JPH0216487B2 - - Google Patents

Abstract

PURPOSE:To set the exit end of a light guide in a prescribed direction without chip members, by forming the tip part of the outside tube of an insertion part to a shape like a ball. CONSTITUTION:In an insertion part 13 of a hard endoscope, the tip of an outside tube 16 is formed to a shape like a ball, and this ball-shaped tip is cut in the direction of the observation visual field to form an aperture part 20. An inside tube 17 where lens systems 18 and 19 and a cover glass 24 are incorporated is inserted into the outside tube 16 eccentrically to the side of the aperture part 20 and is fixed, and a light guide 25 is inserted into the outside tube 16 on the outside circumference of the inside tube 17, and the tip of the light guide 25 is led out from the aperture part 20, and an exit end side 25' is curved along the ball-shaped inside circumference at the tip of the outside tube 16 and the outside circumference of a curved member 22 of the inside tube 17, and this curved light guide is fixed by an adhesive. Finally, the light guide 25 is cut and polished in the end face of the aperture part 20 to constitute the insertion part 13. The tip part of the outside tube of the insertion part may be formed to a shape like a cone or conical trapezoid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a rigid endoscope that is improved so that the direction of the exit end of a light guide can be set in a predetermined direction.

[Prior Art and Problems to be Solved by the Invention] FIGS. 1 to 3 show the configuration of a conventional example of the distal end of a rigid endoscope insertion section. What is shown in FIG. 1 is the distal end of a rigid endoscope insertion section of a perspective type, and the relay lens system 3 is assembled into the inner tube 2 in the outer tube 1 of the insertion section.
The objective lens system 4 is set so that the observation field of view is α degrees with respect to the axial direction of the insertion section, and the output end side of the light guide 5 disposed on the outer periphery of the inner tube 2 is at the tip of the outer tube 1. It is curved so as to illuminate the observation visual field by the attached tip member 6, and is held by the tip member 6.

The one shown in Figure 2 is the tip of a rigid endoscope insertion section of the direct viewing type that narrows the field of view to the near side, and is arranged around the outer periphery of the inner tube in which the relay lens system 3 and objective lens system 4 are installed. The output end side of the light guide 5 is
A tip member 7 attached to the inner periphery of the tip of the outer tube 1 narrows the tube and illuminates the adjacent side.

What is shown in FIG. 3 is the tip of a side-viewing rigid endoscope insertion section, in which the observation field of view is set to the side-viewing direction by the objective lens system 4, and a light guide is provided along this direction of the observation field of view. The output end side of the outer tube 5 is also curved and is held by a tip member 8 attached to the tip of the outer tube 1, while the tip opening of the outer tube 1 is closed by the tip member 8.

In this way, in the case of a conventional rigid endoscope, the tip members 6, 7, and 8 are attached to the tip of the insertion section, and the light guide output end side is curved or constricted by the tip members 6, 7, and 8. The tip members 6, 7, and 8 must be formed to match the light guide output end, and are small and do not depend on the arrangement of the light guide. This results in a complicated shape that is difficult to process, and furthermore, the number of man-hours for parts management and assembly increases, leading to higher manufacturing costs.

To deal with this, the present applicant filed a patent application filed in 1983.
No. 112529 proposed an endoscope in which a part of the tip of the outer tube was bent toward the inner tube in order to direct the output end of the light guide toward the viewing direction without using a tip member at the tip of the outer tube. There is.

However, as in this endoscope, it is difficult to bend a part of the tip of the outer tube so that the output end of the light guide faces the viewing direction. There is a problem in that the inner wall of the tip does not have a smooth three-dimensional shape, and the end face of the light guide also has an angular shape, which tends to result in uneven distribution of illumination light. Further, in the endoscope, the end face shape of the light guide and the cross-sectional shape within the outer tube are different from each other, making it difficult to insert the light guide.

The present invention has been made in view of these circumstances, and uses a chip member at the tip of the outer tube to eliminate the need to set the extending direction of the output end of the light guide and also without bending the tip of the outer tube. By forming the inner wall at the tip of the outer tube, the output end of the light guide can be set in the viewing direction, and this setting can be easily performed.
In addition, the shape of the inner wall at the tip of the outer tube can be formed into a smooth three-dimensional shape, making the distribution of illumination light uniform.
Furthermore, it is an object of the present invention to provide a method for manufacturing a rigid endoscope in which the shape of the inner wall of the distal end of the outer tube changes smoothly, making it easier to insert the light guide.

In order to achieve the above object, the method for manufacturing a rigid endoscope according to the present invention includes the steps of: forming the distal end of the outer tube of the insertion section into a spherical, conical, or truncated conical shape, and positioning the distal end of the outer tube at a predetermined position. , a step of cutting in a plane perpendicular to the viewing direction of the internal objective lens system to form an opening, a step of inserting an inner tube into the outer tube, and a step of forming an opening in the space between the outer tube and the inner tube. A step of inserting a light guide fiber and pulling out the distal end of the light guide fiber from the opening of the distal end of the outer tube, and connecting the fibers at the distal end of the light guide and the inner periphery of the outer tube and the outer periphery of the inner tube with each other. and a step of cutting and polishing the light guide fiber at the opening at the tip of the outer tube.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

4 and 5 show a rigid endoscope according to the manufacturing method of the first embodiment of the present invention. This embodiment relates to a perspective type rigid endoscope.

In these figures, reference numeral 11 denotes a rigid endoscope, which is composed of an operating section 12 and an insertion section 13, and the operating section 12 has an eyepiece section 14 and a joint 15 for connecting a light guide cable. The insertion section 13 includes an inner tube 17 eccentrically disposed within an outer tube 16, a relay lens system 18 disposed inside the inner tube 17, and an observation field of view of, for example, 45 degrees at the tip of the relay lens system 18. An objective lens system 19 is arranged. On the other hand, a light guide 25 whose entrance end extends to the joint 15 is inserted between the outer circumference of the inner tube 17 and the outer tube 16. The distal end of the outer tube 16 of the insertion section is formed into a spherical shape, and the inner tube 17 side is diagonally cut and opened, and the distal end of the inner tube 17 faces the opening 20. The objective lens system 19 is attached to the inner tube 17 via a frame 21, and a bending member 22 is attached to the distal end of the inner tube 17 to curve the distal end of the inner tube 17 in the viewing direction. A cover glass 2 is attached to the open end of the member 22 via the frame 23.
4 is fixed. Further, as shown in FIG. 5, the output end side 25' of the light guide 25 has an opening 20 at the tip of the outer tube along the spherical inner circumference at the tip of the outer tube 16 and the outer circumference of the curved member 22 at the tip of the inner tube 17. In other words, it is curved in the direction of the observation field, and its tip is attached to the cover glass 2.
4 and the open end of the outer tube tip.

Therefore, in the rigid endoscope 11 having the above configuration, the tip of the outer tube 16 of the insertion portion is formed into a spherical shape as shown by the two-dot chain line in FIG. Then, an opening 20 is formed.
The inner tube 17 in which the relay lens system 18, objective lens system 19, and cover glass 24 are assembled is eccentrically inserted into the outer tube 16 toward the opening 20 and fixed by brazing or the like, and the outer circumference of the inner tube 17 is outer tube 16
Insert the light guide 25 inside from the joint 15 side, pull out its tip side from the opening 20, and align the output end side 25' with the spherical inner circumference of the tip of the outer tube 16 and the outer circumference of the curved member 22 of the inner tube 17. and curve it,
The light guide (fibers) on the curved output end side 25' and the inner periphery of the outer tube 16,
It is constructed by fixing the curved member 22 and the outer circumference of the inner tube 17 with an adhesive, and then cutting and polishing the light guide 25 at the end face of the opening 20.

In this way, by forming the tip of the outer insertion tube 16 into a spherical shape, the output end 2 of the light guide 25 can be removed without using the conventionally used tip member.
5' can be curved along the spherical inner circumference to obtain a predetermined illumination direction.

In this embodiment, a separate curved member 22 is attached to the tip of the inner tube 17.
7 The tip may be curved.

Further, according to the insertion section outer tube 16 used in this embodiment, the illumination direction at a predetermined angle can be set by the position of the opening 20 formed at the spherical tip.

FIG. 6 shows a direct-viewing rigid endoscope according to a manufacturing method according to a second embodiment of the present invention. In this embodiment, an opening 20 is formed by cutting out the center of the spherical tip of the outer tube 16 of the insertion section, and is configured to condense light in the right direction for illumination. In this figure, the inner tube 17 incorporating the relay lens system 18 and the objective lens system 19 is arranged concentrically within the outer tube 16, but it goes without saying that they may be eccentrically arranged.

FIG. 7 shows a rigid endoscope according to a manufacturing method according to a third embodiment of the present invention. This example is
The tip of the outer insertion tube 26 is formed into a conical or truncated conical shape as shown by the two-dot chain line, and the opening 20 is formed by cutting the inner tube 17 side, which is installed eccentrically, in an oblique direction.
The output end side 25' of the light guide 25 is bent along a cone or truncated cone to illuminate a predetermined oblique direction.

FIG. 8 shows a rigid endoscope according to a manufacturing method according to a fourth embodiment of the present invention. In this embodiment, an opening 20 is formed by cutting out the center of the conical or truncated conical tip of the outer tube 26 of the insertion portion, and is constructed as a direct view type that focuses light in the right direction for illumination. In this figure, the inner tube 17 incorporating the relay lens system 18 and the objective lens system 19 is arranged concentrically within the outer tube 26, but it goes without saying that the inner tube 17 may be arranged eccentrically.

[Effects of the Invention] As explained above, according to the present invention, it is possible to bend the outer tube tip without using a tip member at the outer tube tip to set the extending direction of the light guide's output end. By forming the inner wall at the tip of the outer tube, the output end of the light guide can be set in the viewing direction.
The settings can be easily made, and the shape of the inner wall at the tip of the outer tube can be formed into a smooth three-dimensional shape, resulting in uniform illumination light distribution (light distribution). The effect is that the light guide can be inserted easily because it changes smoothly.

[Brief explanation of drawings]

1 to 3 show conventional examples of the configuration of the distal end of the insertion section of a rigid endoscope, and FIG. 1 is a perspective cross-sectional view;
2 is a sectional view of a direct view type, FIG. 3 is a sectional view of a side view type, FIGS. 4 and 5 show a rigid endoscope according to the manufacturing method of the first embodiment of the present invention, and FIG. 5 is an enlarged sectional view showing the tip of FIG. 4, FIG. 6 is an enlarged sectional view showing the rigid endoscope according to the manufacturing method of the second embodiment, and FIG. 7 is an enlarged sectional view showing the rigid endoscope according to the manufacturing method of the second embodiment. Enlarged sectional view showing the rigid endoscope according to the manufacturing method of the third embodiment, No. 8
The figure is an enlarged sectional view showing a rigid endoscope according to the manufacturing method of the fourth embodiment. DESCRIPTION OF SYMBOLS 11... Rigid endoscope, 12... Operation part, 13... Insertion part, 16, 26... Outer tube, 17... Inner tube, 20... Tip opening, 25... Light guide, 25'... Outgoing end side of light guide.

Claims (1)

[Scope of Claims] 1. A step of forming the distal end of the outer tube of the insertion portion into a spherical, conical or truncated conical shape, and forming the distal end of the outer tube at a predetermined position with respect to the viewing direction of the internal objective lens system. cutting in a vertical plane to form an opening; inserting an inner tube into the outer tube; inserting a light guide fiber into the space between the outer tube and the inner tube; a step of pulling out the distal end side of the light guide from the opening of the distal end portion of the outer tube; a step of fixing the fibers at the distal end side of the light guide to each other and the inner circumference of the outer tube and the outer circumference of the inner tube with an adhesive; A method for manufacturing a rigid endoscope, comprising the steps of cutting and polishing a guide fiber at the opening of the distal end of the outer tube.