JPH0256647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an annular optical fiber bundle at the distal end of an endoscope inserted into the body, and a member used in the method. The purpose of this invention is to increase the filling rate of the annular illumination optical fiber bundle at the tip of the emission side.

Conventionally, in rigid endoscopes and ultra-thin diameter endoscopes, an objective lens is placed at the center of the distal end on the side that is inserted into the body, and a bundle of optical fibers for illumination is arranged in a ring shape around the objective lens. There are many.

However, in an endoscope having the above-described configuration, when the illumination optical fiber bundle is disposed in a ring shape around the objective lens, the holding frame of the objective lens is attached to the distal end member on the side to be inserted into the body in advance. When it was attached, the optical fiber bundle could not be filled sufficiently and the filling rate was 70 to 80%.

Furthermore, even if you insert the optical fiber bundle into the tip member in advance and then push the objective lens frame later, there is a risk of damaging the optical fibers because the objective lens is metal, and the objective lens holding frame may It is difficult to fill more than 85% of the optical fibers into the annular space formed between the tip member and the optical fibers, as shown in FIG. 1, resulting in unnecessary gaps between the optical fibers. This has the disadvantage that the amount of light transmitted through the illumination optical fiber bundle is also reduced.

In order to eliminate the above-mentioned drawbacks, the diameter of the distal end on the side to be inserted into the body may be increased, but increasing the diameter causes drawbacks such as increased difficulty for the patient to insert the endoscope. Hitherto, methods for increasing the filling rate of the optical fiber bundle have been proposed such as a heat-sealing method and a method using a shape memory metal, but these methods have the following drawbacks.

In the thermal separation method, gaps between optical fibers are filled by deformation of the optical fibers due to heating, so the cross-sectional shape of the core of the optical fibers is no longer circular, and as a result, light leakage from the optical fibers increases, resulting in a decrease in the amount of emitted light, which is insufficient. No effect can be obtained.

Furthermore, methods using shape memory metals have not been put to practical use because the shape memory metals themselves are very expensive and have poor workability.

The present invention has been made to overcome the above-mentioned drawbacks, and provides a method for forming an annular optical fiber bundle that increases the filling rate of the optical fiber bundle at the body-insertion side tip of an endoscope to 85% or more. and the equipment used in the method.

An embodiment of the present invention will be described below with reference to the drawings.

First, members necessary for explaining the steps of the method for forming an annular optical fiber bundle according to the present invention will be explained.

Tip cylindrical member 1 on the side to be inserted into the body of an endoscope
consists of a hollow large-diameter portion 1a and a small-diameter portion 1b, and a connecting portion 1c connecting the large-diameter portion 1a and the small-diameter portion 1b has a tapered shape that tapers toward the small-diameter portion 1b.

The releasable resin member 3 has approximately the same shape as the objective lens frame 4, and has a large diameter portion 1a of the tip cylindrical member 1.
The outer circumferential surface of the fitting part 3a consists of a part 3a that fits into the inside and a shaft part 3b that inserts the optical fiber 2 into the small diameter part 1b of the tip cylindrical member 1 in a ring-shaped manner. In the axial direction, a recess 3c through which the optical fiber bundle 2 is inserted is located at a symmetrical position 4.
It is formed in places. Moreover, the releasable resin member 3
has mold releasability with respect to adhesives such as epoxy resin adhesives and phenolic resin adhesives.

The releasable resin member 3 is desirably made of a material that can be appropriately deformed without damaging the optical fibers even when pushed between bundles of optical fibers that are not well aligned. D50~65, tensile modulus 3× ¹⁰³ ~
The one having 20×10 ³ Kg/cm ² is optimal.

Next, the steps of the method for forming an optical fiber bundle for illumination according to the present invention will be explained.

(1) As shown in Fig. 3, the optical fiber bundle 2, whose number and diameter are configured so that the final filling rate is 85 to 90%, is placed in the hollow part of the tip cylindrical member 1 in a substantially annular shape. The optical fiber bundle 2 is inserted through the diameter portion 1a, and the optical fiber bundle 2 near the tip cylindrical member 1 is soaked in a volatile liquid such as methanol or ethanol.
The reason why the optical fiber bundle 2 is inserted from the large diameter portion 1a side is because the optical fiber bundle 2 has a tapered surface that tapers from the large diameter portion 1a toward the small diameter portion 1b, making it easy to insert.

(2) Next, as shown in FIG. 4a, the mold-releasing resin member 3 is fitted into the tip cylindrical member 1 from the large diameter portion 1a side, and the shaft portion 3b of the mold-releasing resin member 3 is tapered. The optical fiber bundle 2 is pushed into the small diameter portion 1b from the surface between the optical fiber bundles arranged in a ring shape, and one end of the optical fiber bundle 2 is inserted into a recess provided in the outer peripheral surface of the releasable resin member 3 as shown in FIG. 4b. 3c
Insert it in sections and pull it out outwards.

(3) After immersing the optical fiber bundle 2 in the above state again in a volatile liquid such as methanol or ethanol, the releasable resin member 3 is rotated or moved back and forth with respect to the tip cylindrical member 1. When it is moved, the legs 3d formed between the recesses 3c of the releasable resin member 3 move the optical fiber bundle around the axis, and the misaligned optical fiber bundles 2 gradually become aligned. The optical fibers are filled in a ring shape between the tip cylindrical member 1 and the releasable resin member 3 at a filling rate of 85 to 90%.

(4) Furthermore, after volatilizing the methanol etc. adhering to the optical fiber bundle, adhesive is applied to the optical fiber bundle 2 protruding from the end of the small diameter portion 1b of the tip cylindrical member 1, and by leaving it or heating it. The adhesive is thoroughly penetrated to the inside of the tip cylindrical member 1 and solidified. Thereafter, the optical fiber bundle 2 is cut on substantially the same plane as the end face of the small diameter portion 1b.

(5) The cut end face (light emitting end face) of the optical fiber bundle 2 is polished with the releasable resin member 3 still in place in order to maintain the flatness of the cut end face and the alignment of the optical fibers, and after polishing is completed, By releasing the releasable resin member 3, a bundle of optical fibers for illumination having a ring-shaped light emitting end is completed.

(6) As shown in FIGS. 5 and 6, the objective lens frame 4 is inserted into the annular illumination optical fiber bundle thus completed.

As mentioned above, the releasable resin member 3 has approximately the same shape as the objective lens frame 4, so you will feel a slight resistance when inserting the objective lens 4, but the optical fiber bundle 2 hardened with adhesive , there is some room for deformation, so it does not interfere with insertion. If adhesive is applied to the outer peripheral surface of the objective lens frame 4 when inserting the objective lens frame 4, the connecting agent will act as a lubricant,
Even smoother insertion is possible.

As shown in Figure 2, the filling rate is 85.
~90% of the optical fiber bundle for illumination can be obtained.

The present invention employs the above-mentioned configuration, so that (a) the optical fibers have a higher filling rate than conventional optical fiber bundles, and the brightness of the light emitting end face is higher, so that the side of the endoscope inserted into the body Brighter illumination light can be obtained compared to conventional products with the same tip diameter.

(b) In addition, if the same brightness as conventional products is sufficient, the diameter of the endoscope's end on the side to be inserted into the body can be reduced, which can reduce the discomfort experienced by the patient when the endoscope is inserted.

(c) Compared to the conventional method of increasing the filling rate, there are fewer steps and the cost is lower.

(d) When forming the annular optical fiber bundle, a releasable resin member having substantially the same shape as the objective lens frame is used, so a high filling rate can be achieved without damaging the optical fibers.

You can obtain effects such as

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the filling state of the optical fiber bundle on the distal end surface of a conventional rigid endoscope, ultra-thin endoscope, etc. on the side of insertion into the body, and FIG. 3 is a cross-sectional view showing the filling state of the optical fiber bundle on the end surface, FIG. 3 is a cross-sectional view before inserting the releasable resin member into the tip cylindrical member, and FIG. 4b is a right side view of FIG. 4a, and FIG. 5 is a cross-sectional view after insertion, and FIG. 5 is a cross-sectional view of the objective lens in the state shown in FIG. FIG. 6a is a cross-sectional view before the frame is inserted, FIG. 6a is a cross-sectional view after the objective lens frame is inserted and fixed, and FIG. 6b is a right side view of FIG. 6a. 1... Cylindrical tip member, 2... Optical fiber, 3...
A releasable resin member, 4...Objective lens frame, 5...Objective lens.

Claims (1)

[Claims] 1. Inserting an optical fiber bundle into the tip cylindrical member,
A step of immersing the inserted optical fiber bundle in a volatile liquid such as ethanol, and fitting a releasable resin member to the tip cylindrical member in the above state, and rotating or moving the releasable resin member back and forth. a step of arranging the optical fiber bundles in an annular shape; applying an adhesive to the aligned optical fiber bundles with a releasable resin member fitted thereon;
Insertion of an endoscope into the body, which includes a step of solidifying, cutting the optical fiber bundle in the solidified state, polishing the cut end surface (light emitting end surface), and then releasing the mold-releasing resin member. A method for forming an annular optical fiber bundle at the side tip. 2. The material must be releasable to adhesives, deform appropriately without damaging the optical fibers even when pushed between bundles of optical fibers that are not well aligned, and have approximately the same shape as the objective lens frame. A releasable resin member used in a method for forming an annular optical fiber bundle at a distal end portion of an endoscope on the side to be inserted into the body.