JPS62279312A - Endoscope - Google Patents

Abstract

PURPOSE:To prevent draining and observation performance from deteriorating by molding integrally a tip cover of synthetic resin and an optical member which is positioned as a different component at the outermost position of an objective optical system. CONSTITUTION:The tip cover 22 which covers the tip end surface side of a main body 12 is molded of the synthetic resin which is optically transparent or opaque and when this tip cover 22 is molded, a cover lens 23 is united with the tip cover 22 by insert molding. The cover lens 23 may be formed of glass or transparent synthetic resin and when the transparent synthetic resin is used, the tip cover 22 use the opaque synthetic resin preferably. Consequently, there is no gap between the tip cover 22 and cover lens 23 and washing water when the cover lens 23 is washed flows smoothly from the cover lens 23 along the tip cover 22, so that draining is done excellently. Further, the deterioration of observation is never caused.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an endoscope in which the main body of the distal end component of the insertion section is covered with a distal end cover made of synthetic resin.

[Prior Art] An endoscope generally includes an operating section and an insertion section. The insertion section has a distal end component provided at the distal end of a flexible tube section via a curved tube section. This tip component has a hard body made of metal or the like, and the tip side of this body is covered with a tip cover made of synthetic resin. Further, the main body is provided with an objective optical system, and a cover lens, which is the outermost optical member, is attached to the tip cover.

When the cover lens is attached to the distal end cover, a gap is likely to occur between them, so the gap is filled with an adhesive. However, in doing so, an adhesive layer is created around the cover lens, which causes the problem that cleaning water from cleaning the objective lens tends to adhere to this area, reducing water drainage. arise.

Although no endoscope with a structure that solves these problems has been found, an endoscope with a similar structure is disclosed in Japanese Patent Application Laid-Open No. 60-2491.
What is shown in Publication No. 14 has been proposed. This prior art has an optically clear plastic objective head that allows the lens to be molded as a single integral part. In other words, when molding the objective head, the lens is also molded at the same time. According to such a structure, there is no possibility that the water drainage performance is deteriorated unlike when the cover lens is adhesively fixed to the distal end cover. However, since the above lens is not optically shielded from other parts of the objective head, when the above lens constitutes an objective optical system, extra light enters this lens from the objective head, resulting in good observation. The problem arises that it becomes impossible to do so.

SUMMARY OF THE INVENTION An object of the present invention is to provide an endoscope in which an optical member can be provided on a distal end cover without causing deterioration in water drainage or observation performance.

[Problems to be Solved by the Invention] This invention includes a front end cover 22 made of synthetic resin and an optical member 2 located at the outermost side of the objective optical system, which is a separate part.
By integrally molding 3 and 3, deterioration in water drainage and observability can be prevented.

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The endoscope shown in Fig. 3 has an operating section 1 and an insertion section 2.
It is composed of. The operation section 1 is connected to a universal cord 3, and is also provided with a bending operation knob 5, an air/water supply button 6, a suction button 7, and the like. Further, the insertion section 2 includes a distal end forming section 11 provided at the distal end of a flexible tube section 8 via a curved tube section 9 . As shown in FIG. 1, this tip component 11 has a main body 12 made of a hard material such as metal. A first mounting hole 13 and a pair of second mounting holes 14 (only one shown) are bored in the main body 12 along the axial direction. One end portion of an objective lens frame 16 in which a number of objective lenses 15 are held is fitted into the first attachment hole 13 . A solid-state image sensor 17 is provided at the other end of the objective lens frame 16 to face it. Further, an illumination lens frame 19 in which a number of illumination lenses 18 are held and a light guide fiber 21 optically connected to the illumination lenses 18 are fitted and held in the second mounting hole 14. .

Further, the distal end surface side of the main body 12 is covered with a distal end cover 22. The objective lens 15 is attached to this tip cover 22.
A cover lens 23, which together with the objective lens 15 constitutes an objective optical system, is provided at a location facing the objective lens 15, as will be described later.
Further, a fitting hole 24 is provided at a location facing the illumination lens 18, and the illumination lens frame 19 is fitted into the fitting hole 24.

The tip cover 22 is molded from optically transparent or opaque synthetic resin, and when the tip cover 22 is molded, the cover lens 23 is integrated with the tip cover 22 by insert molding as shown in FIG. There is. The cover lens 23 may be made of either glass or transparent synthetic resin, and if it is made of transparent synthetic resin, it is desirable that the tip cover 22 be made of opaque synthetic resin.

As shown in FIG. 2, the tip cover 22 has an opening 2 that communicates with a nozzle 25 and a forceps channel (not shown).
5a is provided. The nozzle 25 can eject cleaning water for cleaning the cover lens 23 and air for removing the cleaning water after cleaning by operating the upper air/water supply button 6.

According to the endoscope having such a structure, since the distal end cover 22 and the cover lens 23 are integrally molded, there is no possibility that a gap will be formed between them. therefore,
Since the cleaning water used when cleaning the cover lens 23 flows smoothly along the tip cover 22 through the cover lens 23, water drainage is improved. Further, since the distal end cover 22 and the cover lens 23, which are integrally molded, are separate parts, the refractive index of light of these two is different. Therefore, even if the tip cover 22 is optically transparent, it is difficult for light to enter the cover lens 23 from the tip cover 22.
There is no need to worry about the decline in observability. Furthermore, if the cover lens 23 is made of an optically transparent material and the tip cover 22 is made of an opaque material, it is clear that such concerns are completely eliminated.

FIG. 4 shows another embodiment of the invention. In this embodiment, a recess 26 into which the cover lens 23 is fitted is formed on the front end surface of the objective lens block 16, and by these fittings, the front end cover 2
Position 2. Further, a first gap 27 is provided between the inner circumferential surface of the tip cover 22 and the outer circumferential surface of the main body 12, and a second gap 28 is provided between the illumination lens frame 19 and the fitting hole 24. And these first and second gaps 2
7.2g allows the positioning of the tip cover 22 to be adjusted when the cover lens 23 is fitted into the recess 26. In addition, the tip cover 2 is installed in each of the gaps 27 and 28 above.
After positioning 2, adhesive 29 is filled.

〔Effect of the invention〕

As described above, in the present invention, the synthetic resin tip cover and the outermost optical member of the objective optical system, which is a separate part, are integrally molded. Therefore, since there is no gap between the tip cover and the optical member of the objective optical system unlike in the conventional case, there is no possibility of deterioration in water drainage performance. Furthermore, even if the tip cover and the optical member are integrally molded, they are separate parts and have different light refractive indexes, so there is no possibility that excess light may enter the optical component through the tip cover. Nor.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the distal end component showing one embodiment of the present invention, FIG. 2 is a perspective view thereof, FIG. 3 is a perspective view of the entire endoscope, and FIG. 4 is another embodiment of the present invention. FIG. 3 is a cross-sectional view of a tip component showing an example. 2... Insertion section, 11... Tip component, 12... Main body, 22... Tip cover, 23... Cover lens (
optical components). Applicant's agent Patent attorney Atsushi Tsuboi Procedural amendment

Claims (1)

[Claims] In an endoscope in which the main body of the distal end component at the distal end of the insertion section is covered with a synthetic resin distal cover, the distal cover and the outermost optical member of the objective optical system, which is a separate component, are integrated. An endoscope characterized by being shaped like a.