JPH08136828A - Endoscope - Google Patents

Abstract

PURPOSE: To provide an endoscope which is extended to an operator side without increasing the diameter at the front end of the endoscope and without allowing a light guide disposed around an image pickup unit to be held in a spacing between a juncture and a signal cable. CONSTITUTION: The central axis (b) of the signal cable 22 extended from the rear end face of the image pickup unit 20 disposed in the front end constituting part 10 of the endoscope 50 is offcentered by a distance (c) from the central axis (a) of the image pickup unit 20. The spacing B between the juncture 60 of the front end constituting part 10 and the curving part 40 and the signal cable 22 extended from the image pickup unit 20 is made wider by as much as the eccentricity-component between the central axis (a) and the central axis (b). The part covered with a silicone tube 32 of a light guide bundle 33 covering the image pickup unit 20 is thereby disposed by assuring a sufficient clearance in the spacing B between the juncture 60 and the signal cable 22.

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 image pickup unit provided with an image pickup means in an insertion portion, and more particularly to an endoscope having a light guide arranged around the image pickup unit.

[0002]

2. Description of the Related Art In recent years, medical endoscopes that can observe the inside of a body cavity by inserting an elongated insertion portion into the body cavity have been widely used. In the industrial field, industrial endoscopes for observing the inside of turbines, engines, etc. are also used.

[0003] In these endoscopes, for example, an insertion portion is flexible and is inserted from a mouth or the like into a bent body cavity to observe an observation target portion inside the body cavity, and an insertion portion is rigid and an observation target portion inside the body cavity. There is one to observe by inserting it straight toward.

In an endoscope in which the insertion portion is flexible, an optical type in which an object image of an observation target portion formed on an image guide inserted through the endoscope is transmitted to an eyepiece portion for observation with the naked eye An electronic device in which an endoscope and an image pickup device such as a CCD are provided as image pickup means at the distal end of the endoscope insertion portion, and a subject image of an observation target portion formed on the image pickup device is displayed on a monitor screen for observation. There is an endoscope.

In the electronic endoscope, the objective lens system, the objective lens frame, the solid-state image pickup device, the electronic circuit board, and the fixed image pickup device and the electronic circuit board are integrally formed as an image pickup unit. It was fixed to the tip forming part that forms the tip of the endoscope. In addition to the image pickup unit, a light guide for transmitting illumination light, a treatment instrument channel for inserting a treatment instrument, an air / water feeding channel, and the like are provided in the distal end configuration portion.

[0006] In Japanese Utility Model Laid-Open No. 60-9041, a light guide is arranged so as to surround the image pickup unit arranged at the tip of the endoscope to increase the amount of illumination light. A mirror is shown.

[0007]

However, when the endoscope disclosed in Japanese Utility Model Laid-Open No. 60-9041 is applied to an endoscope having a curved portion, at the time of assembly or use, the light guide element is used. In order to prevent the line from breaking and reducing the amount of emitted light, when the light guide bundle that is arranged around the imaging unit is extended toward the hand side, an image is taken inside the distal end of the endoscope that is closer to the distal end than the curved part. It was necessary to cover the light guide bundle with a silicon tube or the like at the rear end of the unit to form a bundle. However, as shown in FIG. 5, when the light guide 4 disposed around the imaging unit 3 built in the distal end forming portion 2 of the endoscope 1 is extended to the hand side, the distal end forming portion 2 and the bending portion are arranged. The gap A between the connection portion 6 with the tip end side of 5 and the signal cable 7 extending from the imaging unit 3 was narrow. Therefore, the portion covered with the silicon tube 8 is sandwiched in the gap A between the connection portion 6 and the signal cable 7, and when the bending operation is repeated many times, the light guide wires are generated near the silicon tube sandwiched in the gap A. It may break.

On the other hand, in order to prevent the light guide 4 from being broken inside the tip forming portion, the connecting portion 6 and the signal cable 7 are provided.
If the outer diameter of the distal end forming portion 2 is made large in order to widen the gap A between them, it goes against the idea of reducing the diameter of the endoscope insertion portion in order to alleviate the pain during insertion.

The present invention has been made in view of the above circumstances, and a light guide disposed around the image pickup unit is provided in the gap between the connection portion and the signal cable without increasing the diameter of the distal end portion of the endoscope. It is intended to provide an endoscope that can be extended to the hand side without being pinched.

[0010]

An endoscope according to the present invention is an endoscope including a light guide in an insertion portion of the endoscope and an image pickup unit in which the image pickup means is arranged. The central axis of the signal cable that is connected and extends from the image pickup unit is eccentrically provided with respect to the central axis of the image pickup unit.

[0011]

According to this structure, since the central axis of the signal cable extending from the image pickup unit is eccentric with respect to the central axis of the image pickup unit, the distance between the image pickup unit end surface and the signal cable end surface can be different, By passing the light guide through the wider gap, the light guide is extended to the hand side without being pinched.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention.
Is a perspective view showing the schematic configuration of the endoscope tip portion, FIG. 2 is a perspective view showing the endoscope tip portion, and FIG. 3 is a sectional view showing the configuration of the endoscope tip portion.

As shown in FIG. 1, an objective lens system 21, an objective lens frame (not shown), a solid-state image pickup device, an electronic circuit board, etc. are integrally formed in an inner hole 11 of a tip forming portion 10 which constitutes a tip portion of an endoscope. The light guide bundle 33 having the image pickup unit 20 provided in the image pickup unit 20 and the light guide tip portion 30 that is formed so as to cover the periphery of the image pickup unit 20 and is formed in a substantially crescent shape is arranged. There is.

A curved portion, which will be described later, is connected and fixed to a proximal end portion of the tip forming portion 10 to form a step portion 12.

A signal cable 22 extends from the rear end of the image pickup unit 20. The central axis of the signal cable 22 extending from the rear end surface of the imaging unit 2 is
It is provided eccentrically with respect to the central axis of 0.

The light guide tip portion 30 at the tip portion of the light guide bundle 33 is formed by adhering the light guide 31 in a substantially crescent shape so as to surround the image pickup unit 20, and the step portion 12 of the tip forming portion 10 is formed. The light guide 31 is gradually formed to have a smaller diameter toward the vicinity of the inner hole, and the light guide 31 formed to have the smaller diameter is covered with a silicon tube 32 to prevent the light guide strand from being broken.

Now, the assembly of the image pickup unit 20 and the light guide bundle 33 into the distal end forming section 10 will be described. First, the periphery of the image pickup unit 20 is covered with the light guide tip portion 30 of the light guide bundle 33. At this time, the central axis of the signal cable 22 extending from the imaging unit 20 is the farthest position from the imaging unit 2.
The outer surface of 0 is covered with the light guide tip 30.

Next, the image pickup unit 20 covered with the light guide tip portion 30 is arranged in the inner hole 11 of the tip forming portion 10, and the curved portion 40 is connected to the step portion 12 of the tip forming portion 10 to connect the bending portion 40 to the step portion 12 of FIG. The insertion portion 51 of the endoscope 50 as shown in FIG.

As shown in FIG. 3, the central axis b of the signal cable 22 extending from the rear end surface of the image pickup unit 20 disposed in the inner hole 11 of the distal end forming portion 10 of the endoscope 50 is the same as that of the image pickup unit 20. It is provided so as to be eccentric by a distance c with respect to the central axis a. Therefore, the gap B between the connection portion 60 between the step portion 12 of the tip forming portion 10 and the tip side of the bending portion 40 and the signal cable 22 extending from the image pickup unit 20 is shown in the conventional example of FIG. As compared with the gap A in which the center axis b of the signal cable 22 and the center axis a of the image pickup unit 20 are coaxially provided, the gap is widened by the amount of eccentricity between the center axis a and the center axis b. As a result, the portion of the light guide bundle 33 covering the image pickup unit 20 covered by the silicon tube 32 has a gap B between the connection portion 60 and the signal cable 22.
It is arranged with a sufficient clearance secured.

The step portion 12 of the tip forming portion 10 is fitted with a mesh tube 41 and a rubber outer skin 42 which form the curved portion 40, and a thread winding fixing portion 43 is formed on the outer periphery of the outer sheath 42 to form the curved portion 40. Are fixed to the tip forming unit 10.

In this way, the central axis of the signal cable extending from the rear end surface of the image pickup unit is eccentric with respect to the central axis of the image pickup unit, so that the connecting portion between the tip forming portion and the bending portion and the signal cable are connected. The gap between and can be widened without increasing the diameter of the endoscope tip component.

Further, by guiding the light guide bundle to the hand side through the light guide bundle arranged around the image pickup unit in the widened gap, there is a margin in the portion of the silicon tube, so that the light guide element can be repeatedly bent. It is possible to provide an endoscope in which the line is not broken.

Further, by connecting and fixing the tip end side of the bending portion to the step portion provided in the tip forming portion, the outer diameter of the connecting portion between the tip forming portion and the bending portion becomes larger than the outer diameter of the tip forming portion. Never.

The light guide bundle does not necessarily have to be formed in a substantially crescent shape so as to surround the image pickup unit, but may be formed in a cylindrical shape and arranged. Further, a plurality of light guide bundles formed on a cylinder may be arranged around the image pickup unit. Further, a cylindrical protection member may be provided on the outer peripheral portion of the light guide for protecting the light guide.

By the way, in the electronic endoscope in which the solid-state image pickup device is disposed in the endoscope insertion portion, the solid-state image pickup device may be electrically adversely affected by static electricity or high-frequency current generated from the electric knife. Therefore, in order to protect the solid-state image sensor from the external current, the metal endoscope exterior part is covered with an insulator. However, in order to keep the outer diameter of the endoscope small, it may not be possible to cover the metallic exterior part of the endoscope with an insulator. Therefore, there has been a demand for an electronic endoscope that does not adversely affect the solid-state image pickup device electrically even if the metal is exposed on the exterior portion of the endoscope. Therefore,
The vicinity of the solid-state image sensor of the electronic endoscope is configured as follows.

As shown in FIG. 4, a metallic tip forming portion 71 is provided.
The image pickup unit 20 disposed in the field lens group 26 is a lens frame 26 formed of an insulating member in which the objective lens group 25 is disposed, and a crystal lens 27 and a field so that the optical axis of the CCD bare chip 24 housed in the CCD package 29 is aligned. Lens 2
8 is adhered and fixed to the image pickup frame 23, and the outer periphery of the image pickup frame 23 is covered with an insulating tube 35 formed of a heat shrinkable tube. A light guide bundle 33, which covers the light guide tip portion 30 formed in a substantially crescent shape, is arranged on the outer periphery of the image pickup unit 20 in the tip forming portion 71.

As described above, by forming the lens frame 26 with the insulating member, even if a high frequency current such as an electric knife flows through the exposed metallic tip forming member 71 and the lens frame 26, the lens frame 26 is formed. Also, since the insulating tube 35 is formed of an insulating member, the high frequency current does not reach the CCD 24.

When the lens frame 26 is formed of a metal member, the image pickup frame 23 is formed of an insulating member rather than a metal member, so that the high frequency current such as an electric knife is applied to the tip forming portion 71 and the lens frame 26. Even if the current flows, the high frequency current does not reach the CCD 24.

By the way, in the image pickup unit 20, the lens frame 26 is inserted into the image pickup frame 23, the shield pipe 36 is fitted into the rear end of the image pickup frame 23, and the image pickup frame 2 is inserted.
3 and the shield pipe 36 were covered with the insulating tube 35. Therefore, the portion where the three members of the image pickup frame 23, the shield pipe 36, and the insulating tube 35 overlap each other is the maximum outer diameter of the image pickup unit 20. In addition,
The outer circumference of the lens frame 26 and the outer circumference of the insulating tube 35 have substantially the same diameter.

On the other hand, the rigid light guide tip portion 30 formed into a substantially crescent shape by the adhesive of the light guide bundle 33 arranged so as to surround the image pickup unit 20 has a length l.
The light guide base 38 of FIG. When the light guide tip portion 30 is formed by bonding, if the adhesive is squeezed out, the length of the hard portion of the light guide bundle 33 may become longer than necessary.

The outer diameter of the insulating tube 35 covering the image pickup frame 23 and the shield pipe 36 also varies due to slack in the process of contraction, and the outer diameter of the image pickup unit at the rear portion of the shield pipe is larger than necessary. Sometimes For this reason, when the image pickup unit 20 having the crescent-shaped light guide tip 30 formed in the tip forming portion 71 is incorporated, the portion of the light guide bundle 33 that should be soft becomes hard, and the image pickup unit 20 is made. Since the rear portion of the shield pipe has a large diameter, the hardened light guide may not fit well in the distal end configuration portion, and the endoscope distal end portion may not be configured.

For this reason, the hard length L of the light guide tip portion 30 formed of an adhesive is the portion where the three members of the image pickup frame 23, the shield pipe 36, and the insulating tube 35 where the image pickup unit 20 has the maximum outer diameter portion overlap. The length L up to this side is set.

As a result, even if the outer diameter of the insulating tube 35 covering the shield pipe after contraction varies, the light guide forming the light guide bundle disposed in this portion is fixed with an adhesive. Since the light guide wire is not provided, it can be easily assembled because it can escape into the gap 39 corresponding to the thickness of the light guide base.

[Additional Notes] 1. In an endoscope including a light guide in an insertion portion and an image pickup unit having an image pickup unit, a central axis of a signal cable connected to the image pickup unit and extending from the image pickup unit is a central axis of the image pickup unit. Eccentric with respect to the endoscope.

2. The endoscope according to Appendix 1, wherein the cross-sectional area of the imaging unit in the circumferential direction is larger than the cross-sectional area of the signal cable in the circumferential direction.

3. The endoscope according to appendix 1, wherein the light guide is arranged around an imaging unit.

4. The endoscope according to supplementary note 1 or supplementary note 3, wherein the light guide is inserted between an end surface of the signal cable in which the central axis of the signal cable is eccentrically widened and an end surface of the imaging unit.

5. An endoscope in which an image pickup means is arranged in the insertion part, wherein at least one insulating member is arranged between the tip part of the insertion part and the image pickup means.

6. The endoscope according to Appendix 5, wherein the insulating member is a lens frame that holds an objective lens system.

7. The endoscope according to appendix 5, wherein the insulating member is an imaging frame that holds an imaging unit.

8. In an endoscope in which a light guide having a hard portion is arranged around an image pickup unit arranged in a distal end configuration portion of an endoscope, the hard portion formed by an adhesive of the light guide is in front of the maximum outer diameter portion of the image pickup unit. Located in the.

[0042]

As described above, the endoscope of the present invention is
(EN) Provided is an endoscope in which a light guide arranged around an imaging unit is extended to a hand side without being sandwiched in a gap between a connection portion and a signal cable without making a distal end portion of the endoscope thick. You can

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention, and FIG. 1 is a perspective view showing a schematic configuration of a distal end portion of an endoscope.

FIG. 2 is a perspective view showing a distal end portion of an endoscope.

FIG. 3 is a cross-sectional view showing the configuration of the distal end portion of the endoscope.

FIG. 4 is a cross-sectional view showing a relationship between a distal end constituent portion of an endoscope distal end portion and an imaging unit.

FIG. 5 is a cross-sectional view showing a configuration of a conventional endoscope tip portion.

[Explanation of symbols]

 20 ... Imaging unit 22 ... Signal cable 50 ... Endoscope

Claims (1)

[Claims] 1. An endoscope comprising a light guide in an insertion portion of an endoscope and an image pickup unit having an image pickup means, wherein a center of a signal cable connected to the image pickup means and extending from the image pickup unit. An endoscope, wherein an axis is provided so as to be eccentric with respect to a central axis of the imaging unit.