JP2000149627A - Light diffusing device for light duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusing device for a light duct which can effectively diffuse the incident light inside the light duct with little damping of the light. SOLUTION: In a light duct device for indoor lighting which takes the natural light into a light duct 4, a diffusing device which diffuses the incident natural light inside the light duct 4 is installed to uniformize the density of the light beam inside the light duct device. The diffusion device is, for example, constituted of a reflector 15 which is parallel with the longitudinal direction of the light duct 4 and cross section thereof is a semi-circle, and reflects the light in different direction depending on its incident position to uniformize the density of the light beam inside the light duct 4. A cross sectional shape of the reflecting surface of the diffusing device can be any shape such as a curve or approximate curve by a combination of straight lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light diffusion device used in a light duct for guiding light into a building through a light duct to illuminate the inside of the building.

[0002]

2. Description of the Related Art In recent years, attention has been paid to the necessity of environmental protection by energy saving and reduction of carbon dioxide emission. As one of means for responding to this demand, sunlight is constituted by a member having a high reflectance on the inner surface. 2. Description of the Related Art An optical duct device has been proposed which is introduced into a room through a duct and used as an illumination light source. This device does not convert energy into other energy such as electricity, but uses it as it is, so it has high energy use efficiency and can contribute to energy saving and reduction of carbon dioxide emissions.

FIGS. 11 and 12 are conceptual diagrams of an optical duct device to which the present invention is applied. FIG. 11 shows a horizontal optical duct device that takes in light from the south side wall of a building and uses it for lighting of offices and the like. FIG. 12 shows a vertical optical duct device having a portion for transmitting light downward when there is a height difference between a lighting position and a lighting position such as a basement or a roof. FIG.
(B) is a perspective view of a horizontal duct main body. 11 and 12, 1 is natural light (sunlight), 2 is a lighting opening, 3
Is a reflector, 4 is a light duct, 5 is a building wall, 6 is a room, 7
Is a glass cover, 8 is a light emitting port, and 9 is a rooftop or the ground. As shown in FIG. 11B, the light duct 4 has a rectangular cross section and an inner surface formed of a reflective surface. FIG. 11, FIG.
In the above, the sunlight 1 is taken directly into the duct 4 after being reflected from the daylighting port 2 or after being reflected by the reflector 3, carried to the irradiation position while repeating reflection on the inner surface, and irradiated from the light emission port 8. .

FIG. 13 is a view conceptually showing an optical path when sunlight enters a horizontal optical duct device. FIG.
13 (a) is a perspective view, FIG. 13 (b) is a view of an optical path in the light duct viewed from a direction A in FIG. 13 (a), and FIG. 13 (c) is a light path in the light duct in FIG. FIG. 13 is a view from the direction B.
FIG. 2D is a view of the optical path in the optical duct viewed from the direction C in FIG. As shown in the figure, light incident on the light duct device travels in the depth direction of the light duct while being repeatedly reflected on the reflection surface of the light duct.

[0005]

The light incident on the light duct device travels inside the light duct along the light path as shown in FIG. On the other hand, sunlight incident on the light duct is a parallel light beam whose irradiation direction changes greatly depending on time and season. Therefore, when a parallel light beam enters the light duct device, as shown in FIG. 14, a large density difference occurs in the light density inside the duct. If the light is directly emitted into the room through the light emitting port 8, problems such as a variation in the illuminance distribution at the indoor position and the appearance of a light and shade pattern on the light irradiation surface occur.
In order to solve such a problem, it is conceivable to attach means for diffusing light to the light duct device.

As a means for diffusing light, for example, there is a method of obtaining a diffusion effect by inserting a film 10 having a light diffusion function in the middle of an optical path as shown in FIG. However, this method does not provide a sufficient effect on the diffusion of sunlight having a strong directivity, and furthermore, a large attenuation of light of 20% or more occurs when the light passes through a film or a glass or a resin to which the film is attached. This leads to a reduction in the efficiency of the device. The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a light duct diffusion device that can reduce light attenuation and effectively diffuse light incident into the light duct. To provide.

[0007]

When sunlight enters the optical duct device from obliquely above the duct, a reflector parallel to the depth direction of the optical duct and inclined with respect to incident light is placed in the optical path. Thus, the light path in the light duct can be changed. Hereinafter, for convenience of explanation, the depth direction of the optical duct is defined as an X-axis direction, a direction on a horizontal plane including the X-axis and orthogonal to the X-axis is defined as a Y-axis direction, and a direction perpendicular to the XY plane is defined as a Z-axis direction. FIG. 1 is a diagram showing an optical path when the reflecting plate 12 parallel to the X axis and inclined with respect to the XY plane is placed as described above, and FIG. 1 shows that the light obliquely incident on the YZ plane is reflected by the reflecting plate. 12 shows an optical path when the light is reflected at 12, and a solid line shows an optical path when the reflective plate 12 is placed, and a dotted line shows an optical path when the reflective plate 12 is not placed. FIG. 1A is a perspective view, and FIG.
Is a view of the optical path in the light duct viewed from the X-axis direction, FIG.
Is a view of the optical path in the light duct viewed from the Y-axis direction, FIG.
FIG. 3 is a view of an optical path in an optical duct viewed from a Z-axis direction.

As shown in FIG. 1, the light incident from obliquely above the light duct and reflected by the reflector 12 repeats reflection on the right side surface R → the upper surface U → the left side surface L → the right side surface R of the light duct. Proceed in the X-axis direction of the duct. That is, by arranging the reflection plate 12, the optical path 1 'indicated by the dotted line can be changed to the optical path 1 indicated by the solid line. Here, as shown in FIG. 2A, when the reflecting surface of the reflecting member 12 is rotated about the X axis, the reflected light of the light incident on the light duct at the incident angle α is shown in FIG. As shown in ()), the angle between the point 14 and the X axis moves on the conical surface of α. When the reflected light is projected onto the YZ plane, the direction of the reflected light changes to a 360-degree full-circumferential direction as shown in FIG. 3C, and the parallel light reflected on the light duct is reflected according to the rotation angle of the reflecting surface. The direction can be changed (here, dispersing light in different directions is referred to as diffusion).

That is, a reflecting surface in which the inclination of the sectional straight line of the reflecting surface or the inclination of the tangential line of the sectional curve which varies in the plane perpendicular to the X axis differs depending on the light reflection point has a function of diffusing light inside the light duct. Have. For example, as shown in FIG. 3A, when a reflecting material 15 having a curved cross-sectional shape that appears on a plane parallel to the X-axis direction and perpendicular to the X-axis is installed in the optical duct, the drawing in FIG. As shown, light 1 is reflected 15
Since the light path is the same as that when the light is reflected by the plane 16 that is in contact with the light, even if parallel light is incident, the light path of the reflected light can be changed in a different direction depending on the position of the reflection, and as described with reference to FIG. Can be obtained. That is, in this case, one reflector 15 has a function as the diffusion device 20.

FIG. 4 is a diagram showing a state of diffusion of incident light by the reflector 15 having a curved cross-sectional shape shown in FIG.
The solid line (1 in the figure) shows the optical path when the reflective material 15 is provided, and the dotted line (1 'in the figure) shows the original optical path when the reflective material 15 is not provided. FIG. 2A is a diagram of the optical path in the light duct viewed from the X-axis direction, FIG. 2B is a diagram of the optical path viewed from the Y-axis direction, and FIG. is there. As shown in the figure, when parallel light is incident from obliquely above the light duct (in the figure, it is assumed that a row of parallel lights is incident in the Y-axis direction), the parallel light enters the semicircular reflector 15. The optical path of the reflected light varies depending on the incident position, and the density of the light in the optical duct becomes uniform. Therefore, as shown in FIG. 14, the light density inside the duct does not vary greatly.

As shown in FIG. 6 described later, similar effects can be obtained even if the reflecting material 15 has a shape similar to a curve formed by a set of straight lines whose mutual angles form an obtuse angle. In addition to the semicircular shape as described above, similar effects can be obtained even if the cross-sectional shape is a set of curves or a set of straight lines as shown in FIG. By providing one or more diffusing devices having the above-described configuration at the lighting port side, the end side, or an appropriate location of the light duct, the light density in the light duct can be made uniform, and the illuminance distribution in the room can be made uniform. Thus, the problem that a light and shade pattern is formed on the light irradiation surface can be solved.

The present invention has been made in view of the above points, and solves the above-mentioned problems as follows. (1) A light duct device for use in a light duct device that uses natural light for illumination and for diffusing parallel light introduced into the light duct device inside the light duct, wherein the light diffusing device is a light duct It is composed of a reflective material that is parallel to the longitudinal direction and has a reflecting surface that reflects the incident light in different directions according to the incident position of the light. Uniform density. (2) A light diffusion device for a light duct, which is used in a light duct device that uses natural light for illumination and diffuses parallel light introduced into the light duct device inside the light duct. A cross-sectional shape of the reflection surface, which is formed of a reflection material having a reflection surface parallel to the longitudinal direction and appears on a plane perpendicular to the depth direction of the light duct, is formed by a curve, or a straight line and a straight line in which the angle between adjacent lines forms an obtuse angle. , Straight lines and curves,
Alternatively, the shape approximates to a curve composed of a combination of curves. Further, the present invention can also be configured as follows. (3) The light diffusing device is formed of a reflecting material having a reflecting surface parallel to the longitudinal direction of the light duct, and the cross-sectional shape of the reflecting surface appearing on a plane perpendicular to the depth direction of the light duct has two or more curves. And a combination of (4) The light diffusing device is formed of a reflecting material having a reflecting surface parallel to the longitudinal direction of the light duct, and the sectional shape of the reflecting surface appearing on a plane perpendicular to the depth direction of the light duct is two or more spaced apart. And a combination of the curves.

[0013]

FIG. 5 is a diagram showing an example of the configuration of a diffusion device according to an embodiment of the present invention. FIG. 5 shows a diffusion device using a reflective material formed in an arc shape. FIG. 5A shows a semicircular reflector used in the present embodiment, and two aluminum mirrors 17 (for example, a 0.5 mm thick aluminum mirror mill made by Alanod, Germany). To
As shown in the figure, the duct is bent into a semicircle having the same diameter as the width of the bottom surface of the duct, and bonded with an epoxy-based adhesive so that both surfaces are mirror surfaces. Two sets of the reflecting materials formed as described above are prepared [15a, 15c in FIGS.
b], the two are fixed back-to-back by riveting through fixing holes 17a provided in the reflectors 15a, 15b, and assembled as shown in FIG. 5 (b). It is installed in the light duct as shown in Fig. By installing the diffusing device 21 configured as described above in the light duct, the parallel light incident on the light duct is diffused as shown in FIGS. 3 and 4, and the light density in the light duct is made uniform. Can be

FIG. 6 is a view showing another example of the structure of the diffusing device. FIG. 6 shows a diffusing device using a reflecting member formed in a polygonal shape. In FIG. 6, the reflecting material 18 is a reflecting material obtained by bonding two aluminum materials so that the mirror surface is on the outside as described above. The reflecting material 18 has a polygonal cross section as shown in FIG. Shape (shape approximated to a curve consisting of a set of straight lines whose mutual angles form an obtuse angle).
By fixing the reflecting member 18 as described above with the back thereof as shown in FIG.
And a diffusion device similar to that described above. Although FIG. 6 shows an example in which adjacent lines are a combination of straight lines and straight lines, the adjacent lines may be combinations of straight lines and curved lines, or curved lines and curved lines.

The cross-sectional shape of the reflector does not necessarily have to be point-symmetric with respect to the central axis of the light duct or line-symmetric with respect to a straight line passing through the central axis. For example, when the incident direction of the light to the light duct is deviated, the light can be efficiently diffused by using a diffusing device having a sectional shape that is not line-symmetric or point-symmetric. FIG.
Shows a cross-sectional shape of the diffusion device 22 suitable for the case where light enters the light duct 4 from the upper right diagonal direction, and the figure shows the light duct viewed from the X-axis direction. When the light is obliquely incident from the upper right of the light duct 4, as shown in the figure, two reflectors 19a and 19b having a quarter-circular cross section are used to form two reflectors 19a and 19b. Reflector 19a, 1
9b are arranged concentrically and arranged in the diagonal direction of the light duct, and are installed in the light duct 4 so that the reflecting surfaces of the reflectors 19a and 19b are parallel to the longitudinal direction of the light duct device. Thereby, light incident from the upper right can be diffused efficiently.

FIG. 8 is a diagram showing an example of the configuration of a diffusion device.
The diffuser can be configured as follows. (1) As shown in FIG. 8 (a), a reflector having a semicircular cross section is used in a light duct so that the reflection surface of the reflector is parallel to the longitudinal direction of the light duct device (see the above figure). 3 is the same as the configuration shown in FIG. (2) As shown in FIG. 8B, reflectors having a semicircular cross section are connected back to back, and the reflectors are installed in the light duct such that the reflection surface of the reflector is parallel to the longitudinal direction of the light duct device. (The same as the configuration shown in FIG. 5). (3) As shown in FIG. 8 (c), four reflection members having an arc-shaped cross section formed into a quarter circle are used, and four reflection members are formed so that the cross section has a shape approximate to a rhombus. Connect the ends of the material arc. And it installs in a light duct so that the reflection surface of a reflection material may become parallel to the longitudinal direction of a light duct apparatus.

(4) As shown in FIG. 8 (d), the reflector is formed in a cylindrical shape, and is installed in the light duct so that the reflection surface of the reflector is parallel to the longitudinal direction of the light duct device. . (5) As shown in FIG. 8E, an optical duct is formed by using two arc-shaped reflectors having a cross section formed into a quarter circle and aligning the two reflectors concentrically. 7 is installed in the light duct 4 such that the reflecting surface of the reflecting material is parallel to the longitudinal direction of the light duct device (see FIG. 7 at 90).
° rotated shape). (6) As shown in FIG. 8 (f), a plurality of reflectors bent in a U-shape are brought into contact with each other at their both ends, the intermediate portions are separated from each other, and a plurality of reflectors are superposed. It is installed in the light duct 4 so as to be parallel to the longitudinal direction. (7) As shown in FIG. 8 (g), a reflector having a parabolic cross section is used, and the reflector is installed in the light duct so that the reflection surface is parallel to the longitudinal direction of the light duct device.

(8) As shown in FIG. 8 (h), one end of a plate-like second reflector is attached around the first cylindrical reflector, and the other end of the second reflector is attached. Is mounted in the light duct 4 so that the reflecting surfaces of the first and second reflecting members are parallel to the longitudinal direction of the light duct device. (9) As shown in FIG. 8 (i), a corrugated reflecting material is arranged in a diagonal direction of the light duct, and the light duct 4 is arranged such that the reflecting surface of the reflecting material is parallel to the longitudinal direction of the light duct device. Install inside. (10) As shown in FIG. 8 (j), the two reflectors having a semicircular cross section are separated from each other, and the two reflectors are arranged in the horizontal direction with the tops of the arcs facing each other. It is installed in the light duct so that the reflecting surface of the reflecting material is parallel to the longitudinal direction of the light duct device.

(11) As shown in FIG. 8 (k), two arc-shaped reflectors each having a substantially 略 circular cross section are separated from each other with the tops of the arcs facing each other. The reflector is arranged in the diagonal direction of the light duct, and is installed in the light duct such that the reflection surface of the reflector is parallel to the longitudinal direction of the light duct device. (12) As shown in FIG. 8 (l), the ends of two reflectors having a semicircular cross section are connected such that the semicircular convex portions are on the upper side and the lower side, and the reflective surface is formed. Is formed in the light duct so that the reflection surface of the reflection material is parallel to the longitudinal direction of the light duct device. (13) As shown in FIG. 8 (m), the tops of two reflectors each having a parabolic cross section are connected to each other, and the two reflectors are arranged in the horizontal direction. Is installed in the light duct so that is parallel to the longitudinal direction of the light duct device.
The diffusion device shown in FIGS. 8A to 8M may be used after being rotated by an arbitrary angle around the X axis of the light duct.

By configuring the diffusing device as described above, the parallel light incident on the light duct can be effectively diffused based on the principle described with reference to FIGS. When a higher diffusion effect is required, a plurality of diffusion devices having different shapes may be used in combination as shown in FIG. FIG. 9 shows the diffusion device 2 shown in FIG.
5 shows an example in which the diffusion device 21 shown in FIG. 5 is combined. However, the diffusion devices having various shapes described above can be appropriately combined. Further, the various diffusion devices shown in FIG. 8 may be installed at a plurality of locations, such as being installed on the daylighting port 2 side and the duct end side as shown in FIG. By providing the diffuser at the end of the light duct, light reflected at the end can be re-diffused and utilized.

When the length of the diffusion device in the X direction increases, the number of times of light reflection increases, and the attenuation increases. Therefore, the length of the diffusion device in the X direction needs to be set appropriately. Further, the shape of the curve of the diffusion device may be an arc or a circle, a parabola, or another curve such as an elliptic curve as described above. Further, the cross section of the diffusion device having various shapes shown in FIG. 8 may be shaped similar to a curve formed by a combination of straight lines in which the angles of adjacent lines form an obtuse angle as shown in FIG.

[0022]

As described above, according to the present invention, since the diffusion device for diffusing light is provided in the light duct device, the density of the light in the light duct can be made uniform, and the indoor light duct can be made uniform. The illuminance distribution can be made uniform, and the problem that a light and shade pattern is formed on the light irradiation surface can be solved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in an optical path when a reflecting material is inserted in the middle of the optical path.

FIG. 2 is a diagram illustrating a change in an optical path when a reflecting member provided in the middle of the optical path is rotated.

FIG. 3 is a diagram illustrating a configuration example of a diffusion device using a reflective material having a curved surface.

FIG. 4 is a diagram showing a state of diffusion of incident light by a reflecting material.

FIG. 5 is a diagram illustrating a configuration example of a diffusion device according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration example of a reflector having a curved surface approximated by a straight line.

FIG. 7 is a diagram showing an example of a cross-sectional shape of a diffusion device suitable for a case where light enters a light duct from an oblique direction from the upper right.

FIG. 8 is a diagram illustrating a configuration example of a cross-sectional shape of a diffusion device.

FIG. 9 is a diagram showing a case where a plurality of diffusion devices having different shapes are used in combination.

FIG. 10 is a view showing an example of the installation position of the diffusion device in the light duct.

FIG. 11 is a conceptual diagram of a horizontal duct type light duct device.

FIG. 12 is a conceptual diagram of a vertical duct type optical duct device.

FIG. 13 is a diagram illustrating an example of an optical path of light incident on an optical duct.

FIG. 14 is a diagram illustrating a density difference of light generated when parallel light enters the duct.

FIG. 15 is a diagram illustrating a configuration example of a diffusion device using a diffusion film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Natural light (sunlight) 2 Lighting opening 3 Reflecting material 4 Duct 5 Building wall surface 6 Room 7 Glass cover 8 Light emitting opening 9 Rooftop or ground 10 Film 12 Reflecting plate 15 Reflecting material 17 Mirror surface material 18 Reflecting material 19a, 19b Reflecting material 20 , 21,22,23 Diffusing device

Claims (2)

[Claims] 1. A light diffusion device for a light duct, which is used in a light duct device that uses natural light for illumination and diffuses parallel light introduced into the light duct device inside the light duct, wherein the light diffusion device is A light duct that is parallel to the longitudinal direction of the light duct and has a reflecting surface shaped to reflect the incident light in different directions according to the incident position of the light. A light diffusion device for a light duct, characterized in that the density of light in the inside is made substantially uniform. 2. A light diffusion device for a light duct, which is used in a light duct device using natural light for illumination and diffuses parallel light introduced into the light duct device inside the light duct, wherein the light diffusion device is The light duct is formed of a reflective material having a reflective surface parallel to the longitudinal direction of the light duct, and the cross-sectional shape of the reflective surface appearing on a plane perpendicular to the depth direction of the light duct is a curve, or an angle of an adjacent line is an obtuse angle. A light diffusion device for a light duct, characterized by having a shape approximating a straight line and a straight line, a straight line and a curve, or a curve formed by a combination of a curve and a curve.