JP3105641B2 - Endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope having an insertion section provided with an observation optical system including an objective lens, an image guide fiber, and a light guide fiber.

[0002]

2. Description of the Related Art A technique for maximally incorporating an image guide optical system and a light guide fiber in the same lumen of a tube body forming an insertion portion of an endoscope is disclosed in Japanese Patent Application Laid-Open No. 63-119732. It has been disclosed.

In this technique, as shown in FIG. 9, a distal end surface of an image guide fiber 106 is joined to a proximal end surface of a rod lens 112 as an objective lens,
2 and the light guide fiber 104 are arranged on the side of the image guide fiber 106 such that the tip thereof is substantially aligned with the tip of the rod lens 112.
An adhesive is applied to the distal end side of the endoscope 4 to integrally bond and fix them, and a rod lens 112 is inserted into the same inner hole of the tube body 102 forming the insertion portion 110 of the endoscope 100.
And the image guide fiber 106 and the light guide fiber 104 are integrally loaded.

The specific assembling method is shown in FIG.
As shown in the figure, the image guide fiber 106 and the light guide fiber 104 are inserted from the distal end of the tube body 102.
After the rod lens 112 is integrally joined to the image guide fiber 106 and the light guide fiber 104 as described above, the outer periphery of the distal end side of the rod lens 112, the image guide fiber 106, and the light guide fiber 104 (FIG. 9) The adhesive is applied to (b) the adhesive application range). Then, the rod lens 112
And the image guide fiber 106 and the light guide fiber 104 are integrally pulled into the tube 102, and these are fixedly held by the inner hole at the distal end of the tube 102.

[0005]

As described above, the base end face of the rod lens 112 and the image guide fiber 10
6 is usually bonded with an adhesive, and this bonding is carefully performed before drawing the rod lens 112 and the image guide fiber 106 into the tube body 102. This is because the proximal end surface of the rod lens 112 and the distal end surface of the image guide fiber 106 are not bonded, or the rod lens 11
When the base end surface of the rod lens 112 is brought into contact with the distal end surface of the image guide fiber 106 for the first time, the rod lens 112 and the image guide fiber 106 become eccentric, or the base end surface of the rod lens 112 and the image guide fiber 106
This is because there is a risk that a good endoscope image may not be obtained due to separation from the distal end surface of the lens. However, when bonding the image guide fiber 106 and the rod lens 112,
The adhesive is not allowed to largely protrude outward from the joint surface between the rod lens 112 and the image guide fiber 106. If the adhesive protrudes greatly, the protruding adhesive protrudes largely in the radial direction, and obstructs the light guide fiber 104 arranged side by side with the rod lens 112 and the image guide fiber 106. This is because the lens 112, the image guide fiber 106, and the light guide fiber 104 may not be able to be integrally pulled into the tube body 102 in some cases.

Further, in order to pull the rod lens 112 and the image guide fiber 106 together with the light guide fiber 104 which has become thicker in the radial direction by the protruding adhesive, the outer diameter of the tube body 102 is reduced. If the diameter is increased, the diameter of the insertion section 110 of the endoscope 100 cannot be reduced. Conversely, if the outer diameter of the tube body 102 is reduced in order to reduce the diameter of the insertion section 110 of the endoscope 100, the necessary number of image guide fibers 106 and light guide fibers 104 can be reduced.
02, the optical performance of the endoscope 100 is degraded.

That is, in order to assemble a small-diameter, high-performance endoscope, it is necessary to load as much of the optical system built-in material into the inner hole of the limited space of the tube body 102 as possible. In the conventional configuration described above, the only option is to prevent the adhesive from largely protruding outward from the joint surface between the rod lens 112 and the image guide fiber 106. Therefore, the bonding portion between the rod lens 112 and the image guide fiber 106 is basically limited to only the end surfaces of both.

However, when the adhesive is used for the rod lens 11
It is extremely difficult to work so as not to largely protrude outward from the joint surface between the image guide fiber 106 and the image guide fiber 106, and careful attention is required. On the other hand, if the bonding portion between the rod lens 112 and the image guide fiber 106 is basically only the end faces of both, the rod lens 112
If only a small force is applied to the bonding portion between the adhesive and the image guide fiber 106, the bonding portion may be easily peeled off.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope capable of reliably and easily joining an objective lens and an image guide fiber. .

[0010]

In order to solve the above-mentioned problems, the present invention provides an image guide having an insertion portion formed of a tube, and having an objective lens joined to the same inner hole of the tube at the tip. In an endoscope in which a fiber and a light guide fiber are loaded side by side, the distal end of the light guide fiber is disposed closer to the proximal end than the joint surface between the objective lens and the image guide fiber, and the distal end of the light guide fiber is Also, a light-transmitting adhesive is filled in the inner hole of the tube body on the distal end side, and illumination light emitted from the distal end of the light guide fiber is emitted from the distal end of the tube body via the light-transmitting adhesive. It was made.

[0011]

The illumination light emitted from the distal end of the light guide fiber is transmitted from the distal end of the tube via the transparent adhesive without disposing the light guide fiber around the joint surface between the objective lens and the image guide fiber. Can be emitted.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. As shown in FIG. 1B, the endoscope 1 according to the present embodiment has a small-diameter insertion portion 10 inserted into a body cavity, for example. The insertion section 10 is connected to an extension cord 22 via a connection section 20, and the extension cord 22 branches to an image guide code 28 and a light guide cord 26 via a branch section 24.

The light guide fiber 4 and the image guide fiber 6 are inserted through the entire length of the insertion section 10 and the extension cord 22. The light guide fiber 4 is further inserted through the light guide cord 26,
The light guide cord 26 is connected to a light source device (not shown) via a light guide connector 32 provided at a base end thereof. Also, after the image guide fiber 6 is inserted through the extension cord 22, the image guide fiber 6 is also inserted through the image guide cord 28, and is connected to a TV (not shown) via an image guide connector 30 provided at the base end of the image guide cord 28.
Connected to camera control unit.

FIG. 1A is a view showing A in FIG. 1B.
FIG. 2 is an enlarged cross-sectional view of a portion, that is, a distal end portion of the endoscope insertion portion 10. The insertion portion 10 is formed of a small-diameter and long tube body 2. The tube body 2 has one inner hole 2a, and the light guide fiber 4 and the image guide fiber 6 are inserted through the inner hole 2a as described above.

The image guide fiber 6 comprises a plurality of fibers each having a core and a clad, which are housed in a jacket glass, and the outer periphery of the jacket glass is coated with a silicon resin containing light-shielding carbon.
At the tip of the image guide fiber 6, a columnar objective lens 12 having substantially the same diameter as this is adhered and fixed by a translucent adhesive 14 such as an epoxy adhesive. In this case, the translucent adhesive 14 protrudes outward from the joint surface 8 between the objective lens 12 and the image guide fiber 6 and protrudes largely in the radial direction. Further, the light guide fiber 4 is disposed in a ring-shaped cavity formed by the outer peripheral surface of the image guide fiber 6 and the inner peripheral surface of the tube body 2. In this case, the distal end of the light guide fiber 4 is located closer to the base end than the joint surface 8 between the objective lens 12 and the image guide fiber 6.

Further, a light-transmitting adhesive 16 such as an epoxy-based adhesive is filled in an inner hole of the tube body 2 on the distal end side of the light guide fiber 4 from the distal end thereof.
The distal end portion of the image guide fiber 6 and the objective lens 12 are adhered and fixed to the inner peripheral surface on the distal end side of the tube body 2.
Further, the tip of the light guide fiber 4 slightly enters into the inside of the translucent adhesive 16, thereby fixing and holding the light guide fiber 4.

Next, a method of assembling the insertion portion 10 shown in FIG. 1A will be described with reference to FIG.
First, the image guide fiber 6 and the light guide fiber 4 whose end faces are polished are inserted into the inner hole 2a of the tube body 2 from the base end side and projected from the distal end of the tube body 2. Thereafter, a translucent adhesive 14 is applied to the base end surface of the objective lens 12 or the front end surface of the image guide fiber 6, and the two members are joined with their optical axes aligned. that time,
Although the translucent adhesive 14 protrudes outward from the joint surface 8 and projects in the radial direction, it is not necessary to wipe off the protruding adhesive 14.

Next, as shown in FIG. 1C, the light guide fiber 4 is positioned so that the front end thereof is not on the front end side of the joint surface 8 between the objective lens 12 and the image guide fiber 6, and the objective lens is adjusted. 12 and the image guide fiber 6 and the light guide fiber 4 are integrally pulled into the inner hole 2a of the tube body. Then, when the tip of the objective lens 12 and the tip of the tube body 2 match, the translucent adhesive 16 is poured into the tip of the tube body 2 using a syringe or the like. In this case, a gap between the outer peripheral surface of the objective lens 12 and the inner peripheral surface of the tube body 2;
If there is a certain relationship between the viscosity of the translucent adhesive 16,
The translucent adhesive 16 causes the objective lens 1 to move by capillary action.
2 is sucked into the distal end portion of the tube body 2 through a gap between the outer peripheral surface of the tube body 2 and the inner peripheral surface of the tube body 2. As described above, the image guide fiber 6, the objective lens 12, and the light guide fiber 4 are fixedly held at the distal end of the tube body 2 by the translucent adhesive 16.

Therefore, in the endoscope 1 having the above configuration, the illumination light supplied from the light source device is transmitted to the distal end side of the insertion section 10 by the light guide fiber 4 and emitted from the distal end of the light guide fiber 4. The illumination light emitted from the distal end of the light guide fiber 4 passes through the translucent adhesive 16 and the translucent adhesive 14 protruding outward from the joint surface 8, and is inserted into the insertion portion 10, that is, the distal end of the tube body 2. And irradiates the object to be irradiated. Also,
Object light from the irradiated object is sent to a TV camera control unit connected to the image guide fiber 6 via the objective lens and the image guide fiber 6, and can be observed on a TV monitor of the TV camera control unit.
Note that a coating may be provided on the outer periphery of the objective lens 12 and the outer periphery of the image guide fiber 6 to prevent incidence of illumination light.

As described above, the endoscope 1 of the present embodiment.
Since the distal end of the light guide fiber 4 is disposed closer to the base end than the joint surface 8 between the objective lens 12 and the image guide fiber 6, even if the adhesive 14 protrudes outward from the joint surface 8, it protrudes in the radial direction. However, this does not disturb the light guide fiber 4 disposed on the outer periphery of the image guide fiber 6, and therefore, the adhesive 1
The outside diameter of the light guide fiber 4 does not become larger than the outside diameter of the light guide fiber 4 due to the protrusion of 4.
As a result, a desired amount of the light guide fiber 4 and the image guide fiber 6 that can ensure optical performance can be loaded into the inner hole 2a in the limited space of the tube body 2. Since the adhesive 14 has translucency, it does not block illumination light emitted from the tip of the light guide fiber 4.

Further, in the above configuration, since the protrusion of the adhesive 14 from the bonding surface 8 does not affect the disposition of the light guide fiber 4, even if the adhesive 14 protrudes outward from the bonding surface 8, Even if it protrudes in the direction, there is no need to wipe it off, and as in the conventional case, care must be taken so that the adhesive 14 does not largely protrude outward from the joint surface 8 between the objective lens 12 and the image guide fiber 6. Difficult work is not required, and the work of joining the objective lens 12 and the image guide fiber 6 becomes easy.

Further, the endoscope 1 of the present embodiment fills the inner hole 2a of the tube body 2 on the tip side of the light guide fiber 4 with the translucent adhesive 16 so that the objective lens 12 The bonding part with the image guide fiber 4
Not only the bonding surface 8 but also the outer peripheral portion of the objective lens 12 filled with the translucent adhesive 16 and the outer peripheral portion of the distal end portion of the image guide fiber 4 are formed over a wide range. Strength is strengthened and secure bonding is performed. Therefore, the objective lens 12 and the image guide fiber 4 are not easily separated from each other at the joint surface 8.

The translucent adhesive 16 guides the illumination light emitted from the distal end of the light guide fiber 4 to the distal end of the tube body 2 by its translucency. Is not different from the case where the light guide fiber 4 is provided at this position.

FIG. 2 shows another method of assembling the insertion portion 10 shown in FIG. That is, in this method, first, the objective lens 12 and the image guide fiber 6 that have been bonded in advance with the translucent adhesive 14 are inserted into the inner hole 2 a of the tube body 2. This insertion is tube 2
May be performed from the distal end side or from the proximal end side. In this state, the translucent adhesive 14 may protrude outward from the bonding surface 8 and protrude in the radial direction.

After the positions of the distal end of the tube 2 and the objective lens 12 are aligned, a translucent adhesive 16 is filled in the distal end of the tube 2, and before the translucent adhesive 16 is cured. The light guide fiber 4 is inserted into the inner hole 2a of the tube body 2 from the base end side.
Is inserted into the translucent adhesive 16. With the curing of the translucent adhesive 16, the image guide fiber 6, the objective lens 12, and the light guide fiber 4 are fixedly held at the distal end of the tube body 2.

FIG. 3 shows a second embodiment of the present invention. In the endoscope 35 of the present embodiment, a multi-component or quartz glass portion serving as a fiber main body is peeled off at the distal end side of the image guide fiber 6 joined to the objective lens 12 by peeling the outer skin 6a (made of silicone resin). Is exposed. Then, the distal end surface of the exposed portion 6b of the image guide fiber 6 whose exposed fiber body is reduced in diameter and the base end surface of the objective lens 12 are joined by a translucent adhesive 14 such as an epoxy adhesive. The translucent adhesive 14 is applied to the periphery of the joint surface 8 between the image guide fiber 6 and the objective lens 12, that is, from the base end side of the objective lens 12 through the exposed portion 6 b of the image guide fiber 6. The coating is applied over a wide area up to the outer skin portion 6a of the sixth. The other configuration is the same as that of the first embodiment.

In the above-described configuration, the light-transmitting adhesive 14 such as an epoxy-based adhesive is applied to the exposed portion 6b made of a glass portion having better adhesiveness than the outer skin portion 6a made of a silicone resin. And objective lens 12
And the joining force is extremely strong. Further, as described above, by applying the light-transmitting adhesive 14 over a wide range, the light-transmitting adhesive 14 covers the joint 15 between the image guide fiber 6 and the objective lens 12 in a cylindrical shape. Can have the same strength as when the lens barrel is provided. Therefore, the insertion portion 1
At the time of the assembling operation of No. 0, the objective lens 12 and the image guide fiber 6 do not separate at the joint surface 8.

FIG. 4 shows a third embodiment of the present invention. In the endoscope 40 of the present embodiment, the light guide fibers 4 are integrally formed into a cylindrical shape by aligning the end surfaces of the light guide fibers 4 and bonding the end portions with a translucent adhesive. Things. The inner hole 4d of the light guide fiber 4 integrally formed in a cylindrical shape has a size that allows the image guide fiber 6 to be inserted. The other configuration is the same as that of the first embodiment.

In the above configuration, since the light guide fiber 4 integrally molded in a cylindrical shape is inserted into the tube body 2, the light guide fiber 4 is inserted into the tube body 2 in a separated state. Good insertability. If the light guide fiber 4 is inserted into the tube body 2 in a separated state, the fiber of the light guide fiber 4 may be broken, but in the case of the present embodiment, such a situation is unlikely to occur.

FIG. 5 shows a fourth embodiment of the present invention. The endoscope 50 according to the present embodiment includes the inner hole 2 of the tube body 2.
a is provided with a channel tube 52. The light guide fiber 4, the objective lens 12, and the image guide fiber 6 are loaded into a cavity formed by the outer peripheral surface of the channel tube 52 and the inner peripheral surface of the tube body 2 by the same means as in the above embodiments. ing. This configuration has the same operation and effects as the above embodiments, and is convenient because a treatment tool or the like can be inserted through the channel hole 64 of the channel tube 52. In the present embodiment, instead of providing the channel tube 52 in the tube body 2, the tube body 2 and the channel tube 52 are provided.
So-called multi-lumen tube 6 integrally formed with
2 may be used as a tube body.

FIG. 7 shows a fifth embodiment of the present invention. The endoscope 70 of the present embodiment is different from the endoscope 4 of the third embodiment.
0 (see FIG. 4) with a bending function added. That is, the light guide fiber 4 integrally molded into a cylindrical shape is provided with the insertion hole 4b through which the bending operation wire 72 is inserted. Two insertion holes 4b are provided symmetrically with respect to the long axis of the integrally formed light guide fiber 4. The bending operation wire 72 inserted through the insertion hole 4b is
At its tip, there is an enlarged portion 72a having an outer diameter larger than the diameter of the insertion hole 4b.
Is locked at the leading edge. In addition, the bending operation wire 72
Is inserted through the insertion hole 4b in a free state, and is connected to a bending operation unit (not shown) on the hand side. Therefore, in this configuration, the bending operation wire 7 is provided by the bending operation section.
If one of the two is pulled, the distal end side of the tube body 2 can be bent in the direction of the pulled bending operation wire 72. As shown in FIG. 8, a groove 4 extending along the axial direction is formed on the outer peripheral surface of the light guide fiber 4 integrally molded into a cylindrical shape.
c may be provided, and the bending operation wire 72 may be provided in the groove 4c. Also in this case, the enlarged portion 7 of the bending operation wire 72
2a is locked at the leading edge of the insertion hole 4b.

[0032]

As described above, in the endoscope according to the present invention, since the distal end of the light guide fiber is located closer to the base end than the joint surface between the objective lens and the image guide fiber, even if the adhesive is used, Even if it protrudes outward from the surface and projects radially, it does not disturb the light guide fiber disposed on the outer periphery of the image guide fiber, and therefore, the outer diameter of the light guide fiber is protruded by the protrusion of the adhesive. However, it does not grow beyond the outside diameter that it has. As a result, a desired amount of light guide fiber and image guide fiber that can ensure optical performance can be loaded into the inner hole of the limited space of the tube body.

In the endoscope according to the present invention, since the protrusion of the adhesive from the joint surface between the objective lens and the image guide fiber does not affect the disposition of the light guide fiber, even if the adhesive is Even if it protrudes outward from the surface and projects radially, there is no need to wipe it off, and unlike the conventional case, the adhesive does not protrude greatly from the joint surface between the objective lens and the image guide fiber. This eliminates the need for careful and extremely difficult work, and facilitates the joining work between the objective lens and the image guide fiber. Therefore, the working time is shortened, and the cost required for the assembling work can be reduced.

Further, the endoscope of the present invention fills the inner hole of the tube body at the distal end side with respect to the distal end of the light guide fiber with a translucent adhesive so that the bonding portion between the objective lens and the image guide fiber is bonded. Is formed not only at these joint surfaces but also over the outer peripheral portion of the objective lens filled with the translucent adhesive and the outer peripheral portion of the distal end portion of the image guide fiber. The bonding force with the metal is strengthened, and reliable bonding is performed. Therefore, the objective lens and the image guide fiber are not easily separated from each other at the joint surface. Further, the translucent adhesive can guide the illumination light emitted from the distal end of the light guide fiber to the distal end of the tube body due to its translucency, and thus has the same operation and effect as the light guide fiber.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a main part of a distal end side of an insertion portion of an endoscope according to a first embodiment of the present invention, FIG. 1B is an overall configuration diagram of the endoscope of FIG. () Is an explanatory diagram showing a method of loading an optical system into the tube.

2 is a cross-sectional view of the endoscope having the same configuration as that of FIG. 1 and showing a state in which an optical system is loaded into a tube body by a method different from that of FIG. 1C.

FIG. 3 is a cross-sectional view of a main part on the distal end side of an insertion section of an endoscope, showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part on the distal end side of an insertion portion of an endoscope, showing a third embodiment of the present invention.

FIG. 5A is a front view of a distal end of an insertion portion of an endoscope according to a fourth embodiment of the present invention, and FIG. 5B is a side view of the distal end side of the insertion portion.

FIG. 6 is a front view of an endoscope distal end showing a modification of FIG. 5;

FIG. 7 is a cross-sectional view of a main part on the distal end side of an insertion portion of an endoscope, showing a fifth embodiment of the present invention.

FIG. 8 is a perspective view showing a modification of the endoscope of FIG. 7;

FIG. 9 shows a conventional endoscope related to the present invention;
FIG. 2 is an explanatory view showing a conventional method for loading an optical system into a tube, and FIG. 2B is a schematic view showing a state in which the optical system is drawn into the tube.

[Explanation of symbols]

1, 35, 40, 50, 60, 70 endoscope, 2 tube body, 4 light guide fiber, 6 image guide fiber, 8 joining surface, 10 insertion section, 12 objective lens, 16 ... Translucent adhesive.

Claims (1)

(57) [Claims] 1. An endoscope having an insertion portion formed of a tube body, wherein an image guide fiber and a light guide fiber each having an objective lens joined to the tip thereof are arranged and loaded in the same inner hole of the tube body. The distal end of the light guide fiber is disposed on the proximal end side of the joint surface between the objective lens and the image guide fiber, and a translucent adhesive is applied to the inner hole of the tube body on the distal end side of the distal end of the light guide fiber. An endoscope, which is filled and emits illumination light emitted from the distal end of the light guide fiber from the distal end of the tube through the translucent adhesive.