JPS59129806A - Manufacture of image guide - Google Patents

Abstract

PURPOSE:To obtain an image guide having flexibility by a few manufacturing processes by sticking fine particles of a high melting point, having functions of a lubricant and a separating material, to the circumferential surface of a strand fiber. CONSTITUTION:First of all, fine particles of a high melting point are stuck to the circumferential surface of a strand fiber. As for said fine particles, graphite, aluminum oxide, etc. are used. Subsequently, plural strand fibers to which the fine particles are stuck are arranged most tightly and one end is fixed. A strand rod is prepared by bundling plural strand fibers, and thereafter, this strand rod is heated and elongated through a heater 2 and a tension roller 3, etc. In these heating and elongating processes, each strand fiber can be prevented from being welded to each other because the fine particles of a high melting point, having also a function as a separating material are stuck. Accordingly, in this way, the welding preventing process of the strand fiber becomes unnecessary, and an image guide having flexiblity can be obtained by a few manufacturing processes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method of manufacturing an image guide made of a large number of bare fibers.

(Technical background of the invention and its problems) Image guides are applied to medical endoscopes and the like, but since they need to be inserted into vertebrae within the human body, it is desirable that they have flexibility.

Therefore, in the past, a glass layer that is resistant to acids or other chemicals was provided on the cladding of the bare fiber, and a plurality of these raw fibers were bundled together, heated and stretched, and after being integrated, both ends were removed. The glass layer was removed using acid or the like, thereby obtaining a flexible image guide in which the centers of the silicon wire fibers were separated from each other.

However, in this manufacturing method, since the responsive glass layer is present at both ends, only an image guide with a small core occupancy of the bare fiber can be obtained, and a large-scale process is required to elute the responsive glass layer. Special equipment (Utility Model Publication No. 56-47604) and waste liquid treatment are required.

In addition, in recent years, a method has been proposed in which a fusion prevention layer is provided on the surface of a bare fiber to prevent the fibers from being thermally fused together during the spinning process, thereby obtaining a flexible image guide ( Japanese Patent Publication No. 56-1111815).

However, in this manufacturing method, since the anti-fusing layer does not have the function of a lubricant, in addition to the step of providing the anti-fusing layer, a step of attaching a lubricant to the bare fiber or dipping it in a lubricant is required. is required separately.

(Object of the invention) The object of the invention is to provide a method for manufacturing an image guide having flexibility and a large core occupation rate with a small number of steps and without using large-scale special equipment. .

(Summary of the invention) The invention is based on the process of attaching a lubricant and the formation of an anti-fusion layer, etc. by attaching high-melting point fine particles having functions as a lubricant and a separating agent to the circumferential surface of a wire fiber before being drawn. The core occupancy rate can be increased by removing fine particles from both ends of a raw material rod made of a plurality of drawn strand fibers and heat-sealing both ends made of only the core and cladding layer. It is characterized by a big friend.

That is, in the method for manufacturing an image guide according to the present invention, first, fine particles having a high melting point are attached to the peripheral surface of a bare fiber.

As the fine particles, various fine particles such as graphite, aluminum oxide, mental nitride, and titanium nitride can be used.
It has a melting point of 650°C or higher. In order to attach such fine particles to the bare fiber, there is a choreography method in which the fine particles are rubbed on the peripheral surface of the fine gold-plated fiber, an electro-N coating method in which the fiber or fine particles are charged with static electricity, and a fine fine gold-plated gold coat method is applied by applying an adhesive to the fiber circumferential surface. A binder attachment method may be used, such as applying a layer or coating containing fine particles to the fiber, or treating the surface of the fine particles with an adhesive and attaching it to the fiber.Other methods include vacuum evaporation, sputtering, Ion blating method is considered, and in the case of vacuum evaporation method, the temperature is 1800℃~
It has a melting point in the range of 2500 °C! Particles are required.

Next, a plurality of cable fibers having fine particles attached thereto are arranged in a close-packed Vc array using a focusing device, and one end is fixed with a constrictor.

In this step of bundling a plurality of bare fibers, fine particles having a lubricant function are attached to each bare fiber, so it is possible to effectively prevent the peripheral surface of each bare fiber from being damaged.

In this way, a plurality of bare fibers are bundled to form a raw material rod, and then the raw material rod is heated by an annular heater and pulled by a tension roller to be heated and stretched.

In this heating and stretching step, since the fine particles with a high melting point that also function as a separating agent are attached to the valley strand fibers, it is possible to prevent the strand fibers from being fused together.

After hot-stretching the raw material rod' by 71D, the arrangement state is maintained by fixing the vicinity of both ends with a tightening tool, and fine particles are removed from both ends and the both ends vI-
7F11 Heat fusion by heating. In this thermal fusion step, since fine particles are removed, only the core and cladding layer that constitute each elemental fiber are present at both ends.

After both ends of the stretched material rod are heat-sealed as described above, an end fixing layer made of synthetic resin is coated with a gold film on both ends, and an image guide is obtained by polishing both ends. As mentioned above, each bare fiber is separated from each other, and the fused parts at both ends are formed only from the core and cladding of the bare fiber, so this image guide is flexible and has both ends. Core occupancy rate is larger than before.

In addition, in the manufacturing method of the present invention, since fine particles with a high melting point that have the functions of both a lubricant and a separating agent are used, the step of preventing the cable fibers from being fused, which was conventionally required, becomes unnecessary. In addition, in the inventive manufacturing method, it is necessary to attach fine particles to the bare fiber and remove only the fine particles at both ends of the cable fiber even after drawing, so there is no need for any large-scale special equipment.

(Example of the invention) Hereinafter, embodiments of the present invention will be described with reference to all the drawings.

Tip, core diameter 640μm 1 cladding thickness 180μm length 5
00 ■ quartz optical fiber strand 't'' 217 was not prepared,
The fiber assembly 1 (see drawing) was entirely prepared by closely aligning these optical fiber cables with a converging device to have a regular cross-sectional shape.

Next, as shown in the drawing, this fiber assembly 1 is heated at 1900° C. in a heating furnace 2 and pulled by a tension roller 3 to form a multi-fiber 4 as a bare fiber.
At the same time, this Multi 7 Eyepa 4 tray was passed as it was through a die 5 containing an emulsion containing graphite powder and an electric furnace 6, and wound up on a drum 7. The multi-fiber 4 thus produced had a hexagonal cross section and a major axis of 1.02-.

A thin layer of graphite powder was formed on its surface. Note that the process of creating the multi-fiber 4 and adhering graphite powder is performed in an inert atmosphere such as argon, thereby effectively preventing the reaction between graphite and oxygen, and adhering graphite to the circumferential surface of the multi-fiber 4. I was able to do that. In this way, after graphite powder was attached to the multi-fibers 4 as bare fibers, the multi-fibers 4Th241 were not prepared and were closely aligned with a circular cross section using a focusing device to create a bare wire rod.

Then, this wire rod was heated at 1850°C in a heating furnace and pulled with a tension crawler to a diameter of 2 m.
An IC-stretched cable rod was prepared. The multi-fibers 4 forming this drawn strand rod were completely separated from each other.

Next, by using a constrictor to tighten all the positions 10 m from both ends of the extended cable rod, both ends are added together. The graphite powder on both ends was removed and fused together by heating in an oxygen atmosphere. Finally, both terminals were hardened with epoxy resin, and
Created an image guide.

The obtained image guide had flexibility with an allowable bending radius of 300 mm or less, and had a large core occupation rate, so it could project clear images.

In addition, in a non-example, graphite powder is put into the die 5, and even if a graphite ladle is rubbed against the circumferential surface of the multi-fiber 4 using a rubbing roller set immediately after the die 5, the graphite powder is not applied to the fiber 4. It can be attached.

Further, in the non-example, the multi-fiber 4 is used as the bare fiber, but it is also possible to use a bare optical fiber that is thicker as the diameter increases.

In this case, the manufacturing process can be simplified, but the flexibility of the resulting image guide is somewhat inferior.

(Effects of the Invention) According to the invention, fine particles with a high melting point that have the functions of a lubricant and a separating agent are attached to the surfaces of the bare fibers, so that the #! The process of providing a pressure stop layer can be omitted, and since fine particles are removed from both ends of the material rod made of stretched cable fiber and both ends made of only the core and cladding are heat-sealed, the core occupancy rate can be reduced. Therefore, an image guide having flexibility and a large core occupation rate can be obtained with fewer manufacturing steps.

In addition, to attach the fine particles, you only need to use a small and simple device such as a die. It won't get any bigger. Furthermore, when graphite is used as the fine particles, the graphite can be removed and fused at both ends of the material rod at the same time, which simplifies the work.

[Brief explanation of drawings]

The drawings are schematic diagrams for explaining the process of layering a bluff eye layer on a bare fiber.

Claims (1)

[Claims] 1. After attaching fine particles as a lubricant and a separating agent, which have a higher melting point than that of the fiber, to the circumferential surface of the bare fiber, a plurality of the above-mentioned fibers are arranged in a misaligned manner and bundled. A method for producing an image guide, comprising: preparing a raw material Rondo, heating and stretching the raw material Rondo, removing the fine particles from both ends of the raw material Rondo, and heat-sealing the both ends. 2. The fine particles are made of graphite, and by heating both the terminals, the graphite of the two terminals is formed. 2. The method of manufacturing an image guide according to claim 1, wherein both ends are fused together at the same time as the removal.