JPH07275194A - Top end part for electronic endoscope - Google Patents

Abstract

PURPOSE:To provide the top end part for electronic endoscope for which a light guide fiber bundle for illumination can be sufficiently integrated even in the case of a small diameter electronic endoscope and the protection tube of the light guide fiber bundle is not deviated or turned over inside a bent part. CONSTITUTION:The top end part of a light guide fiber bundle 30 for illumination is charged at a space between a solid-state imaging device housing cylinder 19 and a main body 10 of the top end part, and the light guide fiber bundle 30 is covered with a flexible and thin protection tube 31 backward rather than the rear end of the main body 10 of the top end part. Then, a space generated among the top end part of the protection tube 31, the outer face of the solid- state imaging device housing cylinder 19 and the inner face of a node ring 2a at the top-most end is filled with an elastic adhesive agent 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distal end portion of an electronic endoscope in which a solid-state image pickup device is incorporated in a distal end portion main body.

[0002]

2. Description of the Related Art Since there is a limit to miniaturization of a solid-state image pickup device, in a small-diameter endoscope for bronchial examination, the solid-state image pickup device occupies most of the cross-section inside the distal end body. It is normal.

FIG. 4 shows a cross section of the tip portion of such a conventional electronic endoscope, and a solid-state image pickup device housing cylinder 52 housing a solid-state image pickup device 51 having a substantially rectangular cross section is substantially cylindrical. It is fully arranged in the tip end main body 53 of the cross section.

Light guide fiber bundle 54 for illumination
Must be inserted into the gap between the solid-state image sensor housing tube 52 and the tip end main body 53, but the light guide fiber bundle 54 is protected by a protective tube such as a silicon tube in the curved portion behind the tip end main body. It must be covered and the protective tube must be prevented from slipping or turning over during repeated bending movements.

Therefore, conventionally, as shown in FIG. 4, some of the light guide fiber bundles 54 are so thin that they can be inserted into the gap between the solid-state image pickup device housing cylinder 52 and the tip portion main body 53. The tip of the protective tube was fixed to the rear end of the base 55 through the base 55.

[0006]

However, at the tip of the small-diameter electronic endoscope, the cross-sectional area secured for inserting the light guide fiber bundle is very small, so that there are a plurality of sections as described above. If the light guide fiber bundles are arranged through the respective caps, the caps occupy a considerable area, and the number of light guide fiber bundles to be incorporated becomes very small. As a result, sufficient illumination light cannot be obtained, and good observation cannot be performed.

Therefore, according to the present invention, a sufficient amount of the light guide fiber bundle for illumination can be incorporated even in a small-diameter electronic endoscope, and the protection tube of the light guide fiber bundle is displaced or turned over in the curved portion. An object of the present invention is to provide a tip portion of an electronic endoscope that does not wear.

[0008]

In order to achieve the above object, a distal end portion of an electronic endoscope according to the present invention has a solid-state image pickup element accommodating tube in which a solid-state image pickup element is accommodated inside and has a substantially rectangular cross section. At the distal end of the electronic endoscope in which the distal end of the curved portion is connected to the rear end side so as to project rearward from the inside of the distal end main body having a substantially cylindrical shape. The tip portion of the guide fiber bundle is filled in the space between the solid-state imaging device housing and the tip portion main body, and the light guide fiber bundle is covered with a flexible thin protective tube behind the rear end of the tip portion main body. Then, the space formed between the tip portion of the protective tube, the outer surface of the solid-state imaging device housing cylinder, and the inner surface of the frontmost node ring is filled with an elastic adhesive.

[0009]

Embodiments will be described with reference to the drawings. Figure 1
The tip part of the insertion part of the electronic endoscope is shown, and at the tip of the bending part 1 connected to the tip of a flexible tube (not shown),
The tip body 10 is connected. Their outer diameter is, for example, about 4 to 6 mm.

The bending portion 1 is formed by rotatably connecting a large number of cylindrical node rings 2 with rivets 3 and covering the outside with a mesh tube 4 and an outer tube 5. And
The front part of the most advanced node ring 2a is fitted to the outer surface of the rear part of the tip body 10, and the retaining pin 9 projecting from the tip body 10 is bored in the nodal ring 2a. The tip body 10 and the most advanced node ring 2a are mechanically connected to each other by engaging with the formed holes.

Reference numeral 8 is a fixing ring which is fitted to the distal end portion main body 10 for fixing the distal end of the operation wire 6 and whose rearward movement is restricted by the most advanced node ring 2a. The operation wire 6 has its tip fixed to its fixing ring 8 and is pulled out rearward. Reference numeral 7 is a wire guide projectingly provided on the inner peripheral surface of the node ring 2.

The tip body 10 is formed in a generally cylindrical shape as a whole, and as shown in the front view of FIG. 2, a mirror is provided in a support frame 11 fitted into the tip portion of the tip body 10. The frame 12 is supported and they are joined together.

As shown in FIG. 1, an objective optical system 13 is incorporated in the lens frame 12. 14 is an aperture stop,
Reference numeral 15 is a spacer between lenses, and 16 is a light-shielding mask for cutting unnecessary light.

A solid-state image sensor 18 (for example, a CCD) is housed in a solid-state image sensor housing cylinder 19 at a position where an observation image is formed by the objective optical system 13. In the solid-state image sensor housing tube 19, in front of the solid-state image sensor 18,
A YAG laser light cut filter 20 and a low-pass filter 21 are arranged, and a circuit board 24 on which an electronic circuit component 23 is mounted is arranged behind the solid-state image sensor 18. 25 is a signal cable extended to the rear, 26, 2
Reference numeral 7 is an insulating tape wound around the inner and outer surfaces of the solid-state imaging device housing cylinder 19.

As shown in FIG. 3, the solid-state image pickup device 18
Has a substantially rectangular cross-section, and the solid-state imaging device housing 1
Reference numeral 9 denotes a tubular body formed in a shape along the outer surface of the solid-state image sensor 18 and having a substantially rectangular cross section.

As shown in FIG. 1, the front end of the solid-state image pickup device housing cylinder 19 and the rear end of the lens frame 12 are connected to each other by the connecting cylinder 2.
8, the rear end of the solid-state image sensor housing cylinder 19 projects from the rear end of the front end body 10 and reaches the rearward curved portion 1.

Illumination light guide fiber bundle 30
The tip portion of is filled in the space between the upper and lower surfaces of the solid-state imaging device housing cylinder 19 and the inner surface of the tip portion main body 10, and is joined thereto.

However, if the light guide fiber bundle 30 is filled up to a position where it comes into contact with the outer surface of the solid-state image pickup device housing cylinder 19, the space for covering the protective tube 31 cannot be secured behind it, so that the solid-state image pickup device housing cylinder 19 is not formed. A flat plate-shaped spacer 32, which is slightly thicker than the wall thickness of the protective tube 31, is interposed therebetween.

As a result, as shown in FIG. 3, the maximum possible amount of the light guide fiber bundle 30 passes through the space between the top and bottom of the solid-state image pickup device housing cylinder 19 and the tip end body 10. Has been done.

As shown in FIG. 2, the support frame 11 on the front side is notched in both upper and lower sides in accordance with the cross-sectional shape of the light guide fiber bundle 30, and the light guide fiber bundle 30 is inserted and joined in that part. The emission end face 30a of the light guide fiber bundle 30 is exposed at the tip end face of the tip end body 10.

As shown in FIG. 1, the light guide fiber bundle 30 passes from the rear end of the tip end body 10 through the inside of the curved portion 1 at the rear side and further through the inside of the flexible tube (not shown) for incidence. The end reaches a connector that is connected to an external light source device.

On the rear side of the rear end of the front end main body 10, a thin, flexible tube made of, for example, a silicone rubber tube is provided so that the light guide fiber bundle 30 is exposed and does not come into direct contact with other internal components. Protective tube 31
Are covered by the light guide fiber bundle 30.

The protective tube 31 is coated on the light guide fiber bundle 30 so that the front end surface abuts the rear end of the front end body 10. And the protection tube 31
A few millimeters at the tip of the solid-state image sensor housing tube 1
It is sandwiched between the outer surface of 9 and the inner surface of the most advanced node ring 2a, and the space generated between them is filled with, for example, a silicone adhesive-based elastic adhesive 35.

Therefore, since the adhesive 35 has elasticity at the same time that the tip of the protective tube 31 is joined to that portion, the bending portion 1 is repeatedly bent so that the protective tube 31 is not bent or twisted. Even if added, the adhesive 35 flexibly and elastically deforms accordingly, so that the bonded state is not destroyed, and the protective tube 31 does not shift or turn over.

[0025]

According to the present invention, the tip portion of the illumination light guide fiber bundle is directly filled in the space between the solid-state image sensor housing tube and the tip portion main body without using a cap or the like, so that space By arranging the maximum number of light guide fiber bundles inside, it is possible to obtain a good observation image with bright illumination light even with a thin electronic endoscope, etc. By filling the space between the outer surface of the imaging device housing and the inner surface of the most advanced node ring with an elastic adhesive, the tip of the protective tube is bonded in place even if the curved part is repeatedly bent. The light guide fiber bundle can have excellent durability while maintaining the maintained state.

[Brief description of drawings]

FIG. 1 is a side sectional view of a tip portion of an electronic endoscope of an embodiment.

FIG. 2 is a front view of the distal end portion of the electronic endoscope of the embodiment.

FIG. 3 is a front view (III-II) of the distal end portion of the electronic endoscope of the embodiment.
I) It is a sectional view.

FIG. 4 is a front sectional view of a distal end portion of a conventional electronic endoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Curved part 2a Cutting edge node ring 10 Tip part main body 18 Solid-state imaging device 19 Solid-state imaging device housing 30 Light guide fiber bundle 31 Protective tube 35 Resilient adhesive

Claims (1)

[Claims] 1. A solid-state image sensor housing tube having a substantially rectangular cross-section having a solid-state image sensor housed inside, and a substantially cylindrical cross-section having a curved end of a nodal ring connected to the rear end side. At the tip of the electronic endoscope arranged so as to project rearward from the inside of the body, the tip portion of the illumination light guide fiber bundle is filled in the space between the solid-state image sensor housing tube and the tip body. In addition, the light guide fiber bundle is covered with a flexible thin protective tube behind the rear end of the tip end main body, and the tip portion of the protective tube, the outer surface of the solid-state image sensor housing tube, and the most advanced node. A tip portion of an electronic endoscope, characterized in that a space formed between the inner surface of the ring and the inner surface of the ring is filled with an elastic adhesive.