JPS6144162Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber, and more particularly to a decorative optical fiber suitable for optical decoration or various types of optical display.

Generally, an optical fiber emits light that enters from its input surface from its output end surface.
When using this for optical communication, the light incident from the input end face leaks and is emitted from places other than the output end face, for example, from minute defects called microcracks that occur on the surface of the fiber. If this happens, it will become a serious problem in terms of optical transmission loss.

However, when optical fibers are used for decorative miscellaneous goods or various demonstration products, and the beauty of the emitted light is simply utilized, the above-mentioned light leakage is not a problem at all. do not have.

On the contrary, if we actively utilize this phenomenon of light leakage to emit light from parts other than the end faces of the fiber, we can create interesting and fresh optical decorations or optical displays that do not exist in conventional products. It can be realized.

Therefore, it is conceivable to form a notch on the outer periphery of the optical fiber so that the light incident from the end face of the optical fiber leaks from the notch. It turned out that there were various problems.

Below, we will explain the results of this experiment.
Figure A shows core 1 and cladding 2 used in this experiment.
These are enlarged partial cross-sectional views showing homogeneous plastic optical fiber strands a, b, and c, each having a diameter of 1 mm and a length of 1 m. 10 light leakage parts 3 were formed at a pitch of 2 cm, each having a V-shaped notch with an angle R of 60 degrees (FIG. B).

Here, the depth H of the light leakage portion 3 cut out in each of the wires a to c was sequentially increased to 0.2 mm, 0.3 mm, and 0.4 mm, respectively.

Figure 2 is a graph showing the ratio of the amount of light emitted from the light leakage part 3 to the amount of incident light when a constant amount of light is incident from both end faces of each element wire, and the X axis is plotted at a pitch of 2 cm. The arrangement order of the light leakage portions 3 formed at 10 locations is shown, and the Y axis represents the ratio of the amount of light emitted from each light leakage portion 3 to the amount of incident light.

Moreover, line graphs (a), (b), and (c) show changes in the emitted light amount ratio at each light leakage portion 3 of each of the wires a, b, and c, respectively.

From the results of the experiments described above, the depth H of the light leakage part 3
When is 0.2 mm, that is, when forming a light leakage part with a depth equivalent to 1/5 of the fiber diameter, the ratio of the amount of emitted light from each light leakage part 3 is less than 10%, compared to other cases. It can be seen that the radiation efficiency of light is extremely poor.

Therefore, in order to obtain a practical amount of light for various optical decorations or optical displays, it is necessary to have a depth of about 0.3 mm, that is, a depth corresponding to approximately 1/3 of the fiber diameter.

However, if a notch with a depth equivalent to 1/3 of the diameter is formed on the surface of the fiber, the fiber itself becomes brittle, and there is a serious problem that it may break due to bending or tension. be.

Further, there is also the problem that dust and dirt accumulate in the cutout light leakage portion, which prevents light leakage.

Therefore, the purpose of this invention is to solve these problems all at once.The present invention aims to solve these problems all at once. It is also characterized by comprising a transparent protective coating layer coated on the outside of the .

Hereinafter, the present invention will be explained based on the embodiments shown in the drawings.

FIG. 3 shows an example of an optical fiber according to the present invention, in which the outer periphery of a plastic optical fiber strand 4 consisting of a core 1 and a cladding 2 is coated with silicone, for example.
A primary coat 5 made of urethane or the like is coated, and a light leakage portion 3 is formed by cutting a V-shaped cross section from the surface of the primary coat 5 to the core 2.
Further, on the outside of the primary coat 5, a transparent protective coating layer 6 made of, for example, nylon or polyethylene is provided.
is covered.

Here, the concave portion of the light leakage portion 3 is filled with a resin such as the above-mentioned nylon, which forms the protective coating layer 6, and is integrated.

By the way, in order to manufacture such an optical fiber, for example, as shown in FIG.
A so-called primary coated fiber 10 whose surface is coated with a primary coat 5 is first cut into a V-shaped cross section from the surface of the primary coat 5 to the core 2 through a notch device 11, and then cut into a die 12. Nipple 1 installed concentrically
3 and coating the nipple 13 and the fiber 10 extruded from the die 12 at the outlet of the die 12 with a molten resin 14 to form a protective coating layer 6, as shown enlarged in FIG. 4B. It can be easily manufactured by

As described above, according to this embodiment, the protective coating layer 6 is provided on the outside of the fiber wire 4 in which the light leakage portion 3 is cut out.
Since it is coated, it is possible to prevent the accidental cutting of the light leakage part 3 due to tension, and at the same time, the drawback that dust and dirt accumulate inside the light leakage part 3 is eliminated.

In particular, as in this embodiment, when the molten resin 14 forming the protective coating layer 6 is filled in the light leakage part 3,
When the notch surface of the light leakage portion 3 and the protective coating layer 6 are integrated, accidents of cutting the light leakage portion 3 due to bending can be prevented.

In addition, in the above embodiment, an example was shown in which a light leakage part was formed by cutting out the core and cladding.
The present invention is not limited to this, and the cladding 2 may be formed by cutting out only the cladding 2 in an annular shape, for example, as shown in FIG.

In short, the light leakage portion may have any form as long as it has a structure in which a portion of the outer peripheral surface of the fiber wire is cut out.

[Brief explanation of the drawing]

Figures 1A, B and 2 are explanatory diagrams of experiments related to the present invention, Figure 3 is a schematic cross-sectional view showing an example of an optical fiber according to the present invention, and Figures 4A and B are shown in Figure 3. FIG. 5 is an explanatory diagram showing an example of a method for manufacturing an optical fiber, and FIG. 5 is a schematic cross-sectional view showing another example of the optical fiber according to the present invention. Explanation of symbols 1... Core, 2... Clad, 3
...Light leakage part, 4... Fiber wire, 6... Protective coating layer.

Claims (1)

[Scope of utility model registration request] A decorative light comprising a plurality of light leakage parts formed by cutting out the outer peripheral surface of a fiber strand consisting of a core and a cladding, and a transparent protective coating layer coated on the outside of the fiber strand. Faiba.