JPS62235908A - Optical multiple fiber - Google Patents

Abstract

PURPOSE:To obtain a multiple fiber stabilizing its flexibility without generating rugged surfaces or flaws on its outer periphery by aligning and inserting many optical fiber preforms into a pipe consisting of quartz glass and having a square section and drawing the pipe charged with the optical fiber preforms so as to contract its diameter. CONSTITUTION:Many optical fiber preforms are aligned and inserted into the square pipe 2 consisting of quartz glass and the pipe 2 and the respective optical fiber preforms in the pipe 2 are drawn at a high temperature to contract respective diameters, so that a multiple fiber 1 consisting of many optical fibers closing up together in the pipe 2 can be obtained. In this case, optical fiber preforms consisting of quartz glass are used to fill the pipe 2. When the obtained multiple fiber 1' is used as an image guide for a TV, an image can be projected to the whole screen, so that the screen can be effectively utilized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a multiple fiber with a rectangular cross section used as an image guide. A large number of preforms (hereinafter both are collectively referred to as optical fiber preforms unless otherwise specified) are arranged and filled into a pipe, and the pipe and each optical fiber preform in the pipe are further heated at high temperature in the filled state. This relates to multiple fibers with a rectangular cross section manufactured by drawing and reducing the diameter.

[Conventional technology]

Conventionally, it is well known that pipes used to manufacture multiple fibers used as image guides have a circular cross-sectional shape, and within this circular pipe there are approximately 3,000 to 100 fibers.
000 optical fiber preforms are arranged and filled, and the pipe and each optical fiber preform in the pipe are further drawn and reduced in diameter at high temperature to produce multiple fibers in which each optical fiber is fused to each other. was.

Also, multiple fibers are well known, which are made by stacking a large number of optical fiber preforms into a rectangular bundle, drawing and reducing the diameter at high temperature, and holding points at regular intervals so that the rectangular shape does not collapse. .

(Problems to be Solved by the Invention) The cross-sectional shape of the multiple fiber manufactured using the circular pipe described above is approximately circular like the pipe. When such circular multiple fibers are used as an image guide for a television, the disadvantage is that the image is not projected onto the entire screen when projected through the image guide, since the television screen is usually rectangular. . For example, as shown in Figure 3, when a circular image guide is used to project to the maximum extent on a screen with a size of 3A by 48, the area that can be projected by the circular image guide and the area of the screen are The ratio 1 is 3a·4816, which poses the problem that only about 60% of the screen can be used.

In addition, when optical fiber preforms are stacked in a rectangular shape, it is difficult to form a rectangular shape unless the optical fiber preforms have the same shape and diameter, and there are problems in that many gaps occur. , it is necessary to stack optical fiber preforms of the same shape and diameter. However, the reality is that it is extremely difficult to manufacture optical fibers with the same shape and diameter.

Furthermore, multiple fibers stacked in a rectangular shape like this are not protected and retained over the entire length of the image guide like multiple fibers manufactured by filling a circular pipe, so there may be irregularities or scratches on the outer circumferential surface. If there are any unevenness or scratches, the multiple fibers will be more likely to break when bent, reducing flexibility.

Therefore, there is a problem that it is difficult to obtain something with stable flexibility.

Therefore, an object of the present invention is to manufacture a multiple fiber that overcomes the above-mentioned problems.

[Means for solving problems]

In order to achieve the above object, the multiple fiber of the present invention is produced by arranging and filling a large number of optical fiber preforms into a pipe having a rectangular cross-sectional shape and made of quartz glass, and then drawing and reducing the diameter of the pipe. It is characterized by the fact that

Note that the term "rectangular" in the context of the multiple fiber of the present invention means a quadrilateral in which all corners are right angles, and therefore also includes a square.

τ Example] Hereinafter, the multiple fiber of the present invention will be explained in detail with reference to FIG.

FIG. 1 shows a multiple fiber (1 fiber) according to an embodiment of the present invention.
), and this multiple fiber (1) is produced by arranging and filling a rectangular pipe (2) with a large number of optical fiber preforms, and heightening both the pipe (2) and each optical fiber preform in the pipe (2). The pipe is drawn and reduced in diameter at temperature (
2) A large number of optical fibers (3) are arranged in a condensed layer.

The rectangular pipe (2) used in manufacturing the multiple fibers of the present invention is made of glass, and the glass used here may be any quartz glass6, for example, an outer diameter of 2.61 m, When pulling out a pipe made of quartz glass with an inner diameter of 2.3 mm at a rate of 0.5 m/min, the minimum temperature at which the pulling tension is 500 g or less (hereinafter referred to as the drawing temperature) is low (both 1800°C, especially The drawing temperature is preferably at least 1900°C.
If the temperature is higher than 00°C, it is difficult to uniformly deform the preform by heating it to the same degree, especially when the silica glass constituting the optical fiber preform contains additive elements, and therefore, it is difficult to heat the preform uniformly to the degree of wire drawing. It is difficult to reduce the diameter.

In addition, if the drawing temperature is lower than 1700°C, the preform should not be heated, especially if the quartz glass constituting the optical fiber preform contains pure quartz. Even when heated to L degrees, it is difficult to deform pure quartz, and therefore it is difficult to draw or reduce the diameter.

The optical fiber preform filled in the rectangular pipe (2) is also made of glass, but the glass used here may be any quartz glass, for example, the core material is pure quartz and the cladding material is 81F element. For example, silica-based glass containing

As is clear from Figure 1, when multiple fibers are manufactured using rectangular pipes, ! ! The cross-sectional shape of the multiple fibers in Structure 1 is rectangular or approximately rectangular, but the rectangular shape in a rectangular pipe does not necessarily have to have four corners pointed at right angles, and may be a gentle arc shape.

When actually using the multiple fiber of the present invention as an image guide for a television, for example, if an image is projected onto the television screen using one multiple fiber (l'') as shown in Figure 28, the image will be projected onto the entire screen. It can be projected and the screen can be used effectively.

Furthermore, instead of one multiple fiber, a combination of multiple fibers may be used. For example, as shown in FIG. 2B, four multiple fibers (l"
) can also be used in combination. in this case,
Projection can be performed using a single fiberscope with four multiple fibers inserted, or a combination of four single fiberscopes with one multiple fiber inserted.

When manufacturing the multiple fibers of the present invention, it is not necessarily necessary to use optical fiber preforms with the same cross-sectional shape and diameter, and there is no particular problem even if the shapes and diameters are slightly different. When drawn with an optical fiber preform filled inside the fiber, the diameter of the optical fiber preform is reduced, deformed, and ＼.As a result, there are almost no gaps between each optical fiber after manufacture, making it possible to create more densely packed multiple fibers. can be manufactured.

Furthermore, in the multiple fiber of the present invention, since the optical fiber is protected and held by the pipe, there is no unevenness or damage to the optical fiber itself, and it is flexible.
multiple fibers can be produced.

〔Effect of the invention〕

As explained above, the multiple fiber of the present invention is
It is manufactured using a rectangular pipe, and the radial cross section is rectangular or rectangular, which not only makes it possible to effectively utilize the entire TV screen, but also creates an optical fiber preform with a uniform shape during manufacturing. It is excellent in productivity as it is not always necessary to use

[Brief explanation of drawings]

Fig. 1 is a perspective view of a multiple fiber according to an embodiment of the present invention manufactured using a rectangular pipe, and Fig. 28 shows a case in which an image is projected onto a television screen using one multiple fiber of the present invention. Figure 2B is a diagram showing a case where four multiple fibers of the present invention are used to project a 'ζ image, and Figure 3 is a diagram showing a case where an image is projected onto a television screen using circular multiple fibers. It is a diagram. (1)...Multiple fibers (2)...
...Rectangular pipe (3) ...Optical fiber

Claims (1)

[Claims] Multiple fibers are made by arranging and filling a large number of optical fiber preforms in a pipe made of quartz glass with a rectangular cross-sectional shape, and then drawing and reducing the diameter of the pipe.