Transparent optical conductor for reflecting and radiating out of the conductor light rays transmitted through the conductor

A light radiator for effectively diffusing radiating light rays, transmitted through an optical conductor cable or the like, out of the optical conductor cable. The light radiator includes a transparent cylinder positioned almost horizontally, an optical conductor for guiding light rays into the cylinder, an optical means movably installed in the cylinder for reflecting the light rays guided into the cylinder and for radiating the reflected light rays out of the cylinder and driving means for moving the optical means along an axis of the cylinder. The optical means includes a cylindrical member having an outer diameter approximately equal to an inner diameter of the cylinder. One end surface of the cylindrical member is inclined in relation to an axis line of the cylindrical member and is formed as a reflection surface. A cavity is provided at a longer-axis side of the cylindrical member to eliminate the need for complex regulation means to regulate the direction of reflection of the light rays.

BACKGROUND OF THE INVENTION 
The present invention relates to a light radiator for effectively diffusing 
and radiating light rays, which have been transmitted through an optical 
conductor cable or the like out of of the optical conductor cable. 
The present applicant has previously proposed various ways to focus solar 
rays or artificial light rays by use of lenses or the like, to guide the 
rays into an optical conductor cable, and thereby to transmit them onto an 
optional desired place through the optical conductor cable. The solar rays 
or the artificial light rays transmitted and emitted in such a way are 
employed for photo-synthesis, for use in illuminating, or for other like 
purposes, for example, to promote the cultivation of plants. 
However, when utilizing light energy for cultivating plants as mentioned 
above, light rays transmitted through an optical conductor cable have 
directional characteristics. If the end portion of an optical conductor 
cable is cut off and light rays are emitted therefrom, the radiation angle 
for the focused light rays is, in general, equal to approximately 
46.degree., which is quite narrow. When utilizing light energy as 
described above, it is impossible to attain a desirable amount of 
illumination simply by cutting off the end portion of an optical conductor 
cable and letting the light rays emit therefrom. 
Therefore, the present applicant has already proposed various kinds of 
light radiators capable of effectively diffusing light rays which have 
been transmitted through an optical conductor cable and radiating them for 
illumination over a desired area. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a light radiator 
capable of effectively emitting solar rays or artificial light rays 
transmitted through an optical conductor cable out of the same for 
nurturing plants. 
It is another object of the present invention to provide a light radiator 
capable of effectively moving an optical means installed in a transparent 
cylinder. 
It is another object of the present invention to provide a light radiator 
in which an optical means moving in a cylinder has a buoyancy for always 
directing light rays reflected on the optical means to a predetermined 
direction. 
It is another object of the present invention to provide a light radiator 
constructed simply and at a lower cost which is capable of effectively 
diffusing light rays. 
The above-mentioned features and other advantages of the present invention 
will be apparent from the following detailed description which goes with 
the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 is a cross-sectional view of an embodiment of a light radiator 
previously proposed by the present applicant. In FIG. 1, 10 is a 
transparent cylinder, 20 an optical conductor, 30 an optical means, 40 a 
pump, and 50 a foundation. 
The cylinder 10 is filled with water or optical oil. A light emitting end 
portion 20a of the optical conductor 20 is installed at one end portion of 
the cylinder 10. The light rays transmitted through the optical conductor 
20 are emitted into the cylinder 10 from the light emitting end portion 
20a of the optical conductor 20 and transmitted in the cylinder 10 toward 
the other end portion thereof by being reflected on the inner wall surface 
and outer wall surface of the cylinder 10. 
A cylindrical optical means 30 is movably installed in the cylinder 10. The 
optical means 30 consists of a cylindrical optical conductor 31 having one 
end surface 31a at a light ray transmission side which is formed on a 
plane surface (not inclined), another surface 31b opposite thereto which 
is formed on an inclined surface, and a cover member 32 for forming an air 
chamber at the side of the inclined surface 31b by tightly closing the 
side of the inclined surface 31b. 
Consequently, light rays L guided into the cylinder 10 enter the optical 
means 30 through the plane 31a of the optical conductor 31 and are 
reflected on the inclined surface 31b at the opposite side of the optical 
conductor 31. Reflected light rays Lo are emitted out of the cylinder 10. 
Plants or the like are raised beneath the cylinder 10. In this manner, the 
light rays emitted from the cylinder 10 are supplied to the plants as a 
photo-synthesis reaction light source for the plants. 
Furthermore, an open end of a pipe 41 is located at one end portion of the 
cylinder 10 and that of another pipe 42 is located at another end portion 
thereof. A differential pressure is applied between the right side and the 
left side of the optical means 30 by use of pipes 41 and 42. The optical 
means 30 can be moved to the right and left in the cylinder 10 by the 
action of the above-mentioned differential pressure. In such a manner, it 
is possible to supply the light rays to the plants. 
In FIG. 1, 61 and 62 are photo sensors mounted on an outer circumferential 
surface of the cylinder 10 at the side where the light rays reflected by 
the optical means 30 pass through. The arrival of the optical means 30 at 
the right end of the cylinder 10 is detected by the photo sensor 61. The 
detection signal thereof controls the pump 40 so as to generate a 
differential pressure for moving the optical means 30 to the left. On the 
other hand, the arrival of the optical means 30 at the left end of the 
cylinder 10 is detected by the photo sensor 62. The detection signal 
thereof controls the pump 40 to generate a differential pressure for 
moving the optical means 30 to the right. 
Photo sensors 61 and 62 are constructed to be capable of being mounted on 
and removed from the cylinder 10, or to be movable along the cylinder 10. 
In such a manner, when plants are small, the photo sensors 61 and 62 can 
be arranged at a smaller distance, and when the plants grow up and become 
taller, the distance between them can be widened. Therefore, the light 
rays transmitted through the optical conductor 20 can be effectively 
supplied to the plants. A reflection surface 11 is installed at the left 
end of the cylinder 10, that is, at the end portion thereof at the side 
opposite to the optical conductor 20. The light rays leaking leftward from 
the cylinder 10 after passing through the optical means 30 are reflected 
on the reflection surface 11 and discharged to the outside portion of the 
cylinder 10. 
A permanent magnet 33 is installed on the outer circumferential surface of 
the optical means 30, at a location where the light rays reflected on the 
reflection surface 31b of the optical means 30 can pass through without 
being interrupted. When permanent magnet or magnetic substance 33 is 
unitarily attached to the optical means 30, it is possible to detect the 
position of the optical means by detecting the permanent magnet or 
magnetic substance 33. On that occasion, magnetic sensors 63 and 64 are 
employed instead of the photo sensors 61 and 62. 
Moreover, a position signal detected by the magnetic sensors 63 and 64 is 
used for controlling the pump 40, as in the case of the afore-mentioned 
photo sensors. Namely, the optical means 30 is moved to the right and left 
in accordance with the detected position signal. However, in relation to 
the movement area of the optical means, it is not always necessary to move 
the optical means within the designated area by detecting the position 
thereof. Instead, the revolution of the liquid pump 40 is repeatedly 
reversed in an appropriate timing. In such a manner, the movement area of 
the optical means can be easily remotely controlled. 
A permanent magnet or magnetic substance 12 installed on the outer surface 
of the cylinder 10 is elongated along the axis of the cylinder 10. The 
optical means 30 is regulated to move it in a desired direction by use of 
the permanent magnet or magnetic substance 12. At least one of the 
permanent magnet or magnetic substance 33 installed on the optical means 
30 and the permanent magnet or magnetic substance 12 installed on the 
cylinder 10 is constructed of a permanent magnet. Consequently, a magnetic 
attractive force occurs between permanent magnets or magnetic substances 
33 and 12. The optical means 30 therefore is moved by the action of the 
magnetic force, when the permanent magnet or magnetic substance 33 is 
opposed to the permanent magnet or magnetic substance 12 on the cylinder 
10. 
However, the light radiator as mentioned heretofore comprises the permanent 
magnet or magnetic substance 12 installed on the outer circumferential 
surface of the cylinder 10 along the axis direction thereof and the 
permanent magnet (or magnetic substance) 33, in order to direct the light 
rays reflected by the optical means 30 to a desired direction. Therefore, 
the above-mentioned light radiator has some defects in that construction 
of the optical means 30 is complicated, manufacturing of the optical means 
30 becomes difficult and thus the cost greatly increases. Further, on some 
occasion, an extremely long piece measuring several meters is employed as 
the cylinder 10. Therefore, the permanent magnet 12 installed on the outer 
circumferential surface of the cylinder 10 is necessarily extremely long 
and thereby the cost of the permanent magnet 12 inevitably increases. 
The present invention was made in consideration of the actual circumstances 
as mentioned above. In particular, the primary object of the present 
invention is to provide a light radiator in which the optical means moving 
in the cylinder has a buoyancy for always directing the light rays 
reflected on the optical means to a predetermined direction. As a result, 
regulation means for regulating the reflecting direction of the reflected 
light rays from the optical means, which has been needed in the prior art, 
may be omitted so that the light radiator can be constructed simply and at 
a lower cost. 
FIG. 2 is a cross-sectional view side illustrating the main part of a light 
radiator according to the present invention. In FIG. 2, 10 is a 
transparent cylinder, and 30 is an optical means moving in the cylinder 10 
as mentioned above. One end surface 35 of the optical means 30 is formed 
as an inclined surface. Inclined surface 35 is formed as a reflection 
surface. Consequently, light rays L guided into the cylinder 10 from the 
optical conductor cable not shown in FIG. 2 are reflected on the inclined 
reflection surface 35. The reflected light rays Lo are discharged out of 
the cylinder 10. 
According to the present invention, when the cylinder 10 is employed, it is 
positioned almost horizontally. In the optical means 30, as shown in FIG. 
2, a cavity 36 is provided at the longer axis side of optical conductor 
30. Consequently, in the optical means 30, the shorter axis side thereof 
is always located at the lower side so that the light rays are always 
emitted downward from the cylinder 10. Therefore, it is not necessary to 
provide a regulation means for regulating the direction of the light ray 
radiation by the use of permanent magnet means which has been needed in 
the prior art. It follows that the light radiator can be constructed 
simply and at a lower cost. 
If the right end of the cylinder 10, not shown in FIG. 2, is formed as a 
reflection surface, for instance, light rays L' propagate through the tube 
wall of the cylinder 10 to the right side of the optical means 30 and are 
reflected on the reflection surface. The reflected light rays Lo' 
propagate back into the cylinder 10 and are reflected on the bordering 
surface of the cavity portion 36 and radiated out of the cylinder 10. 
These radiated light rays can be also utilized. 
FIG. 3(A) and FIG. 3(B) are respectively cross-sectional views taken along 
the light II--II of FIG. 2. The inclined reflection surface 35 is usually 
a plane surface. However, it is possible to form it as a concave surface 
30a in relation to the axis Q--Q parallel with the inclined surface 35 as 
shown in FIG. 3(A), or to form it as a convex surface 30b in relation to 
the same as shown in FIG. 3(B). If the inclined surface 35 is formed as a 
concave or convex surface in such a manner, the light rays reflected on 
the inclined surface can be focused or diffused so that the light rays can 
be distributed preferably for the employment purpose thereof. Moreover, if 
the axis Q--Q is inclined to Q'--Q' in relation to the vertical axis as 
shown in FIG. 3(A), the light rays reflected on the reflection surface can 
be directed obliquely downward. 
FIG. 4 is a cross-sectional side view of another embodiment of the present 
invention. In this embodiment, the optical conductor 30 has both ends 
formed as inclined reflection surfaces 35.sub.1 and 35.sub.2 and is so 
constructed that light rays reflected on both reflection surfaces are 
directed in the same direction. According to this embodiment, the light 
rays L.sub.1 and L.sub.2 can be guided into the cylinder 10 from both 
directions and reflected on the respective inclined reflection surfaces 
35.sub.1 and 35.sub.2 to the same direction. 
Consequently, according to this embodiment, the light rays can be guided 
into the cylinder 10 from both sides thereof, so that a larger amount of 
light rays can be diffused over a wider area using only a single optical 
means. Moreover, in the embodiment, the optical means 30 consists of a 
first optical conductor 31.sub.1 having an inclined reflection surface 
35.sub.1, a second optical conductor 31.sub.2 having an inclined 
reflection surface 35.sub.2, and a transparent cylindrical body 37 for 
connecting the optical conductor 31.sub.1 with the optical conductor 
31.sub.2. 
Both optical conductors 31.sub.1 and 31.sub.2 are tightly fixed to both 
sides of the cylindrical body 37. The respective inclined reflection 
surfaces 35.sub.1 and 35.sub.2 of the optical conductors 31.sub.1 and 
31.sub.2 are respectively located outside of the cylindrical body 37 and 
light rays reflected on both reflection surfaces 35.sub.1 and 35.sub.2 are 
directed in the same direction. In such a construction, a cavity 36 is 
formed in the optical means 30. The cavity 36 is formed larger at the 
longer axis side of the optical means 30 than at the shorter axis side 
thereof, as shown in FIG. 4. Consequently, in the embodiment, the longer 
axis side of the optical means 30 is always located at the upper side. As 
in the case of the embodiment shown in FIG. 2, the regulation means for 
regulating the direction of the reflected light rays is not needed, so 
that a light radiator of simple and low-cost construction can be provided. 
FIG. 5 is a cross-sectional view of still another embodiment of the present 
invention. In this embodiment, the inclining direction at one of the 
inclined reflection surfaces as shown in FIG. 4 is reversed while the 
inclining direction at another inclined surface is left as it is. Namely, 
in the embodiment shown in FIG. 5, the light rays L.sub.1 reflected on the 
inclined reflection surface 35.sub.1 are directed downward from the 
cylinder 10 and the light rays L.sub.2 reflected on the inclined 
reflection surface 35.sub.2 directed upward therefrom. In such a manner, 
light rays can be radiated upward and downward from the cylinder 10 by use 
of only one optical means. 
Furthermore, in the embodiments shown in FIG. 4 and FIG. 5, the inclined 
reflection surface can be concave or convex as in the case of the 
embodiment shown in FIG. 2, and the end surface of the cylinder 10 can be 
formed as a reflection surface. Further, it will be easily understood that 
the axis of the inclined surface can be inclined in relation to the 
vertical axis as explained in FIG. 3(A). 
In the embodiments shown in FIG. 4 and FIG. 5, an example of guiding light 
rays from both ends of the cylinder 10 has been explained. However, it is 
not always necessary to guide light rays from both ends thereof. Even when 
guiding light rays from only one end, the following effect can be 
expected. Namely, suppose the end surface of the cylinder 10 is formed as 
the reflection surface. For instance, when light rays are guided from the 
left end of the cylinder 10 and the right end thereof is formed as the 
reflection surface in FIG. 4, the light rays L.sub.1 ' propagating through 
the tube wall of the cylinder 10 toward the right side of the optical 
means 30 are reflected on the reflection surface not shown in FIG. 4 at 
the right end of the cylinder 10. The reflected light rays propagated in 
the cylinder 10 from the right to the left just like the afore-mentioned 
light rays L.sub.2. Further, the light rays are reflected on the 
reflection surface 35.sub.2 ' and discharged out of the cylinder 10. 
FIG. 6 is a cross-sectional view of still another embodiment of the present 
invention. FIG. 6(A) is a cross-sectional side view thereof and FIG. 6(B) 
is a cross-sectional view taken along the line B--B of FIG. 6(A). In this 
embodiment, the afore-mentioned reflection surfaces 35, 35.sub.1 and 
35.sub.2 are divided in two forming a border line at the vertical center 
axis P--P, as shown in FIG. 6(B). Consequently, according to the 
embodiment of FIG. 6, the light rays can be illuminated downward or upward 
from the cylinder 10 over a wider area. 
As is apparent from the foregoing description, according to the present 
invention, it is possible to provide a light radiator constructed simply 
and at a lower cost and capable of effectively diffusing light rays.