component 10.

FIG. 27 (A) is a diagram in which back light tracing is performed from the local region Pa having a strong light intensity shown in FIG. 25 (B) when the boundary portion 10 bc shown in FIG. 21 is adopted. FIG. 27B is a diagram in which ray tracing is performed when the boundary portion 13bc shown in FIG. 26 is adopted.

In FIG. 27 (A), the cause of the local region Pa having a strong light intensity was confirmed by tracing the back light in the direction of the light source from the arrival position of the light. Here, the arrival position of the light ray is the area Pa. As a result, as shown in FIG. 27 (A), the light beam reaching the region Pa is refracted by the prism at the boundary portion 10 bc of the optical component 10 and emitted. The light rays that reach the region Pa are refracted by the _{surface 10 b L and emitted.} That is, the generation of the region Pa is caused by the prism at the boundary portion 10 bc.

On the other hand, in FIG. 27B, the light transmitted through the boundary portion 13bc is divided into a _{surface 13b L} and a surface 13c _{F and refracted.} Then, the light refracted by the respective surfaces 13b _L and 13c _F travels in different directions. That is, the light incident on the boundary portion 13bc is diverged. Therefore, the local light intensity in the region Pa decreases.

≪Boundary part 1cd≫
The boundary portion 13cd between the region 13c and the region 13d of the optical component 13 includes a bottom portion B _13cd . The bottom B _13cd is, for example, a flat surface. The bottom portion B _13cd has, for example, a planar shape. The bottom portion B _13cd is, for example, parallel to the flat surface portion 13e.

FIG. 28 (A) is a diagram in which back light tracing is performed from a local region Pb having a strong light intensity when the boundary portion 10 cd is adopted. The boundary portion 10cd is a portion of the boundary between the region 10c and the region 10d. The boundary portion 10 cd, bottom _{B 10 cd} is shaped end portion of the bottom of the groove between the surface 10c _L and the surface 10d _L are connected. FIG. 28B is a diagram in which ray tracing is performed when the boundary portion 13cd is adopted.

In FIG. 25, the cause of the local region Pb having a strong light intensity was confirmed by tracing the back light in the direction of the light source from the arrival position of the light. Here, the arrival position of the light ray is the region Pb. As a result, as shown in FIG. 28 (A), the light beam reaching the region Pb is refracted by the prism at the boundary portion 10cd of the optical component 10 and emitted. Rays reaching the region Pb is emitted is refracted by the surface 10d _L. That is, the generation of the region Pb is caused by the prism at the boundary portion 10cd.

On the other hand, in FIG. 28 (B), the light transmitted through the boundary portion 13 cd is refracted divided into a surface of the bottom _{B 13 cd} surface 13d _L and the boundary portion 13 cd. The light is refracted by the plane of each face 13d _L and the bottom _{B 13 cd} travels in different directions. That is, the light incident on the boundary portion 13cd is diverged. Therefore, the local light intensity in the region Pb is reduced.

In the X-axis direction, _{the surface of the bottom B 13cd} is arranged on the −X-axis side with respect to the bottom portion of the groove in the region 13c (bottom B _13c ) and the bottom portion of the groove in the region 13d (bottom B _13d). .. That is, the surface of the bottom _{B 13cd} is arranged on the −X axis side with _{respect to the bottom B 13c} and the bottom B _13d. The −X-axis side is the side from which the light of the optical component 13 is emitted. Further, the bottom _{B 13 cd} of the boundary portion 13 cd can be a concave shape in the XY plane.

<Simulation result of optical component 13>
FIG. 29 is a diagram showing a simulation result of the optical component 13. The vertical axis is the relative light intensity normalized by the maximum light intensity when the incident angle α is changed [a. u. ]. The horizontal axis is the position [mm] of the evaluation surface P in the Y-axis direction. The horizontal axis is centered on the intersection of the evaluation plane P and the optical axis C _13. Further, FIG. 12 is used as a substitute for a diagram showing conditions for performing a simulation for explaining the operation of the optical component 13.

In FIG. 29 (A), the case where the incident angle α is 0 degrees is shown by a solid line. The case where the incident angle α is 15 degrees is shown by a broken line. The case where the incident angle α is 30 degrees is shown by the dotted line.

In FIG. 29B, the case where the incident angle α is 45 degrees is shown by a solid line. The case where the incident angle α is 55 degrees is shown by a broken line.

When the incident angles α are 45 degrees and 55 degrees, the result of the optical component 13 has a relatively smooth curve in which the portion where the light intensity is locally strong is reduced as compared with the result of the optical component 10. It has become. As a result, the optical component 13 can reduce the generation of light that is focused in a part of the region. Then, the optical component 13 can smoothly diverge the incident light to reduce glare.

In the above-described embodiment, the draft when the optical component is molded has been described as 0 degree. However, the same effect can be obtained even if the draft is taken into consideration. In that case, it is preferable to locally suppress the generation of a region having high light intensity by devising the shape of the prism at the boundary between the concave lens portion and the convex lens portion.

In each of the above-described embodiments, terms such as "parallel" or "vertical" that indicate the positional relationship between the parts or the shape of the parts may be used. These indicate that they include a range that takes into account manufacturing tolerances and assembly variations. For this reason, when a statement indicating the positional relationship between parts or the shape of a part is described in the claims, it is indicated that the range including the manufacturing tolerance or the variation in assembly is included.

Moreover, although the embodiment of the present invention has been described as described above, the present invention is not limited to these embodiments.

100,200,300 Luminometer, 1,1ns, 1ew, 10,11,12,13 Optical parts, 1a, 1b, 1c, 1d, 10a, 10b, 10c, 10d, 11a, 11b, 11c, 11d, 12a, 12b, 12c, 12d, 13a, 13b, 13c, 13d region, 1bc, 10bc, 10cd, boundary part, 1e, 10e, 11e, 12e, 13e plane part, 1f, 10f, 11f, 12f, 13f optical surface part, 1bc, 1cd, 13bc, 13cd boundary _{portion, 1b L, 1c L, 1d} L, 1b F, 1c F, 1d F, 10b L, 10c L, 10d L, 10b F, 10c F, 10d F, 11a L, 11b L, _{11c L, 11d L, 11a F} , 11b F, 11c F, 11d F, 12a L, 12b L, 12c L, 12d L, 12a F, 12b F, 12c F, 12d F, 13b L, 13c L, 13b F , 13c _F plane, 1b _P , 1c _P , 1d _P , 10b _P , 10c _P , 10d _P , 12a _P , 12b _P , 12c _P , 12d _P prism, 2 optical deflection parts (optical deflection part), 400, 410 Object, 40 stairwell, 81,82 lens, 81a1,81b1,81c1,81d1,81a2,81b2,81c2,81d2,82a1,82b1,82c1,82d1,82a2,82b2,82c2,82d2 region, 9,9 _A , 9 _B , _{9 C} sun, A11a, A11d, A12c, A12d focal point, B13cd, B10cd bottom, C, C11, C12 optical axis, D distance, E1, E2, E3 angle, F81, F82, F11, F12 , F1c focus, Fd focal length, Ha, Hb height, L, La, Lb, Lc ray, P evaluation surface, R region, S light source, T thickness, V10bc peak, Wo, Wp, Ws ₁ , Ws ₂ , Wc length, α incident angle, β angle, γ ₁ , γ ₂ divergence angle, δ exit angle, θ altitude, φ azimuth.

Claims (12)

It has a plate shape including a first surface, a second surface facing the first surface, and a side surface, and a lens surface of a cylindrical concave lens is formed on the first surface, and the lens on the second surface. Equipped with optical components that form a planar shape in the area facing the surface,
The lens surface includes a Fresnel shape formed by a plurality of prisms.
The surface of the prism corresponding to the lens surface is designated as the first prism surface, and the other surface of the prism is designated as the second prism surface.
Assuming that the plurality of prisms include a first prism and a second prism, and the first prism is located closer to the optical axis of the cylindrical concave lens than the second prism.
In the first region, in which light rays parallel to the optical axis incident from the side of the second surface are reflected by the first prism surface and then refracted by the second prism surface and emitted, the plurality of light rays are emitted. By changing the arrangement of the prisms, the angle of incidence at which the light rays parallel to the optical axis are incident on the first prism surface is larger in the first prism than in the second prism. The daylighting apparatus according to claim 1, wherein the first prism surface has a planar shape parallel to a plane in contact with the corresponding lens surface of the cylindrical concave lens. The daylighting apparatus according to claim 1, wherein the first prism surface is a convex lens surface in which the absolute values of the curvature, the cornic constant, and the aspherical coefficient are equal to the corresponding lens surface of the cylindrical concave lens. It has a plate shape including a first surface, a second surface facing the first surface, and a side surface, and a lens surface of a cylindrical concave lens is formed on the first surface, and the lens on the second surface. Equipped with optical components that form a planar shape in the area facing the surface,
The lens surface includes a Fresnel shape formed by a plurality of prisms.
The surface of the prism corresponding to the lens surface is designated as the first prism surface, and the other surface of the prism is designated as the second prism surface.
The first region is a region in which a light beam parallel to the optical axis of the cylindrical concave lens incident from the side of the second surface is reflected by the first prism surface and then refracted by the second prism surface and emitted. As an area,
The first region is a daylighting device having a Fresnel shape of a cylindrical convex lens having the same absolute values of curvature, conic constant, and aspherical coefficient as the cylindrical concave lens. Assuming that the plurality of prisms include a first prism and a second prism, and the first prism is located closer to the optical axis than the second prism.
The fourth aspect of claim 4, wherein in the first region, the incident angle at which a light ray parallel to the optical axis is incident on the first prism surface is larger in the first prism than in the second prism. Daylighting device. Assuming that the plurality of prisms include a first prism and a second prism, and the first prism is located closer to the optical axis than the second prism.
The fourth aspect of claim 4, wherein in the first region, the incident angle at which a light ray parallel to the optical axis is incident on the first prism surface is smaller in the first prism than in the second prism. Daylighting device. Assuming that the region on the optical axis side of the first region is the second region,
A claim in which the apex of the first prism surface of the first region and the apex of the first prism surface of the second region are connected to the boundary portion between the first region and the second region. Item 6. The lighting apparatus according to item 6. The region on the optical axis side of the first region is defined as the second region.
Assuming that the prism of the first region at the boundary between the first region and the second region is the first prism and the prism of the second region is the second prism, it is assumed.
The daylighting apparatus according to claim 6, wherein the height of the first prism and the height of the second prism are lower than the height of the prism in the first region and the height of the prism in the second region. Assuming that the region on the peripheral side of the first region with the optical axis as the center is the third region,
The lighting device according to any one of claims 6 to 8, wherein the boundary portion between the first region and the third region has a planar shape or a concave shape parallel to the plane. It is equipped with a plate-shaped light deflection component that injects light from the sun and suppresses changes in the emission angle in the direction corresponding to the change in altitude with respect to the change in altitude of the sun.
The optical component is arranged so as to be overlapped with respect to the light deflection component.
The daylighting apparatus according to any one of claims 1 to 9, wherein the direction having the curvature of the cylindrical concave lens is parallel to the direction in which the direction of the sun changes. With a set of the optics
The set of optical components includes a first optical component and a second optical component.
The first optical component and the second optical component are arranged so as to be overlapped with each other.
The daylighting apparatus according to any one of claims 1 to 9, wherein the direction having the curvature of the first optical component is perpendicular to the direction having the curvature of the second optical component. The first optical component receives light from the sun and
The second optical component receives the light emitted from the first optical component and receives light.
The direction having the curvature of the first optical component is parallel to the north-south direction.
The daylighting apparatus according to claim 11, wherein the direction having the curvature of the second optical component is parallel to the east-west direction.

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