JPH06110012A - Sunlight collecting device - Google Patents

Abstract

PURPOSE:To improve the effective transmission efficiency of a light collection part by decreasing the probability of a block of transmitted light by a nonoperation surface which is a defect of a flat plate type prism plate. CONSTITUTION:This device consists of the light collection part equipped with a prism plate 2 having plural triangular prism parts 2a1-2an of fine size on the reverse surface of a flat plate prism and a driving part which can rotates this prism plate 2 independently, and the angle alpha of inactive plane of each prism part satisfies 90 deg.<'<=thetaL. At the light collection part constituted by stacking plural prism plates 2, the tip parts of the nonoperation surfaces of the respective prism plates 2 are provided mutually at a specific deviation distance, which is determined preferably so that maximum transmissivity can be obtained. Then the angle alpha of inactive plane of the prism plates 2, preferably, satisfies 90 deg.<alpha<=thetaL and thetaH<=alpha<=thetaL. Here, when thetaL and thetaH are set to the projection angle of the prism plate 2 when the altitude of the sun is high.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a sunlight collecting device for guiding sunlight into a room.

[0002]

2. Description of the Related Art There are the following two conventional technologies. As a sunlight collecting device for efficiently guiding sunlight into the room, there was a sunlight collecting device that was used to track the sun moving in the sky occasionally or throughout the year, and to guide the sun's rays using lenses and mirrors. . Further, as a prior art, Japanese Patent Laid-Open No. 61-180
As disclosed in Japanese Patent No. 217, there has been proposed a device using a prism to make the device thinner and lighter.

[0003]

By the way, the conventional device has the following problems. In the former case, it was necessary to provide an expensive tracking mechanism consisting of a power source and a control mechanism in order to control the angle of the introduction window by tracking the movement of the sun. The latter uses two prisms to control the sun's rays, but especially when the sun's altitude is low, such as in winter, or when the angle of incidence is widened by combining prisms with a larger apex angle. As a result, almost no controlled light was obtained as designed, and therefore the effective transmittance was extremely low. An object of the present invention is to provide a sunlight collecting device that solves the above-mentioned problems (problems) of the conventional one.

[0004]

In order to solve the above-mentioned problems, the sunlight collecting device of the present invention is a prism plate in which a plurality of triangular prisms of minute size are formed on the lower surface of a flat plate prism. And a drive unit capable of independently rotating the prism plate. The non-working surface angle α of each prism unit satisfies 90 ° <α ≦ θ _L. However, θ _L is the exit angle of the prism plate when the solar altitude is low. In this case, a flat plate prism is provided with a plurality of prism plates on the bottom surface of which a plurality of triangular prisms each having a small size are stacked, and a light collecting unit configured by stacking the prism plates on top of each other. In a solar light collecting device including a rotatable driving unit, a deviation distance S is provided between the end portions of the non-acting surfaces of the respective prism plates, and the deviation distance S is determined so as to maximize the transmittance. It may be configured. However, 0 <S <the pitch of each prism. Further, in this case, it is desirable that the non-acting surface angle α of each prism portion of the above-mentioned one or a plurality of prism plates satisfy the following equations, respectively. 90 ° <α ≦ θ _L ··· θ _H ≦ α ≦ θ _L ·············································· defined that θ _H is the exit angle of the prism plate when the solar altitude is high.

[0005]

The prism plate which constitutes the daylighting device of the present invention rotates at an appropriate speed in response to the operation of the sun. During that time, the incident light ray is transmitted through the prism as follows. It has an effect. The non-operating surface angle α of the prism plate arranged on the uppermost surface is set to 9
When 0 ° <α ≤ θ _L , even when the sun rays are in a relatively low altitude time zone, when they enter the adjacent prism part after passing through the prism plate, the non-active surface of the adjacent prism part The probability of blocking is reduced, and the effective transmittance can be improved accordingly. When a plurality of prism plates are vertically stacked to form a daylighting section, even if the tip of the non-acting surface of each prism plate is provided with a gap of a predetermined distance S, the same effect as that is obtained. Occurs, and the effective transmittance of transmitted light is improved. In addition, if multiple prism plates are formed with the non-working surface angle as described above after the deviations described above are provided,
The above-mentioned actions are synergistically combined to significantly improve the effective transmittance.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to an improvement of a sunlight collecting device using a prism of the prior art. First, the examination and analysis which are the premise of the present invention will be described. The structure of the main part of the prism type of the prior art is shown in FIG. In the figure, reference numeral 1 denotes a prism plate, and a plurality of sawtooth-shaped prism portions 1a ₁ , 1a ₂ , 1 having non-acting surfaces (surfaces not to be optical surfaces) K perpendicular to the lower surface side of the flat plate prism.
a ₃ ... Is formed. Therefore, in this case, the non-working surface angle α was 90 °. Y is a drive shaft arranged perpendicularly to the center of the prism plate, and is a motor (not shown),
The prism plate 1 is rotated in response to the operation of the sun in response to a command from a microcomputer or the like. The prism plate 1 may be driven by other torque transmitting means such as transmitting the driving force of the motor to the outer peripheral portion of the prism plate 1. In the above configuration, as shown by the broken line when the sun is in a relatively high altitude made T _1, the transmitted light transmitted through the prism plate 1 in exit angle made theta _H, whereas, the T ₂ becomes relatively low solar When it is at a high altitude, it passes through the prism plate 1 at an emission angle of θ _{L as} shown by the chain double-dashed line. However, when the sun reaches a low altitude indicated by an altitude of T ₃ , the transmitted light is blocked by the non-acting surface K of the prism plate and reflected to the non-effective area. Thus, the following analysis results were obtained by analyzing the properties of the prior art prism plate. That is, it was found that the shape of the non-acting surface that constitutes the prism plate had a great influence. That is, if there is a non-acting surface of the next prism part in the direction of the light emitted from one prism part,
The emitted light is blocked and is not transmitted but reflected. Therefore, it cannot be put to practical use unless a prism plate in which not only the apex angle of the prism portion but also the shape of this non-active surface is designed is used. Further, since this system uses a plurality of prism plates, for example, it is necessary that the emitted light of the first sheet is efficiently incident on the optical surfaces of the second and subsequent sheets. For this purpose, the deviation S of each prism plate must be designed to an appropriate value. The present invention aims to satisfy these conditions, and will be described below with reference to the embodiments shown in the drawings.

First Embodiment: FIG. 1 shows a first embodiment of the present invention, in which a prism plate 2 has a plurality of triangular prism portions 2a of a small size on the lower surface of a flat plate prism.
₁ , 2a ₂ , 2a ₃ ... Are formed, and the drive shaft Y provided at the center of the prism plate 2 can be independently rotated by a motor (not shown). . The prism plate 2 may be driven by other torque transmitting means such as transmitting the driving force of the motor to the outer peripheral portion of the prism plate 1. This motor is adapted to rotate at an appropriate speed in response to the operation of the sun according to a command from a microcomputer (not shown).
The daylighting section including the prism plate 2 thus configured is arranged on the roof of the house shown in FIG. By the way, the prism plate 2 of the present invention is configured so that the non-acting surface angle α of the prism portion satisfies the following equations. That is, 90 ° <α ≦ θ _L ... θ _H ≦ α ≦ θ _L ... Of these two formulas, the formula is particularly important, and it is necessary to satisfy at least this condition 90 ° <α ≦ θ _L. Is. Here, θ _L is the exit angle when the sun altitude is low, θ _H is the exit angle when the sun altitude is high, and P shown in FIG. 1 is the pitch of the prism part. In the present invention, the prism plate 2 is thus
Shows the sun by the large value than 90 ° of that of the non-working face angle α of the prior art of each prism portion formed on the lower surface portion, in Figure 1 even for relatively lower altitude position T ₂ As described above, the structure is characterized in that the probability that the transmitted light of the sun rays is blocked by the non-acting surface is reduced.

Second Embodiment: FIG. 2 shows a second embodiment of the present invention. The one shown in the figure shows a structure in which a plurality of prism plates are normally stacked in the vertical direction in this type of lighting device, and in that case, the stacking method is devised. That is, in FIG. 2, 3 and 4 are the first and second prism plates disposed above and below, respectively, and the prism portions of the prism plates 3 and 4 are different from those of the prior art shown in FIG. Similarly, the non-working surface angle is formed at 90 °.
The first prism plate is provided with a displacement distance S so that the leading end of the non-acting surface of the first prism plate does not coincide with the leading end of the non-acting surface of the second prism portion facing the first prism plate. The feature of the configuration is that they are arranged in this way. When the pitch of each prism part is P,
It is desirable to select 0 <S <P so as to maximize the transmittance. In this case, the deviation distance S in the present embodiment
Is capable of maximizing the increase of the transmittance in this means by tracing the outgoing ray and determining the optimum deviation S under the above conditional expression. Although not shown, when arranging the third prism plate below the prism plate 4, the second prism plate and the third prism plate are also arranged with a displacement portion having a displacement distance S. . In FIG. 2, the pitch P of each prism plate 3 and 4 is 1 mm, the displacement S is 0.3 mm, the apex angles β ₁ and β ₂ are 45 °, and α _A and α _B are 90 °. Then, when the transmittance was tested, the characteristics shown by the alternate long and short dash line in Fig. 4 (b) were obtained. The transmittance in this case is that when each prism plate is rotated so that all emitted light is emitted in the vertical direction (optical axis direction). Comparing this with the characteristic diagram of the prior art shown in (a) when the shift distance S = 0, it can be seen that the transmittance is slightly improved. In this case, at the position of T ₄ where the altitude of the sun is relatively low, the emitted light may be blocked by the non-acting surface of the next prism part and not transmitted as shown in FIG. There was a problem to be solved.

Third Embodiment: FIG. 3 shows a third embodiment of the present invention. In this embodiment, in order to eliminate the problems of the second embodiment described above, the non-acting surface angle α is used as the uppermost surface (first sheet) of the prism plate 5 as in the prism plate 2 shown in FIG.
The structural feature is that _A satisfies the following conditional expression. That is, 90 ° <α _A ≦ θ _L ... θ _H ≦ α _A ≦ θ _L ... In this case, the expression is a more important conditional expression, and the expression is not always satisfied. good. The second
Similar to th is the prism plate 4 a second embodiment, the non-working surface angle alpha _B showed a case of 90 °, even above this alpha _B,
It is desirable that the formula be satisfied. As an experimental example of this embodiment, each pitch P = 1 mm, the deviation distance S = 0.
3 mm, α _A = 110 °, α _B = 90 °, β ₁ = β ₂ = 45
The solar light transmission condition for the case of ° was tested, and the results are shown in the solid line (c) in Fig. 4. Also in this embodiment,
The transmittance is obtained by rotating each prism plate so that all emitted light is emitted in the vertical direction (optical axis direction). As shown in FIG. 3C, the characteristics are improved as compared with both the prior art (a) and the second embodiment (b) described above, and the effective transmittance is remarkably improved particularly in the low solar altitude region. Was confirmed. It should be noted that FIG.
For the sake of simplicity, the characteristic diagrams in (c) are arranged with the data regarded as 0 in consideration of the fact that the reflected light reflected by the non-acting surface does not become effective light.

FIG. 5 shows an example of a house to which the daylighting device of the present invention is applied. In the figure, 10 is a house,
Reference numeral 11 denotes a daylighting device, which is provided with a daylighting part 12 composed of a prism plate (not shown) described in each of the above-mentioned embodiments of the present invention at a proper position on the roof 13 and is provided on the lower side of the daylighting part 12.
A window 14 and a condenser lens (not shown) and a light guide duct 15 communicating with the lens 14 are provided to guide light to the ceiling of the room 16. Although illustration is omitted, it goes without saying that sunlight can be guided to other rooms by means such as a light guide duct or an optical fiber.

[0011]

Since the present invention is constructed as described above,
It has the following excellent effects. The non-acting surface of the prism portion formed on the lower surface of the prism plate is configured to satisfy at least 90 ° <α ≦ θ _L so that the ratio of transmitted light blocked by the non-acting surface is reduced. In this case, the effective transmittance is increased and the lighting efficiency is improved. Also, in the case of the method of stacking multiple prism plates on the top and bottom, by stacking them with a gap between them,
To a lesser extent, a similar effect can be achieved. Furthermore, if a plurality of prism plates are formed into the above prism plate shape and the above-mentioned deviation distance is provided, the effective transmittance due to the synergistic action of each of the above actions, and thus,
The lighting efficiency can be significantly improved. Therefore, the present invention has extremely great applicability as a daylighting device for a house of a solar system.

[Brief description of drawings]

FIG. 1 is a front view of essential parts showing a first embodiment of the present invention.

FIG. 2 is a front view of a main portion showing a second embodiment of the present invention.

FIG. 3 is a front view of an essential part showing a third embodiment of the present invention.

FIG. 4 is an effective transmittance-solar altitude characteristic diagram for comparing characteristics of the prior art and the second and third embodiments of the present invention.

FIG. 5 is a front view of a house with a part cut away showing an application example of the daylighting device of the present invention.

FIG. 6 is a front view of a main part for explaining a configuration and a problem of a conventional prism plate.

[Explanation of symbols]

2 to 5: flat prism plate 2a _{1 to} 2a _n : prism part α _A , α _B : non-acting surface angle S: deviation distance

Claims (4)

[Claims] 1. A sun comprising a prism plate having a prism plate having a plurality of triangular prisms each having a minute size formed on a lower surface of a flat plate prism, and a drive unit capable of independently rotating the prism plate. In the light collecting device, the non-working surface angle α of each prism section satisfies 90 ° <α ≦ θ _L , and the sunlight collecting device is characterized. Where θ _L
Is the exit angle of the prism plate when the altitude of the sun is low. 2. A flat plate prism including a plurality of prism plates, each of which is formed by stacking a plurality of triangular prisms each having a minute size on a lower surface of the flat prism, and a prism unit for each of these prism plates. In a solar light collecting device including an independently rotatable drive unit, a tip of each non-acting surface of each prism plate is provided with a displacement distance S from each other, and the displacement distance S is determined so as to maximize the transmittance. A solar lighting device characterized in that However, 0 <S <the pitch of each prism. 3. The sunlight collecting device according to claim 1, wherein the non-acting surface angle α of each prism portion of the prism plate satisfies each of the following expressions. 90 ° <α ≤ θ _L ··· θ _H ≦ α ≦ θ _L ··· · where θ _L is the exit angle of the prism plate when the solar altitude is low and θ _H is the prism plate when the solar altitude is high Is the emission angle of. 4. The non-acting surface angle α of each prism portion of a plurality of prism plates satisfies the following equation, respectively:
The sunlight collecting device described. 90 ° <α ≤ θ _L ··· θ _H ≦ α ≦ θ _L ··· · where θ _L is the exit angle of the prism plate when the solar altitude is low and θ _H is the prism plate when the solar altitude is high Is the emission angle of.