JPH05295863A - Structure of top light - Google Patents

Abstract

PURPOSE:To provide inexpensive, easily manufacturable, trouble-free and fireproof top light which can keep a high efficiency of natural lighting at any time through the year. CONSTITUTION:A prism sheet 1 made up by arranging in parallel a number of prisms which extend in one direction is arranged to a top light so that the longitudinal side of the prisms approximately face a line connecting the east and the west. Sunlight 3 coming from the zenith toward the south and the north at a certain angle is refracted thereby and is guided downward straightly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skylight structure which is installed on a rooftop of a building or the like and illuminates indoors by shining sunlight.

[0002]

2. Description of the Related Art Since ancient times, skylights have been widely installed on roofs and roofs of various buildings and have been used as effective lighting devices.
This is because the structure is simple, the price is low, there are few failures, and the lighting efficiency is much higher than that of the side window. However, since the skylight itself does not have a light refracting function, the lighting conditions change significantly as the irradiation angle of the sun changes depending on the season and the time of day, but this cannot be maintained in good condition all year round. In the winter, when the sun was desired, the sun was tilted to the south, so there was a problem that the daylighting function was significantly reduced.

For this reason, various devices have been proposed for improving the efficiency of lighting. Looking at these contents, it is a solar tracking type. (JP-A-63-248003
No.) A type that uses various types of Fresnel lenses to focus light on a narrow area. (Actual No. 57-54101) A type that tries to capture light from a wide range of incident angles.
(Japanese Patent Laid-Open No. 3-5671) A type in which a large number of condenser lenses are arranged and any one of them is made to function to take in sunlight. (JP-A-3-58601
No.) is the main subject.

[0004]

In the above-mentioned conventional device ,, has a good lighting efficiency, but requires a sun tracking mechanism, and there is a problem that the device is complicated and expensive. Alternatively, it is considered that the light collection efficiency is low, and since any one of a large number of light collection lenses is used, the light collection efficiency is also considered to be low. Furthermore, there is a problem that sunlight is condensed by a lens and causes a fire.

In view of the above conventional problems, the present invention aims to realize a skylight structure capable of maintaining high daylighting performance throughout the time and year, simple, inexpensive, less prone to failure, and free from the risk of fire.

[0006]

In the skylight structure of the present invention, a prism sheet formed by arranging a plurality of prisms extending in one direction in parallel is installed in the skylight so that the longitudinal directions of the prisms are oriented substantially in the east-west direction. The feature is that the sunlight is obliquely incident at an angle from the zenith to the north-south direction and is guided almost straight down. In addition to the above, the prism sheet is rotatably attached about the east-west direction, and the incident angle and the exit angle of sunlight to the sheet in the north-south direction can be adjusted.

In addition to the above, a plurality of the prism sheets are arranged so that they can be used alone or in combination. In addition to that, it is characterized by having a rectangular light well that is long in the east-west direction. In addition to that, at least one of the prism sheet, the cover plate that covers the skylight, and the support plate that supports the prism sheet has a slight light scattering or mixing function. Also, in addition to that,
It is characterized in that the prism sheet is convexly shaped outward. By adopting this configuration, it is possible to obtain a skylight structure that can maintain high daylighting performance throughout the year and year, is simple, inexpensive, has few failures, and is free from the risk of fire.

[0008]

In the present invention, as shown in FIG. 1, the prism sheet 1 is used for the skylight, and the prisms 1 are arranged so that the longitudinal direction of the prism is oriented in the east-west direction and the sheet surface is inclined toward the south. It is possible to bend the sunlight 3 from right below, and to send a large amount of sunlight into the room.

The prism sheet used here is a linear Fresnel lens whose one surface has the same cross section as a whole, that is, a sheet-shaped article in which a large number of triangular prisms extending in one direction are arranged in parallel. Also, the day's trajectory of the sun as seen from the ground can be considered to lie roughly on one plane, so the bending angle θ (θ = 90 ° -south sun height in the south) corresponding to the inclination angle of that plane is one or a few. It can be generated with a single prism sheet.

Generally, the bending angle of a light beam on a prism sheet changes depending on the angle of incidence on the sheet.
For example, in an MMA (methylmethacrylate) single-sided flat prism with one-sided 45 degrees as shown in FIG. 4, as shown in the figure, when the incident angle is 5, 10, 20, 30 degrees, the bending in the sheet is performed. The corners are 43, 33, 2 respectively
It changes to 7,25 degrees. By utilizing this phenomenon, various bending angles can be realized even with a single prism sheet depending on the incident angle.

However, if an attempt is made to obtain an excessively large bending angle with a single prism sheet, the interface transmittance is extremely low as in the case of the exit surface (second surface) with an incident angle of 5 degrees as shown in FIG. Since it becomes inconvenient because the reflectance becomes large, it is necessary to carefully select the setting range of the incident angle and the outgoing angle.

[0012]

FIG. 2 shows the first embodiment of the present invention. In this embodiment, as shown in FIG. 2, a skylight part 6 having a transparent dome 5 is provided on the roof of a three-story building 4, and a light well 7 is provided downward from the skylight part 6, and the skylight part is also provided. Two prism sheets 1a and 1b are rotatably provided at 6 via bearing portions 8 and 8 '. Reference numeral 9 is a commonly used light diffusing plate.

The dome 5 is a connected large daylighting dome (trade name: Acrydome, FL130 type, handled by Ryoaki Co., Ltd.) and has a total length of about 30 m. The light well 7 has a rectangular shape with a north-south length of 1 m and an east-west length of 30 m. In addition, the prism sheet 1a,
1b is an M of 1.2 mm in length and 1 m in width, with two sheets having a thickness of 3 mm.
It is a single-sided flat or single-sided prism type formed by press-molding an MA (methyl methacrylate) plate (in addition to pressing, appropriate means such as casting, 2P method can be used), and one prism sheet 1a is shown in FIG. 30 as shown
One having a prism surface inclined at an angle, the other prism 1b
4 has a prism surface inclined at 45 degrees as shown in FIG. 4, both prisms have a pitch of 0.2 mm, and the non-lens surface has an inclination angle of 5 degrees. Each of these 30 sheets was arranged so that the longitudinal direction of the prism faces the east-west direction.

The present embodiment thus constructed is used as follows. To be exact, the position of the sun throughout the year in the Tokyo region can be known because it is published each year in the science chronology of the Tokyo Observatory, but it is almost similar to each year. From the same table, the trajectory of the sun in Tokyo (35 ° 45 ′ north latitude) was determined and shown in FIGS. 5 to 7. Figure 5 shows the winter solstice,
FIG. 6 shows the case of spring equinox or autumn equinox, and FIG. 7 shows the case of the summer solstice. In each figure, (a) shows the trajectory of the sun, and (b) shows the state of sunlight incident on the building during the south central sun.

8 to 12 show the results obtained by dividing the usage of the two prism sheets into five patterns on the premise of this solar altitude and performing casework corresponding to each season. The date corresponding to each figure is shown in the figure. If you set it to this position on this month and day, the sunlight will be sent directly downward. That is, if the operation is performed about once a month, sunlight is sent to directly below that day and gradually shifts until the next reset, but the inclination is about 10 degrees at the maximum.

It should be noted here that the second prism B receives light as a substantially vertical surface even when the sun altitude is low (that is, when the most light is desired), such as around January 20 or November 20 in FIG. As a result, the effective lighting area becomes large and a large amount of lighting becomes possible.

In this embodiment, the prism sheet is 2
Although a single sheet was used, it is possible to send sunlight more strictly downwards by further increasing the types and performing detailed operations. The prism sheet used is a flat type on one side, but a type having prisms on both sides can also be used.

Further, in this embodiment, the prism sheet is used in the north-south direction and the light well extending long in the east-west direction is used to obtain a good daylighting performance. Of course, the prism sheet is used in the east-west direction. You can also Further, in the case of a skylight with a large area, a huge prism sheet is expensive, so it is preferable to use several lens sheets in parallel or in series, or in combination of parallel and series.

The rotation control of the lens sheet may be performed manually, but a power system using a motor such as a solar cell or battery drive may be used.

When a conventional condenser lens, mirror or the like is used, there is a danger of fire due to overheating or exposure of a combustible object to high temperature light, so that special consideration must be given to the apparatus. In this embodiment, the light is not condensed at all, and the prism sheet is used to simply bend the optical path, so that the effect of safety is great.

Next, a second embodiment of the present invention will be described. This embodiment uses the same building as the first embodiment shown in FIG.
The same prism sheet having an inclination of 30 degrees is used as the prism sheets 1a and 1b, and the others are the same as those in the first embodiment. In this embodiment having such a configuration, the sunlight can be sent in a substantially downward direction all year round by selecting whether to let the sunlight pass through two prism sheets or one sheet and adjusting the incident angle.

FIG. 13 shows a case where the incident angle is further increased for the same 30-degree prism shown in FIG. 14 to 18 show the results of examining the arrangement of the prisms according to the sun altitude based on the relationship between the incident angle and the bending angle of the prism. From these figures, it can be seen that the sunlight can be sent in a substantially downward direction by operating once a month throughout the year.

According to this embodiment, there are two advantages over the previous embodiment. First, the two prism sheets have the same cross section with the prism having an inclination angle of 30 degrees, and it is sufficient to prepare one molding die, so that the initial investment can be saved. Secondly, the increase of the lighting area is more remarkable than that of the first embodiment, and a larger amount of sunlight can be guided to the indoor space.
The specific effect is that the lighting efficiency is 79% vs. 100% in the comparison between FIG. 8 and FIG. 14, 84% vs. 98% in the comparison between FIG. 9 and FIG. 82% Comparing Fig. 11 and Fig. 17, it is 83% vs. 100%, which is a characteristic that is particularly advantageous in the winter when sunlight is required.

Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is an example of a small and simple type for home use.
There is only one prism sheet, and in midsummer, the straight sheet is taken through without passing through the prism sheet. As shown in the figure, the skylight 6, the prism sheet 1 and the light well are installed in the two-story house 10. 7 and are provided. The light well 7 has a square cross section of 1 m both in the east and west and in the north and south, and the inner walls of the light well are all mirror-polished polished stainless steel plates. The skylight 6 is made of transparent methacrylic resin, and the prism sheet 1 is provided directly below it. The prism sheet 1 is a methacrylic resin 65 degree prism whose cross section and optical path diagram are shown in FIG.
cm × south 70 cm × thickness 3 mm, prism pitch 0.2 mm is rotatably attached so that the inclination angle can be set as shown in FIGS. 21 to 28. Although not shown, the operation portion has an inclination angle. It is displayed so that you can adjust it manually while looking at the scale.

The present embodiment constructed as described above is
Compared with the second embodiment, there remains a season when the light emitted from the prism sheet does not always go out directly below. Since there is no length in the east-west direction, it is difficult to secure the lighting efficiency when the sun tilts to the east or west and irradiates in the morning and evening. However, because the inner wall of the light well is a mirror surface of stainless steel and has excellent reflectivity, sunlight runs diagonally and there is little loss even if it is reflected many times, and the light reaches the first floor. To do. In other words, the high reflectivity of the light well can cover the above weakness to some extent. Also, with the same mechanism, the prism sheet is made slightly smaller than the size of the light well so that scattered light and straight light from the gap around the prism sheet enter the light well and are guided to the first floor.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The present embodiment is an example of a prism sheet that can be used in any of the buildings of the first to third embodiments, and the prism sheet is shaped in a convex shape to the outside, and any part of the prism sheet is used throughout the year. The structure is such that the sunlight incident on is emitted almost directly downward. The prism sheet 1 is a 65 degree prism made of methacrylic resin, 90 cm east and west.
The north-south area is 105 cm, the thickness is 3 mm, and the prism pitch is 0.2 mm. This prism sheet 1 is bent in the longitudinal direction (east-west direction) of the prism at intervals of 15 cm, and is shaped so as to be convex outward.
Form individual faces. Such a prism sheet 1 is provided with a transparent portion as shown in FIG. 29 and a skylight (not shown).
It is provided directly below.

In this embodiment having the above-mentioned configuration, FIG.
As shown in Fig. 9, for sunlight incident at various angles,
It is possible to emit the sunlight almost directly in any part of the prism sheet 1, and it is possible to emit the sunlight almost directly throughout the year without adjusting the incident angle and the emission angle of the sunlight in the north-south direction. It is a thing. In this embodiment, when the prism sheet 1 is outwardly convexly shaped, one prism sheet divided in the longitudinal direction may be joined, or sheets having different prism shapes may be joined. You may combine and join.

Further, in each of the above embodiments, a slight light scattering or mixing function is imparted to either the prism sheet 1 or the cover plate (dome 5) or the supporting plate made of an acrylic plate or a glass plate for supporting the prism sheet. (Mixing of a light diffusing agent or forming an uneven pattern on the surface)
As a result, it is possible to suppress spectral and rainbow phenomena. Further, the prism sheet used in the examples may collect light when curved in a direction perpendicular to the longitudinal direction of the prism,
Condensing can be prevented by making the prism surface slightly curved.

[0029]

According to the present invention, by setting the prism angle of the prism sheet and variously selecting the incident angle, a ray bending angle corresponding to the sun altitude can be given, and high daylighting performance can be secured throughout each year. The device structure can be simple, inexpensive, and have few failures. Since there is no light collection system, there is no risk of fire. It has a large effect in that it contributes to the improvement of the lighting performance of the skylight.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing a first embodiment of the present invention.

FIG. 3 is a diagram showing a prism sheet and its optical path used in the first embodiment of the present invention.

FIG. 4 is a diagram showing a prism sheet and its optical path used in the first embodiment of the present invention.

FIG. 5 is a diagram showing the trajectory of the sun at the winter solstice at the north latitude of 35 ° 45 ', (a) is the trajectory of the sun, and (b) is a diagram showing the state of sunlight incident on the building during the south south of the sun. ..

FIG. 6 is a diagram showing the trajectory of the sun at the equinox or autumn equinox at the north latitude of 35 ° 45 ′, in which (a) is the trajectory of the sun and (b) is
[Fig. 3] is a diagram showing a state of sunlight incident on a building at the time of south central sun.

FIG. 7 is a diagram showing the trajectory of the sun at the summer solstice at the north latitude of 35 ° 45 ′, (a) is the trajectory of the sun, and (b) is a diagram showing the state of incidence of sunlight on the building during the south south of the sun. ..

FIG. 8 is a view for explaining the action of the prism sheet of the first embodiment of the present invention.

FIG. 9 is a view for explaining the action of the prism sheet of the first embodiment of the present invention.

FIG. 10 is a view for explaining the action of the prism sheet of the first embodiment of the present invention.

FIG. 11 is a view for explaining the action of the prism sheet of the first embodiment of the present invention.

FIG. 12 is a view for explaining the action of the prism sheet of the first embodiment of the present invention.

FIG. 13 is a diagram showing a prism sheet used in a second embodiment of the present invention and its optical path.

FIG. 14 is a view for explaining the action of the prism sheet of the second embodiment of the present invention.

FIG. 15 is a view for explaining the action of the prism sheet of the second embodiment of the present invention.

FIG. 16 is a view for explaining the action of the prism sheet of the second embodiment of the present invention.

FIG. 17 is a diagram for explaining the operation of the prism sheet according to the second embodiment of the present invention.

FIG. 18 is a view for explaining the action of the prism sheet of the second embodiment of the present invention.

FIG. 19 is a diagram showing a third embodiment of the present invention.

FIG. 20 is a diagram showing a prism sheet and its optical path used in a third embodiment of the present invention.

FIG. 21 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 22 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 23 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 24 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 25 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 26 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 27 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 28 is a view for explaining the action of the prism sheet of the third embodiment of the present invention.

FIG. 29 is a diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

 1, 1a, 1b ... Prism sheet 2 ... Sun 3 ... Nikko 4 ... Building 5 ... Dome 6 ... Skylight part 7 ... Mitsuisho 10 ... Residence

Claims (6)

[Claims] 1. A prism sheet formed by arranging a plurality of prisms extending in one direction in parallel is arranged in a skylight so that the longitudinal directions of the prisms are oriented substantially in the east-west direction, and the prism sheet is inclined at an angle from the zenith to the north-south direction. The skylight structure is characterized by bending the sunlight that is incident from one direction to the direction directly below and guiding it. 2. The skylight structure according to claim 1, wherein the prism sheet is rotatably attached about an east-west direction, and an incident angle and an exit angle of sunlight to the sheet in the north-south direction can be adjusted. 3. The skylight structure according to claim 1, wherein a plurality of the prism sheets are arranged so that they can be used alone or in combination. 4. The skylight structure according to claim 1, wherein the skylight structure has a rectangular light well that is long in a substantially east-west direction. 5. The prism sheet, the cover plate for covering the skylight, and at least one of the support plates for supporting the prism sheet have a slight light scattering or mixing function, according to claim 1, 2, 3 or 4. Skylight structure. 6. The skylight structure according to claim 1, wherein the prism sheet is formed in a convex shape outward.