JPH04188101A - Natural lighting device - Google Patents

Abstract

PURPOSE:To effectively introduce incident light as diffracted light even in case when the incident angle is varied with time by arranging diffraction grating formed with a plurality of annular grating grooves on a natural lighting part. CONSTITUTION:Transmission type diffraction grating 13 having a plurality of annular grooves is arranged on a natural lighting part 12 for introducing light. The diffraction grating 13 formed with a plurality of annular grooves of concentric circles or ellipses on the transparent plate has a property to improve lighting efficiency as a whole, by dispersing the light not facing to the center but gathering much light facing to the center. Whichever direction the light source is, the diffracted light in the center direction is always available and as a whole much diffracted light is supplied to light introducing duct sides 17, 20. Hereby, even when the incident angle such as that of the solar ray is varied, effective lighting can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to improvements in daylighting devices used for lighting residential buildings, office buildings, and the like.

[Conventional technology] Traditionally, it was used as a daylighting device to guide outdoor light indoors.

There are known devices that are constructed from optical elements such as convex lenses for condensing light and are installed on rooftops, or that are installed by protruding through an opening in the roof or wall.

Furthermore, as a lighting device for this improved plan, Japanese Patent Application Laid-Open No. 64-655
As shown in Publication No. 04, there is also a diffraction grating installation type in which a transparent plate is provided with a hologram in which interference fringes are formed by a plane wave irradiated on one surface and a spherical wave irradiated from the end surface. do.

[Problems to be Solved by the Invention] However, the first conventional daylighting device requires a large light-receiving surface and is therefore large in size, and when transmitting through an optical fiber, an optical element such as a convex lens is required to condense the light. Requires a large number of.

In addition, when transmitting data using a daylight tact, a large-area reflector is required, making it expensive.In addition, it is necessary to provide a unique daylighting device, which reduces the effective space. There was a (challenge).

Furthermore, in the case of the improved proposal, the single diffraction grating is formed in parallel, so in the case of a light source that moves in three dimensions, such as sunlight, the direction of the diffracted light is not fixed, so in order to correspond to the movement of the sun, It is necessary to use a configuration in which multiple sheets are stacked. Therefore, not only is it impossible to make the lighting device thin, but also the attenuation of the amount of light is unavoidable, leading to poor lighting efficiency.
There was a problem.

An object of the present invention is to provide a daylighting device that solves the above-mentioned problems of conventional devices.

[Means for Solving the Problems] The present invention is a lighting device that guides light into a room, in which a transmission type diffraction grating having a plurality of annular grooves is arranged in a lighting section that takes in light.

[Operation] In the present invention, by arranging a transmission type diffraction grating having a plurality of annular light beams in the lighting section, even if sunlight enters from each direction, there will always be diffracted light toward the center, and a certain minute portion will be diffracted. Even if the lighting efficiency is low, a large amount of diffracted light is collected as a whole.

Furthermore, if one reflecting plate is provided, scattered light will be collected as much as possible, and there will be no attenuation of light.

[Example 2] Next, two lighting devices according to the present invention will be explained using FIGS. 1 to 5.

Figure 1 shows an example of a house using the present invention.

The building faces the south side, and there are 1.2N rooms on the first floor, 2 bathrooms, and 4 bathrooms on the north side. Basement basement 5. The roof 6 is equipped with a lighting device 2 having a configuration to be described later.

In this building, not only the basement 5 but also the bath 3 and kitchen 4 on the north side have no windows, so the surrounding wall 8 is made of a sufficiently thick insulation wall, while the FLM lighting in these rooms is Using the light from device E, light is supplied to each room 3°4.5 by means of light diffusing devices 9, 10.11.

In this case, the daylighting device 1if7 includes a light guide duct 20 that is fitted into the roof 6 or placed on the roof as shown in the figure. has been configured.

By the way, since the lighting device (1) of the present invention is characterized by the structure of the lighting section H, the details of the structure will be explained first with reference to FIGS. 2 to 5.

FIG. 2 is a schematic front view showing the characteristics of a normal diffraction grating 13a. When light P is incident on the grating 13a from above, +Qz Q2. +Q).

+Q+, ``Ql, Q2.'' +0th order diffracted light is generated.

In this case, with a diffraction grating having the same pattern, the efficiency decreases and the light becomes darker as the number of orders of diffracted light increases.

The lighting section upper unit of the present invention focuses on such properties of the diffraction grating, and also uses a single diffraction grating as shown in FIG. 3(A).
Its feature lies in the fact that it employs a diffraction grating 13 in which a plurality of concentric or elliptical annular grooves are formed in a single transparent plate.

For example, in the case of the diffraction grating 13 having grating grooves formed in concentric circles, the states of the diffracted lights shown in FIG. 2 are considered to be collected in concentric circles.

As shown in Figure 3 (B), which shows the A-A' cross section of Figure 3 (A), light other than the light directed toward the center is dispersed, but more light is directed toward the center, improving lighting efficiency as a whole. It can be seen that it has the property that it can be used.

FIGS. 4 and 5 show an embodiment of a lighting device using this diffraction grating 13. The downward side wall of the diffraction grating 13 has a cylindrical reflector 14 or two oppositely arranged side walls.
It is formed by two reflecting plates 14 and 14'' and is connected to a light guide duct 17 that guides one diffracted light.

Note that FIG. 5 is a perspective view of the lighting section 1 unit shown in cross section in FIG. 4.

Such a diffraction grating 13 is formed by coating the surface of a substrate made of a transparent material such as glass or film with photoresist (resin), and then etching concentric grating grooves by irradiating the photoresist (resin) from above.

In addition, the reason why the 1 reflecting plates 14 and 14° are arranged between the diffraction grating 13 and the light guiding duct 17 is that these reflecting plates 14 and 14' efficiently collect the scattered light toward the light guiding duct 17 as shown in Fig. 4. This is to ensure that.

Returning to FIG. 1, a light guide duct 20 for indoor supply is connected to the light guide duct 17 of the lighting section 12 configured as described above.

The light supplied to the light guiding duct 20 is guided to each room via the same duct 20.

Instead of using the light guiding ducts 1 to 20 to transport the light to each room, it is also possible to transport the light to each room using one type of optical fiber.

In this case, a Fresnel lens (not shown) may be disposed within the light guide duct 17, and thereafter light may be supplied to each room via an optical fiber.

In the above configuration, during the day the sun's rays are collected by the daylighting device and transported to each room on the north side at 3°4.5°.
Supplied.

By the way, in the embodiment of the present invention, as described above, the lighting section 1λ
The first to 50th orders of diffracted light are emitted from the plurality of grating grooves of the diffraction grating 13 arranged above, respectively, and each grating groove is formed concentrically, so in which direction is the light source directed? Even if there is, there will always be diffracted light toward the center,
As a whole, much diffracted light is supplied to the light guide duct 17.20 side.

In this case, the scattered light is efficiently condensed by the first reflecting plate 14.14 degrees and guided to the duct 17.20 side.

Therefore, regardless of the change in the angle of the incident light ray due to the movement of the sun, the sunlight is efficiently guided from above the lighting section to each of the rooms 1 to 5 via the duct 20.

Note that the present invention is not limited to the use as a lighting device that efficiently guides sunlight indoors as shown in the above embodiments.

It can also be applied to the field of devices that collect a large number of artificial lights installed on a ceiling surface into one place and send them to other places.

[Effects of the Invention] The present invention has excellent first-order effects because the diffraction grating in which a plurality of annular grating grooves are formed is disposed in the lighting section as described above.

■When the incident light comes from various directions, or when the angle of incidence changes over time like sunlight, the predetermined diffraction grating grooves can effectively diffract light toward the center. Incident light can be taken in.

Furthermore, if one reflecting plate is provided, scattered light can also be efficiently collected.

Moreover, in the case of the present invention, there is no need to provide a large-scale tracking mechanism like in the past, and the lighting section is a flat plate type made up of a single diffraction grating.

The daylighting device is thin and lightweight, and can be conveniently installed not only on the roof of a building but also on the wall.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal sectional side view showing the overall configuration of a lighting device to which the present invention is applied. FIGS. 2 to 5 are for explaining the present invention in detail. Among them, FIG. 2 is a front view for explaining the situation of incident light on a normal diffraction grating, and FIG. ) is a plan view showing the diffraction grating of the present invention, and FIG. 4 and 5 are a longitudinal sectional front view and a perspective view, respectively, showing an embodiment of the daylighting device of the present invention. D. Above the lighting device - Lighting section 13 Diffraction grating 14.14': Reflector plate Applicant: Sanyo Electric Co., Ltd. Representative: Patent attorney: Haruya Saito (1 person) Figure 1 7 Daylighting! ! Figure 2 P (incident light) Figure 3

Claims (1)

[Claims] 1. A lighting device that guides light into a room, characterized in that a transmission type diffraction grating having a plurality of annular grooves is arranged in a lighting section that takes in light.