JPH01276110A - Endoscope - Google Patents

Abstract

PURPOSE:To reduce the amount of an adhesive in use, to reduce variation in the volume of the adhesive with temperature, and to prevent peeling, etc., by making the tip part of a ferrule mounted on the tip part of an image guide run through an insertion part thinner than any other part. CONSTITUTION:Plural 1st objectives 16a are held in the tip part of a lens frame 13 and the ferrule 17 fitted integrally onto the tip part of the image guide 16 consisting of a fiber bundle is inserted from the rear end side. The ferrule 17 is fixed with a screw 21 screwed in from a screw hole 19 formed in a boss part 18 on the base end part side of the lens frame 13. A step part 22 is formed on the outer peripheral surface of the tip part of the ferrule 17 to form a small- diameter part 23 of small external size. A 2nd objective 24 is adhered and fixed to the tip surface of the image guide 16 with an adhesive 25, which is interposed between the 2nd objective 24 and not only the image guide 16, but also the end surface of the ferrule 17. Thus, the tip part of the ferrule 17 is formed as the thin small-diameter part 23, so the adhesive 25 contacting the objective 24 is reduced and the influence of temperature variation is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to an endoscope in which an objective lens is adhesively fixed to the distal end surface of an image guide inserted into an insertion section.

[Prior Art] Generally, an endoscope consists of an operating section and an insertion section, and an image guide made of a fiber bundle is inserted through the operating section. The distal end of this image guide faces an observation window provided on the distal end surface of the insertion section via a plurality of objective lenses, and the rear end faces an eyepiece provided on the operating section.

In an endoscope with such a structure, for example,
As shown in Japanese Patent No. 6-150501, there is a system in which one of the plurality of objective lenses is adhesively fixed to the distal end surface of the image guide. Then, the distal end of the image guide to which the objective lens is adhesively fixed is fitted into the cylindrical cap and solidified integrally, and this distal end is fitted into the cylindrical lens frame of the distal end component of the insertion section and screwed. Alternatively, it is fixed with bone cement.

[Problems to be Solved by the Invention] By the way, when the objective lens is adhesively fixed to the end surface of the image guide, the adhesive is not only between the image guide and the objective lens, but also between the end surface of the base and the end surface of the base. There will also be an intervention between them. When the outer diameters of the objective lens and the image guide are substantially the same as shown in the above publication, the adhesive spreads to the periphery of the objective lens by the thickness of the base.

As described above, when the amount of adhesive used to attach the objective lens to the bone increases due to the distal end surface of the base, the volume of the adhesive increases due to temperature changes during the assembly process of the endoscope, etc. The large stress generated between the interface with the agent could cause the objective lens to separate from the image guide.

This invention was made based on the above circumstances, and its purpose is to reduce the amount of adhesive used to adhesively fix the objective lens to the end surface of the image guide, so that the objective lens can be peeled off. The purpose of the present invention is to provide an endoscope that is designed to be tilted.

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides a method in which a cap is attached to the distal end of the image guide inserted into the insertion section, and an objective lens is attached to the distal end surface of the image guide. In an endoscope fixed with adhesive, the distal end of the cap is made thinner than other parts.

Furthermore, the amount of adhesive interposed between the objective lens and the base is reduced.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

The endoscope shown in FIG. 3 is composed of an insertion section 1 and an operation section 2. The endoscope shown in FIG. The insertion section 1 has a curved section 4 at the tip of the flexible tube section 3.
A tip forming portion 5 is provided via the . Above operation part 2
an operation knob 6 for remotely controlling the bending portion 4;
A universal cord 8 is provided to be connected to the eyepiece 7 and a light source device (not shown).

As shown in FIG. 2, a through hole 11 is bored in the main body 9 of the tip component 5 in the axial direction. The tip of this through hole 11 is closed with a cover glass 12 forming an observation window. Further, a cylindrical lens frame 13 is fitted into the through hole 11 from the rear end side, and is fixed by a screw 15 screwed into a screw hole 14 formed in the main body 9.

A plurality of first objective lenses 16a are held within the tip of the lens frame 13, and from the rear end side, a base 17 is integrally fitted onto the tip of an image guide 16 made of a fiber bundle. It is inserted. This base 17 is fixed by a screw 21 screwed into a screw hole 19 formed in a boss portion 18 on the base end side of the lens frame 13.

A step 22 is formed on the outer circumferential surface of the tip of the cap 17, and the step 22 forms the tip into a small diameter portion 23 having smaller external dimensions than other portions. This small diameter part 2
What is the external dimension and internal diameter dimension d of No. 3? (D − d ) /
The relationship is set as follows: 2=0, 2++u*. That is, the wall thickness of the small diameter portion 23 is set to be very thin, 0.21 or less.

The best condition is for the front end surface of the image guide 16 to be flush with the front end surface of the base 17. However, since the tip surface of the image guide 16 is polished after attaching the cap 17 to the tip of the image guide 16, the tip of the image guide 16 is smaller than the tip surface of the cap 17 by a dimension indicated by C in FIG. It protrudes, and its dimension C is 0 after polishing.
The range is within ~0.1 m+s.

A second objective lens 24 is adhesively fixed to the distal end surface of the image guide 16 with bone cement 25 . This bone cement 25 is connected to the second objective lens 24 and the image guide 16.
It will be interposed not only between the end face of the base 17 but also between the end face of the base 17.

In this way, by forming the tip of the base 17 attached to the tip of the image guide 16 into the thin small-diameter portion 23, the tip surface of the small-diameter portion 23 and the second objective lens 2
4 can be reduced in volume of the bone cement 25 interposed between the two. Therefore, even if the volume of the adhesive 25 changes due to a temperature change during the assembly process, for example, the volume change decreases in accordance with the amount of adhesive 25 used. Therefore, a large stress is unlikely to be generated between the bonding surfaces of the adhesive 25 and the second objective lens 24, so that the objective lens 24 is prevented from peeling off.

Since the distal end surface of the mouthpiece 17 is located at a position recessed by the dimension C from the distal end surface of the image guide 16, the volume of the bone cement 25 increases accordingly.

However, it has been confirmed through experiments that if the dimension C is 0.1 mm or less, the amount of increase is small, and therefore the second objective lens 24 does not peel off.

In the above embodiment, the step 22 is formed on the outer peripheral surface of the tip of the cap 17 to provide the small diameter portion 23, but the step 22 is formed on the inner peripheral surface to provide the small diameter portion 23. Good too.

It is also a hot topic that the end surfaces of the cap 17 and the image guide 16 may be flush with each other.

〔Effect of the invention〕

As described above, in the present invention, the tip of the cap, which is attached to the tip of the image guide, is made thinner than the other parts.

Therefore, the volume of the adhesive for fixing the objective lens to the tip surface of the image guide is reduced by the thinner tip of the cap, and the change in volume of the adhesive due to temperature changes is also reduced. The objective lens fixed by the adhesive is prevented from peeling off.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a cross-sectional view of the image guide attached to the distal end component of the insertion section, FIG. 2 is an enlarged cross-sectional view of the distal end of the image guide, and FIG. It is an overall view of an endoscope. 1... Insertion section, 16... Image guide, 17...
・Cap, 22...Stepped part, 23...Small diameter part, 24...
- Second objective lens, 25...adhesive. Applicant's agent Patent attorney Atsushi Tsuboi

Claims (1)

[Claims] In an endoscope in which a cap is attached to the distal end of an image guide inserted into an insertion section, and an objective lens is adhesively fixed to the distal end surface of the image guide, the distal end of the cap is thinner than other parts. An endoscope characterized by: