JPH028805A - Image scope and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image scope with a small diameter and clear image contrast, which is used for medical and industrial purposes, and a method for manufacturing the same.

(Prior Art) A conventional image scope is constructed by attaching a light guide made of glass fiber around an image fiber for image transmission, but light from the light guide enters the image fiber. In order to prevent this, the coating layer constituting the image fiber is made of two layers and a light absorbing substance such as carbon is mixed in the outer layer. The reason why the light-absorbing substance is mixed only in this outer layer is that if the carbon particles come into contact with the glass portion constituting the image fiber, the glass portion will be scratched and its strength will deteriorate.

(Problem to be solved by the invention) However, in recent years, there has been a demand for image scopes to be made smaller in diameter. In view of the above, the present invention aims at reducing the diameter of an image fiber by arranging a metal shielding layer inside or inside the jacket constituting the image fiber. Specifically, the metal shielding layer is formed by melting a metal pipe. That is, a metal pipe is placed inside the jacket glass pipe, a large number of pixel fibers are bundled and stuffed into the metal pipe to form a preform, and one end of the preform is drawn by heating to form a melted and integrated image/fiber. Alternatively, two jacket pipes are placed concentrically, a metal pipe is placed between them, and the following steps are performed in the same manner.

Note that the metal used as the shielding layer is A I % N! ,
, F e % SUS, the thickness of which is 0.5~
A thickness of about 2 μm is sufficient.

(Example) Diameter 20 mark (core diameter 16 mm, clad outer diameter 20 m),
A Ge-doped silica rod with Δ=3% is spun into a diameter of 3.
A pixel fiber of 00tIm was prepared, and 10,000 pieces were prepared by cutting this into a length of 500mm. On the other hand, outer diameter 33m
SU with an outer diameter of 30.03 mm, an inner diameter of 30 mm, and a length of 600 mm in a quartz pipe with an inner diameter of 31 mm and a length of 600 mm.
An S-vib was placed, and the 10,000 pixel fibers previously prepared were packed inside the preform to form a preform, which was heated and drawn from one end to create an image fiber with an outer diameter of 1000 μm. Around this image fiber, 200 separately prepared light guide fibers made of 30 μm multi-component glass were attached to form an image scope. FIG. 1 is a sectional view of the thus obtained image scope of the present invention, but only a portion thereof is shown for the sake of simplicity. In the figure, 1 is a pixel composed of a Ge-doped silica core and a silica cladding with a diameter of 10 μm, and 10,000 pixels are integrated. 2 is a light shielding layer made of SUS with a thickness of 1 μm surrounding these pixels 1, and 3 is a silica jacket with a thickness of 66 μm located on this light shielding layer 2 with a total diameter of 1000 μm.
Since the light shielding layer 2 is thin, it has a small diameter.

4 is 200 pieces of 3 attached around the silica jacket 3.
A light guard made of multi-component glass with a diameter of 0 μm appears.

When an image was transmitted using the image scope with the above configuration, it was found that despite the thinness of the light shielding layer 2, light leakage from the light guide was blocked in the same way as in the conventional one, resulting in an image with clear contrast. Obtained.

(Example 2) A small-diameter image was produced in the same manner as in Example 1 except that a silica core F-doped silica clad type was used as the imaging fiber instead of the Ge-doped silica core silica land type, and Fe was used as the light shielding layer material. A scope was made and used in a radiation atmosphere of 10 Rad. At this time, the image scope was kept at a high temperature by applying a current of 20 mA to the Fe shielding layer to suppress an increase in loss due to radiation. In conventional image scopes, the image quality deteriorated significantly under the above-mentioned radiation, making it unusable, but this example was able to withstand use.

(Effects of the Invention) The present invention has a structure in which a metal shielding layer is provided in the gap between an image transmission pixel constituting an image scope and a light guide located outside the pixel, thereby preventing light leakage from the light guide into the pixel. Therefore, it is possible to obtain an image with high clarity. Further, there are secondary effects that can be achieved by using images according to the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an image scope according to the present invention. 1: Pixel, 3: Metal shielding layer, 4: Jacket, 5 Nilight guide.

Claims (2)

[Claims] (1) An image scope comprising an image fiber consisting of a large number of pixel glass fibers and a glass jacket covering the glass fibers, and a light guide consisting of a large number of glass fibers attached to the outside of the image fiber. An image scope characterized in that a metal shielding layer is provided inside or inside the jacket to prevent light from the light guide from entering the pixel glass fiber. (2) A large number of pixel glass fibers are packed into a glass jacket pipe via metal pipes to form a preform, which is then heated and drawn from one end to form an integrated image fiber that is melted as a whole. A method for manufacturing an image scope, characterized in that a light guide fiber is attached around the image scope.