JPH0524892Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an endoscope that uses a refractive index gradient lens (self-occurring lens) as an image transmitting body.

[Problems to be solved by conventional techniques and ideas] In recent years, it has become common to observe internal organs, etc. in a body cavity by inserting an elongated insertion part into a body cavity, and to perform treatment by inserting a treatment instrument into a channel as necessary. Endoscopes that can perform various therapeutic procedures using instruments are widely used.

The endoscopes include a flexible endoscope with a flexible insertion section that allows observation of a target area within a body cavity through a curved path from the oral cavity, and a flexible endoscope with a rigid insertion section that is approximately linear. There is a rigid endoscope that is inserted.

Among the rigid endoscopes, some conventionally use a needle-like refractive index gradient type lens (trade name "self-occurring lens") in the observation optical system in order to make the diameter of the observation optical system as small as possible. . The refractive index gradient type lens has a diameter of about 1 mm, the refractive index is highest at the central axis, and decreases continuously in the diametrical direction, and transmits images while forming images at regular intervals. It is.

In the rigid endoscope using the gradient refractive index lens, an image formed by the objective optical diameter is transmitted by the gradient index lens, and a prism provided on the rear end side of the gradient index lens is used. bend the optical axis with
There are things that can be observed using the eyepiece diameter. In addition, Japanese Patent Application Laid-Open No. 60-165614 does not use a prism,
A rigid endoscope that allows observation without bending the optical axis has been disclosed.

By the way, due to the characteristics of the manufacturing method of the gradient refractive index lens, the overall length cannot be made constant.
% or more variation occurs. The magnitude of this variation is 4 to 7 mm in a long refractive index gradient type lens, and the structure must be devised to absorb it.

Here, the variation in length of the gradient index lens means that the length of the lens tube extending from the tip of the endoscope body having the gradient index lens varies. Generally, when using an endoscope, irrigation fluid is pumped in to secure the field of view, treatment tools are inserted together, and the endoscope insertion part is inserted into the mantle tube to guide the insertion of the endoscope. used. It is desirable that the distal end of the mantle tube be located approximately near the distal end of the optical tube in order to secure a field of view. For this reason, if the length of the lens tube becomes short, it becomes impossible to secure a field of view with the cannula, and conversely, if the length of the lens tube becomes too long, only the lens tube protrudes and becomes unable to act as a guide for the cannula, or it becomes difficult to insert treatment tools. When using the treatment instrument, the tip of the treatment instrument is exposed and the positional relationship between the endoscope and the mantle tube is shifted, resulting in poor operability.

As a method for absorbing the above-mentioned variations, in a rigid endoscope that uses the prism to bend the optical axis, the space between the prism and the rear end of the gradient index lens plays the role of absorbing variations.
In this case, when the total length of the gradient index lens becomes short and the space becomes large, the light that must pass through the prism spreads out and cannot pass through the prism. Conversely, in order for all light to pass through the prism, regardless of the size of the space, a large prism must be used, which increases the size of the endoscope. Furthermore, since the length of the optical system behind the prism changes in accordance with the variation in the overall length of the gradient index lens, there is a problem in that the eyepiece lens and the eyepiece cover glass come into contact with each other.

Furthermore, in order to absorb the variations in the rigid endoscope disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 60-165614, the exterior of the eyepiece is made after the war, and the observation optical system is used for positioning the front and back of the exterior of the eyepiece. A method is used in which the inner end surface of the eyepiece exterior is brought into contact with the rear end of the system. In this method, if the exterior of the eyepiece is tightly tightened, there is a possibility that the observation optical system will be deformed, so it cannot be tightened strongly. However, if it is not tightened strongly, the solid exterior of the eyepiece will not be strong enough to be used with TV cameras or other objects.
There were problems with the 35mm camera becoming unreliable to mount, and the exterior of the eyepiece becoming loose and falling off.

[Purpose of the invention] The present invention was made in view of the above circumstances, and it is possible to reduce the variation in the overall length of the gradient index lens without affecting the optical system installed behind the gradient index lens. The purpose is to provide an endoscope that is absorbable and easy to manufacture.

[Means and effects for solving the problems] An endoscope according to the present invention includes an optical tube having a gradient index lens, and an eyepiece capable of forming an optical image transmitted by the gradient index lens. The endoscope body is equipped with an endoscope body having a lens system, and a connecting portion slidably provided at the front end of the endoscope body through which the optical tube is inserted, and the outer tube connecting portion is connected to the optical tube. It protrudes or retreats from the endoscope body depending on the length of the tube.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 relate to the first embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the overall configuration of the endoscope;
Figure 2 is an exploded perspective view showing the method of configuring the prism, Figure 3 is a perspective view showing the overall configuration of the prism, Figure 4 is an explanatory diagram of the exit end of the gradient index lens, and Figure 5 a. Explanatory diagram of the tip of the insertion tube, Fig. 5b
5a is a front view of the insertion section taken along the line A-A' in FIG. 5a, and FIG. FIG.

The endoscope 1 includes a rigid and elongated insertion section 2, a large-diameter operation section 3 connected to the rear of the insertion section 2, and an operation section 3 that branches diagonally backward from the side of the operation section 3. It is comprised of an eyepiece section 4 and a treatment instrument attachment section 6 provided at the rear end of the operation section 3.

The insertion section 2 is composed of a lens tube 7 and a light guide tube 8, and the lens tube 7 passes through the operating section 3 and is inserted to the vicinity of the part where the eyepiece section 4 extends. There is.

The operating section 3 includes an operating section main body 5 having the eyepiece section 4 and a treatment tool attachment section 6, and a connection that is slidably provided at the front end of the operating section main body 5 and fixed after being positioned. A connecting member 9 as a part. This connecting member 9 is adapted to connect a sheath (not shown) inserted through the insertion section 2 to the distal end thereof, and is connected to the operating section main body 5 by the positional relationship between the sheath (not shown) and the distal end surface of the insertion section 2.
It is adapted to determine the protruding dimension from.

The lens tube 7 is provided with an objective lens system 11 and behind the objective lens system 11 the gradient index lens 12 . A light guide fiber 13 is inserted through the light guide tube 8, and after the light guide fiber 13 is adhesively fixed at the object side end of the light guide tube 8, the front end surface 14 receives polished illumination light. , this front end surface 14
It has become possible to emit more radiation. The light guide fiber 13 is inserted into the light guide tube 8 and bent laterally within the operating section 3.
The end face 17 is polished after being adhesively fixed to a light guide base 16 extending on the side of the light guide. This end surface 17 serves as an incident surface for illumination light supplied from a light source device (not shown).

A positioning member 1 is provided on the rear end side of the connecting member 9.
8 are fitted and fixed. This positioning member 18
is provided with a fixing hole 19 into which the rear end of the gradient index lens 12 exposed from the lens tube 7 is inserted, and furthermore, the lens tube 7 is inserted into the operating section main body 5 from the front end surface of the connecting member 9. A channel tube 22 forming a treatment instrument channel 21 extending parallel to the treatment instrument attachment portion 6 is inserted therethrough.

In FIG. 4, the rear end of the gradient index lens 12 is inserted into the fixing hole 19. The rear part of this fixing hole 19 is formed with an enlarged diameter part 24 whose diameter is enlarged by a stepped part 23.
, the lens 26 has its front end surface aligned with the stepped portion 23.
They are fitted and fixed with adhesive so that they come into contact with each other. Further, the lens 26 is a gradient index lens 12.
It is attached and fixed with adhesive. This stepped portion 23 forms a surface for positioning the rear end surface of the gradient index lens 12. The rear end surface 27 of the positioning member 18 provided with the fixing hole 19 comes into contact with a step portion 28 provided inside the operating section main body 5, thereby positioning the refractive index gradient type lens 12. I'm starting to be able to do it.

An eyepiece tube 29 is attached to the eyepiece section 4 . An eyepiece system frame 33 is provided within the eyepiece tube 29 to which a triangular prism 31 and a trapezoidal prism 32 are attached, which are provided behind the lens 26 so as to bend the optical axis of the observation optical system. . An eyepiece exterior 34 is provided at the rear end of the eyepiece tube 29, and an eyepiece 36 is further provided at the rear end of this eyepiece exterior 34.

The treatment instrument mounting portion 6 includes a closing member 38 that is fitted into the rear end of the operating section main body 5 and fixed by a screw 37, and a detachable ring 39 is screwed into the rear end of the closing member 36. Therefore, the treatment tool adapter 41 is detachably attached.

The outer circumferential surface on which the closing member 38 is fitted is kept airtight by the operation section main body 5 and an airtight member 42 such as an O-ring, and furthermore, the channel pipe 22 is fitted in the center part. A matching hole 43 is formed. An airtight member 44 such as an O-ring is disposed in the hole 43 so as to maintain airtightness between the hole 43 and the channel pipe 22 .

The treatment tool adapter 41 is fitted and fixed to the closure member 38 while being airtightly maintained by an airtight member 40 such as an O-ring, and has a treatment tool adapter connected to the treatment tool channel 21 on its rear end surface. It includes an adapter body 47 provided with an instrument insertion port 46 and a socket 48 that can open and close the treatment instrument insertion port 46. A lever 45 is provided at the upper part of this socket 48, and a nut 49 is screwed into the lower part thereof so as to attach the socket 48 to the adapter body 47.

In FIG. 2, the trapezoidal prism 32 is formed by bending a flat plate to form side plates 50a, 50b and a substrate 50.
prism frame 5 formed into a U-shape by c and
1 is fixed with adhesive. The upper edges 52 of the side plates 50a, 50b of the prism frame 51 are positioned to match the lower bottom surface 53 of the trapezoidal prism 32. Side plates 50a, 50 of the prism frame 51 where the height side of the trapezoidal prism 32 is located
One end of the trapezoidal prism 32 extends from the end of the trapezoidal prism 32 to form holding portions 54a and 54b. These holding parts 54a, 54b
have their tips bent inward from one-dot chain line 56 in FIG.
7b is formed.

On the other hand, a support member 59 having a cylindrical protrusion 58 aligned with the longitudinal center of the triangular prism 31 is adhesively fixed to both end faces forming the triangular prism of the triangular prism 31 . This triangular prism 3
1 is a holding part 5 of a prism frame 51 as shown in FIG.
4a, 54b are urged to spread out, and the projections 58 are fitted into the notches 57a, 57b.
It is possible to adjust the position relative to the Moreover, since it is fixed elastically, it will not fall off. Note that the size of the notches 57a and 57b is the same as that of the protrusion 5.
8, the triangular prism 31 can not only rotate but also translate.

In FIG. 5, the distal end of the insertion section 2 includes a lens tube 7 and two light guide tubes 8, 8 provided in parallel at slightly lower positions on both sides of the lens tube 7.
It is formed by. When this insertion portion 2 is inserted into the sheath 61 indicated by the dashed line in the figure, it is positioned at the upper part of the sheath 61. A region 62 indicated by a dashed line in the figure, which corresponds to the lower part of the insertion section 2, is designed to be a space into which a treatment instrument or the like inserted through the channel tube 22 is inserted.

The operation of the endoscope configured as described above will be explained.

The insertion section 2 of the endoscope 1 is inserted into the sheath 61 and connected to the sheath 61 at the distal end of the connecting member 9. The refractive index gradient lens 12 provided in the lens tube 7 forming the insertion portion 2 has a slight variation in overall length from the predetermined length due to the characteristics of the manufacturing method, and the connecting member 9 and the positioning member 18 are used to absorb this variation. They are fixed by changing the length of their mutual fit. That is, when the gradient index lens 12 is made long, the length of the fitting between the connecting member 9 and the positioning member 18 is shortened by the length of the long dimension, and when the gradient index lens 12 is made short, the fitting length is The length is adjusted to maintain a constant positional relationship between the distal ends of the sheath 61 and the insertion section 2.

After the above state is established, a light guide cable (not shown) is connected to a light source device (not shown). Illumination light emitted from the light source device is supplied to the endoscope 1 from the light guide base 16. The supplied illumination light is transmitted through the light guide fiber 13 inserted through the light guide tube 8, and is irradiated onto the observation site from the front end surface 14. The observation image illuminated by the illumination light is formed on the front end surface of the gradient index lens 12 by the objective lens system 11 provided at the distal end of the insertion section 2 . This optical image is incident on the triangular prism 31 through the lens 26 provided at the rear end while being formed at regular intervals within the gradient index lens 12. The distance between this lens 26 and the triangular prism 31 is fixed by the positioning member 18 for any length of the refractive index gradient type lens 12, and the spread of light incident on the triangular prism 31 is becomes constant.

This triangular prism 31 bends the optical axis diagonally backward, causing the optical image to be incident on the trapezoidal prism 32. The optical image is transmitted through the trapezoidal prism 32 and an eyepiece system provided in an eyepiece system frame 33, and the surgeon observing through an eyepiece 36 can observe the optical image.

In the case of the bendable endoscope 1 as in this embodiment, the distance between the triangular prism 31 and the lens 26 is always constant, so this distance can be set to an advantageous value in terms of design. As a result, the spread of the light rays incident on the triangular prism 31 does not fluctuate, and the size of the triangular prism 31 can be minimized.
Design difficulties are reduced. Also, triangular prism 3
Since the length of the optical system behind 1 does not change, the eyepiece and the eyepiece cover glass do not come into contact with each other.

In addition, in the case of a non-flexible endoscope, the position of the eyepiece lens system does not change, and the end surface of the outer cover of the eyepiece can be brought into contact with the operation part and firmly tightened and fixed. This allows TV cameras and
The 35mm can be installed more securely, and the exterior of the eyepiece won't come loose and come off.

The connecting member 9 and the positioning member 18 may be connected by adhesion at the fitting portion, soldering or brazing at the fitting portion, or by providing a screw hole in the connecting member 9 and fixing with a screw.

In addition to the structure of the adjustment part between the connecting member 9 and the positioning member 18, in addition to the method of fitting and sliding them as in this embodiment, the adjusting part of the connecting member 9 and the positioning member 18
8 may be screwed together for adjustment.

Furthermore, if only the positional relationship between the connecting member 9 and the positioning member 18 is changed, the refractive index gradient type lens 1
If the variation in 2 cannot be absorbed, the connection member 9
It is also possible to prepare a plurality of different lengths for selection.

FIG. 6 relates to the second embodiment of the present invention, and FIG.
6 is a plan view of the distal end of the insertion portion, and FIG. 6b is a view taken along the line C-C' in FIG. 6a.

At slightly lower positions on both sides of the lens tube 7 that constitutes the insertion section 2 of the endoscope 1, there are two ride guide tubes 8.
are installed in parallel. The front end surface 14 of the light guide fiber 13 inserted into the light guide tube 8 protrudes from the distal end surface of the lens tube 7, and furthermore, this front end surface 14 faces obliquely forward and forms an angle of θ° in the opening direction. It has been held and polished.

By inclining the output surface of the light guide fiber 13 by θ degrees in this way, the output light can be refracted and the output direction of the illumination light can be directed more inward. Thereby, it is possible to irradiate illumination light to a closer object, and it is possible to improve illumination during close observation.

Other configurations, operations, and effects are the same as those in the first embodiment.

FIG. 7 is an explanatory diagram showing the overall configuration of an endoscope according to a third embodiment of the present invention.

The endoscope 1 includes a rigid and elongated insertion section 2, a large-diameter operation section 3 connected to the rear of the insertion section 2, and an operation section 3 that branches diagonally backward from the side of the operation section 3. It is comprised of an eyepiece section 4 and a treatment instrument attachment section 6 provided at the rear end of the operation section 3.

The insertion section 2 is composed of a lens tube 7 and a light guide tube 8, and the lens tube 7 passes through the operating section 3 and is inserted to the vicinity of the part where the eyepiece section 4 extends. There is.

The operation section 3 has the eyepiece section 4, an operation section main body 5 in which an adjustment member 66 is fitted in the rear end, and a treatment instrument attachment section 6 provided at the rear end of the adjustment member 66. , and a connecting member 9 that is slidably provided at the front end of the operating section main body 5 and fixed after being positioned. This connecting member 9 is
A sheath (not shown) inserted through the insertion section 2 is connected to the distal end, and the size of the protrusion from the operation section main body 5 is determined by the positional relationship between the sheath (not shown) and the distal end surface of the insertion section 2. I'm starting to do that.

The adjustment member 66 is connected to the operating section main body 5, for example.
It is slidably provided while being airtightly maintained by an airtight member 67 such as a ring, and is positioned and fixed by a positioning screw 68 screwed into the operation section main body 5.

The treatment instrument attachment section 6 includes a closure member 38 and a treatment instrument adapter 41, and the closure member 38 is fitted into the adjustment member 66 while being airtightly maintained by an airtight member 42 such as an O-ring. and screw 3
It is fixed by 7.

The other configurations are the same as in the first embodiment.

The operation of the endoscope 1 configured as described above will be explained.

In the first embodiment, the dimension A in the figure changes due to variations in the length of the gradient index lens 12, and the overall length of the endoscope 1 changes. When the overall length of the endoscope 1 changes in this way, the amount of protrusion of the treatment tool inserted through the treatment tool channel 21 of the endoscope 1 also changes. In order to keep it constant, the fitting length of the adjusting member 66 provided at the rear end of the operating section main body 5 is changed.

That is, when the gradient index lens 12 is made long, the length A of the connecting member 9 that protrudes from the operating section main body 5 becomes long. Therefore, endoscope 1
Although the overall length of the endoscope 1 becomes longer, the overall length of the endoscope 1 can be made to a predetermined size by retracting the adjustment member 66 from the operating section main body 5 by the length of the increase. On the other hand, when the A dimension becomes shorter, the adjustment member 66 is made to protrude.

As described above, according to this embodiment, the entire length of the endoscope 1 can be made constant, and the amount of protrusion of the treatment tool inserted through the endoscope 1 can be made constant.

In each of the above embodiments, observation with the naked eye through an eyepiece has been described, but a television (TV) camera may be attached to the eyepiece. Also, if it is to be used exclusively for observation on a TV, for example, a CCD
An image sensor such as the above may be provided at the rear end of the eyepiece system. Furthermore, since a real image is formed at the rear end of the gradient refractive index lens, it is necessary to provide an imaging device in close contact with the rear end of the gradient index lens, or to install the imaging device through the lens. You can.
By configuring in this way, the eyepiece,
Alternatively, the eyepiece system becomes unnecessary, allowing the endoscope to be made smaller.

[Effect of the invention] As explained above, according to the invention, variations in the total length of the gradient index lens can be absorbed without affecting the optical system provided behind the gradient index lens. , manufacturing can be made easy.

[Brief explanation of the drawing]

1 to 5 relate to the first embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the overall configuration of the endoscope;
Figure 2 is an exploded perspective view showing the method of configuring the prism, Figure 3 is a perspective view showing the overall configuration of the prism, Figure 4 is an explanatory diagram of the exit end of the gradient index lens, and Figure 5 a. Explanatory diagram of the tip of the insertion tube, Fig. 5b
5a is a front view of the insertion section taken along the line A-A' in FIG. 5a, and FIG. FIG. 6 is a cross-sectional view of the second embodiment of the present invention, FIG. 6a is a plan view of the distal end of the insertion section, and FIG.
7 is an explanatory view showing the overall structure of an endoscope according to a third embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Endoscope, 7... Lens tube, 9... Connection member, 12... Refractive index gradient type lens, 18... Positioning member, 26... Lens, 31... Triangular prism, 32... Trapezoidal prism .

Claims (1)

[Claims for Utility Model Registration] An optical tube having a gradient refractive index lens; an endoscope body having an eyepiece system capable of forming an optical image transmitted by the gradient index lens; a sheath connecting member attached at a predetermined distance from the distal end of the optical tube; and a positioning member attached to the rear end of the sheath connecting member, the positioning member for positioning the rear end of the optical tube as described above. the sheath connecting member is fitted into the front end of the endoscope main body, the positioning member is positioned at a predetermined position of the endoscope main body, and the sheath connecting member is fixed at a predetermined position in the endoscope body. An endoscope that is fitted and fixed to the front end of the endoscope body.