JPS59162508A - Manufacture of optical fiber bundle - Google Patents

Abstract

PURPOSE:To perform excellent vapor deposition by deforming the outer circumference of an end surface of a conduit which is chamfered and deformed from a sharp-ridge state to a surface state. CONSTITUTION:Numbers of optical fibers each formed by coating core glass 1 which has a relatively high refractive index with coating glass which has a relatively low refractive index and acid-soluble glass (glass 2a including both) are heat-sealed and drawn to form the conduit 3. The end surface of the conduit 3 is polished and the ridge formed of the end surface and side surface is chamfered by a chamfering dish 9a; and vapor deposition on the end surface is carried out and acid is brought into contact while the end surface is coated to elute the acid-soluble glass 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical fiber bundle, and in particular to chamfering a ridge formed by the end and side surfaces of a conduit to provide a durable optical fiber bundle.

First, to explain the method for producing an optical fiber bundle using the acid dissolution method, a sheath glass pipe having a relatively low refractive index and an acid-soluble glass pipe are set around the outer periphery of a core glass rod having a relatively high refractive index. Thereafter, one end is heated and stretched to reduce the diameter to a medium diameter, thereby forming a triple glass wire. Next, after collecting a large number of triplet IIJ.

By integrating this under heat and pressure, a parent conduit is formed, which is further heated and stretched from one end of this parent conduit t' to reduce the outer diameter to the required degree. Form a child conduit (hereinafter referred to as a conduit).

The conodit thus obtained can be used for the purpose of image transmission, but the entire outer periphery of each strand 1, which has an effective image transmission ability, is covered with an acid-dissolved glass layer 2aK. When viewed from the end, as shown in the enlarged sectional view button of the AT diagram (usually, each strand 1 is assembled in a close-packed manner, and a hexagonal acid-molten glass layer 2a is seen between each strand 1).

Therefore, bundles having such a structure tend to deteriorate over time and cannot withstand long-term use.

That is, in general, acid-soluble glass is not only easily dissolved in resistant liquids such as nitric acid and sulfuric acid, but also has insufficient weather resistance and water resistance.

And % busy medical endoscope (in vivo portal moisture).

When moisture comes into contact with the end face of the above-mentioned flexible bundle by rinsing with water, adding ethylene oxide sterilization, or immersing the IC in a sterilizing chemical solution, the acid of each strand l at this end is removed. The molten glass layer 2a is easily deteriorated. Even a small amount of the acid-dissolved glass layer 2 & that has changed in quality flows in and out on the end face, flows and spreads, and as a result of repeating melting and drying crystallization (repeatedly), it has a large adverse effect on the image transmission efficiency of each strand 1.

Therefore, in order to resolve such defects, the end face of the conduit is polished and then the end face at the end of the conduit is polished to allow clear image transmission.

A transparent glass coating is deposited on the outer peripheral surface near the end face by vacuum deposition. As the next step, covers made of wax or plastic are attached to both ends of the fungit to cover it, and then the whole is immersed in an acidic liquid. The acid-dissolved glass layer formed by the glass vibe of each wire in the exposed portion of the conduit that contacts the acidic liquid other than both ends covered by the cover is dissolved in the acidic liquid from its outer periphery, and therefore the above force/ % - [Each strand in the center of the conduit other than the covered ends loses its cohesive strength and separates into pieces. As a result, the central portion of the conduit can be provided with sufficient flexibility.

After performing known treatments such as neutralization and water washing on the part, remove the covers 7 at both ends.Click the button to maintain the condensed and connected ends as in the case of the conduit 60, and connect the ends between these two ends. Flexible bare bundles can be manufactured.

In the above optical fiber bundle manufacturing process, after polishing the end face of the conduit, the ridge (outer periphery of the end face) formed by the blending of the polished end face and side surface of the conduit is a sharp groove.In this state, the conduit When a transparent glass film is deposited on the edge of the end face and the outer peripheral surface near the end face by vacuum evaporation, the evaporation agent is difficult to clean on the sharp edges (and even if it is evaporated, it is not easily peeled off). Therefore, there is a drawback that moisture and the like come into contact with the device during the primary process or when it is used as an endoscope, making reliable image transmission impossible.

Furthermore, during the busy transportation or setting process for depositing the conduit, sharp edges were sometimes lost.

The purpose of the present invention is to solve the above-mentioned problems, to polish the ridge formed by the end face and side face of the conduit using a polishing plate, and to provide a solid transparent glass coating by X-evaporation, thereby creating an optical system that can transmit clear images. There is a fiber bundle to offer.

Hereinafter, two embodiments of the present invention will be explained based on the drawings.

FIG. 2 shows an apparatus for polishing the sharp edge 4 where the end face of the conduit 3 and the measurement surface meet.

A motor 7 supported by a KL-shaped channel 6 on the mounting table 5 is fixed, and a polishing surface 9 is provided at the tip of a drive shaft 8 of the motor 7.
is firmly supported with adhesive or the like.

As shown in FIG. 3, four types of polishing surfaces 9 are available, 9a to 9d. Polishing surfaces 10a to 10d of conical recesses are formed on the end face of each polishing surface, and the opening angles θa to θd of the conical recesses forming each polishing surface are set to 90 degrees, 90 degrees, 45 degrees, and 135 degrees. , polish the edge 4 in this order.

The polishing surface 9a has diamond mixed therein, and the other three types are pellet plates made of cerium oxide.

In the polishing process, the polishing surface 9a containing diamond is attached to the polishing device shown in FIG.
The edge 4 of the button is roughly polished to approximately 90 degrees, and then the button is polished at a predetermined angle using polishing surfaces 9b, 9c, and 9d made of cerium oxide. The resulting edges 4 of the conduit 3 have polished angles αb and α, as shown in FIG. and 9 of αd
Continuous chamfering at 0 degrees, 45 degrees and 135 degrees is possible.

As can be seen from the chamfer shown in Figure 3, it is preferable for the chamfer to be close to an arc shape, so the opening angle of the conical recess provided in the polishing plate does not necessarily have to be the above-mentioned angle. It is.

The outer periphery of the end face of the conduit, which has been chamfered and deformed in this way, has been deformed from a sharp ridge state to a surface state.
It is easy for the vapor deposition agent for reinforcement to adhere to the material (which allows for good vapor deposition. Also, since the sharp edges have been blunted, there is no chance of damage to the outer periphery of the end face during the work process such as carrying it in).

When used endoscopically, the polished optical fiber bundle can transmit a clear image.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the end of the conduit, Figure 2 is a device for polishing the end of the conduit, Figure 3 is a sectional view showing the polished surface, and Figure 4 is a diagram showing the end polished. . 3... Conduit, 9... Polishing plate poison 2/8204504 2ri

Claims (1)

[Scope of Claims] (Li) A large number of optical fibers are assembled in which a core glass with a relatively high refractive index, a coating glass with a relatively low refractive index, and an acid-melting glass are sequentially soldered to surround the core glass. , which is heat-fused and then heat-stretched to form a conduit.
The end face is polished and the ridge (1ie outside the end face) formed by the blending of the end face and side face is chamfered with a chamfering plate, and then the end 1 m is vacuum deposited and the end is further coated and brought into contact with acid. 1. A method for producing an optical fiber bundle, comprising the steps of: 1 dissolving acid-dissolved glass; (2) The method for manufacturing an optical fiber bundle according to claim M1, wherein the edge of the conoguit chamfered with the chamfer plate is formed to approximate a circular arc. (3) The method for manufacturing an optical fiber bundle according to claim 1, wherein the chamfering is performed using a chamfering plate having a concave polished surface. (4) The method for manufacturing an optical fiber bundle according to claim 3, wherein the four parts of the chamfered plate are conical and have different opening angles. (5) The opening angle of the conical recess provided in the above chamfered plate is 4
5. The method for manufacturing an optical fiber bundle according to claim 4, wherein the angles are 5 degrees, 90 degrees, and 135 degrees. (6) The method for manufacturing an optical fiber bundle according to any one of claims 1 to 5, characterized in that the conical recess of the chamfered plate is installed in the direction of the lateral force.