JPH0351032A - Tip section for endoscope - Google Patents

Abstract

PURPOSE:To prevent an illumination window cover lens from being simply broken when a shock is applied to a tip section by providing a metallic protective ring surrounding the outer periphery of the illumination window cover lens and electrically insulated from the metal portion of a tip section main body. CONSTITUTION:A tip section main body 1 is formed with a stainless metal section 1a and an electrically insulating synthetic resin section 1b so that the metal section 1a is not exposed at all to the outside. A transparent illumination window cover lens 36 made of a flat concave lens is arranged at an illumination window 35 formed on the periphery of the synthetic resin section 1b and lighting the observation visual field, and the light distribution angle of the illumination light is expanded. A protective ring 37 made of stainless steel is coupled and stuck on the outer periphery of the illumination window cover lens 36, and the protective ring 37 is coupled and stuck to the illumination window 35. An epoxy resin adhesive 38 is filled at the chamfered portion on the mouth inside at the depth of the protective ring 37, and the protective ring 37 and the base 31 of a light guide fiber 30 are surely insulated electrically. The illumination window cover lens 36 is rarely broken, and the durability against a shock is sharply improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the tip of an endoscope, and more particularly to the tip of an endoscope whose tip body is made of electrically insulating synthetic resin.

[Prior Art] The core of the distal end of an endoscope is made of metal such as stainless steel in order to ensure the strength of the mechanical connection.

However, in endoscopes that use solid-state image sensors,
It is important to ensure the electrical insulation of the tip body, and even in endoscopes that do not use solid-state imaging devices, the tip of the endoscope It is necessary to electrically insulate between the exposed part of the main body and the metal part of the core.

Therefore, the tip of the endoscope is made of electrically insulating synthetic resin, at least the portion of the tip body that is exposed on the outer surface.
An illumination window for illuminating the observation field is formed in the synthetic resin part. Then, a transparent illumination window cover lens is fitted into the illumination window and bonded and fixed, and the output end of the light guide fiber is arranged inside of the transparent illumination window cover lens.

[Problems to be Solved by the Invention] With the remarkable progress in electronic technology in recent years, solid-state imaging devices can now be made quite small, but they are still very thick compared to image guide fibers. However, the tip of the endoscope must be made as thin as possible to reduce pain to the patient.

Therefore, if the light guide fiber used for illumination is arranged so as not to interfere with the solid-state imaging device, the illumination window will inevitably be located at the periphery of the endoscope's tip body, and the The wall thickness of the main body (synthetic resin part) becomes very thin.As a result, even if a small impact is applied to the end of the endoscope, the thin part of the main body of the endoscope will deform, causing the illumination to deteriorate. Sometimes the window cover lens broke.

If the lighting window cover lens breaks, it not only causes damage due to wood leakage, but also causes electrical safety problems due to electrical leakage.

In addition, even in endoscopes that do not use solid-state image sensors,
A similar situation occurred with smaller diameter ones.

The present invention eliminates such conventional drawbacks and provides a tip end of an endoscope in which the illumination window cover lens fitted in the illumination window is not easily damaged even if an impact is applied to the tip of the endoscope. The purpose is to provide the following information.

[Means to solve the problem]

In order to achieve the above object, the distal end of the endoscope of the present invention has at least the portion exposed on the outer surface of the distal end main body made of electrically insulating synthetic resin, and an illumination lamp for illuminating the observation field. A window is arranged near the periphery of the tip body, and a transparent illumination window cover lens is fitted into the illumination window. A protective ring made of metal is provided to surround the outer periphery of the illumination window cover lens, or a synthetic resin portion of the tip body is provided with a protective ring made of metal so as not to be electrically conductive to the metal portion of the tip body. The device is characterized by a metal protective ring surrounding the outer edge of the device.

[Function] The synthetic resin part of the tip of the main body around the lighting window cover lens is
The protective ring increases rigidity and does not easily deform even if a shock is applied.

[Example] Examples will be described with reference to the drawings.

Figure 2 is a front view of the tip of the endoscope, Figure 1 is its l-0
3 is a sectional view taken along line mm in FIG. 1.

The tip body 1 includes a metal part 1 made of stainless steel, for example.
a, and a synthetic resin portion 1b made of electrically insulating synthetic resin. This synthetic resin portion 1b is adhesively fixed to the metal portion 1a so as to cover the periphery of the metal portion 1a, and the metal portion 1a is not exposed on the outer surface of the tip body 1 at all.

2 is a curved part that is connected to the base of the tip main body l and bent by remote control, and the most advanced node ring 3
is fitted onto the outer periphery of the rear end of the tip body 1, and is connected and fixed with a countersunk screw or the like (not shown). The outer surface of the curved portion 2 is covered with an insulating cover 5 made of synthetic rubber that is flexible and has electrical insulation properties, and the insulating cover 5 is adhesively fixed to the outer periphery of the rear half of the tip body l.

6 is a node ring, and 7 is a connecting shaft that rotatably connects the node rings.

10 is a solid-state image sensor made of, for example, a charge-coupled device (COD), and 10a is its light receiving section. 10b is a transparent layer made of, for example, transparent epoxy resin, formed on the surface of the light-receiving part in order to prevent dust from adhering to the light-receiving part;
loc is a filter that cuts the YAG laser.

and.

The output signal from the solid-state image sensor 10 is amplified by an electronic circuit formed on the substrate 11, and the signal is amplified by the electronic circuit formed on the substrate 11.
It is connected to a monitor device (not shown) by a cord 13 that passes through the rear signal processing circuit.

An electrically insulating tape 14 made of, for example, synthetic resin is wrapped around the outer periphery of the solid-state image sensor 10 and the substrate 11 and is adhesively fixed within a metal frame 15. A tape 16 made of, for example, a synthetic resin and having electrical insulation properties is wound around it. The frame 15 is then fitted into a through hole 17 made in the metal part 1a of the tip main body, and is pressed and fixed to the metal part 1a of the tip main body l by a fixing screw 18, as shown in FIG. has been done. Note that a thin plate is interposed between the fixing screw 18 and the frame 15 to prevent the tape 16 from being damaged when the fixing screw 18 is tightened.

Also, the frame 15 penetrates through the through hole 17 and protrudes forward thereof, and the tip of the frame 15 is the synthetic resin part of the tip main body! The insulating tape 16 on the outer periphery is in contact with the synthetic resin part lb, reaching into the hole 8 formed on the back surface of the frame 15.
The metal part 1a of the tip body is not electrically connected to the metal part 1a of the tip body.

Further, the vicinity of the end of the shielded cable 12 is filled with a silicone resin filler 19 to completely secure and insulate each member in the vicinity.

The frame 15 is grounded via the ground wire of the shielded cable 12 to prevent noise from entering the solid-state image sensor 10. On the other hand, the metal part 1a of the tip main body is not grounded, and high-frequency waves are generated when using a high-frequency treatment instrument. It can be electrically connected to the negative side of the lt position.

Reference numeral 21 denotes an objective optical system that forms an observation image on the light receiving section 10a of the solid-state image sensor 10.The objective optical system 21 is adhesively fixed within a metal lens frame 22, and the lens frame 2
The rear end portion of 2 is electrically connected to and fixed to the frame 15 by fitting. 23 is a spacer, and 24 is an aperture of the objective optical system. This diaphragm 24 is made of metal, is electrically connected to and fixed to the lens frame 22, and is electrically grounded via the frame 15. Therefore, the aperture 24, the spacer 23, and the lens frame 22 play the role of preventing noise from entering the solid-state image sensor 10 from the front.

An observation window cover lens 21a is protrudingly bonded to the front end portion of the lens frame 22 with the diaphragm 24 in between. It consists of Further, an electrically insulating means 25 formed in a stepped cylindrical shape from an electrically insulating synthetic resin so as to surround the lens frame 22 is fitted around the front side of the lens frame 22 and fixed with adhesive. . and,
The front end of the electrical insulation means 25 protrudes forward from the lens frame 22 and is arranged to surround the side wall of the observation window cover lens 21a. Strictly speaking, the surface of the electrically insulating means 25 is arranged so as to be slightly lower (for example, 0.2 m) than the surface of the observation window cover lens 21a, and the observation window cover lens 21a is placed on the electrically insulating means 25 in a watertight manner. Fixed with adhesive.

For this bonding, a completely defoamed epoxy adhesive is used. This allows the withstand voltage performance to be further improved. Then, apply enough adhesive to the joint surface side A to prevent water leakage.

Then, the adhesive flows into the inside of the electrically insulating means 25, but this is the gap between the lens frame 22 and the electrically insulating means 25, and since these are the parts that are originally joined to each other, no problem occurs.

Observation window cover lens 21 joined to electrical insulation means 25
The outer peripheral surface of a is colored black in advance with electrically insulating black paint 20. Therefore, reflections on that surface are prevented, and flare and ghosts are prevented from occurring. As this paint, for example, a lacquer-based black paint with no electrical conductivity can be used.

The outer periphery of the electrical insulation means 25 is the synthetic resin part of the tip body!
It fits into the hole 26 drilled in b. The gap is watertightly sealed by an electrically insulating O-ring 27 interposed therebetween. Therefore, water does not enter into the tip main body 1 through the gap, and therefore, the outside and the inside of the tip main body 1 are well electrically insulated in this part.

In this embodiment, a frame 15 for fixing the solid-state image sensor 10, a lens frame 22 for fixing the objective optical system 21.21a, and an electrically insulating means 25 are integrally fixed to each other by adhesive. An optical system support frame unit is configured. The entire unit is fixed to the tip body 1 by a fixing screw 18, and by loosening the fixing screw 18, the unit can be pulled out rearward from the tip body 1 and easily disassembled.

30 is an illumination light guide fiber for illuminating the observation field; 31 is a stainless steel cap on the output end side;
32 is a flexible outer tube. The illumination light guide fiber 30 is arranged so as not to interfere with the solid-state image sensor 10 etc. in terms of layout, and as shown in FIG.
It is screwed and fixed to the metal part 1a of the tip body 1 by a fixing screw 33.

Reference numeral 35 denotes an illumination window formed at the peripheral edge of the synthetic resin portion 1b of the tip body so that the illumination light emitted from the output end face 30a of the light guide fiber illuminates the observation field. A transparent illumination window cover lens 36 made of a plano-concave lens is disposed in the illumination window 35 to widen the light distribution angle of illumination light.

A stainless steel protection ring 37 is fitted and adhered to the outer periphery of the illumination window cover lens 36, and the protection ring 37 is fitted and adhered to the illumination window 35.

In addition, the chamfered part on the inside of the mouth on the back side of the protective ring 37 has
It is filled with an epoxy resin adhesive 38 to ensure electrical insulation between the protective ring 37 and the base 31 of the light guide fiber.

In this way, the outer periphery of the illumination window cover lens 36 is surrounded by the stainless steel protective ring 37, so even if an impact is applied to the tip body l, the illumination window cover lens 36 will not be easily damaged. In addition, the illumination light that is emitted from the output end face 30a of the light guide fiber and passes through the side surface of the illumination window cover lens 36 is conventionally absorbed by the synthetic resin portion 1b of the tip body, but in this case In the embodiment, as shown by the arrow, the light is reflected on the inner surface of the protective ring 37 and can illuminate the observation field.

FIG. 4 shows a second embodiment of the present invention, in which a protective ring 40 is formed to surround the illumination window cover lens 36 from the outer periphery to the bottom. This protective ring 40 further improves the effect of reinforcing the illumination window cover lens 36. However, since there is electrical continuity between the protective ring 40 and the base of the light guide fiber, one base is separated from the part 31b located within the synthetic resin part lb of the tip body and the part located within the metal part la. It is divided into two with an interval between 31a and 31a. This ensures electrical insulation between the protective ring 40 and the metal portion 1a of the tip body.

FIG. 5 shows a third embodiment of the present invention, in which the illumination window cover lens 36 and the output end face 3 of the light guide fiber
A transparent parallel plane plate 51 is disposed between the base plate and the base plate 0a. 50 is a protective ring. Even if you do this, the protective ring 5
0 and the base 31 can be ensured.

FIG. 6 shows a fourth embodiment of the present invention, in which a protective ring 6
0 is not placed directly on the outer periphery of the illumination window cover lens 36, but is placed so as to surround the outer periphery of the front end portion of the synthetic resin portion 1b of the tip body and fixed with adhesive. With this configuration, the rigidity of the first synthetic resin portion 1b is increased, so that even if an impact is applied to the tip body 1, the illumination window cover lens 36 will not be easily damaged.

7 and 8 show fifth and sixth embodiments of the present invention, in which a male threaded portion for screwing a tip hood (not shown) is formed on the outer periphery of the tip main body l. This is an example in which there is a In the case shown in FIG. 7, a metal protective ring 70 is adhesively fixed so as to surround the outer periphery of the front end portion of the synthetic resin portion 1b of the tip body, as in the case shown in FIG. 6 described above. In this case, the threaded portion is entirely formed with a protective ring 80 made of metal.

In addition, in the embodiment shown in FIGS. 7 and 8,
As shown in FIG. 9, the frame 15 is.

It is sandwiched between two flat plates 78 and 79, and is fixed to the metal part 1a of the tip body by being pressed from the outside with a fixing screw 77.

Although each of the above embodiments has been described with a solid-state imaging device built into the main body of the tip, the present invention is not limited thereto, and an image guide fiber or the like may be used instead of the solid-state imaging device. It may be.

[Effects of the Invention] According to the tip of the endoscope of the present invention, the rigidity of the synthetic resin part of the tip body is increased by the protective ring, and the illumination window cover lens is not easily deformed even when an impact is applied. It is less likely to be damaged and its durability against impact is greatly improved.

Further, when a protective ring is provided around the outer periphery of the illumination window cover lens, the inner surface of the protective ring reflects the illumination light, so that the effect of increasing the amount of illumination light can also be obtained.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of the first embodiment of the present invention (a sectional view taken along the line l-0-I in FIG. 2), FIG. 2 is a front view of the first embodiment of the present invention, and FIG. The figure is the first
The m-ttr line cross-sectional view of the figure. FIG. 4 is a side sectional view of the second embodiment of the invention, FIG. 5 is a side sectional view of the third embodiment of the invention, and FIG. 6 is a side sectional view of the fourth embodiment of the invention. , FIG. 7 is a side sectional view of the fifth embodiment of the invention, FIG. 8 is a side sectional view of the sixth embodiment of the invention, and FIG. 9 is a sectional view taken along the line IX-IX in FIG. 7. It is. DESCRIPTION OF SYMBOLS 1... Tip body, la... Metal part, tb... Synthetic resin part, 10... Solid-state image sensor, 30... Light guide fiber, 35... Illumination window, 36... Lighting window cover lens, 37, 40, 50, 60, 70.80・
...protective ring.

Claims (4)

[Claims] (1) At least the part exposed on the outer surface of the tip body is made of electrically insulating synthetic resin, and an illumination window for illuminating the observation field is arranged near the periphery of the tip body, and the illumination window is arranged near the periphery of the tip body. At the distal end of an endoscope with a transparent illumination window cover lens fitted into the window, a metal protective ring is provided around the outer periphery of the illumination window cover lens to prevent electrical conduction to the metal part of the distal end body. A distal end portion of an endoscope, characterized in that it is provided with. (2) The distal end portion of an endoscope according to claim 1, wherein a solid-state image sensor that converts an observed image into an electrical signal is built into the distal end main body. (3) At least the portion exposed on the outer surface of the tip body is made of electrically insulating synthetic resin, and an illumination window for illuminating the observation field is arranged near the periphery of the tip body, and the illumination window is arranged near the periphery of the tip body. In the distal end of an endoscope in which a transparent illumination window cover lens is fitted into the window, a metal surrounds the outer edge of the synthetic resin part of the distal end main body so as not to be electrically conductive to the metal part of the distal end main body. A distal end portion of an endoscope characterized by being provided with a protective ring made of aluminum. (4) The distal end portion of an endoscope according to claim 3, wherein a solid-state image sensor that converts an observed image into an electrical signal is built into the distal end main body.