JPS59204007A - Method and device for manufacturing image guide - Google Patents

Abstract

PURPOSE:To array in parallel and most densely an optical fiber strand extending over the overall length by providing a tapered hole which is redued toward the lower part, maintaning its prescribed sectional shape in a similar shape, and opened to the lower face, on a head placed in the lower part of a holder. CONSTITUTION:A holder 1 and a head 2 are continued as one body, a hole 4 whose cross section is roughly circular is provided on the holder 1, and a tapered hole 5 whose cross section is a regular hexagon is provided on the head 2. As for the tapered hole 5 of this head 2, its section is reduced gradually toward the lower part from the upper part, but any section forms a regular hexagon. Optical fiber strands 8 of a prescribed number are inserted from the upper part of the holder 1 so that its end faces all contact with the tapered hole 5 of the head 2. Subsequently, when it is vibrated, first of all, the optical fiber strand of the center is fixed, the strand is collected successively to its circumference, and an almost complete dense array is obtained except the outside circumferential part since the section of the tapered hole 5 is a regular hexagon.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention provides an apparatus for aligning optical fibers parallel to each other and in the closest density before manufacturing an image guide using a plurality of optical fibers. and a method for manufacturing an image guide using the same.

(Technical Background of the Invention) Image guides can transmit images efficiently and accurately even if their outer diameter is very small, so they are useful for RDT inspection from remote locations in narrow spaces, dark areas, and dangerous locations and properties. Alternatively, the field of use of it as a measurement device is rapidly expanding in recent years.

An image guide is made by bundling a large number of optical fibers with diameters ranging from several microns to several tens of microns in a one-to-one manner with both ends arranged in a one-to-one manner. In other words, the higher the number of pixels, the higher the resolution and the higher the performance of the image guide. Therefore, it is desirable that the diameter of the optical fibers be smaller and that they be arranged more closely with fewer gaps.

Examples of methods for manufacturing an image guide include the following methods.

(1) Single winding method A single Rc7) loop-shaped bundle is created and cut using a method in which thin optical fiber strands with a diameter of ten or more microns are arranged regularly from the beginning.

The method of laminating this in the array section is called the foil stacking method.

(2) Multi-fiber method Four relatively thick optical fibers with a diameter of several hundred microns to several millimeters are bundled into a brief bundle, which is heated and stretched to a predetermined outer diameter. Flexible in the multi-fiber method. A method for producing sexual image guides. A bundle is created using a wire with a glass layer that is soluble in a certain kind of drug on the cladding, and in a later process, the soluble glass layer in the middle, excluding both ends, is eluted with a drug to break up the wire and make it flexible. to have.

(Problems with the conventional technology) The single 7 eye per winding method has been carried out since ancient times and was used as a manufacturing method for conventional endoscopes, etc. However, it is a 0 (1) wire that has the following drawbacks. wire diameter must be highly controlled).

(2) Requires special equipment and jigs for arrangement.

(3) Wires with diameters of microns or less tend to break using this method, making it virtually impossible.

(4) It is difficult to manufacture long image guides over 100 meters long, which have recently become possible using quartz fibers, because the equipment becomes huge.

On the other hand, in the multi-fiber method, (1) the wire diameter (pixel diameter) can be easily reduced and freely selected;

(2) Extremely easy to lengthen and mass produce.

(3) The number of pixels can be dramatically increased by using multi-fiber wires (multi-multi-fiber method)
It has the advantage of 0.

To manufacture an image guide using the multi-fiber method, it is necessary to prepare a preform bundle in which wires are arranged parallel to each other and as densely as possible. This is because, as is clear from the manufacturing principle of the multi-fiber method, the arrangement of the wires in the image guide product is determined by the arrangement of the wires in the preform bundle during heating and stretching. Furthermore, in the case of the multi-multifiber method, the multifibers produced in the first step are cut into predetermined lengths and bundled, and then heated and stretched again in the second step.

In either case, disorder in the arrangement of the middle part of the 7-ohm bundle is not allowed.

A method for regularly arranging optical fiber strands is described in the following publications.

JP-A-57-73703, JP-A-55-40483
No. 57-58104 and JP-A No. 56-
No. 50132 discloses a method of filling and arranging strands in a pipe. However, with this method, the first
As shown in the figure, the arrangement of the outer periphery of the bundle near the inner wall of the pipe is disrupted, creating voids. In order to arrange them neatly and completely fill the pipe with optical fiber strands, extremely skillful skill is required to replenish the created voids with strands later, as shown in Japanese Patent Application Laid-open No. 56-72405. Manual work is required.

Time 56-35843, JP 50-12308, JP 51-104359 and JP 51-
The method described in Publication No. 53829 attempts to align the wires using a liquid flow or in addition to this, ultrasonic vibration, etc., but in all of these methods, one end of the bundle to be aligned is fixed in advance. It is necessary to do this, and the quality of the bundle alignment is determined at this stage of fixing the terminal. In reality, it is difficult to obtain a wire in which the wires are arranged in parallel and closest by simply bundling the ends of the wire bundle. Furthermore, this method requires a large-scale device called a fluid circulation device, and further requires complicated steps such as setting unaligned bundles into the device and removing liquid from between the bundle wires after alignment.

JP 50-20736, JP 53-83638, JP 49-123633, and Time 57-
The method described in Japanese Patent No. 16322 involves arranging strands in parallel in a single layer, fixing them with a binder or tape to form a sag, and winding them up to form an array bundle. Due to the presence of binders and tapes, it is impossible to form dense bundles.

(Objective of the Invention) The first object of t' ft, (114) is to provide a method for manufacturing an image guide in which all optical fiber strands are arranged parallel to each other and close-packed over the entire length.

A second object of the present invention is to provide a manufacturing apparatus that achieves the first object with simple operations and in a short time.

(Summary of the Invention) The present invention consists of a holder that holds a plurality of optical fiber strands almost vertically, and a head disposed below the holder, and the head maintains a predetermined cross-sectional shape similar to the holder. It has a tapered hole that shrinks downward while being
The present invention also relates to an image guide manufacturing apparatus characterized in that the tapered hole has an opening on the lower surface.

The present invention also provides a step of arranging a plurality of optical fiber strands almost vertically on a tapered hole whose lower ends are in contact with the tapered hole while maintaining a predetermined cross-sectional shape in a similar manner. In this state, the optical fiber strands are vibrated to arrange them densely, and the lower surface of the tapered hole is opened and the optical fiber strands with their lower ends disposed in this opening are pulled out downward as a whole. The present invention relates to a method for manufacturing an image guide characterized by the following.

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

FIG. 2 is a partially cutaway longitudinal sectional view of an embodiment of the image guide manufacturing apparatus of the present invention.

This is composed of a holder 1, a head 2, and a base 3 in order from the top. The holder 1 and the head 2 are integrally continuous, and the holder 1 is provided with a hole 4 having a substantially circular cross section, and the head 2 is provided with a tapered hole 5 having a regular hexagonal cross section. The cross section of the tapered hole 5 of this head 2 gradually decreases from the top to the bottom, but each cross section has a regular hexagonal shape. The tapered hole 5 is directly connected to the tapered hole 6 of the base 3. Therefore, the tapered hole 6 of the base 3 also has a regular hexagonal cross section.

The base 3 and the head 2 can be separated, and when the base 3 is separated from the head 2, the lower opening of the lower surface of the head 2 is opened.

FIGS. 3 and 4 are explanatory diagrams showing an embodiment of the method of the present invention.

First, a predetermined number of optical fibers 8 are inserted from above the holder 1 shown in FIG.
Make sure that all of its end surfaces touch.

Next, when vibration is applied to this, the central optical fiber strand is first fixed, and the strands gather around it in order.Since the tapered hole 5 has a regular hexagonal cross section, it is almost completely removed except for the outer periphery. It becomes a dense array.

When the back base 3 is separated from the head 2 and lowered, the bundles (with outer edges in a hexagonal shape) are tightly arranged in the opening T.
It is drawn out more.

During this work as well, it is preferable to apply vibration to the optical fiber strand 8 or the holder 1 in order to reduce the friction between the optical fiber strand 8 and the peripheral edge of the open lower part. This vibration may be selected depending on the situation, such as by tapping with a hand or using a vibrator.

In the above method, the size of the aperture of the head 2 is accurately calculated and set in advance from the outer diameter of the optical fiber strand 8. In addition, if a number of optical fiber strands that are sufficiently larger than the number of optical fiber strands to be drawn out at this time are put into the holder 1, the excess strands press against the bundle from the outer periphery, so that the strands can be arranged quickly and accurately. . Also, the tapered hole 6 of the base 3
has a lowest part 9 at its center, but if this part is not sufficiently sharp, the strands will not start arranging from the center, which will slow down the arranging speed.

FIG. 5 shows that bundles 10, which have been arranged densely in advance, are inserted into a head 12 having an opening 11 that is sufficiently wider than the bundles 10.
After that, the optical fiber wire 8 is inserted into the tapered hole 19 on the outer periphery.
It shows you how to apply it accordingly.

According to this method, the base 13 may be a flat plate or one having a shape corresponding to the shape of the opening 11 as shown in the figure and having a hole 14 with a flat bottom surface.

In this embodiment, the holder 15 is similar to that described above and the head 1
The opening 11 of No. 2 has a predetermined length in the vertical direction while maintaining its cross-sectional shape.

At this time, if an adhesive or the like is applied to the bottom surface 16 of the base 13, and the lower end of the bundle is fixed to the base 13 L[J and the base 13 is lowered, the following process can be performed.

FIG. 6 shows that both ends of the bundle 1T are supported by the head 12 and base 13 of FIG. 5, and a two-part sheath 1B, whose cross-sectional shape is shown in FIG. 7, is placed over the outer periphery of the bundle 17. ing.

If such a sheath is placed over the bundle, the arrangement of the optical fibers constituting the bundle will not be disturbed and it will be easy to handle. Therefore, as shown in FIG. 9, a dummy rod 20 is fused to the end face of the bundle 17. It can be made into a structure that is easy to stretch in the subsequent thinning process.

Without this sheath, when fusing the dummy rod 20, the optical fiber strands on the outer periphery of the bundle 17 would bend outward, making it difficult to uniformly fuse all the strands to the dummy rod 20.

It is also possible to insert the bundle into the tube 21 shown in FIG. This tube 21 is heated and thinned together with the bundle 21 as shown in FIG.

When a bundle obtained in an intermediate step is stretched by a multi-multi-fiber method or the like, it is easier to rearrange the bundle if the outer shape is hexagonal. However, since the final product is easier to handle and has better flexibility if it has a rounded outer shape, a tube with a rounded outer shape is used in this way to adjust the bundle outer shape. During stretching, dummy rods 23 and 24 are fused to both ends of the tube 21, one dummy rod 23 is attached to a chuck, and the bundle 11 is heated while the other dummy rod 24 is being held. When directly welding the bundle and the dummy rod as shown in FIG. 9, the work will be easier if a short tube is used.

The above method is suitable for manufacturing an image guide that is a collection of optical fibers whose main component is quartz glass.The boulder and base are made of Teflon or metal, and the sheath and tube are made of quartz glass. . If the optical fiber wire is made of multi-component glass or the like, the sheath or tube can be made of glass or the like with lower heat resistance.

Further, the holder may be tilted slightly from the vertical as long as it is sufficient for arranging the optical fiber strands. Furthermore, although the tapered hole of the head is shown as an example of a regular hexagonal shape, it is possible to similarly arrange the strands densely in a circular shape or a regular polygonal shape except for the multi-circumferential portion.

(Effects of the Invention) According to the apparatus and method of the present invention, it is possible to easily arrange optical fibers in a dense array in a short time.

Moreover, since no unnecessary external force or shock is applied to the wire, the wire is less likely to be damaged or broken.

Furthermore, it is easy to handle after alignment, simplifying the manufacturing of the image guide.

Example 1 Approximately 1,500 quartz glass optical fibers with an outer diameter of 493 μm and a length of 50 cm were inserted into the device shown in Fig. 2, and after being vibrated for 5 minutes with an electromagnetic vibrator, the base was pulled away from the head and the fibers came out of the opening. The bundle was pulled out while being vibrated. The optical fiber strands became a bundle of 919 regular hexagonal pieces with no disorder in their arrangement.

This was housed in a tube with an average wall thickness of 1 fin as shown in FIG. 8, heated at 2000° C., and stretched to an outer diameter of 2.

The outer shape was circular and no disturbance occurred in the wire arrangement. The allowable bending radius of the one stretched without a tube was 52 mm, while the one with a tube covered had 29 fins.

Example 2 The same optical fiber wire as in Example 1 was prepared in advance at 217 mm.
The books are arranged in a dense hexagonal arrangement and inserted into the device shown in Figure 5, and approximately 120
A bundle similar to that of Example 1 was obtained by feeding 0 pieces from the outer periphery.

When this end face was covered with the sheath shown in Figure 7 and the dummy rod was fused, the bundles were lined up approximately 5 m apart near the end, and all...! I was able to turn it into a W.

[Brief explanation of drawings]

FIG. 1 is a partial end view of optical fibers arranged in a cylinder, FIG. 2 is a partial longitudinal sectional view of the device of the present invention, and FIGS. 3 and 4 are detailed explanatory views of the present invention. Fig. 5 is an explanatory diagram of another embodiment, Fig. 6 is an explanatory diagram of how to handle the bundle, and Fig. 7 is an explanatory diagram of another embodiment.
Figure 8 is a cross-sectional view of the sheath, Figure 8 is a cross-sectional view of the tube, Figure 9 is a side view showing how the dummy rod is fused to the end of the bundle, and Figure 10 is a vertical cross-sectional view of the bundle covered with the tube. be. 8 ----1------ Optical fiber wire 1, 15------ Holder 2, 12---Head 3, 13------ -- Base 5.19 --- 1 ~ -- Head taper hole 7 --
---1--------

Claims (1)

[Claims] 1. Consisting of a holder that holds a plurality of optical fiber strands substantially vertically, and a head disposed below the holder, the head maintains a predetermined cross-sectional shape similar to the holder. An image guide manufacturing apparatus 2 characterized by having a tapered hole that does not shrink downward and having an opening on the lower surface of the tapered hole, the image guide manufacturing apparatus 2 has a tapered hole that does not shrink downward, and has an opening on the lower surface of the tapered hole, and the image guide 2 has a tapered hole that does not shrink downward. The step of arranging a G number optical fiber strand almost vertically on the taper hole to be touched, with its lower end in contact with the taper hole, and in that state, vibrating the optical fiber strand to shape it into a shape. A method for manufacturing an image guide, comprising: arranging the optical fibers densely; and opening the lower surface of the tapered hole and placing the lower end in the opening. 3. The method for manufacturing an image guide according to claim 2, wherein the optical fiber is a multi-fiber. 46. The method for manufacturing an image guide according to claim 2, wherein a portion of the tapered cross section is a regular polygon.