JPS6146411B2 - - 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.

The optical viewing tube of a rigid endoscope is generally constructed by inserting a treatment instrument insertion channel, an observation optical system channel, an optical fiber bundle for illumination, etc. into a jacket tube made of metal or the like. and as shown in Figure 2, the mantle a and each channel b, c
The existence of dead space s that is not used effectively in the gaps, etc., is an obstacle to reducing the diameter of the optical viewing tube.
Since the outer diameter of the lamp cannot be made too large, it has the disadvantage that sufficient illuminance cannot be obtained. Moreover, the assembly work of inserting and fixing pipe materials for each channel, optical fiber bundles for illumination, etc. into the jacket tube is time-consuming, making it unsuitable for mass production and high in cost.

This invention was made based on the above circumstances, and the purpose is to create an optical viewing tube that can be formed into a small diameter optical viewing tube, provides bright illumination, and can be mass-produced to reduce costs. The purpose is to provide a manufacturing method.

Hereinafter, an embodiment of the first invention will be described with reference to FIGS. 3 to 6. In the figure, reference numeral 1 denotes the main body of the rigid endoscope, which is composed of an eyepiece section 2 and an optical viewing tube 3. The optical viewing tube 3 also includes a glass jacket tube 4, a large number of illumination optical fibers 5 inserted into the tube, an observation optical system channel 7 and a treatment instrument insertion channel 8 formed as described below. It is configured with. As shown in FIG. 5, the illumination optical fibers 5 are made by covering the outside of a core glass 9 with a relatively high refractive index with a covering glass 10 with a relatively low refractive index. 5 are tightly inserted throughout the glass jacket tube 4 except for the channels 7 and 8. An observation optical transmission body (not shown) is inserted through the observation optical system channel 7 so that the inside of the body cavity can be observed. On the other hand, a biopsy device such as biopsy forceps or other treatment device (not shown) is inserted through the treatment device insertion channel 8 .

Next, a method of manufacturing the optical viewing tube 3 will be explained. First, as shown in FIG. 6, acid-soluble glass rods 11 and 12 for forming channels that can be dissolved with acids are placed in a large-diameter glass jacket tube 4 before being heated and stretched.
At the same time, the optical fibers 5 are inserted and arranged densely throughout the gap between the glass rods 11, 12 and the inner surface of the glass jacket tube 4. The glass jacket tube 4, glass rods 11, 12, and optical fibers 5 are heated together by a heater 13 and stretched by rollers 14 to a predetermined diameter.
As a result, the diameter of each glass material housed inside the glass jacket tube 4 is reduced at the same rate, and when the glass jacket tube 4 has been reduced to a desired diameter, it is cut to a predetermined length by the cutter 15. do. After cutting, the glass rods 11 and 12 are immersed in an acid solution such as nitric acid to dissolve and remove only the glass rods 11 and 12, forming hollow channels 7 and 8.

However, according to the first method of the present invention described above,
Since the illumination optical fibers 5 are arranged in all parts of the glass jacket tube 4 other than the channels 7 and 8, the space of the jacket tube 4 can be effectively used and expanded without creating a dead space as in the conventional case. A passage for illumination light can be secured. Therefore, bright illumination can be obtained, and the optical viewing tube 3 can be formed to have a small diameter in order to obtain the same amount of light as the conventional one. In addition, since there is no pipe material to form the channel as in the past, the optical viewing tube 3
This allows the outer diameter to be made even thinner.

Furthermore, according to the above method, the materials initially include the large-diameter glass jacket tube 4, the glass rods 11 and 12,
Since each glass material such as the optical fiber 5 is heated and stretched and reduced in diameter at the same rate to achieve the desired diameter, small-diameter optical viewing tubes can be produced easily and continuously, and unlike conventional methods. This eliminates the need for troublesome assembly work. Moreover, the channels 7 and 8 can be easily formed by melting the acid-dissolved glass rods 11 and 12, allowing for mass production and high efficiency and low cost manufacturing. Moreover, glass rods 11 and 12
By using materials with various cross-sectional shapes, channels with irregular cross-sections can be easily obtained.

Next, the second method of the present invention will be explained. This second method is almost the same as the first method of the present invention described above, but differs from the first method in that acid-melted glass is used as the glass jacket tube 4, and this glass jacket tube 4 is The purpose is to dissolve and remove the glass rods 11 and 12 in the same manner as the acid-dissolved glass rods 11 and 12. That is, the gist of the second method of the present invention is to insert an acid-dissolved glass rod for forming a channel into an outer tube made of acid-dissolved glass, and to insert the acid-dissolved glass rod between the inner surface of the glass outer tube and the acid-dissolved glass rod. A large number of optical fibers for illumination are inserted densely throughout the gap, each of these glass materials is heated and stretched to reduce the diameter, and then cut to a predetermined length.Then, the acid-melted glass rod is heated with acid. The channel is formed by dissolving and removing the outer tube made of acid-soluble glass, and the outer tube made of acid-soluble glass is also removed by dissolving with acid.

Therefore, according to the second method of the present invention, since the glass jacket tube 4 can be removed, there is an advantage that the optical viewing tube 3 can be formed to have a smaller diameter.

Furthermore, the third method of the present invention will be explained below. This third method is almost the same as the first method of the present invention described above, but differs from the first method in the following points:
An acid-dissolved layer is formed by thinly arranging acid-dissolved glass fibers over the entire inner circumference of the glass jacket tube 4, and this acid-dissolved layer is applied at the same time as or before or after melting the acid-dissolved glass rods 11 and 12. The objective is to extract and remove the glass jacket tube 4 by melting it. In other words, the gist of the third method of the present invention is as follows:
An acid-dissolved glass rod for channel formation is inserted into the glass envelope tube, and a large number of optical fibers for illumination are inserted densely throughout the gap between the inner surface of the glass envelope tube and the acid-dissolved glass rod, and the An acid-dissolved layer is formed by thinly arranging acid-dissolved glass fibers over the entire inner circumference of the glass jacket tube, and each of these glass materials is heated and stretched to reduce its diameter, and then cut into a predetermined length. Thereafter, the acid-dissolved glass rod is dissolved and removed with an acid to form a channel, and the acid-dissolved glass fiber, that is, the acid-dissolved layer is dissolved with an acid, and the glass jacket tube is extracted and removed.

Therefore, according to this third method, the second
Since the glass jacket tube can be removed in the same way as in the method described above, there is an advantage that the optical viewing tube can be formed to have a smaller diameter.

Note that various modifications can be made in carrying out the present invention as long as they do not go against the gist of the present invention. For example, the inner surface of each channel may be coated to protect the inner surface of the channel and prevent reflection of illumination light. Further, glass having a relatively low refractive index may be used as the glass jacket tube.

As explained above, according to each of the present inventions, since the illumination optical fiber can be disposed throughout the interior of the glass jacket tube except for the channel, there is no dead space, and the space inside the jacket tube can be effectively used to provide a wide illumination light. A passageway can be secured. Therefore, bright illumination can be obtained, and the optical viewing tube can be formed to have a smaller diameter. Moreover, each large-diameter glass material is heated and stretched together to reduce the diameter and obtain an optical viewing tube with a desired diameter.
Since each channel can be easily formed by dissolving and removing an acid-dissolved glass rod, troublesome assembly work is eliminated, and small-diameter optical viewing tubes can be easily and continuously produced in large quantities at low cost. . Moreover, channels with irregular cross sections can be easily formed.
It has various excellent effects. Moreover, the second and third
According to the method of the present invention, the glass jacket tube can be removed, so in addition to the effects of the first method of the present invention,
This has the advantage that the diameter of the optical viewing tube can be made even smaller.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional optical viewing tube, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a vertical sectional side view of an 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 longitudinal sectional front view of the optical fiber, and FIG. 6 is a process explanatory diagram schematically showing the steps of the first method of the present invention. 3... Optical viewing tube, 4... Glass jacket tube, 5... Optical fiber, 7, 8... Channel, 11, 12... Acid-dissolving glass rod, 13... Heater, 14... Roller, 15... Cutter.

Claims (1)

[Claims] 1. Inserting an acid-dissolved glass rod for forming a channel into a glass jacket tube, and inserting optical fibers tightly throughout the gap between the inner surface of the glass jacket tube and the acid-dissolved glass rod. Then, each of these glass materials in the glass jacket tube is heated and stretched together with the glass jacket tube to reduce the diameter, and then cut into a predetermined length, and then the acid-melted glass rod is dissolved and removed with acid to form a channel. A method for manufacturing an optical viewing tube. 2. Insert an acid-dissolved glass rod for forming a channel into a glass jacket tube made of acid-dissolved glass, and insert an optical fiber tightly throughout the gap between the inner surface of the glass jacket tube and the acid-dissolved glass rod. Each of these glass materials in the glass jacket tube is heated and stretched together with the glass jacket 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. A method for manufacturing an optical viewing tube, further comprising dissolving and removing the glass outer tube with an acid. 3. Insert an acid-dissolved glass rod for forming a channel into the glass jacket tube, and insert the optical fiber tightly throughout the gap between the inner surface of the glass jacket tube and the acid-dissolved glass rod, and An acid-dissolved layer is formed by thinly arranging acid-dissolved glass fibers over the entire inner circumference of the tube, 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. The method is characterized in that the acid-dissolved glass rod is cut to a predetermined length, and then the acid-dissolved glass rod is dissolved and removed with an acid to form a channel, and the acid-dissolved layer is dissolved with an acid to extract and remove the glass jacket tube. A method for manufacturing an optical viewing tube.