JPS5814642B2 - Zou Densou You Kougakusen Isoku no Seizou Hohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tape-shaped aggregated fiber bundle in which a large number of optical fibers coated with a transparent material such as glass having a relatively high refractive index are integrated in parallel. The optical fiber bundle for image transmission is rolled up into a ring shape around a cylinder having an outer circumference equal to the length of the desired optical fiber bundle for image transmission, and the regularly stacked parts are fixed with adhesive and cut. The present invention relates to an improvement in a method for manufacturing an optical fiber bundle.

Conventionally, when manufacturing optical fiber bundles for image transmission, the optical fibers have been stacked and arranged using the so-called square method in which the fibers in the upper layer are aligned and stacked in a perpendicular direction to the fibers in the lower layer when winding up the tape-shaped aggregated fiber bundle mentioned above. Although arranging methods are known, such square arranging methods have the disadvantage that the ratio of the total cross-sectional area of the fiber cores to the unit cross-sectional area of the fiber bundle is low, resulting in poor brightness and resolution.

In order to eliminate this drawback, a method of winding a tape-shaped aggregated fiber bundle by shifting the fibers of the upper layer by half a pitch in the transverse direction with respect to the fibers of the lower layer alternately to the left and right in successive layers, so-called bale stacking or hexagonal arrangement. is proposed.

However, when an image is transmitted from one end to the other using an optical fiber bundle for image transmission obtained by stacking tape-shaped aggregated fiber bundles in a hexagonal arrangement method according to the conventional method, one When the image of the letter "A" is sent by the fibers I, H, T, L, Force, Yo, Yu, Re, Ne, La, Chi, Ku, and Co on the end face of , on the other end face I, H! , 4, etc., a blurred image is formed.

As described above, according to the conventional method, a sawtooth effect occurs and good resolution cannot be obtained, and a different image is transmitted to the other end, resulting in a disadvantage that a good optical fiber bundle for image transmission cannot be obtained.

An object of the present invention is to provide a method for easily manufacturing an optical fiber bundle for image transmission that has excellent brightness and resolution.

Therefore, in the method of the present invention, a large number of optical fibers coated with a transparent material having a relatively low refractive index are arranged in a horizontal row around a core material of a transparent material having a relatively high refractive index. A tape-shaped aggregated fiber bundle is created by stacking the fibers arranged in parallel in an even number of stages in a dense packing, and this tape-shaped aggregated fiber bundle is shaped into a cylindrical body so as to obtain an optical fiber bundle for image transmission with a desired length. It is characterized in that a part of the tape-shaped aggregated fiber bundle is stacked regularly in bales and wound up.

Embodiments of the present invention will be described with reference to the drawings.

According to the present invention, a plurality of optical fibers 1 each having a core material made of glass, plastic, or other similar transparent material having a relatively high refractive index and a coating having a relatively low refractive index are provided as second optical fibers. As shown in the figure, a long tape-shaped aggregated fiber bundle 2 is prepared by stacking the fibers densely packed and stacked in even number stages such as two or four stages in parallel.

The tape-shaped aggregated fiber bundle 2 can be prepared by a known method in the form of an integral tape, or by combining a large number of individually produced optical fibers 1 by adhesion, welding, or the like.

The tape-shaped aggregated fiber bundle is integrated with sufficient strength to prevent it from falling apart during subsequent winding and other image transmission optical fiber bundle manufacturing processes, and also provides flexibility to the intermediate portion in the length direction of the fiber bundle. Therefore, it is desirable to be able to tear it apart relatively easily and without adversely affecting the optical properties by applying some force for the purpose of breaking it apart.

As a means of loosening the fiber bundles, a chemical method can be used instead of the mechanical method described above. In this case, an adhesive that is soluble in a specific solvent, such as polyvinyl alcohol or polyvinyl butyl alcohol, which is soluble in water, can be used. By integrating optical fibers using rolls, an acrylic adhesive soluble in aromatic organic solvents such as toluene and xylene, and ester-based organic solvents, the middle part of the optical fiber bundle for image transmission, excluding both ends, can be cleaned with a solvent. This melts the adhesive, which allows the individual fibers to break apart and provide flexibility.

The tape-shaped aggregated fiber bundle 2 prepared as described above is wrapped around a winding cylinder (not shown) having an outer circumferential length equal to the length of the desired image transmission optical fiber bundle. are stacked regularly and wound up, a portion is fixed with adhesive or the like, and then cut at the fixed portion.

Figure 3 is an explanatory drawing diagrammatically showing the cut end face in an open state. In the drawing, ■ is a tape-shaped aggregated fiber bundle at the beginning of winding, which was continuous to ■ before cutting. can be,
■ is a continuation of ■', and ■' is a continuation of ■ before cutting.

The following continues in the same way, and ■′ is consecutive to ■,
Indicates the end of the winding.

As is clear from FIG. 3, according to the method of the present invention, a tape-shaped aggregated fiber bundle 2 is wound up by stacking a large number of optical fibers arranged horizontally in one row in an even number of stages and integrating them. As a result, compared to the conventional method shown in FIG. 1, better image transmission can be performed without causing image shift.

In the optical fiber bundle for image transmission obtained by the method of the present invention, when light is uniformly incident on one end surface of the optical fiber bundle for image transmission as shown in FIG. The corresponding tape-like aggregated fiber bundles, ie, ■ or ■ do not contribute to light transmission.

Therefore, an undesirable dead space occurs due to the portion of the tape-shaped aggregated fiber bundle that does not contribute to the transmission of light, that is, images, but even low-resolution optical fiber bundles that are in practical use are composed of several thousand or more optical fibers. Therefore, in practice, there is no problem in making the dead space described above inconspicuous.

However, as the number of laminated layers of tape-shaped aggregated fiber bundles increases, the number of fiber bundles that make up the fiber bundle increases accordingly, resulting in a decrease in flexibility. increase is restricted.

Figure 4 shows the number of laminated layers of tape-shaped aggregated fiber bundles: 2 or 4.
This is an example of the cross-sectional shape of the fiber bundle in the case of tiers. For convenience, the cross-sectional shape of each fiber is shown as circular, but it may also be hexagonal, for example, and the upper layer to be laminated has irregularities for each fiber. Other shapes can also be used as long as the position of the aggregated fiber bundle can be set accurately.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing how the sawtooth effect occurs when image transmission is performed using an optical fiber bundle for image transmission obtained by stacking one stage of tape-shaped aggregated fiber bundles using a hexagonal arrangement method according to a conventional method. FIG. 2 is a diagrammatic perspective view of a tape-shaped assembled fiber bundle having an even number of stacked layers obtained by the method of the present invention, and FIG. Explanatory diagrammatic perspective view showing the case where
The figures are schematic diagrams showing various cross-sectional shapes of tape-shaped aggregated fiber bundles. 1... Optical fiber, 2... Tape-shaped aggregated fiber bundle.

Claims (1)

[Claims] 1 An even number of optical fibers made of a core material of a transparent material with a relatively high refractive index and covered with a transparent material with a relatively low refractive index are arranged horizontally in one row. A tape-shaped aggregated fiber bundle is formed by stacking densely packed layers in stages, and the tape-shaped aggregated fiber bundle is wrapped around a cylinder to obtain an optical fiber bundle for image transmission of a desired length. 1. A method for manufacturing an optical fiber bundle for image transmission, which comprises stacking and winding a part of the bundle in a regular manner in bales.