JPH0358724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope light guide connector for optically connecting an incident end side of an endoscope light guide to a light source device.

Generally, in a light guide connector for an endoscope, the light guide is guided and fixed within a guide tube protruding from the connector body. When the above-mentioned connector is connected to the socket of the endoscope light source device, the incident end surface of this light guide is
It is positioned near the focal point of the light source.

By the way, the above-mentioned light guide is constructed by tightly bundling a large number of thin optical fiber elements and hardening them with an adhesive. However, such a light guide connector has the following drawbacks. First, when a large number of thin optical fiber elements are glued together, air bubbles are created between them. If the bubbles and the adhesive are directly hit by the focused light from the light source, the incident end face may be burned out by the heat of the light. Secondly, in order to adjust the amount of light that enters the light guide, a diaphragm is provided on the light source device side that changes the aperture degree, but this diaphragm prevents the light from uniformly hitting the entire incident end surface of the light guide. Rather, focus on one part. As a result, only a portion of the incident end face is heated and easily burnt out. Thirdly, as mentioned above, when bonding each optical fiber element with adhesive, a certain amount of minute gaps inevitably occur. and,
If the connector part gets wet, there is a drawback that water or the like can enter the connector through the gap due to capillary action. Fourthly, the above-mentioned adhesive must be selected from a particularly special and expensive adhesive in consideration of its heat resistance.

In order to solve these various problems, instead of directly applying the light from the light source to the incident end surface of the light guide, it is possible to indirectly direct the light from the light source through an optical member, which is a single rod-shaped optical element consisting of a core and a cladding. A method is used to apply That is, the optical member is provided in a guide tube that projects from the connector body so as to face the incident end surface of the light guide.

However, the outer diameter of the optical member cannot be made highly accurate due to manufacturing technology reasons. Therefore, in order to be able to provide this optical member within the guide tube, the inner diameter of the guide tube must be made larger. As a result, the optical member becomes loose within the guide tube, reducing the alignment accuracy between the optical member and the light guide, and a portion of the light emitted from the optical member no longer enters the light guide, resulting in a large loss in the amount of transmitted light. This has the disadvantage of becoming. Additionally, adhesive is used to hold the optical member within the guide tube. However, when an adhesive is used, the optical member and the incident end face of the light guide may become dirty, and this dirt may cause burnout.

This invention was made based on the above circumstances, and its purpose is to improve the alignment accuracy of the optical member with the light guide within the guide tube, and to be able to reliably install the optical member without using adhesive. An object of the present invention is to provide a light guide connector for an endoscope.

An embodiment of the present invention will be described below with reference to the drawings. 1 in FIG. 1 indicates an endoscope. This endoscope 1 includes an insertion section 2, an operation section 3, and a light guide cable 4. This light guide cable 4
A light guide connector 7 that is detachably connected to the socket 6 of the light source device 5 is provided at the end of the light guide. This connector 7 is constructed as shown in FIGS. 2 and 3. That is, the connector 7 has a connector body 8 formed in a cylindrical shape. A connection port body 9 is provided protruding from one end surface of this connector body 8 . This connection port body 9 is provided with a connection member 10, and the end portion of the light guide cable 4 is connected to the connector body 8 by this connection member 10. The outer peripheral surface of this connector body 8 includes a water supply port 11, a suction port 12, and a high frequency ground connection terminal 1.
3 and an air supply port 14 for water leakage testing are provided, and an air receiving nozzle 15 and a guide tube 16 are provided protruding from the front end surface of the connector body 8. This guide tube 1
When the connector 7 is attached to the socket 6 of the light source device 5, the end surface of the connector 6 is located near the focal point of the lens 18 that focuses the illumination light from the light source 17 built into the light source device 5, as shown in FIG. I'm starting to do that.

The guide tube 16 includes a first tube body 19 that is screwed to the connector body 8 in an airtight manner, and a second tube body 19 that is screwed to the first tube body 19 in an airtight manner and with the same axis. This tube body 20 and this second
The holding cylinder body 21 is fitted onto the tip of the tube body 20 and fixed airtightly by, for example, an interference fit or an adhesive. The tip of this presser cylinder 21 is bent inward in the radial direction, and the bent portion 22 and the second
A cover glass 23 is airtightly held between the cover glass 23 and the end surface of the tube body 20 via an O-ring 24. In other words, the inside of the guide tube 16 has an airtight structure with respect to the outside. Further, one end portion of a light guide 25 made of an optical fiber bundle is inserted and held in the first tube 19 with its axis aligned with the first tube 19 . This light guide 25 is provided across the light guide cable 4 and the insertion section 2, and the other end thereof faces an illumination window (not shown) provided on the distal end surface of the insertion section 2. Further, a pair of mounting grooves 26 are formed on the inner circumferential surface of both axial ends of the second tube body 20, and in these mounting grooves 26, an O-ring as an annular elastic member made of an elastic material such as rubber is formed. 27 are provided. A shaft-shaped optical member 28 inserted into the second tubular body 20 is supported by the pair of O-rings 27 on the outer peripheral surface of both axial ends thereof. The inner diameter of the second cylindrical body 20 is larger than the maximum variation in the outer diameter of the optical member 28, and the inner diameter of the O-ring 27 is larger than the minimum variation in the outer diameter of the optical member 28. It is also formed small. Therefore, the optical member 28 is attached to the second tube body 20 regardless of its dimensional accuracy.
can be inserted into the O-ring 27
is held in an elastically deformed state. The optical member 28 is formed from a single optical fiber or the like, and has a core 28a and a cladding 28b as shown in FIG. That is, the optical member 28 is elastically held between the entrance end surface of the light guide 25 and the cover glass 23 by the O-ring 27.

According to the connector 7 having such a structure, the optical member 28 is held within the second tube body 20 by uniformly elastically deforming the O-ring 27 in the radial direction. Even if there are variations,
Its axis coincides with the axis of the second tubular body 20. Therefore, the axis of the optical member 28 is aligned with the first tube body 19.
This also coincides with the axis of one end of the light guide 25 held by the optical member 28 and the light guide 25, so that there is no misalignment of the mutually opposing end surfaces of the optical member 28 and the light guide 25, and the transmission of light between them is prevented. This can be done with little loss. Furthermore, since the optical member 28 can be held within the second cylindrical body 20 with high precision regardless of variations in its outer diameter, the tolerance of the outer diameter of the optical member 28 can be increased. In other words, the optical member 28 can be manufactured easily. In addition, since the optical member 28 can be held without using an adhesive or the like, not only is assembly easy, but there is no possibility of staining the optical member 28 due to the adhesive.
8 is elastically held within the guide tube 16 via the O-ring 27, the optical member 28 is unlikely to be damaged even if an impact is applied to the connector 7.

In the present invention, the elastic member that holds the optical member is not limited to an O-ring, but may be a gasket or packing having a rectangular cross section. Moreover, the connection between the second pipe body and the presser cylinder body may be a screw connection or the like. Furthermore, the number of elastic members that hold the optical member is not limited at all.

As described above, in the present invention, the optical member provided in the guide tube so as to face the entrance side tip of the light guide is held within the guide tube by a plurality of annular elastic members. Therefore, due to the alignment action of the elastic member, the axis of the optical member can be aligned with the axis of the guide tube, that is, the axis of the light guide, regardless of variations in the outer diameter of the optical member. There is no possibility that the end face and the end face of the optical member become misaligned, thereby causing an increase in optical transmission loss between the end face and the end face of the optical member. Further, since the support accuracy of the optical member can be improved regardless of variations in the outer diameter of the optical member, the tolerance of the outer diameter of the optical member can be increased and the manufacturing thereof can be facilitated. Furthermore, since the optical member can be held within the guide tube without using adhesive, assembly is not only facilitated, but there is no possibility of contamination caused by adhesive. Furthermore, even if a radial impact is applied to the guide tube, the elastic member prevents the optical member from coming into contact with the guide tube, so that the optical member will not be damaged.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of an endoscope, FIG. 2 is a perspective view of a connector, and FIG. 3 is a perspective view of an endoscope.
The figure is a sectional view, and FIG. 4 is an enlarged sectional view of the main part. 8... Connector body, 16... Guide tube, 25
... Light guide, 27 ... O ring (elastic member), 28 ... Optical member.

Claims (1)

[Scope of Claims] 1. A connector main body, a guide tube that protrudes from the connector main body and has an entrance side tip of a light guide disposed therein, and a guide tube that faces the entrance side tip of the light guide. 1. A light guide connector for an endoscope, comprising: an optical member disposed in the guide tube; and a plurality of annular elastic members elastically supporting both ends of the optical member within the guide tube. 2. The endoscope light guide connector according to claim 1, wherein the annular elastic member is an O-ring.