JP2002323619A - Method for condensing light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently condensing incident light. SOLUTION: A light transmission body 5 has a circular section of a desired outer diameter, the core part 5A of which has a prescribed refractive index n1 and a diameter D and is located on the central axis line, and a clad part 5B which has a prescribed smaller refractive index n2 than the index n1 and a diameter d, and is located around the core. The outer diameter of the light transmission body 5 gradually and continuously decreases along the longitudinal direction while keeping a similar sectional form, and the outer diameter is kept constant after the outer diameter reaches a prescribed value. The end face on the side of the maximum outer diameter of the light transmission body 5 is defined as an incident end face 51 and the end face on the side of the minimum outer diameter located at the opposite side in the longitudinal direction is defined as an emission end face 52. The method for condensing light is characterized by the fact that the light energy density of the incident light from the incident end face 51 is enhanced at the emission end face 52 by approximately (D/d)<2> times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light collecting method for collecting light and increasing its light energy.

[0002]

2. Description of the Related Art FIG. 5 illustrates an earliest endoscope, and a method of condensing light will be described. In the figure, reference numeral 101 denotes a bundle of optical fibers,
Reference numeral 2 denotes an incident end face of the optical fiber bundle. In order to make light incident from the incident end face 102, the following method is employed.

That is, light emitted from a light source 1 such as a xenon lamp is collected by a reflecting mirror 2 and guided to a convex lens 3,
In this method, the bright spot image 4 formed by the convex lens 3 is formed on the incident end face 102. In other words, in this case, the light is incident on the optical fiber bundle 101 by using the light condensing method using the method using the reflecting mirror 2 and the method using the convex lens 3 twice.

[0004] Referring to FIG.
Considering the case where the interior is illuminated, the roof 61 is conventionally used.
Many panel-type solar cells 10 on a building or on the side of a building
3 is provided, and electric energy from these is supplied to a lighting circuit 8.
1 to turn on an appropriate lighting lamp 8.

[0005]

However, depending on the focusing method shown in FIG. 5, light can be effectively introduced into all the individual optical fibers in the optical fiber bundle 101, as can be easily inferred from the drawing. However, there is a disadvantage that light can be introduced only into a part of optical fibers directly facing or close to the bright spot image. That is, in the conventional focusing method, it is not possible to focus the light so that the spread of the focused light beam coincides with the entrance of the next device so as to be suitable for the next stage of the optical device as in this case. It was possible.

In the case of irradiating the inside of a building with the use of sunlight, conventionally, the power is once generated by using a solar cell, and the current is used to indirectly illuminate with a lighting lamp. Power distribution equipment is also required, which has the drawback of low solar energy utilization efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and the invention according to claim 1 has a circular cross section having a desired outer diameter. The diameter D of the predetermined refractive index located at the center axis position
Core portion and a surrounding clad portion having a diameter d having a predetermined refractive index smaller than the core portion, and the outer diameter is sequentially and continuously reduced in the longitudinal direction while the cross-sectional shape is similar, and the predetermined outer diameter is reduced. Thereafter, the light guide continuously formed with its outer diameter remains, and the end face on the maximum outer diameter side is used as the incident end face, and the end face with the minimum outer diameter located on the opposite side in the longitudinal direction is used as the output end face, and the light enters from the incident end face. The light condensing method is characterized in that the light energy density of the emitted light is increased substantially (D / d) ² times at the exit end face.

According to a second aspect of the present invention, there is provided a light guide wherein one or a plurality of the light guides are disposed in a building such that an incident end face of the light guide receives sunlight. And a sunlight condensing method for directly irradiating sunlight into the building from the irradiation lens.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a light guide 5 which plays an important role in carrying out the light collecting method of the present invention will be described. This is exactly the spinning process from the optical fiber preform, the lower end of the optical fiber preform gradually decreases in outer diameter, and considering the spinning situation where the outer diameter continues after the predetermined fiber diameter,
It can be understood that a thin fiber extending downward including the conical portion at the lower end of the base material is cut out.

That is, a core portion 5A having a predetermined refractive index n ₁ is provided at the center axis position of the light guide 5 having a conical shape, and a clad portion 5B having a predetermined refractive index n ₂ smaller than the core portion 5A is provided therearound.
Is provided.

Thus, the outer diameter of the light guide 5 becomes smaller continuously in the axial direction (longitudinal direction) from the incident end face 51 having the maximum core diameter (D) while the cross section is similar (one in the longitudinal direction). The core diameter may be the minimum (d) at the emission end face 52 at the opposite end.

In the case of the light guide 5 of the present invention, the outer diameter is reduced to 0.125 mm, which is equivalent to that of an ordinary optical fiber.
You do not need to decrease it. If the flexibility is not required, the reduced diameter on the smaller diameter side is arbitrary.

For example, in FIG. 1, if the section is taken along the PP plane and this is taken as the exit end face 52, the core diameter of the exit end face is d ₁ which is larger than the minimum d as shown in the figure. FIG. 2 shows a plurality of such light guides 5 combined.

Light incident from the incident end face 51 of the light guide 5 enters through an entrance port having an area of (πD) ² and exits from the exit end face 5.
In No. 2, since the area is reduced to (πd) ² , the light energy density becomes almost (D / d) ² times.

The advantage of the light guide 5 of the present invention is that
2 can be arbitrarily selected. As already described, if Kiritore in PP plane can be the size of the exit end face 52 to any core diameter d _1. That is, this is the optical fiber bundle 101 of the conventional endoscope described with reference to FIG.
It is also possible to completely match the circle of the incident end face of the lens, and the increase in illumination efficiency is extremely large.

FIG. 3 shows a case where the light guide 5 of the present invention is used for indoor lighting of a building 6. That is, the plurality of light guides 5
Are arranged so as to easily receive sunlight, and each emission end face is directly connected to an appropriate irradiation lens 7 such as a glass sphere. The irradiating lens 7 is selected to act to cause diffuse reflection, and the sunlight is directly illuminated indoors via the irradiating lens 7.

FIG. 4 shows an example in which the light guide 5 is used for an output section of solid-state laser light. In the figure, reference numeral 9 denotes a laser rod, and 10 denotes an excitation lamp, which are arranged at respective focal positions of an elliptical converging reflecting mirror 11. Reference numeral 12 denotes a total reflection mirror, 13 denotes a Q-switch modulation element, and 14 denotes an aperture (small hole). By using the light guide 5 for the output unit, the energy of the laser light can be increased, and the utilization efficiency of laser processing, measurement, and the like can be further improved.

[0018]

According to the present invention, the area of the light incident end face can be arbitrarily increased, so that a large amount of incident light can be efficiently introduced, and the light can be made to coincide with the entrance of the next optical device. Since the area of the emission end face can be arbitrarily selected,
There is an advantage that light can be collected without loss of light in a light path inside an optical device or the like.

Further, according to the present invention, light introduced from the incident end face having a relatively large area is made to exit from the relatively small exit end face, and there is almost no loss in the path, so that light energy is substantially incident. There is an advantage that it can be suitably applied to a laser beam processing apparatus or the like by being magnified by the square ratio of the area of the emission end faces.

Further, when sunlight is used for lighting the interior of a building, there is an advantage that it can be used directly for indoor lighting without the need for conventional solar cells or power generation / distribution facilities.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a light guide used to carry out the method of the present invention.

FIG. 2 is a perspective view showing a state in which a plurality of light guides of the present invention are put together.

FIG. 3 is a simplified side sectional view showing a configuration when the light guide of the present invention is used for indoor lighting.

FIG. 4 is a simplified perspective view showing a case where the method of the present invention is applied to focusing of laser light.

FIG. 5 is a simplified side cross-sectional view showing a condensing transmission device used in a conventional endoscope.

FIG. 6 is a schematic diagram showing a configuration of a conventional indoor lighting device using a solar cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Reflector 3 Convex lens 4 Bright spot image 5 Light guide 5A Core part 5B Cladding part 51,102 Incident end face 52 Emitting end face 6 Building 61 Roof 7 Irradiation lens 8 Lighting lamp 81 Lighting circuit 9 Laser rod 10 Excitation lamp 11 Condensing reflection mirror 12 Total reflection mirror 13 Q-switch modulation element 14 Aperture

Claims (2)

[Claims] 1. A core part (5A) having a circular cross section with a desired outer diameter and having a predetermined refractive index (n ₁ ) having a diameter D located at the center axis and a predetermined predetermined refractive index around the core part. (N ₂ ) having a clad portion (5B) having a diameter d, wherein the outer diameter decreases continuously and continuously in the longitudinal direction while the cross-sectional shape is similar, and the outer diameter continues after the predetermined outer diameter. The light guide (5) thus formed has an end face on the maximum outer diameter side as an incident end face (51), and an end face with a minimum outer diameter located on the opposite side in the longitudinal direction as an emission end face (52). A light condensing method characterized by increasing the light energy density of the light incident from (51) on the emission end face (52) almost (D / d) ² times. 2. A light guide or a plurality of light guides (5).
Are arranged in the building (6) such that the incident end face (51) receives sunlight, and each of the exit end faces (5) of the light guide (5).
(2) A method of condensing light by connecting the illumination lens (7) to the sunlight directly from the illumination lens (7) into the building (6).