JP3462545B2 - Electronic endoscope tip - Google Patents

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 built in a distal end portion main body provided at the distal end of an insertion portion.

[0002]

2. Description of the Related Art A solid-state image sensor arranged in a body of a distal end portion of an electronic endoscope is generally formed in a rectangular shape, and such a solid-state image sensor and an electronic component unit therefor are formed in the body of the distal end portion. A hole having a cross-sectional shape that just fits is bored from the rear, and holes for inserting a forceps channel, a light guide fiber bundle, etc. are bored back and forth through the tip end main body, respectively (Japanese Patent Laid-Open No. Hei 4- 35811
No. 4).

[0003]

However, since the tip body is generally made of stainless steel, it is a very difficult process to make a square hole. Therefore,
It is conceivable to form a large round hole in the tip body so that other built-in objects can be accommodated together with the solid-state image sensor.

However, a forceps channel is generally made of a tetrafluoroethylene resin tube or the like having good sliding property, and in order to join the tip end portion to the tip end main body, it is necessary to make the bonding margin considerably long.

For this reason, if a hole into which the tip of the forceps channel is independently fitted is formed in the tip body, a square solid-state image sensor will not fit even if a round hole is formed in the remaining portion.
The holes for accommodating the solid-state image pickup device and the electronic component unit are inevitably almost square.

Further, when the exit end of the light guide fiber bundle is arranged to be tilted in the observation direction in order to improve the illumination condition, a hole slantingly formed in the tip of the tip body is thinned from the rear. The exit end of the light guide fiber bundle must be plugged in via. This is also a fairly difficult task.

Therefore, according to the present invention, the distal end body can be easily processed, the cost of parts thereof can be greatly reduced, the forceps channel can be surely connected to the distal end body, and the light guide fiber bundle can be assembled. An object is to provide an easy electronic endoscope tip.

[0008]

In order to achieve the above object, the tip portion of the electronic endoscope according to the present invention is a solid-state image pickup device having a non-circular cross section in a tip portion main body provided at the tip of the insertion portion. In the distal end portion of the electronic endoscope in which the distal end of the forceps channel is joined in the distal end portion main body while accommodating the element, the portion of the distal end portion main body in which the non-circular cross-section part is accommodated and the rear side thereof are accommodated. The portion is formed in a cylindrical shape, and the tip portion of the forceps channel is joined to the metal connecting pipe in the cylindrical portion, and the tip portion of the connecting pipe is joined to the hole formed in the tip portion main body. It is characterized by having done.

The hole for fitting the emission end of the illumination light guide fiber may be formed obliquely in the front end face of the tip end body and penetrates the cylindrical portion.

[0010]

Embodiments will be described with reference to the drawings. Figure 2
The electronic endoscope is shown, and a tip body 3 made of, for example, stainless steel is attached to the tip of a bending portion 2 formed on the tip side of the flexible tube 1.
Are connected to form an insertion portion.

The operation portion 5 connected to the base end of the flexible tube 1 is provided with bending operation knobs 6 and 7 for remotely bending the bending portion 2 in a desired direction and at a desired angle. Reference numeral 8 is an air supply / water supply operation button, and 9 is a suction operation button.

The forceps channel 11 for inserting a treatment tool and projecting it from the tip of the insertion portion is composed of the insertion portions 1, 2, 3
It is inserted over the entire length, the inlet is provided in the vicinity of the lower end of the operating portion 5, and the outlet is open to the tip portion main body 3.

FIG. 3 is a front view of the tip end main body 3, and 11
a is a forceps outlet hole, 13 is an observation window, and 14 is an illumination window.
1 shows a cross section taken along the line AB in FIG. 3, and FIG.
The -EFGH cross section is shown.

The bending portion 2 has a large number of node rings 16 and rivets 1.
7, rotatably connected, the outer periphery of which is covered with a net-like tube 18, which is further covered with a rubber tube 15 or the like,
The end portion is tightly bound and joined to the outer peripheral surface of the tip portion main body 3. 1 and 4 show two node rings 1 on the tip side.
Only the portions 6a and 16b are shown.

Reference numeral 19 denotes a connecting cylinder for connecting the most advanced node ring 16a and the tip end main body 3 to each other.
Also, as shown in the figure, the tip body 3 is connected by a pin 20. The tip of the bending operation wire 21 is also fixed to the connecting cylinder 19 by, for example, silver brazing.

Two illumination windows 14 are provided symmetrically with the observation window 13 in between, and the concave lens 2 for expanding the light distribution angle.
The output end of the light guide fiber bundle 23 is fixed to the inside of 2 by inclining slightly inward toward the observation optical axis.

Inside the observation window 13, an objective optical system 25 is fixedly arranged in a metallic lens frame 24. 26
Is an aperture stop, and 27 is a spacer. The lens frame 24 and the tip body 3 and the lens frame 24 and the objective optical system 25 are watertightly joined. The first lens 25a on the surface is mechanically fixed to the lens frame 24 by crimping.

An insulating connection ring 30 made of an electrically insulating plastic material is fitted, joined and held on the outer periphery of the rear portion of the lens frame 24, and the outer periphery of the rearmost third lens 25b and the insulating connection ring. It is sealed with a defoamed epoxy adhesive 31 between it and 30.

The outer periphery of the insulating connection ring 30 is formed such that the latter half portion thereof is slightly thinner than the former half portion, and the metallic shield cylinder 32 is fitted and joined thereto and held. The shield cylinder 32 is formed in a substantially rectangular cross-sectional shape as shown in FIG. This is in conformity with the cross-sectional shape of the solid-state image sensor 35 arranged therein.

The rear end of the shield cylinder 32 reaches the boundary with the curved portion 2, and an electrically insulating tape 36 is wound around the entire outer periphery thereof. The rear end of the insulating tape 36 covers the outer periphery of the front end of the signal cable 43 described later.

Inside the frontward position of the shield cylinder 32, for example, a charge-coupled device (CCD) having a rectangular cross section is formed.
The solid-state image sensor 35 made of is fixed with the image receiving surface facing forward.

A transparent cover glass 37 is arranged in close contact with the front side thereof, and a YAG laser light cut filter 38 is attached to the front surface thereof. The observation light image is formed on the image receiving surface of the solid-state image sensor 35 by the objective optical system 25 through the transparent members 37 and 38. Three
Reference numeral 9 is a light-shielding mask.

Reference numeral 42 is a wiring board to which electronic components 40 forming a drive circuit of the solid-state image pickup device 35 and an amplification circuit for amplifying an output signal from the solid-state image pickup device 35 are attached. The wiring board 42 is soldered to the three long contact pins 41 projecting rearward from the solid-state image sensor 35 by soldering.
It is fixed straight rearward (that is, parallel to the central axis of the objective optical system 25) and is electrically connected at the same time.

The position of the rear end of the wiring board 42 and the position of the rear end of the shield cylinder 32 are substantially coincident with each other. From there, the signal cable 43 enters the bending portion 2 and the flexible tube 1. Has been towed. The shield tube body 32 is connected to the shield 44 of the signal cable 43 by soldering.

The core wire 45a and the shield 45b of the lead wire 45 using the coaxial shield wire pulled out from the signal cable 43 to the front are provided with short contact pins 46 protruding from the solid-state image pickup device 35 and solder on the wiring board 42. It is connected to the pad 47 or the like by soldering.

The wiring board 42 is located outside the center of the solid-state image sensor 35, and the short contact pin 46 is located inside the center of the solid-state image sensor 35. Large-shaped capacitors and transistors are arranged on the front half of the wiring board 42, and small-shaped resistors and the like are arranged on the rear half of the wiring board 42. Further, the signal cable 43 is eccentrically connected to the side portion (lower side in FIG. 4) of the wiring board 42 instead of the center thereof.

In the space around the wiring board 42, that is, in the space inside the shield cylinder 32 on the rear side of the solid-state image sensor 35, for example, an epoxy adhesive 4 having an electrical insulation property is used.
9 is filled and hardened to reach the front end portion of the signal cable 43, and an electronic component unit including the wiring board 42 and the electronic component 40 is integrated with the solid-state image sensor 35 and the signal cable 43.

Further, an insulating tape 34 is continuously wound around the entire surface of the components arranged in the shield cylinder 32 to ensure the electrical insulation between the shield cylinder 32 and the shield cylinder 32. There is.

In this way, the electronic component unit is arranged immediately after the solid-state image pickup device 35 in conformity with the region (rear projection region) of the shape in which the solid-state image pickup device 35 is projected backward.

The tip end main body 3 is formed in a cylindrical shape that opens rearward except for a short portion on the tip end side shown as A portion in FIG.
As shown in FIGS. 5 and 6, all internal components, including 0 and the shield cylinder 32 behind it, are housed in the cylindrical portion 3a.

In the tip body 3, the observation window 13, the illumination window 14 and the forceps outlet hole are provided in the front portion A so as to penetrate between the front end surface of the tip body 3 and the cylindrical portion 3a. 11a
Etc. Four circular through holes are drilled.

Therefore, the tip end body 3 is formed by grinding the outer peripheral surface with a lathe, forming the inner cavity of the cylindrical portion 3a from the rear by counter boring, and punching four holes with a circular cross section at the tip end portion. It can be easily manufactured.

Further, the illumination window 14 is directed obliquely in the portion A, and the tip of the light guide fiber bundle must be inserted into the portion from the rear at the time of assembly, but the space from the rear end of the tip portion main body 3 to that portion. Since the cylindrical portion 3a forming the is very thick, such an assembling work can be performed easily.

The forceps channel 11 is a tube made of tetrafluoroethylene resin and having a regular circular cross section.
The connection pipe 50 is made of stainless steel and is formed in a cylindrical shape having a step in the middle and is fitted and adhered from the rear.
Since the tetrafluoroethylene resin does not have a good adhesiveness as it is, a chemical pretreatment is carried out before the adhesive to allow a long adhesive margin.

The connecting pipe 50 is arranged in the cylindrical portion 3a of the tip body 3, and its tip portion is rearward to the through hole (forceps outlet hole 11a) formed in the A portion of the tip body 3. It is inserted and joined from. Since metals have good adhesiveness, sufficient bonding strength can be obtained even with a short adhesion margin.

The forceps channel 11 is arranged adjacent to one side (long side) of the solid-state image pickup device 35 having a rectangular cross section, and is drawn rearward along the shield tube body 32. As shown in FIGS. 1 and 6, the shield tubular body 32 and the forceps channel 11 are arranged in the cylindrical portion 3a of the distal end portion main body 3 so that there is almost no gap in the diametrical direction. .

The shield cylinder 32 does not project or retract from the rear projection area of the solid-state image sensor 35 on the front side of the intermediate position between the rear end portion and the solid-state image sensor 35.
It is formed in a cross-sectional shape that exactly matches the shape of the rear projection area of the solid-state image sensor 35.

However, in the portion on the rear side thereof, that is, the portion along the latter half of the electronic component units 42, 40, the shield cylinder 32 is provided behind the solid-state image pickup device 35 on the side facing the forceps channel 11 and the back side thereof. The forceps channel 11 is arranged so as to be inclined toward the inside of the projection region, and the forceps channel 11 is inclined at a gentle angle so as to gradually approach the inside as it goes backward.

In this way, the forceps channel 11 smoothly inclines inward at a position along the rear half of the electronic component units 42, 40 and enters the rear projection area of the solid-state image pickup device 35, and inside the bending portion 2. It is arranged so that it is slightly displaced toward the center of the tube axis. Further, the wall thickness of the forceps channel 11 in the bending portion 2 is slightly thickened so as not to buckle due to bending.

The electronic component units 42, 40 of such an electronic endoscope have a latter half portion with an epoxy adhesive 49 in a state where the solid-state image pickup device 35, the wiring board 42 and the signal cable 43 are connected by soldering. 1 is pre-molded into the shape shown in FIG. 1 which is recessed inward, and then the insulating tape 34 is wound around the entire outer periphery of this unit and then inserted into the shield cylinder 32.
After the focusing adjustment with the objective optical system 25 and the like are performed, the latter half portion of the shield cylinder 32 is deformed inward to be manufactured.

[0041]

According to the present invention, since the non-circular component accommodating portion of the tip body and the rear portion thereof are formed in a simple cylindrical shape, the machining is very easy and the cost of the tip body component is greatly increased. It can be reduced.

Along with this, the tip portion of the forceps channel is joined to a metallic connection pipe capable of long bonding margin in the cylindrical portion of the tip body, and the tip of the connection pipe is joined to the tip body. Since the tip of the forceps channel is joined to the drilled hole, the tip of the forceps channel can be easily and reliably connected to the tip body within the tip body.

Further, even if a hole for inserting the emitting end of the light guide fiber for illumination is formed obliquely, the cylindrical portion has a thick space, and therefore the tip of the light guide fiber is inserted into the hole from the rear. It can be easily inserted and assembled.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AB of the tip of an electronic endoscope according to an embodiment.

FIG. 2 is a side view of the electronic endoscope of the embodiment.

FIG. 3 is a front view of the distal end portion of the electronic endoscope of the embodiment.

FIG. 4 is a C-D-E-F at the tip of the electronic endoscope of the embodiment.
It is a GH sectional view.

FIG. 5 is a cross-sectional view taken along the line I-J of the tip of the electronic endoscope of the embodiment.

FIG. 6 is a K-L cross-sectional view of the distal end portion of the electronic endoscope of the embodiment.

[Explanation of symbols]

3 Tip body 3a cylindrical part 11 forceps channel 11a Forceps outlet hole 30 insulating connection ring 35 Solid-state image sensor 40 electronic components 42 wiring board 50 connection pipe

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Claims (2)

(57) [Claims] 1. A tip body provided at a tip of an insertion portion,
The tip body, which houses a solid-state imaging device having a non-circular cross-sectional shape, is formed as one component from one material at the tip of an electronic endoscope in which the tip of a forceps channel is joined to the tip body. of, forming a part and the rear side of the portion where the cross-sectional shape non-circular part is housed in a cylindrical shape, the cylindrical portion of the distal portion
If a through hole that becomes an observation window is drilled in the tip wall that closes
In both of the above cylindrical parts, the inner diameter of the front side part is
The inner diameter of the tip of the forceps channel is about the same,
The inner diameter should be the same as the outer diameter of the tip of the forceps channel.
On the formed metal connection pipe, insert the forceps
The tip portion of the channel is fitted and adhered, and the tip portion of the connecting pipe is penetrated into the tip wall portion of the tip body.
Tip of the electronic endoscope, characterized in that joined to the through hole. 2. An electron according to claim 1, wherein a hole for fitting the emitting end of the illumination light guide fiber is obliquely formed in the front end face of the tip end main body and penetrates the cylindrical portion. The tip of the endoscope.