JP2991536B2 - The tip of a forward-looking electronic endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward-looking electronic endoscope in which an objective optical system is disposed forward in a distal end body and a solid-state image pickup device is disposed at an observation image forming position. About.

[0002]

2. Description of the Related Art In a conventional forward-looking electronic endoscope,
A light guide fiber bundle for illuminating the observation field is arranged in parallel with the objective optical system, and a cover lens for expanding the illumination range is arranged at the exit end.

[0003]

However, since the light guide fiber bundle passes beside the solid-state image pickup device which is thicker than the objective optical system, it is positioned relatively outside the distal end main body. Further, the diameter of the cover lens is larger than the diameter of the light guide fiber bundle.

Therefore, in the distal end portion of the conventional forward-looking electronic endoscope as described above, the outer edge of the cover lens approaches the outer edge portion of the distal end body, and that portion of the distal end body becomes very thin. And the cover lens may be easily broken by an impact or the like. In addition, since the outer edge of the distal end of the distal end body cannot be largely rounded and has an edge shape, there is a possibility that the mucous membrane in the body cavity may be damaged.

In order to prevent such inconvenience, the distal end main body has to be thickened, and there has been a drawback that the insertability into the body cavity is deteriorated conventionally.

Accordingly, the present invention provides a forward-looking electronic endoscope in which even if a cover lens is attached to the output end of the light guide fiber bundle, the distal end body does not become thick and the cover lens is unlikely to be damaged. The purpose of the present invention is to provide a tip portion.

[0007]

In order to achieve the above object, the distal end of a forward-looking electronic endoscope according to the present invention is provided with an observation image of an objective optical system disposed forward in a distal end body. A solid-state imaging device is arranged at an image forming position, and at the tip of a forward-looking electronic endoscope in which a cover lens is arranged on an emission end face of a light guide fiber bundle for illuminating an observation field of view of the objective optical system, Passing the distal end of the light guide fiber bundle through a straight pipe shorter than the length of the objective optical system, inclining inward, and inserting and fixing the pipe through a hole formed in the distal end body. Features.

[0008]

An embodiment will be described with reference to the drawings.

FIG. 2 is a front view of the distal end body 1 constituting the distal end of the insertion portion of the forward-looking electronic endoscope, wherein 2 is an observation window, 3 is a pair of illumination windows, and 4 is a forceps port. It is a cum suction port.

FIG. 1 shows an I-port including an observation window 2 and an illumination window 3.
It is a side sectional view by I section. 50 is the tip body 1
The bending portion is provided at the rear of the connecting tube 5 and is bent by remote operation.
3 and is connected and fixed to the rear end of the front end body 1.

The outer surface of the curved portion 50 is covered with an elastic outer tube 52, which is fixed to the rear half of the connecting tube 53 by binding and bonding.

Reference numeral 10 denotes a solid-state image pickup device formed of, for example, a charge-coupled device (CCD), and reference numeral 10a denotes an image receiving unit. 1
Reference numeral 0b denotes a transparent layer made of, for example, a transparent epoxy resin or the like formed on the surface of the image receiving unit 10a to prevent dust or the like from adhering to the image receiving unit 10a. Reference numeral 10c denotes a filter for cutting the YAG laser.

An output signal from the solid-state imaging device 10 is amplified by an electronic circuit formed on the substrate 11, and is connected to a monitor device via a signal processing circuit on the rear by a cord 13 passing through a shielded cable 12. (Not shown).

Outside the solid-state imaging device 10 and the substrate 11,
An electrically insulating tape 14 made of, for example, synthetic resin is wound and adhered and fixed in a metal frame 15, and the outer periphery of the frame 15 is also made of an electrically insulating tape made of, for example, synthetic resin. 16 are wound.

Reference numeral 21 denotes an image receiving section 10a of the solid-state imaging device 10.
This objective optical system 21 is adhered and fixed in a metal lens frame 22. 23 is a spacer and 24 is a brightness stop.

The rear end of the lens frame 22 is fitted and joined to the frame 15 on which the solid-state imaging device 10 is mounted. However, the thickness of the solid-state imaging device 10 is
It is very thick compared to the diameter of 1. Therefore, as shown in FIG. 3, the rear end portion of the lens frame 22 is formed in a rectangular shape thicker than the front half portion in accordance with the shape of the frame 15.

A cover lens 21a is joined to a front end portion of the lens frame 22 with a brightness stop 24 interposed therebetween. In the present embodiment, the cover lens 21 a is a concave lens and forms a part of the objective optical system 21 and is located at the observation window 2.

An electrically insulating member 25 formed of a stepped cylinder made of an electrically insulating synthetic resin so as to surround the lens frame 22 is fitted around the front end of the lens frame 22 and defoamed. It is bonded and fixed by the epoxy adhesive.

The outer solid part of the electric insulating member 25 may be
Is fitted in a hole 26 formed in the hole. The gap is watertightly sealed by an electrically insulating O-ring 27 interposed therebetween.

Reference numeral 30 denotes a light source for illuminating the observation visual field range.
It is a light guide fiber bundle for illumination. The light guide fiber bundle 30 is inserted through the entire length of the insertion portion of the endoscope, and is covered with a flexible silicone rubber tube 31. In the distal end body 1, it is arranged so as to pass through a position on the outer side of the distal end body 1 in a slightly flattened state in parallel with the frame 15 to which the solid-state imaging device 10 is attached.

The light emitting end 30a of the light guide fiber bundle 30 is inserted into a short straight metal pipe 32, and an adhesive is poured into the metal pipe 32 to be solidified and joined.

The distal end body 1 is provided with a hole 33 into which a metal pipe 32 is inserted. The objective optical system 21 is thinner than the solid-state image pickup device 10 and a space is provided around the objective optical system 21. Utilizing the fact, the hole 33 is formed by inclining the tip side inward toward the observation window 2 side. The angle is, for example, about 3 to 15 degrees.

The metal pipe 32 is fitted into and fixed to the hole 33 so that the illumination direction is directed toward the observation window 2.

The front end of the frame 15 to which the solid-state imaging device 10 is attached is connected to the light guide fiber bundle 30.
In order not to interfere with the metal pipe 32, the front end portion of the frame body 15 is cut off only at that portion as shown in FIG.

Note that the entire length of the metal pipe 32 is shorter than the entire length of the objective optical system 21 so that the straight metal pipe 32 can be arranged at an inclined angle without difficulty. Thereby, the rear end portion of the metal pipe 32 does not protrude outward, and the distal end main body 1 can be formed to a minimum thickness.

At the position of the illumination window 3, that is, at the position facing the exit end face 30b of the light guide fiber bundle 30,
A cover lens 35 composed of a concave lens is bonded and fixed to the front end surface of the distal end body 1, and the light distribution of the illumination light is expanded by the cover lens 35.

The cover lens 35 is located inward on the end face of the distal end body 1 because the output end 30a of the light guide fiber bundle 30 is provided to be inclined inward. .

Therefore, since the outer edge of the cover lens 35 is separated from the outer edge of the tip body 1, the tip body 1
Does not need to be formed thick, and the outer peripheral edge of the tip can be largely rounded.

The portion of the distal end main body 1 without the built-in part (part A shown in FIGS. 1 and 2) is tapered off to improve the insertability.

FIG. 4 shows a cross-section through the center of the forceps port / suction port 4. It is joined to the main body 1. However, the forceps channel tube 9 has a large thickness in the curved portion 50 to be bent and a small thickness in the tip body 1 that is not bent, and has a gradually changing thickness at the boundary. .

FIG. 5 shows a cross section taken along line V--V in FIG. 1. Reference numeral 58 denotes a pin for connecting the connecting cylinder 53 and the node ring 51. Reference numeral 59 denotes a distal end portion of the bending operation wire fixed to the node ring 51.

[0032]

According to the distal end portion of the forward-looking electronic endoscope of the present invention, the cover lens can be arranged at a position closer to the inside away from the outer edge of the distal end portion main body. The outer diameter of the distal end can be reduced to improve the insertion performance of the endoscope, and the distal end outer edge of the distal end body can be formed to be largely rounded, so that the mucosal surface may be damaged in the body cavity. Also decreases.

Further, since the cover lens is located near the inner side of the distal end main body, it is hard to be broken by an impact or the like, so that the durability is improved, and the illumination state when the subject is at a short distance is also improved. Has the effect of

[Brief description of the drawings]

FIG. 1 is a side sectional view (II sectional view) of an embodiment.

FIG. 2 is a front view of the embodiment.

FIG. 3 is a sectional view taken along line III-III of the embodiment.

FIG. 4 is a partial side sectional view of the embodiment.

FIG. 5 is a sectional view taken along line VV of the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tip main body 10 solid-state imaging device 21 objective optical system 30 light guide fiber bundle 32 pipe 33 hole 35 cover lens

Claims (1)

(57) [Claims] 1. A the observation image formed position of the objective optical system disposed forward in the distal portion within the body as well as arranging the solid-state imaging device, said to illuminate the observation field of the objective optical system
At the distal end of a forward-looking electronic endoscope provided with a cover lens on the exit end surface of the light guide fiber bundle disposed on the distal end surface of the distal end body, Through a straight pipe shorter than
The direction that moves away from the outer edge of the tip body as it approaches the mouth
A distal end portion of the forward-looking electronic endoscope, wherein the pipe is inserted and fixed in a hole formed in the distal end portion main body at an angle .