JP2691621B2 - Endoscope tip - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a distal end portion of an endoscope, and more particularly to a distal end portion of an endoscope in which a distal end main body is made of electrically insulating synthetic resin.

[Prior Art] The tip portion of the endoscope is formed of a metal such as stainless steel in order to secure the strength of a mechanical connecting portion.

However, in an endoscope or the like that uses a solid-state image sensor, it is important to ensure the electrical insulation of the distal end body, and even in an endoscope that does not use a solid-state image sensor, use a high-frequency treatment tool or the like. To ensure safety in case of
Between the exposed part of the endoscope main body and the metal part of the core,
Must be electrically isolated.

Therefore, at the tip of the endoscope, at least the portion exposed to the outer surface of the tip body is formed of electrically insulating synthetic resin, and the illumination window for illuminating the observation field is formed in the synthetic resin portion. doing. Then, a transparent illumination window cover lens is fitted into the illumination window and fixed by bonding, and the emission end of the light guide fiber is arranged inside thereof.

[Problems to be Solved by the Invention] With the recent remarkable progress of electronic technology, a solid-state imaging device can be made quite small, but it is still much thicker than an image guide fiber. However, the tip of the endoscope must be as thin as possible in order to reduce the pain to the patient.

Therefore, if the light guide fiber used for illumination is arranged so as not to interfere with the solid-state image sensor, the illumination window is inevitably located at the peripheral portion of the tip end body of the endoscope, and at that portion, the tip end of the endoscope is located. The wall thickness of the main part (synthetic resin part) becomes very thin. As a result, the thin-walled portion of the tip body may be deformed and the illumination window cover lens may be broken just by applying a moderate impact to the tip portion of the endoscope.

If the lighting window cover lens breaks, not only a failure due to water leakage but also an electrical safety problem due to electrical leakage occurs.

In addition, even in an endoscope that does not use a solid-state image sensor, the same situation has occurred with a small diameter.

The present invention eliminates such conventional drawbacks, and even when a shock is applied to the tip of the endoscope, the tip of the endoscope is not easily damaged by the illumination window cover lens fitted in the illumination window. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the distal end portion of the endoscope of the present invention has at least a portion exposed on the outer surface of the distal end body formed of an electrically insulating synthetic resin. , Arranging an illumination window for illuminating the observation field of view in the vicinity of the peripheral edge of the tip body, and at the tip of the endoscope in which a transparent illumination window cover lens is fitted in the illumination window, A metal protective ring surrounding the outer periphery of the illumination window cover lens is provided so as not to be electrically conducted to the metal portion,
Alternatively, a metal protective ring surrounding the outer edge of the synthetic resin portion of the tip body is provided so as not to be electrically conducted to the metal portion of the tip body.

[Function] The synthetic resin portion of the front end main body around the illumination window cover lens is increased in rigidity by the protective ring and is not easily deformed even when an impact is applied.

Example An example will be described with reference to the drawings.

FIG. 2 is a front view of the tip of the endoscope, and FIG.
FIG. 3 is a sectional view taken along the line O-I, and III-III in FIG.
FIG.

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

Reference numeral 2 denotes a curved portion which is provided by being connected to the base portion of the tip portion main body 1 and which is bent by remote control, and the frontmost node ring 3 is fitted on the outer periphery of the rear end portion of the tip portion main body 1 and is shown in the drawing. Not fixed by screws such as flat head screws. 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, and the insulating cover 5 is adhesively fixed to the outer periphery of the rear half of the tip body 1.
Reference numeral 6 is a node ring, and 7 is a connecting shaft for connecting the node rings rotatably.

Reference numeral 10 is a solid-state image pickup device including, for example, a charge coupled device (CCD), and 10a is a light receiving portion thereof. Reference numeral 10b is a transparent layer formed on the surface of the light-receiving portion to prevent dust and the like from adhering to the light-receiving portion, and 10c is a filter for cutting the YAG laser. Then, an output signal from the solid-state imaging device 10 is amplified by an electronic circuit formed on the substrate 11 and the code 13
Connected to the monitor device via the rear signal processing circuit (not shown).

On the outer periphery of the solid-state imaging device 10 and the substrate 11, a tape 14 made of, for example, synthetic resin having electrical insulation properties is wound and adhered and fixed in a metal frame 15, and also on the outer periphery of the frame 15. ,
A tape 16 made of, for example, synthetic resin having electrical insulation properties is wound thereon. Then, the frame body 15 is fitted into the through hole 17 formed in the metal portion 1a of the tip portion main body, and is pressed and fixed to the metal portion 1a of the tip portion main body 1 by the fixing screw 18 as shown in FIG. Has been done. A thin plate-shaped plate is interposed between the fixing screw 18 and the frame body 15 so that the tape 16 is not damaged when the fixing screw 18 is tightened.

Further, the frame body 15 penetrates the through hole 17 and projects to the front thereof,
The tip portion of the frame body 15 reaches the inside of the hole portion 8 formed on the back surface of the synthetic resin portion 1b of the tip portion main body, and the insulating tape 16 on the outer periphery thereof is in contact with the synthetic resin portion 1b. And the metal portion 1a of the tip body is not electrically connected.

In addition, a silicone resin-based filler 19 is filled in the vicinity of the end of the shielded cable 12 to completely fix 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 imaging device 10. On the other hand, the metal portion 1a of the distal end body is not grounded, and can be electrically connected to the negative side of the high frequency generator when using the high frequency treatment device.

Reference numeral 21 denotes an objective optical system for forming an observation image on the light receiving portion 10a of the solid-state image pickup device 10. The objective optical system 21 is adhesively fixed in a metal lens frame 22, and the rear end portion of the lens frame 22 is fixed. Are electrically connected to and fixed to the frame body 15. 23 is a spacer, and 24 is a stop of the objective optical system. The 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 diaphragm 24, the spacer 23, and the lens frame 22 play a role of preventing noise from entering the solid-state imaging device 10 from the front.

An observation window cover lens 21a is joined to the front end portion of the lens frame 22 so as to sandwich the diaphragm 24. In this embodiment, the observation window cover lens 21a is a concave lens,
It constitutes a part of the objective optical system. Further, an electrically insulating means 25, which is formed in a stepped cylindrical shape with 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 is adhesively fixed. . The front end portion of the electric insulating means 25 projects forward from the lens frame 22 and is arranged so as to surround the side wall portion of the observation window cover lens 21a. Strictly speaking, the surface of the electric insulating means 25 is arranged so as to be slightly lower (for example, 0.2 mm) than the surface of the observation window cover lens 21a, and the observation window cover lens 21a is arranged so that the electric insulating means 25
It is watertightly bonded and fixed.

A completely defoamed epoxy adhesive is used for this adhesion. Thereby, the withstand voltage performance can be further improved. Then, an adhesive is sufficiently applied to the joint surface side A so as not to cause water leakage. Then, the adhesive flows into the inside of the electric insulating means 25, but there is no gap between the lens frame 22 and the electric insulating means 25, since they are originally joined to each other.

Observation window cover lens 21a joined to the electric insulating means 25
The outer peripheral surface of is colored black beforehand with an electrically insulating black paint 20. Therefore, reflection on the surface is prevented, and flare and ghost are prevented from occurring. As the paint, for example, a lacquer-based black paint having no electrical conductivity can be used.

The outer periphery of the electrical insulating means 25 is the synthetic resin portion 1b of the tip body.
It is fitted in a hole 26 formed in the. The gap is water-tightly sealed by an electrically insulating O-ring 27 interposed therebetween. Therefore, water does not enter the tip main body 1 from the gap. Therefore, in this portion, the outside and the inside of the distal end portion main body 1 are also electrically insulated well.

In this embodiment, a frame body 15 for fixing the solid-state imaging device 10, a lens frame 22 for fixing the objective optical systems 21 and 21a, and an electric insulating means 25 are integrally fixed to each other by bonding, and the objective An optical system support frame unit is configured. The entire unit is fixed to the tip body 1 by a fixing screw 18, and if the fixing screw 18 is loosened, the unit can be pulled out from the tip body 1 rearward and easily disassembled.

30 is a light guide fiber for illumination for illuminating the observation visual field. 31 is a stainless steel base on the emitting end side. 32
Is a flexible outer tube. The light guide fiber 30 for illumination is arranged so as not to interfere with the solid-state image sensor 10 or the like in the layout, and as shown in FIG.
It is screwed and fixed to the metal portion 1a of the tip body 1 by 33.

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

A protective ring 37 made of stainless steel is fitted and adhered to the outer periphery of the illumination window cover lens 36, and the protective ring 37 is attached to the illumination window cover lens 36.
It is fitted and bonded to 35. The chamfered portion on the inner side of the mouth of the protection ring 37 on the inner side is filled with an epoxy resin adhesive 38, and the protection ring 37 and the base of the light guide fiber are
It is surely electrically insulated from 31.

In this way, the outer periphery of the illumination window cover lens 36 is surrounded by the protective ring 37 made of stainless steel.
Lighting window cover lens, even if it is impacted by
36 does not break easily. Further, the illumination light emitted from the emission end face 30a of the light guide fiber and passing through to the side surface of the illumination window cover lens 36 was conventionally absorbed by the synthetic resin portion 1b of the tip body, but this embodiment Then, as shown by the arrow D, the light is reflected on the inner surface of the protective ring 37,
The observation field of view can be illuminated.

FIG. 4 shows a second embodiment of the present invention, in which a protective ring 40 is formed so as to surround the illumination window cover lens 36 from the outer periphery to the bottom. With this guard ring 40,
The effect of reinforcing the illumination window cover lens 36 is further improved. However, since there is electrical conduction between the protective ring 40 and the mouthpiece of the light guide fiber, the mouthpiece is a portion located inside the synthetic resin portion 1b of the tip body and a portion located inside the metal portion 1a. It is divided into two parts with a space at 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 light emitting end face 30 of the light guide fiber are shown.
A transparent plane-parallel plate 51 is arranged between a and a. Five
0 is a guard ring. Even with this, the protective ring 50 and the base 3
The electrical insulation between 1 and can be secured.

FIG. 6 shows a fourth embodiment of the present invention, which includes a protective ring.
60 and the illumination window cover lens 36 are not directly arranged on the outer peripheral portion, but are arranged so as to surround the outer periphery of the front end portion of the synthetic resin portion 1b of the tip end main body and are fixed by adhesion. With this structure, the rigidity of the synthetic resin portion 1b is increased, so that the illumination window cover lens 36 will not be easily damaged even if an impact is applied to the tip portion main body 1.

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

In the embodiment shown in FIGS. 7 and 8, as shown in FIG. 9, the frame 15 is composed of two flat plates 7.
It is sandwiched between 8, 79, and is fixed to the metal portion 1a of the tip body by being pressed by the fixing screw 77 from the outside.

In addition, although each of the above-described embodiments has been described with respect to the one in which the solid-state image sensor is incorporated in the tip end body, the present invention is not limited thereto, and an image guide fiber or the like is used instead of the solid-state image sensor. It may be.

EFFECTS OF THE INVENTION According to the distal end portion of the endoscope of the present invention, the synthetic resin portion of the distal end body is increased in rigidity by the protective ring and is not easily deformed even when an impact is applied. It is less likely to be damaged and its durability against shock is greatly improved.

Further, when the protective ring is provided on 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 brightening the illumination light amount can be obtained.

[Brief description of the drawings]

1 is a side sectional view of a first embodiment of the present invention (a sectional view taken along the line I-O-I of FIG. 2), and FIG. 2 is a front view of the first embodiment of the present invention. 1 is a sectional view taken along the line III-III in FIG. 1, FIG. 4 is a side sectional view of a second embodiment of the present invention, and FIG. 5 is a side sectional view of a third embodiment of the present invention. FIG. 7 is a side sectional view of a fourth embodiment of the present invention, FIG. 7 is a side sectional view of a fifth embodiment of the present invention, and FIG. 8 is a side sectional view of a sixth embodiment of the present invention. FIG. 9 is a sectional view taken along the line IX-IX in FIG. 1 ... Tip body, 1a ... Metal part, 1b ... Synthetic resin part,
10: Solid-state image sensor, 30: Light guide fiber, 35
...... Lighting window, 36 …… Lighting window cover lens, 37,40,50,60,
70,80 …… Protection ring.

Claims (4)

(57) [Claims] 1. A tip body is formed of at least a portion exposed on the outer surface of an electrically insulating synthetic resin, and an illumination window for illuminating an observation visual field is arranged near the periphery of the tip body. At the tip of an endoscope in which a transparent illumination window cover lens is fitted in the illumination window, it does not electrically connect to the metal part of the tip body, and does not retract the outer periphery of the illumination window cover lens from its surface. A distal end portion of an endoscope, characterized in that a protective ring made of metal surrounded by the aspect is provided. 2. The distal end portion of the endoscope according to claim 1, wherein a solid-state image sensor for converting an observed image into an electric signal is built in the distal end portion main body. 3. The tip body is formed of at least a portion exposed on the outer surface of an electrically insulating synthetic resin, and an illumination window for illuminating an observation visual field is arranged near the periphery of the tip body. At the tip of the endoscope in which a transparent illumination window cover lens is fitted in the illumination window, the outer edge of the synthetic resin portion of the tip body is not electrically connected to the metal portion of the tip body. A distal end portion of an endoscope, characterized in that a metal protective ring is provided so as to surround the surface in a manner not to recede. 4. The distal end portion of the endoscope according to claim 3, wherein a solid-state image sensor for converting an observed image into an electric signal is built in the distal end portion main body.