JPS6146412B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical viewing tube for a rigid endoscope.

Conventionally, in the optical tube of a rigid endoscope, for example, as shown in FIG. 1A, a pipe material b for an observation optical system channel is fixed in an outer tube a, and an optical fiber bundle c for illumination is inserted and fixed. There is also a method in which an optical fiber bundle C is fixed to a pipe material b and a mantle tube a is placed over it, as shown in FIG. 1B. An observation optical system d using a light transmission body as shown in A or an observation optical system e using an optical fiber bundle as shown in FIG. 2B is inserted and fixed. Therefore, in both cases, many steps are required for assembly, and these minute parts must be handled with great care during assembly, requiring skill to assemble, making them unsuitable for mass production. It was expensive.

The present invention was made based on the above circumstances, and its purpose is to simplify the manufacturing process by allowing continuous mass production, and by simultaneously incorporating an observation optical system into one piece. It is an object of the present invention to provide a method for manufacturing an optical viewing tube, which enables cost reduction.

Hereinafter, the first invention will be explained based on an embodiment shown in FIGS. 3 to 7. In the figure, 1 indicates an optical viewing tube in a rigid endoscope, and this optical viewing tube 1
is composed of a glass jacket tube 2, a glass pipe 3 inserted inside the tube for forming a treatment instrument insertion channel, an observation optical system, that is, an observation optical fiber bundle 4, and an illumination optical fiber 5. . The optical fiber bundle 4 for observation is made into a rod shape by bundling a large number of optical fibers 4a shown in FIG. 5 by heat welding or the like. The optical fiber 4a has a covering glass 6 having a relatively high refractive index covered with a covering glass 7 having a relatively low refractive index. On the other hand, as shown in FIG. 6, the illumination optical fiber 5 is made by covering the outside of a core glass 8 with a relatively high refractive index with a covering glass 9 having a relatively low refractive index, and then melting the outside with an acid. The optical fiber 5 for illumination is covered with a layer 10 of acid-soluble glass and has such a structure.
is tightly inserted throughout the inside of the glass jacket tube 2. It should be noted that a biopsy tool and other treatment tools (not shown) are inserted into the treatment tool insertion channel 3a formed by the glass pipe 3.

Next, a method of manufacturing the optical viewing tube 1 will be explained. First, as shown in FIG. 7, a glass pipe 3 for forming a channel and a glass pipe for observation, which are bundled in advance into a rod shape by means such as heat welding, are placed inside a large diameter glass jacket tube 2 before being heated and stretched. Optical fiber bundles 4 are arranged in parallel, and an acid-dissolving glass rod 11 is inserted into the glass pipe 3. Then, the illumination optical fiber 5 is tightly inserted through the entire gap between the inner surface of the glass jacket tube 2, the glass pipe 3, and the observation optical fiber bundle 4. Then, each of these glass materials in the glass jacket tube 2 is heated together with the glass jacket tube 2 by the heater 12, and is stretched by the rollers 13 until it reaches a predetermined diameter. As a result, the diameter of each glass material housed inside the glass jacket tube 2 is reduced at the same rate, and when the glass jacket tube 2 has been reduced to a desired diameter, it is cut to a predetermined length by the cutter 14. do. Furthermore, glass pipe 3
Since the glass rod 11 is inserted inside, the diameter of the glass pipe 3 is uniformly reduced without being distorted during heating and stretching.

After cutting with the cutter 14, only the acid-dissolved glass rod 11 is dissolved and removed by immersing it in an acid solution such as nitric acid to form a hollow channel 3a, thereby forming an optical viewing tube as shown in FIG. 1 is completed. Note that when melting the glass rod 11, the end faces of the illumination optical fibers 5 are coated to prevent the acid-soluble glass layer 10 from being eroded by the acid.

However, according to the first method of the present invention described above,
Initially, the material is a large-diameter glass jacket tube 2 and each glass material housed inside the tube is heated and stretched to reduce its diameter at the same rate to the desired diameter.At the same time, the observation optical system is Since the optical fiber bundle 4 can be integrated at the same time, small-diameter optical viewing tubes can be easily and continuously produced, and the troublesome assembly work required in the conventional art is eliminated.
In addition, the channel 3a can be easily formed by melting the acid-dissolved glass rod 11, making mass production possible, and manufacturing can be performed at high efficiency and at low cost. In addition, glass pipes 3 with various cross-sectional shapes are available.
By using this method, channels with irregular cross sections can be easily obtained. Note that if it is desired to obtain a plurality of channels, a plurality of glass pipes 3 may be provided.

Next, the second method of the present invention will be explained. Since this second method is almost the same as the first method of the present invention described above, a description of the common parts will be omitted and only the different points will be described. That is, in this second method of the present invention, the steps up to obtaining the optical viewing tube 1 shown in FIG. Cut and remove the length of the optical fiber for illumination 5.
expose... By immersing this exposed portion in an acid solution, the acid-dissolved glass layers 10 of the illumination optical fibers 5 are dissolved and removed. When the acid-dissolved glass layer 10... is removed, each optical fiber 5
...The mutual welding is released and the fibers become independent of each other, allowing them to bend freely. Therefore, as shown in FIG. 8, when the illumination light source 15 is located on the side of the optical viewing tube 1, the leading end portions 5a of the illumination optical fibers 5 are bent toward the light source 15. It is possible to do so. In addition,
Since the observation optical fiber bundle 4 remains in the welded state, it is maintained in a straight rod shape.

As described above, according to the second method of the present invention, by melting the acid-soluble glass layer 10, the illumination optical fiber 5 can be made bendable, so that it can be bent according to the position of the illumination light source or the like. The end of the illumination optical fiber 5 can be freely shaped to suit the direction of illumination in front of the visual tube.

Next, a third method of the present invention will be explained. This third method is almost the same as the second method of the present invention, but differs from the second method in that acid-melted glass is used as the glass jacket tube 2. That is, when removing the glass jacket tube 2 by its length, the illumination is removed by dissolving and removing the glass jacket tube 2 over its length with acid, instead of cutting it as in the second method of the present invention. The optical fibers 5 are exposed and the acid-soluble glass layer 10 is eluted.

Therefore, according to this third method, the end portion of the glass jacket tube 2 can be removed without cutting the glass jacket tube 2, which has the advantage of further facilitating manufacturing.

As explained above, according to each of the methods of the present invention, a large diameter glass jacket tube, a glass pipe as a material,
Optical viewing tubes of the desired diameter are obtained by heating and stretching various glass materials such as optical fibers to reduce the diameter.Since channels can be easily formed by dissolving and removing acid-dissolved glass rods, optical viewing tubes are It can be produced easily and continuously, and costs can be reduced. Moreover, since the optical fiber bundle for observation is heated and drawn at the same time and is housed in one piece, there is no need to carefully insert and fix observation optical system members into the outer tube, which was required in the past. Manufacturing can be made easier. Furthermore, according to the second method of the present invention, by dissolving and removing the acid-dissolved glass layer covering the optical fiber for illumination, the optical fiber for illumination can be made bendable, so the position of the illumination light source, etc. This allows the optical fiber to be freely bent and molded to suit the needs of the user, increasing the degree of freedom in designing the endoscope. Furthermore, according to the third method of the present invention, by using acid-melted glass for the glass mantle, unnecessary parts of the mantle can be removed without cutting, in addition to the effects of the first and second inventions. This has the advantage of further simplifying the manufacturing process.

[Brief explanation of the drawing]

FIGS. 1A and B are longitudinal side views of a conventional optical viewing tube, FIGS. 2A and B are longitudinal side views of a conventional observation optical system member, and FIG. 3 is a side view of a conventional optical viewing tube manufactured by the first method of the present invention. FIG. 4 is a perspective view of the optical viewing tube, FIG. 5 is a vertical front view of the observation optical fiber, FIG. 6 is a vertical front view of the illumination optical fiber, and FIG. 7 is a vertical side view of the optical viewing tube. 8 is a process explanatory diagram schematically showing the steps of the first method of the present invention, and FIG. 8 is a longitudinal sectional side view of an optical viewing tube manufactured by the second or third method of the present invention. DESCRIPTION OF SYMBOLS 1... Optical viewing tube, 2... Glass jacket tube, 3... Glass pipe for channel formation, 4... Optical fiber bundle for observation,
4a... Optical fiber for observation, 5... Optical fiber for illumination, 1
0...Acid-dissolved glass layer, 11...Acid-dissolved glass rod.

Claims (1)

[Scope of Claims] 1. A glass pipe for forming a channel and a pre-bundled optical fiber bundle for observation are arranged side by side in a glass jacket tube, and an acid-dissolving glass rod is inserted into the glass pipe for forming a channel. and over the entire gap between the inner surface of the glass jacket tube and the glass pipe and optical fiber bundle for observation,
Optical fibers for illumination each having a surface covered with a layer of acid-fused glass are inserted closely, and each of these glass materials in the glass jacket tube is heated and stretched together with the glass jacket tube to reduce its diameter, and then the diameter is reduced to a predetermined length. A method for producing an optical viewing tube, which comprises cutting the acid-dissolved glass rod into pieces, and then dissolving and removing the acid-dissolved glass rod with an acid to form a channel. 2 A glass pipe for forming a channel and a pre-bundled optical fiber bundle for observation are arranged in parallel in the glass jacket tube, and an acid-dissolving glass rod is inserted into the glass pipe for forming the channel, and the glass jacket Throughout the gap between the inner surface of the tube and the glass pipe and optical fiber bundle for observation,
Optical fibers for illumination each having a surface covered with a layer of acid-fused glass are inserted closely, and each of these glass materials in the glass jacket tube is heated and stretched together with the glass jacket tube to reduce its diameter, and then the diameter is reduced to a predetermined length. The acid-dissolved glass rod is then dissolved and removed with acid to form a channel, and the acid-dissolved glass layer of the illumination optical fiber led out from the end of the glass jacket tube is dissolved and removed with acid to form an optical fiber. 1. A method for manufacturing an optical viewing tube, characterized in that the tubes are bendable independently of each other. 3 A glass pipe for forming a channel and a pre-bundled bundle of optical fibers for observation are arranged side by side in a glass jacket tube made of acid-dissolved glass, and an acid-dissolved glass rod is inserted into the glass pipe for forming the channel. , and the illumination optical fibers each having a surface covered with an acid-dissolved glass layer are closely inserted throughout the gap between the inner surface of the glass jacket tube, the glass pipe, and the optical fiber bundle for observation. Each of these glass materials in the outer tube is heated and drawn together with the glass outer tube to reduce the diameter, and then cut into a predetermined length, and then the acid-dissolved glass rod is dissolved and removed with acid to form a channel, The end portion of the glass jacket tube is dissolved and removed over a desired length with an acid to expose the illumination optical fiber, and the acid-dissolved glass layer of the optical fiber is dissolved and removed with an acid at this portion, and the optical fibers are mutually removed. A method for manufacturing an optical viewing tube, characterized in that the tubes are independently bendable.