JPH11149811A - Light diffusing reflection mirror for sunlight lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusing reflection mirror which is able to reflect the light from a sunlight collecting part in a sunlight lighting system directly using the sunlight without waste, is able at all times to keep the diffusion of the light constant, irrespective of the position of the sun for diffusing and reflecting the light to a place to be aimed, and is able to return the light separated spectrally by a prism sheet to a natural white light. SOLUTION: A mirror surface 5a of a light diffusing reflection mirror 5 consists of an aggregate of a number of small-sized convex mirrors 5b having a diffusion reflection surface. The small-sized convex mirrors 5b are arranged to be in mass formation, without laying a flat part or a curved surface part different from the convex mirror 5b at an adjacent part of adjoined convex mirrors 5b. Since the light from a sunlight collecting part is reflected by the entire surfaces of at least some of the small-sized convex mirrors 5b when irradiated only to a part of the mirror surface 5a of the reflection mirror 5, the extent of diffusion and the radiating direction of the reflected light become constant and stable at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-diffusing reflector used for a lighting device directly utilizing sunlight. More specifically, the present invention relates to a light diffuse reflector for reflecting light transmitted from a sunlight collecting unit in the lighting device while diffusing the light into a room.

[0002]

2. Description of the Related Art Conventionally, in a building or a basement where a space between an adjacent building is small and it is difficult to receive sunlight from a window, sunlight is collected on a roof portion thereof.
Lighting devices that lead indoors are used, and several types of solar light devices are currently in practical use.

For example, Japanese Patent Laid-Open Publication No. Sho 63-30801 discloses that sunlight is condensed by using two concave parabolic reflectors and converted into parallel light, and the parallel light is used by a plurality of plane reflectors. There is disclosed an illuminating device that transmits air through a light duct to a room while changing the course.

[0004] In addition, the sunlight illuminating device disclosed in Japanese Unexamined Patent Publication No. Hei 5-295633 has a prism sheet formed by arranging a large number of triangular prisms extending in one direction in parallel, arranged in a predetermined direction, and entering from an oblique direction. This is to guide the incoming sunlight by bending it almost directly downward. Further, JP-A-6-27
Japanese Patent Application Publication No. 3689 discloses an illuminating device that uses the above-described prism sheet and a reflecting mirror in combination to transmit sunlight in the air in a direct downward direction.

On the other hand, Japanese Patent Application Laid-Open No. 1-114706 discloses that a sunlight is condensed by a Fresnel lens provided in a sunlight collecting portion which automatically changes an angle toward the sun, and the sunlight is condensed in the vicinity of the focal point. Into one end of the optical fiber,
A sunlight illuminating device that guides light to a target place by the optical fiber is disclosed.

[0006] In any of these solar lighting devices, the light transmitted from the sunlight collecting unit by air transmission (projection light) or optical fiber transmission is diffused to a target location and softened. Finally, a simple convex mirror, for example, a stainless or plastic convex mirror which is widely marketed as a road curve mirror, is used. When a mirror is used in the sunlight collecting part, this is called a primary mirror, and the above-mentioned convex mirror is called a secondary mirror. In some cases, another mirror is used in the optical path to change the direction of light. In this case, the convex mirror is called a tertiary mirror.

[0007]

However, depending on the above-mentioned sunlight illuminating device, as shown in FIG. 17 and FIG. 18, the light beam L reflected and sent by the daylighting mirror 2a of the sunlight daylighting section 2 is transmitted. The cross-sectional shape and the cross-sectional area of each of them often change momentarily depending on the position of the sun, that is, the irradiation angle of the sunlight. When a single convex mirror as described above is used as a light-diffusing reflector for sunlight illumination in such a sunlight illumination device, any of the following defects usually occurs. (1) In order to always keep the spread of light constant irrespective of the position of the sun, it is necessary to shine light on the entire convex mirror. For this purpose, as shown in FIG. 13, it is necessary to use a convex mirror 3 having a size to be accommodated inside the light beam L sent from the sunlight collecting unit 2. In this case, the light of the light flux L protruding from the convex mirror 3 is wasted without being reflected by the convex mirror 3, and a sufficient amount of light cannot be delivered to a target place.

(2) In order to eliminate the waste of light,
As shown in FIG. 14, it is conceivable to use a large convex mirror 4 so as to be able to reflect all the light fluxes L sent from the sunlight collecting part 2. However, in this case, since light impinges on only a part of the convex mirror 4, the spread angle of the reflected light is reduced, and the irradiation range is also reduced. Further, as shown in FIG. 15 and FIG. 16, a portion of the convex mirror 4 to which the light from the sunlight collecting unit 2 irradiates differs depending on the position of the sun. There is also a problem that the direction changes with time.

Further, in a sunlight illuminating device using the prism sheet for the sunlight collecting section 2, the light sent from the lighting section 2 may be split like a rainbow.
Even if the light is reflected by using a single convex mirror as described above, there is also a problem that such split light cannot be returned to natural white light.

Accordingly, the present invention provides a method of reflecting light from a sunlight collecting part without waste, and at the same time, keeping the spread of light constant irrespective of the position of the sun and diffusing and reflecting light to a target place. Provided is a light diffusing reflector for a solar illuminating device capable of returning spectroscopic light to natural white light even in a solar illuminating device using a prism sheet. With the goal.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention illuminates a target place by diffusing and reflecting light sent from a solar lighting unit in a solar lighting device. A reflector for a solar lighting device, characterized in that the mirror surface of the reflector is constituted by an aggregate of at least two or more small reflectors having a diffuse reflection surface. It has a main configuration. Preferably, the small reflecting mirror is a convex mirror or a concave mirror.

Here, the "aggregate of small reflecting mirrors" refers to an assembly of small reflecting mirrors without leaving a flat portion between adjacent small reflecting mirrors.
Further, it refers to a group of collective mirrors formed by closely adjoining the small reflecting mirrors without forming a curved surface portion different from the diffuse reflection surface of the small reflecting mirror. If a flat portion remains in the adjacent portion between the small reflecting mirrors, the light reflected by the flat portion is split into intense stripes while trying to diffuse with soft light by the convex or concave mirror, It is very unpleasant and unfavorable. Further, even if the adjacent portion has a curved surface portion different from the diffuse reflection surface of the small reflecting mirror even if it is not a flat portion, it is not preferable because a light and dark pattern different from the small reflecting mirror occurs in the reflected light. . for that reason,
Ideally, there is no such flat portion or different curved surface portion on the mirror surface of the reflecting mirror, but if the area of the flat portion or the curved surface portion is small compared to the area of the small reflecting mirror, Since the light reflected on the flat portion or the curved surface portion is weak, the flat portion or the curved surface portion may exist within a practically acceptable range.

[0013] Even if the mirror surface is formed of a convex mirror or a concave mirror, a function of sufficiently diffusing light can be obtained. However, when a concave mirror is used, sunlight concentrates at one point near the focal point. Since there is a risk of ignition if any object is present in this portion, special measures are required in order to avoid such a risk when adopting it.

Further, the mirror surface may be formed by at least two or more small reflecting mirrors, and there is no particular upper limit on the number. Therefore, it is possible to arrange as many small reflecting mirrors as possible. In addition, the relationship between the radius of curvature of the small reflector and each unit size is an important factor that determines how light is diffused, and these factors are appropriately optically determined according to the place and purpose of use. The design is made.

[0015] Preferably, the outer shape of the small reflector is all the same polygonal shape, or the outer shape of the small reflector is a combination of at least two or more different polygons. Can also be configured. As the polygonal shape, a square, a hexagon, etc.
Any shape may be used as long as it is a shape that can be brought into close contact with an adjacent small reflecting mirror without forming a gap as much as possible and that conforms to the object and spirit of the invention described above.

Further, it is preferable that a dust passing hole penetrating to the back surface of the reflecting mirror is formed at a corner of the polygonal small reflecting mirror. When the small reflectors are arranged in a dense state, a depression is formed at the boundary between the small reflectors,
In particular, dust and the like adhering to the surface of the small reflector due to rainwater are collected at the corners, and the dust is collected and easily stained.
However, by forming the garbage passage hole as described above, if garbage and the like are washed away with rainwater,
Dirt can be prevented from accumulating in the corners, depressions, and their surroundings, and the light reflection efficiency is not impaired.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG.
FIG. 2 is a schematic view of a sunlight illuminating device 1, FIG. 2 is a plan view showing an entire light diffusing reflector 5 according to a first embodiment of the present invention used in the illuminating device 1, and FIG. 5 is a partial plan view of the mirror surface 5a, and FIG. 4 is a partial perspective view of the same.

The solar lighting device 1 is mounted, for example, on the northern eaves of a building, and tracks the sun and projects the sun light directly downward. A light diffuse reflection mirror 5 that is installed to diffuse and reflect the light sent from the sunlight collecting unit 2 into the room.
It is composed of

In the example shown in FIG. 2, the outer shape of the reflecting mirror 5 has a rectangular shape with chamfered corners and a width W of 900.
mm, and the vertical dimension H is 1800 mm. The mirror surface 5a of the reflecting mirror 5 of the reflecting mirror 5 is polished stainless steel having a thickness of 0.7 mm, L5 × 50 × 50 angle iron, and 300 × 30.
It is lined with a 0-size lattice frame (shoji) to maintain a flat surface and ensure wind resistance. Furthermore, the mirror surface 5
As shown in FIG. 3, "a" is a small square having an outer shape of P = Q = 15 mm, and is composed of an aggregate of a number of small convex mirrors 5b having a diffuse reflection surface composed of a spherical surface of R = 90 mm.

The light transmitted from the sunlight collecting section 2 is reflected indoors while being diffused by the light diffusing reflector 5. At this time, all the light from the sunlight collecting unit 2 is irradiated to the mirror surface 5a of the light diffusing reflector 5, and is reflected without waste. Further, as described above, the mirror surface 5a of the reflecting mirror 5 has a large number of small convex mirrors 5b arranged in a dense state, so that even if the light is applied to any part of the reflecting mirror 5, a large number of The entire surface of some of the convex mirrors 5b among the convex mirrors 5b is irradiated. Therefore, light is sufficiently diffused irrespective of the position and angle of the sun, and a predetermined place can always be irradiated with a required amount of light.

Also, for example, when the sunlight is collected in the sunlight collecting section 2 using a prism sheet, and the light transmitted to the light diffuse reflection mirror 5 is dispersed, the light is reflected by the reflection mirror. 5 are reflected by the entire surface of some of the convex mirrors 5b, and the reflected lights overlap each other, so that the light illuminating the target portion is a natural light in which light of each color is mixed, that is, a light close to white light.

In the present invention, the outer shape of the small convex mirror constituting the mirror surface of the light diffusing reflector is the first shape described above.
It is not limited to a square as shown in the examples,
Any shape may be used as long as the convex mirrors can be arranged in close contact with each other without interposing a surface having another curvature or a flat surface between adjacent small convex mirrors. Good. Also, the number of convex mirrors may be any number as long as it is at least two or more.

Hereinafter, the polygon of the present invention will be described with reference to several embodiments, but as described above, the present invention is not limited to the following embodiments. For example,
In the second embodiment of the present invention shown in FIG. 5, the mirror surface 5a is composed of a group of densely packed rectangular small convex mirrors 5c having different widths P and Q. 6 and 7
As in the third embodiment of the present invention shown in FIG.
It can also be constituted by an aggregate consisting of a large number of convex mirrors 5d having a regular hexagon of mm and a spherical surface radius R = 120 mm.

Further, as in the fourth embodiment of the present invention shown in FIG. 8, the small convex mirror 5e having a regular octagon and the small convex mirror 5f having a square shape may be regularly arranged and arranged in a dense state. In this case, the light reflected by the regular octagonal small convex mirror 5e and the square small convex mirror 5f
The arrangement of the two, the curvature of the convex surface, and the like are set so as not to generate a light and dark pattern with the light reflected by the light source.

Further, the material of the reflecting mirror is not limited to the above-mentioned first embodiment. By applying mirror finishing, sunlight can be reflected efficiently, and even if it is installed outdoors, it can withstand wind and rain. A material having the obtained weather resistance can be appropriately selected. For example, in the third case shown in FIGS.
In the embodiment, the light diffusion reflecting mirror 5 is made of a plating grade ABS.
Injection molding with resin, metal plating on its surface,
Further, a clear acrylic protective film is spray-coated to form a mirror surface 5a.

By the way, in the light diffusing reflector 5 according to the above-described first to fourth embodiments, since the reflector 5 is installed and used outside the room, a short time after the installation, the small convex mirrors 5b to 5f are changed. The attached dust is collected and washed away by rainwater or the like, and is accumulated in the depressions at the boundaries between the adjacent convex mirrors 5b to 5f, so that the light reflection efficiency is reduced. Therefore, there is an inconvenience that the reflecting mirror 5 needs to be frequently cleaned in order to maintain a predetermined reflection efficiency.

FIGS. 9 and 10 show a light diffusing reflector 6 according to a fifth embodiment of the present invention, which is improved to avoid such inconvenience. Similar to the first embodiment, the reflecting mirror 6 has small square convex mirrors 6b arranged on a mirror surface 6a in a dense pattern like a grid, and furthermore, the reflecting mirrors are provided at all corners of the square. A circular dust passing hole 6c having a diameter of 3 mm and penetrating to the back surface of 6 is formed by punching.

As described above, by forming the circular dust passage hole 6c at a corner where dirt is likely to accumulate, dust attached to the surface of the small convex mirror 6b and washed away by rainwater can be removed from the convex mirror 6b. Since dust can be discharged together with rainwater from the dust passage hole 6c without being accumulated at the boundary or the corner, the light reflection efficiency is not significantly reduced even during long-term use, and the reflection mirror 6 is not damaged. There is no need to wash frequently.

The shape of the dust passing hole is not limited to the above-mentioned circular shape, but may be a square dust passing hole 6d as in the sixth embodiment shown in FIG.
As shown in the seventh embodiment, a cross-shaped dust passage hole 6e can be used, and various modifications are possible.

Further, in all of the above-mentioned embodiments, convex mirrors having polygonal mirror surfaces are formed in a dense state, but light can be diffused even when a concave mirror is used. However, when a concave mirror is used, sunlight concentrates near the focal point, and if there is any object in this portion, there is a risk of causing a fire. Therefore, a separate fire prevention measure is required.

[0031]

As described above, according to the present invention, the mirror surface of the light diffusing reflector is constituted by arranging a large number of small reflectors in a dense state. Even if the light from the mirror is locally applied to only a part of the entire mirror surface, at least some of the small reflecting mirrors will be applied to the entire surface, the degree of diffusion of the reflected light and the irradiation direction It is always constant and stable.

(2) Also, since the light from many small reflecting mirrors reaches the target irradiation point in an overlapping manner,
Even if the light sent from the sunlight collecting part is dispersed like a rainbow, light of each color is mixed and natural light, that is, light returned to a state close to white light reaches the irradiated point Becomes

Further, even when the reflector is installed outdoors and used, a dust passage hole is provided at the boundary between adjacent small reflectors, particularly at the corners, so that dirt on the reflector surface can be removed by rainwater. It is possible to prevent the reflection efficiency from being lowered due to the flow out of the passage hole and the contamination.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a solar lighting device.

FIG. 2 is an overall plan view of the light diffusing mirror according to the first embodiment of the present invention.

FIG. 3 is a partial plan view of the reflecting mirror.

FIG. 4 is a partial perspective view of the reflecting mirror.

FIG. 5 is a partial plan view of a light diffusing reflector according to a second embodiment of the present invention.

FIG. 6 is a partial plan view of a light diffusion mirror according to a third embodiment of the present invention.

FIG. 7 is a partial perspective view of the light diffusion reflector.

FIG. 8 is a partial plan view of a light diffusion mirror according to a fourth embodiment of the present invention.

FIG. 9 is a partial plan view of a light diffusing reflector according to a fifth embodiment of the present invention.

FIG. 10 is a partial perspective view of the light diffusion reflector.

FIG. 11 is a partial plan view of a light diffusion mirror according to a sixth embodiment of the present invention.

FIG. 12 is a partial plan view of a light diffusion mirror according to a seventh embodiment of the present invention.

FIG. 13 is an explanatory view showing a conventional solar lighting device.

FIG. 14 is an explanatory diagram showing a conventional solar lighting device different from the above.

FIG. 15 is an explanatory diagram of light reflection by a light diffusion mirror of the illumination device.

FIG. 16 is an explanatory diagram of light reflection by a light diffuse reflection mirror of the illumination device.

FIG. 17 is an explanatory diagram showing characteristics of a sunlight lighting unit in the sunlight lighting device.

FIG. 18 is an explanatory diagram showing characteristics of a sunlight lighting unit in the sunlight lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sunlight illuminating device 2 Sunlight lighting part 2a Lighting mirror 3 Convex mirror 4 Convex mirror 5 Reflector 5a Mirror surface 5b-f Small convex mirror 6 Reflector 6a Mirror surface 6b Small convex mirror 6c Circular dust passage hole 6d Square dust passage hole 6e Cross dust Passing hole L luminous flux

Claims (5)

[Claims] 1. A reflecting mirror for diffusing and reflecting light sent from a sunlight collecting section in a solar lighting device to irradiate a target place, wherein the mirror surface of the reflecting mirror has a diffuse reflecting surface. A light diffusing reflector for a solar illuminator, comprising: an assembly of at least two or more small reflecting mirrors. 2. The light diffuse reflecting mirror according to claim 1, wherein said small reflecting mirror is a convex mirror or a concave mirror. 3. The light diffusing reflector according to claim 1, wherein the outer shape of the small reflector is all the same polygonal shape. 4. The light diffusing reflector according to claim 1, wherein the outer shape of the small reflector is at least two or more different polygons. 5. A dust passing hole penetrating to a back surface of the reflecting mirror is provided at a corner of the small reflecting mirror.
Or the light diffusion reflecting mirror according to 4.