JP2003161814A - Optical path changing device and optical guide device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical path changing device in which almost no loss of light whenever an advance direction of light is changed and of which facility cost is lower when being compared with an optical fiber, and an optical guide device using the same. <P>SOLUTION: The optical path changing device is provided with an incident face part 2a provided with a plane, constituting a part of a surface 2 and arranged in the condition of incident light from a prescribed direction being able to reach by holding an angle of a critical angle or greater with respect to atmosphere to a rear face 3 comprising the plane after incidence, and a radiation face part 2b comprising a plane, constituting a part of the surface 2 and arranged in the condition of the light being totally reflected on the rear face 3, after incidence from the incident face part being able to radiating to the outside at a target angle to the advance direction before incidence from the incident face part 2a. The light is made incident from the incident face part 2a in the prescribed direction, and after it is totally reflected on the rear face 3, it is radiated from the radiation face part 2b to the outside. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical path changing device for changing the traveling direction of light and a light guiding device for guiding light using the same.

[0002]

2. Description of the Related Art Conventionally, it is possible to change the traveling direction of light by reflecting the light with a reflector such as a mirror. According to the reflector, the light can be guided to a target position along a path bent in multiple stages. For example, sunlight can be guided along a multi-stage bent duct installed in a building, so that indoor lighting can be performed. In addition, it is possible to guide light along a path that is bent in multiple stages by using an optical fiber.

[0003]

However, according to the reflector such as the mirror, most of the energy of the light proceeds to the inside of the reflector, so that the light is attenuated each time the reflection is repeated. Therefore, there are cases where a sufficient amount of light cannot be secured at the target location. Moreover, since the optical fiber has almost no attenuation of light as compared with a reflection plate such as a mirror, a sufficient amount of light can be secured at a target location, but the amount of light that can be guided by one optical fiber is small, and it is suitable for indoor lighting. In order to secure the required amount of light, high equipment costs were required.

Therefore, according to the present invention, there is almost no loss of light each time the traveling direction of light is changed, and the equipment cost is much lower than that of an optical fiber, and a light guide device using the same. The challenge is to provide.

[0005]

According to a first aspect of the present invention, there is provided an optical path changing device which comprises a flat surface and constitutes a part of the front surface, and after incident light from a predetermined direction is incident, a critical angle with respect to the atmosphere toward the rear surface of the flat surface. The incident surface portion arranged under the conditions that can be reached while maintaining the above angle, and a part of the front surface that is composed of a flat surface, and the light totally reflected on the back surface after being incident from the incident surface portion travels before the incidence from the incident surface portion. And a radiation surface portion arranged under the condition that radiation can be performed to the outside at a desired angle with respect to the direction.

Here, the angle formed by the traveling direction of the light before entering the incident surface portion and the traveling direction of the light after being emitted from the emission surface portion is set in the range of, for example, about 45 ° to 90 ° according to the purpose. Is practical, but is not limited to these values.

According to the optical path changing device of the invention of claim 1,
Light incident from a predetermined direction on the front incident surface reaches the back surface at an angle equal to or greater than the critical angle to the atmosphere,
Totally reflected on the back side. The light totally reflected on the back surface is then radiated from the radiation surface portion to the outside at a desired angle. Therefore, the traveling direction of light can be changed by total reflection.

The optical path changing device according to the invention of claim 2 is
The optical path changing device according to claim 1, wherein an angle formed by a traveling direction of the light before being incident on the incident surface portion and a traveling direction of the light after being emitted from the emission surface portion is a right angle. Therefore, in addition to the operation of the optical path changing device according to the first aspect, the traveling direction of light can be changed to a right angle.

The optical path changing device according to the invention of claim 3 is
The optical path changing device according to claim 2, wherein the incident surface portion and the emission surface portion are orthogonal to each other, and are made of a transparent material having a refractive index of which the critical angle to the atmosphere is less than 45 °, and the incident surface portion and the emission surface with respect to the back surface. Any angle of the surface portion forms 45 °. Here, the transparent material having a refractive index of which the critical angle to the atmosphere is less than 45 ° is, for example, methacryl having a refractive index of 1.49.

According to the optical path changing device of the third aspect of the present invention, when light is made to enter at an incident angle orthogonal to the incident surface portion, all of the light fluxes incident on the surface of the optical path changing device will have an optical path somewhere in the incident surface portion. The light travels inside the changing device without refraction, is totally reflected on the back surface of the optical path changing device at an incident angle of 45 °, and is emitted from the emission surface portion to the outside without refraction. That is, in addition to the effect of the optical path changing device according to the second aspect, the direction of light changing direction is maintained at a right angle in the entire region where the light is incident. Further, since the incident surface portion and the emission surface portion are completely symmetrical, it is possible to use the incident surface portion and the emission surface portion by replacing them.

According to a fourth aspect of the present invention, there is provided a light guide device in which the optical path changing device according to any one of the first to third aspects is arranged at a bending position of a path for guiding light in accordance with the bending angle. Here, the number of bent positions of the light guiding path of one light guiding device is not limited, and the number of optical path changing devices arranged at the bent position of the light guiding route is not limited.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a partial end view showing an optical path changing device according to a first embodiment of the present invention, and FIG. 2 is an explanatory view showing how the traveling direction of light is changed by the optical path changing device according to the first embodiment of the present invention. .

As shown in FIG. 1, the optical path changing device 1 according to the first embodiment of the present invention is made of a transparent material having a refractive index of which the critical angle to the atmosphere is less than 45 °, and has a substantially flat plate shape as a whole. There is. For example, a transparent material having a refractive index of less than 45 ° with respect to the atmosphere is methacrylic having a refractive index of 1.49, and methacrylic has a light transmittance and a refractive index higher than those of other transparent synthetic resin materials. The rate is high. The back surface 3 of the optical path changing device 1 is a flat surface, and the front surface 2 of the optical path changing device 1 is an incident surface portion 2a that makes an angle of 45 ° with the back surface 3 and an angle of 45 ° with the back surface 3 that is orthogonal to this. And a radiation surface portion 2b that forms The surface 2 of the optical path changing device 1 has a plurality of incident surface portions 2a and emission surface portions 2b alternately and adjacently arranged, and has a shape in which peaks and valleys are alternately repeated when viewed from the end face. The incident surface portion 2a and the emission surface portion 2b which are adjacent to each other have a symmetrical shape with respect to a plane that passes through the intersection line and is orthogonal to the back surface 3, and thus can be replaced with each other.

According to the optical path changing device 1 of the first embodiment of the present invention configured as described above, as shown by an arrow 4 in FIG. 2, light is made incident on the incident surface portion 2a at an incident angle orthogonal to each other. Then, as shown by an arrow 5, the light travels without refraction, and as shown by an arrow 6, 4 on the back surface 3 of the optical path changing device 1.
The light is totally reflected at an incident angle of 5 ° and is emitted from the emission surface portion 2b to the outside without refraction as shown by an arrow 7.

Next, a second embodiment of the present invention will be described. FIG. 3 is an explanatory view showing how the traveling direction of light is changed by the optical path changing device according to the second embodiment of the present invention. In the figure, the same reference numerals and symbols as those of the first embodiment are the same as or equivalent to those of the first embodiment.

As shown in FIG. 3, the optical path changing device 11 according to the second embodiment of the present invention has a critical angle with respect to the atmosphere such as methacryl of less than 45 °, like the optical path changing device 1 according to the first embodiment. It is made of a transparent material with a refractive index of, and is generally flat. The optical path changing device 11 is common to the optical path changing device 1 of the first embodiment in that the back surface 3 is a plane and the incident surface portion 2a and the emission surface portion 2b, which are the planes forming the surface 2 of the optical path changing device 11, are orthogonal to each other. is doing.
The incident surface portion 2a and the emission surface portion 2 of the optical path changing device 11
b is 45 with respect to the back surface 3 unlike the case of the first embodiment.
Not at an angle of °.

The angle relationship between the incident surface portion 2a and the radiation surface portion 2b with respect to the back surface 3 is as shown by the arrow 12.
Light incident on a at an incident angle of 30 ° is refracted, and then the arrow 13
As shown by the arrow, the light reaches the back surface 3 at an incident angle θ that is equal to or greater than the critical angle with respect to the atmosphere, and after being totally reflected by the back surface 3 as shown by an arrow 14, it reaches the radiation surface portion 2b in a direction orthogonal to the arrow. As shown in FIG. 15, the relationship is such that the light is emitted to the outside and the change in the traveling direction of the light after being emitted from the emitting surface portion 2b is 60 ° with respect to the traveling direction of the light before being incident on the incident surface portion 2a. .

Focusing on the common points of the optical path changing device 1 of the first embodiment of the present invention and the optical path changing device 11 of the second embodiment, both are made of a flat surface and constitute a part of the surface 2. An incident surface portion 2a arranged under the condition that incident light from a predetermined direction can reach the back surface 3 formed of a flat surface after being incident at an angle equal to or more than the critical angle with respect to the atmosphere.
The light which is made of a flat surface and constitutes a part of the front surface 2 and which is totally reflected by the back surface 3 after being incident from the incident surface portion 2a can be emitted to the outside at a desired angle with respect to the traveling direction before the incident from the incident surface portion 2a. The radiation surface portion 2b arranged under the condition.

Therefore, according to the optical path changing device 1 of the first embodiment of the present invention and the optical path changing device 11 of the second embodiment, the light incident from the incident surface portion 2a of the front surface 2 in a predetermined direction is incident on the rear surface 3 with respect to the atmosphere. Since the light arrives while maintaining an angle equal to or more than the critical angle, the back surface 3 is totally reflected. The light totally reflected by the back surface 3 is then emitted to the outside from the emission surface portion 2b at a target angle. That is, since the traveling direction of the light can be changed by total reflection, the traveling direction of the light can be changed with almost no attenuation of the light amount. Moreover, the equipment cost is significantly lower than that of the optical fiber.

In the optical path changing device 1 of the first embodiment of the present invention and the optical path changing device 11 of the second embodiment, the traveling direction of the light before entering the incident surface 2a and the light after the emission from the emitting surface 2b. The angle formed by the traveling direction is 90 °, 60 °
However, in practice, for example, 45 ° to 9 depending on the purpose.
It may be set arbitrarily within a range of about 0 °. However,
It is not limited to these values. As described above, even if the angle formed by the traveling direction of light before entering the incident surface 2a and the traveling direction of light after being emitted from the emitting surface 2b is changed, the light travels with almost no attenuation of the light amount. You can change direction.

Further, in the optical path changing device 1 according to the first embodiment of the present invention, the angle formed by the traveling direction of the light before entering the incident surface portion 2a and the traveling direction of the light after being emitted from the emitting surface portion 2b is a right angle. Is what is. Therefore, the traveling direction of light can be changed to a right angle, and it is possible to change the direction of light that is expected to be most frequently generated when light such as sunlight is propagated inside a building to a right angle.

Further, the optical path changing device 1 according to the first embodiment of the present invention is made of a transparent material having a refractive index whose critical angle with respect to the atmosphere is less than 45 °, and the incident surface portion 2a and the emission surface portion 2b are orthogonal to each other. At the same time, the angles of both the incident surface portion 2a and the radiation surface portion 2b with respect to the back surface 3 are 4
It forms 5 °.

Therefore, according to the optical path changing device 1 of the first embodiment of the present invention, when light is incident at an incident angle orthogonal to the incident surface portion 2a, all the light fluxes incident on the surface 2 of the optical path changing device are incident. The light enters the inside of the optical path changing device 1 without refraction at any part of the surface portion 2a, is totally reflected by the back surface 3 of the optical path changing device 1 at an incident angle of 45 °, and does not refract outside from the emission surface portion 2b. Is emitted. That is, since the light diversion direction is maintained at a right angle in the entire area where the light is incident, the loss before and after the light diversion can be further reduced. Further, since the incident surface portion 2a and the emitting surface portion 2b are completely symmetrical and the incident surface portion 2a and the emitting surface portion 2b can be used by being replaced, it is easy to use without mistaking the orientation during use.

Next, a third embodiment of the present invention will be described. FIG. 4 is a partial end view showing an optical path changing device according to a third embodiment of the present invention, and FIG. 5 is an explanatory view showing how the traveling direction of light is changed by the optical path changing device according to the third embodiment of the present invention. . In the figure, the same reference numerals and symbols as those in the second embodiment are the same as or corresponding to those in the second embodiment.

As shown in FIG. 4, the optical path changing device 21 according to the third embodiment of the present invention is different from the optical path changing device 11 according to the second embodiment in that the corner portion where the incident surface portion 2a and the emitting surface portion 2b intersect is cut out. It is a part 22. According to the optical path changing device 21 of the third embodiment of the present invention, as shown by the arrow in FIG. 5, it is possible to change the traveling direction of light, and the same effect as that of the second embodiment is obtained. . In addition, the notch 22 reduces the overall weight and reduces the material cost. Further, in detail, the cutout portion 22 is configured by a surface parallel to the incident surface portion 2a and a surface parallel to the emission surface portion 2b, and when the light passing through the inside passes through the cutout portion 22. Moreover, the emission direction of the light is maintained in the same direction as when emitted from the emission surface portion 2b.

Next, the fourth and fifth embodiments of the present invention will be described. FIG. 6 is an explanatory view showing a state where the light guiding device of the fourth embodiment or the light guiding device of the fifth embodiment installed in the northern hemisphere is viewed from the east side,
FIG. 7A is an explanatory diagram showing a state where the light guiding device according to the fourth embodiment of the present invention following FIG. 6 is viewed from the north side, and FIG. 7B is a fifth embodiment of the present invention following FIG. It is explanatory drawing which shows a mode that the certain light guide apparatus was seen from the north side. In the figure, the same reference numerals and symbols as those in each of the above-described embodiments are the same or corresponding portions as those in each of the above-described embodiments.

As shown in FIG. 6, in the light guiding device 31 of the fourth embodiment, the sunlight (arrow 34) is reflected by a reflecting plate 32 made of a flat surface such as a mirror so as to travel vertically downward (arrow 35). The optical path changing device 1 of the first embodiment reflects the light in the horizontal direction (arrow 36) to guide it to the second floor in the building 51, and finally diffuses the light (arrow 37) by the diffusion plate 33. Note that, in FIG. 6, the details are as seen from the east side in the northern hemisphere, and the incident angle (indicated by the arrow 34) of the incident light from this direction changes according to the change of the four seasons. In order to deal with this, the reflector 32 is actually oriented in the east-west direction so that the inclination angle can be varied as indicated by an arrow 32b in accordance with a change in the south-middle altitude about the axis 32a passing through the center of the reflector 32. It has become. For this reason, the direction of travel of sunlight after reflection is always downward vertically throughout the four seasons.

The light guiding device 41 of the fifth embodiment, as shown in FIG. 6, until the sunlight (arrow 34) is reflected by the reflecting plate 32 and travels vertically downward (arrow 35).
It is similar to the light guiding device 31 of the fourth embodiment, but thereafter when guiding sunlight to the first floor in the building 51, the light path changing device 11 of the second embodiment or the light path changing device 21 of the third embodiment. Is used in the building 51, not horizontally
Sunlight is incident at a downward inclination of 30 ° (arrow 38). Also in this case, the sunlight that has entered the building 51 is diffused by the diffusion plate 34 similar to the diffusion plate 33 (arrow 39).
In the above description, the diffusion plates 33 and 34 are preferably known condenser lenses or optical path suppression lenses that suppress the traveling direction of light incident from various directions to a substantially constant range by using total reflection. Other diffusion plates such as the above may be used.

When the light guiding device 31 of the fourth embodiment and the light guiding device 41 of the fifth embodiment are viewed from the north side, arrows 34a, 34b, 34 in FIGS. 7 (a) and 7 (b) are used.
As shown in c, the incident angle of sunlight changes from moment to moment due to the influence of the rotation of the earth. Therefore, in the light guiding device 31 of the fourth embodiment and the light guiding device 41 of the fifth embodiment, the reflecting plate 32 is rotatably supported about the vertical shaft 32c. By rotating the reflector 32 about the axis 32c according to the time, the traveling direction of the sunlight after being reflected by the reflector 32 is kept vertically downward even when viewed from the north side (arrow 35). Furthermore, the optical path changing device 1 used in the light guiding device 31 of the fourth embodiment is integrated with the diffusion plate 33, and the optical path changing devices 11 and 21 used in the light guiding device 41 of the fifth embodiment are diffusion plate 34. Integral with each shaft 32
It is supported rotatably around c, and the range of lighting to each floor can be changed.

Next, a sixth embodiment of the present invention will be described. FIG. 8 is an explanatory diagram showing a light guide device according to a sixth embodiment of the present invention. In the figure, the same reference numerals and symbols as those in each of the above-described embodiments are the same or corresponding portions as those in each of the above-described embodiments.

In the light guiding device 61 of the sixth embodiment, when the path 62, which is the path of light, is restricted to a state in which the path is bent in multiple stages, the bent portion of the path 62 is changed according to the bending angle. One of the optical path changing device 1 of the first embodiment, the optical path changing device 11 of the second embodiment, and the optical path changing device 21 of the third embodiment is arranged.

That is, the path 6 through which the light shown in FIG. 8 is guided
2 indicates arrows 63, 6 when sequentially traced from the light incident side.
4, 65, 66, 67, 68, 69, turn at right angles at 6 places, and finally, as shown by arrow 70, 6
Changing the direction by 0 °. Therefore, in the light guiding device 61 of the sixth embodiment, the optical path changing device according to the bending angle is arranged at the seven bent portions of the light path,
Light is guided along a multi-step bent path. It should be noted that the number of bending points and the bending angle of the light path shown here are merely examples, and other arbitrary embodiments in which the number of the bending points and the bending angle of the light path are changed may be adopted.

In a specific example in which the light path is bent in multiple stages as in the case of this example, it is assumed that, for example, sunlight is guided to a specific room in a building or the premises of a subway. As in the present embodiment, it is assumed that the building is inevitably restricted due to the floor plan of each floor, etc., and the path for guiding the light is complicatedly bent.

According to the light guiding device 61 of the sixth embodiment,
At the bent portion of the path, since the traveling direction of light can be changed by total reflection, there is almost no attenuation as compared with the case where a reflecting plate such as a mirror is used before and after the traveling direction of light can be changed. In particular, when light can change its direction in multiple stages, such as when sunlight is shining inside a building,
The difference in the ability to reduce the attenuation of light as compared with the case where a reflector such as a mirror is used becomes large, and the effect is remarkably exhibited.

Next, a seventh embodiment of the present invention will be described. FIG. 9 is an explanatory diagram showing a state where the light guiding device according to the seventh embodiment of the present invention installed in the northern hemisphere is viewed from the east side,
FIG. 10 is an explanatory diagram showing a state where the light guiding device according to the fourth embodiment of the present invention following FIG. 9 is viewed from the north side. In the figure, the same reference numerals and symbols as those in each of the above-described embodiments are the same or corresponding portions as those in each of the above-described embodiments.

When viewed from the east side, the light guiding device 71 of the seventh embodiment is, as shown in FIG. 9, first known as the south and middle altitudes which change due to the factors of the earth's revolution (seasonal changes). The angles of the optical path suppressing lenses 72 and 73 are changed to allow sunlight to pass therethrough, and the traveling direction of the sunlight is kept at an incident angle of approximately 60 ° with respect to the water surface. That is, the building 51 roof slope of the installation destination of the light guiding device 71 of the seventh embodiment is 30 °, and the sunlight is guided to the edge of the roof along the slope of the roof. The optical path suppression lenses 72, 7
3 is a known technique for limiting the traveling direction of light incident in a specific angle range to a substantially constant predetermined direction by performing total reflection or refraction in the process of transmitting light.

The sunlight reaching the edge of the roof of the building 51
Subsequently, the optical path changing device 11 of the second embodiment or the optical path changing device 21 of the third embodiment totally reflects the light and changes the traveling direction to the vertically downward direction. Subsequently, the system is divided into two systems, but in one system, the light is totally reflected by the optical path changing device 1 of the first embodiment and the traveling direction is changed by 90 °.
It is guided to the floor and finally diffused by the diffusion plate 33.
Further, in the other system, the optical path changing device 1 of the second embodiment
The light is totally reflected by the optical path changing device 21 of the first embodiment or the third embodiment, the traveling direction is changed by 60 °, and the light is guided to the first floor in the building 51, and finally diffused by the diffusion plate 34.

As seen from the east side as shown in FIG. 9, the optical path changing device 1 of the first embodiment, the optical path changing device 11 of the second embodiment, or the optical path changing device 2 of the third embodiment.
1 appears to be on the same path of light that travels vertically downward, but in reality, it is at a position deviated from the vertical line of each optical path changing device 1, 11 (or 21), and each optical path changing device 11 The light traveling toward (or 21) is not blocked by the optical path changing device 1.

By the way, known optical path suppressing lenses 72, 7
In the case of changing the course of sunlight, ideally, all the light fluxes should be kept parallel before and after the change of course, but since it is difficult to keep them perfectly parallel, it is slightly different from the intended traveling direction. There is also a part that progresses in the direction.
In order not to waste these leaked light fluxes, the light guiding device 71 of the seventh embodiment is provided with a duct 76 that surrounds the circumference of the light traveling path and prevents light from leaking to the outside.

Next, when the light guiding device 71 of the seventh embodiment is viewed from the north side, as shown in FIG. 10, first, as shown in FIG. Sunlight is condensed in a predetermined range by a known optical path suppressing lens 74 arranged substantially horizontally with respect to the incident angle and a known optical path suppressing lens 75 arranged below it in a fan shape.

Then, the traveling direction of the sunlight is unified vertically downward by the known optical path suppressing lens 76. The optical path suppressing lenses 74, 75, and 76 also limit the traveling direction of light incident in a specific angle range to a substantially constant predetermined direction by performing total reflection or refraction during the light transmission process. Then, as described with reference to FIG. 9, the sunlight is guided to each floor of the building 51. In addition, the duct 77 for preventing the leaked light flux has openings 77a, 7a that lead to the respective floors of the building 51.
7b are formed, and sunlight is guided to each floor through these openings. Then, the optical path changing devices 1, 11, 2
The afterglow that has escaped the use by No. 1 reaches the heat storage tank 78 installed ahead of it. The heat storage tank 78 is filled with water, and a heat absorber 78a such as black stone or charcoal is put on the bottom of the water.

Therefore, the energy of the afterglow transmitted into the water is transferred to the water after being absorbed by the heat absorber 78a, and the energy of the afterglow is extremely efficiently accumulated in the heat storage tank 78. It Hot water is generated by the stored energy and hot water can be supplied.

In the above description, in order to clarify the description, the optical path suppressing lenses 74, 75, and 76 shown in FIG. 10 are omitted in FIG. 9, and the optical path suppressing lenses shown in FIG. 72, 73, optical path changing device 1, 1
Although the description of the reference numerals 1 and 21 and the diffusion plates 33 and 34 is omitted, actually, when viewed from each direction, these omitted portions are present. Thus, the optical path changing device 1 of the present invention
11 and 21 can also use sunlight by combining with a known optical path suppression lens.

[0044]

As described above, according to the optical path changing device of the first aspect of the present invention, since the traveling direction of light can be changed by total reflection, the traveling direction of light can be changed with almost no attenuation of the light quantity. it can. Moreover, the equipment cost is significantly lower than that of the optical fiber.

According to the optical path changing device of the invention of claim 2,
In addition to the effect of the optical path changing device according to the first aspect, it is possible to change the direction of light that is expected to be most frequently generated when light such as sunlight is propagated inside a building at a right angle.

According to the optical path changing device of the invention of claim 3,
In addition to the effect of the optical path changing device according to the second aspect, since the light diversion direction is kept at a right angle in the entire area where the light is incident, the loss before and after the light diversion can be further reduced. Since the incident surface portion and the emitting surface portion can be used by being replaced with each other, the direction is not mistaken during use and the usability is good.

According to the light guiding device of the fourth aspect of the invention, when the traveling direction is changed and the light is guided to the target position,
Attenuation of light can be reduced as compared with the case of using a reflector such as a mirror. Especially when it is necessary to change the traveling direction of light many times, such as when sunlight is shining inside the building,
The effect of reducing the attenuation of light is remarkably exhibited.

[Brief description of drawings]

FIG. 1 is a partial end view showing an optical path changing device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing how the traveling direction of light is changed by the optical path changing device according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a state in which the traveling direction of light is changed by the optical path changing device according to the second embodiment of the present invention.

FIG. 4 is a partial end view showing an optical path changing device according to a third embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a state in which the traveling direction of light is changed by the optical path changing device according to the third embodiment of the present invention.

FIG. 6 is an explanatory view showing a state where the light guiding device of the fourth embodiment or the light guiding device of the fifth embodiment of the present invention installed in the northern hemisphere is viewed from the east side.

7 (a) is an explanatory view showing a state where the light guiding device according to the fourth embodiment of the present invention following FIG. 6 is viewed from the north side, (b).
FIG. 7 is an explanatory view showing a state where the light guiding device which is the fifth embodiment of the present invention following FIG. 6 is viewed from the north side.

FIG. 8 is an explanatory diagram showing a light guide device according to a sixth embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a state where the light guiding device according to the seventh embodiment of the present invention installed in the northern hemisphere is viewed from the east side.

FIG. 10 is an explanatory diagram showing a state where the light guiding device according to the fourth embodiment of the present invention following FIG. 9 is viewed from the north side.

[Explanation of symbols]

1, 11 and 21 Optical path changing device 2 Front surface 2a Incident surface portion 2b Radiating surface portion 3 Back surface 4,5, 6, 7, 12, 13, 14, 15, 32b, 3
4, 34a, 34b, 34c, 35, 36, 37, 3
8, 39, 63, 64, 65, 66, 67, 68, 6
9, 70 Arrow 22 Notch 31, 41, 61, 71 Light guide device 32 Reflector 32a, 32c Shaft 33, 34 Diffuser 51 Building θ Incident angle 62 Path 72, 73, 74, 75, 76 Optical path suppression lens 77 Duct 77a, 77b Opening 78 Heat storage tank 78a Heat absorber

Claims (4)

[Claims] 1. An incident surface portion which is formed of a flat surface and constitutes a part of the front surface, and is arranged under the condition that incident light from a predetermined direction can reach the rear surface of the flat surface after incidence while maintaining an angle equal to or greater than a critical angle with respect to the atmosphere. , Which is a flat surface and constitutes a part of the front surface, and is arranged under the condition that the light totally reflected by the back surface after being incident from the incident surface portion can be emitted to the outside at a target angle with respect to the traveling direction before the incidence from the incident surface portion. Optical path changing device. 2. The optical path according to claim 1, wherein an angle formed by a traveling direction of light before entering the incident surface portion and a traveling direction of light after being emitted from the emission surface portion is a right angle. Change device. 3. A transparent material having a refractive index of less than 45 ° with respect to the atmosphere, the incident surface portion and the emitting surface portion being orthogonal to each other, and any angle between the incident surface portion and the emitting surface portion with respect to the back surface. The optical path changing device according to claim 2, wherein the optical path changing device forms 45 °. 4. A light guiding device, wherein the optical path changing device according to claim 1 is arranged at a bending position of a path for guiding light according to a bending angle.