JPH05211997A - Leading end part of electronic endoscope - Google Patents

Abstract

PURPOSE:To provide the leading end part of an electronic endoscope capable of reducing the hard part length of the leading end part of an insertion part, and further, excellent in the soldering workability or bonding stability of a signal wire with a printed circuit board. CONSTITUTION:In the leading end part of an electronic endoscope wherein a printed circuit board 40 having the electronic circuit connected to a solid-state image sensing element 31 connected thereto by wiring is arranged in the leading end 11 of the insertion part of an endoscope and a signal cable 50 formed by bundling a plurality of signal wires 51 each formed by surrounding a core wire 53 by a shield 54 is inserted in the insertion part to connect the signal wires 51 to the circuit board 40, the shields 54 are drawn out of the respective leading end parts of a plurality of the signal wires 51. Further, the drawn-out parts of the shields 54 are wound around the outer periphery of the bundle of the core wires 53 in a ring shape and the ring-shape part is soldered to the circuit board 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip portion of a so-called electronic endoscope in which a solid-state image pickup device is built in a tip portion of an insertion portion of the endoscope.

[0002]

2. Description of the Related Art In a so-called electronic endoscope, a signal cable in which a plurality of signal lines are bundled and a circuit board on which an electronic circuit connected to a solid-state image pickup device is arranged is arranged in a distal end of an insertion portion of the endoscope. Is inserted into the insertion portion to connect each signal line to the wiring of the circuit board.

FIG. 6 shows such a conventional circuit board 80.
In the figure, the signal line 91 of the signal cable 90 is soldered. Reference numeral 81 is a solid-state image sensor. The core wire 92 of each signal line 91 is soldered to the connection terminal 82 of the circuit board 80, and the shield 93 surrounding the core wire 92 is individually soldered to the ground connection terminal 83 formed in the vicinity of each connection terminal 82. There is. Reference numeral 94 is a jacket tube of the signal cable 90.

When the circuit board 80 is incorporated into the tip of an electronic endoscope, the circuit board 80 is bent at a broken line portion to form a trapezoidal cross section as shown in FIG. It is filled with the synthetic resin 85.

[0005]

In the conventional structure as described above, the position where the shield 93 is soldered to the circuit board 80 is much wider than the diameter of the signal cable 90, so that the signal line 91 is not In order to wire up to the position, it is necessary to leave a space from the tip of the jacket tube 94 and to lengthen a portion where the signal line 91 is exposed.

However, in the structure in which the signal line 91 is left exposed, the signal line 91 may be easily damaged. Therefore, as shown in FIG. It is necessary to apply and solidify to reinforce the mechanical strength.

Therefore, the length of the hard portion at the tip of the insertion portion of the endoscope is from the tip to the rear end portion of the adhesive 86,
The rigid portion is long and causes a great deal of pain to the patient. Moreover, since there is no small turning when guiding in the body cavity, there are drawbacks such as poor sniper performance for a target portion.

Also, after soldering, the circuit board 80
When bent, there are drawbacks such as a problem that the signal line 91 is twisted and the soldering comes off, and it is difficult to individually solder the shield 93 near the core wire 92. ..

Therefore, the present invention provides a tip portion of an electronic endoscope which can shorten the length of the hard portion at the tip of the insertion portion and is excellent in the workability of soldering of the signal line and the circuit board and the joint stability. The purpose is to do.

[0010]

In order to achieve the above-mentioned object, the tip portion of the electronic endoscope of the present invention is such that an electronic circuit connected to a solid-state image pickup device is wired in the tip portion of the insertion portion of the endoscope. A signal cable in which a plurality of signal lines formed by surrounding the core wire with a shield are inserted into the insertion part, and the signal line is connected to the circuit board. In the section, pulling out the shield from the respective tip portions of the plurality of signal lines, winding the pulled out portion of the shield in an annular shape on the outer periphery of the bundle of core wires, and soldering the annular portion to the circuit board. Is characterized by.

[0011]

Embodiments will be described with reference to the drawings. Figure 1
The tip of the insertion part of an endoscope is shown.

In the drawing, reference numeral 1 denotes a curved portion formed at the tip of an elongated flexible tube forming an insertion portion, and a plurality of node rings 2 are rotatably connected by rivets 3. The outer circumference is a mesh tube 4 made of thin metal wire and a jacket tube 5 made of rubber.
Is covered by.

A bending operation wire 7 which is remotely pulled.
Is inserted into the wire guide 8 projecting inwardly from each node ring 2 so as to be able to move back and forth. The tip of each bending operation wire 7 is fixed to the wire guide 8 by silver brazing or the like. Reference numeral 9 denotes a stopper pipe that is fixed to the end of the wire guide 8 by silver brazing or the like to prevent it from coming off.

Reference numeral 11 denotes a tip end body connected to the tip end of the bending portion 1 via a connecting tube 12, and a metal body portion 11b.
And a head portion 11a made of an electrically insulating plastic and joined to the tip portion thereof.

The tip body 11 is on the tip side (left side in FIG. 1).
It has a circular cross-sectional shape when viewed from above, and the objective optical system 13 is built in the head portion 11a. The objective optical system 13 is composed of a plurality of lenses, the axial direction of which coincides with the axial direction of the tip end main body 11, and the object in front is the subject. The observation window 14 is formed by the most advanced lens of the objective optical system 13.

Reference numerals 15 and 16 denote lens frames in which the respective lenses of the objective optical system 13 are fitted and adhered, and the outer lens frame 15 is joined to the head portion 11a of the tip end main body. 17 is an aperture stop. Reference numeral 18 is an O-ring for sealing.

Light guide fiber bundle 21 for illumination
The output end 21a of the optical axis is fixed to the head 11a of the tip body with its axis parallel to the objective optical system 13. A light distribution lens (concave lens) 22 for expanding the light distribution angle of the emitted illumination light is arranged on the end surface.

In this way, the light distribution lens 22 is used for the illumination window 2
3 is formed, and the illuminating light transmitted through the illumination light guide fiber bundle 21 illuminates a subject in front of the tip end main body 11.

A solid-state image pickup device 31 is arranged in the body portion 11b of the tip portion main body 11. As the solid-state image sensor 31, for example, a CCD (charge coupled device) is used. An image receiving surface 31a of the solid-state image pickup device 31 is formed in a square or a rectangle, and is arranged parallel to the central axis of the objective optical system 13.

The objective optical system 13 and the solid-state image sensor 3
A right-angled prism 33 is arranged between the optical axis of the objective optical system 13 and the image receiving surface 31a of the solid-state image pickup device 31.
It is reflected at right angles so that it intersects perpendicularly with the center of.

The right-angle prism 33 and the objective optical system 13
Between the connection tube 34 and the rear half of the lens frame 16.
A light-shielding mask 37, a color correction filter 35, and a low-pass filter 36 are inserted therein.

With such an arrangement, the image of the object on the left side of FIG.
The image is formed on the image receiving surface 31a of. The circuit board 40 to which the solid-state imaging device 31 and other electronic components 41 are attached uses one flexible electrically insulating plastic plate as a material, as shown in a developed view in FIG.

Signal cable 5 connected to the circuit board 40
Reference numeral 0 denotes a plurality of signal lines 51 that are insulated from each other and bundled and passed through the jacket tube 52. Each signal line 51 is formed by surrounding a core wire 53 with a shield 54 over the entire length.

Such a signal cable 50 is connected to the circuit board 4
When connecting to 0, first, as shown in FIG. 3, after removing the front end portion of the jacket tube 52 in a predetermined range, a net-like shield 54 is provided from each signal line 51 to the vicinity of the end of the jacket tube 52. Loosen and pull out.

At this time, as shown in FIG. 3, the tube covering each signal line 51 outside the shield 54 is cut off at the portion where the shield 54 is pulled out, and the tube covering the core wire 53 is soldered at the tip. Leave it as it is except for the cost. In addition, the distal end portion of the outer tube 52 is tightly bound with the thread 56 so that the outer tube 52 is connected to the signal line 51 inside.
Fixed so that it does not move against.

Then, as shown in FIG. 4, the pulled-out portion of the shield 54 is wound around the outer circumference of the bundle of the core wires 53 in an annular shape at a position slightly spaced from the end of the jacket tube 52. Then, solder is further attached to the annular portion of the shield 54 to harden it.

After this state, as shown in FIG. 2, the annular portion of the shield 54 is connected to the circuit board 5.
Solder to the 0 ground connection terminal 43. In this way, the signal line 51 is arranged straight from the rear up to the position where it is soldered to the ground connection terminal 43. Then, on the front side thereof, only the thin core wire 53 is connected to each connection terminal 4
4 is bent and wired, and the tip of each wire is connected to each connection terminal 44.
Be soldered to.

As described above, since the signal line 51 extends straight from the signal cable 50 behind the position where it is soldered and fixed to the ground connection terminal 43, the distal end of the jacket tube 52 and the annular portion of the shield 54. Signal line 5 between
1 The length of the exposed portion can be made extremely short.

Therefore, the tip of the jacket tube 52 can be kept away from the rear end position of the circuit board 40. Further, since only the thin core wire 53 is bent and wired, the wiring work can be performed easily and reliably.

When the soldering is completed, the circuit board 40 is bent at the broken line portion shown in FIG. 2 to form a trapezoidal sectional shape as shown in FIG. 5, and an electrically insulating synthetic resin 46 is formed therein. Fill.

When the circuit board 40 is bent, only the thin core wire 53 can be bent inside. Therefore, the force applied to the soldering portion due to the twist of the wiring when the circuit board 40 is bent is very small, and a large force for peeling the soldering is not applied.

A shield member 48 and an insulating tape 49 are provided on the outer periphery of the circuit board 40 thus formed in a trapezoidal shape.
To cover. Then, as shown in FIG. 1, an adhesive agent 47 is applied to the outer circumference of the distal end of the jacket tube 52 so as to surround the binding thread 56 and hardened.

A right-angle prism 33 is bonded to the solid-state image pickup device 31 provided on the circuit board 40 formed in this way to form one unit. The trapezoidal portion of the circuit board 40 is directly adjacent to the right-angle prism 33. It is placed behind.
Therefore, when viewed from the objective optical system 13 side, the outer edge shape of the right-angle prism 33 and the circuit board 40 just overlap with each other, and neither travels much.

[0034]

According to the tip of the electronic endoscope of the present invention,
Since the shield wound around the outer circumference of the bundle of core wires in an annular shape is soldered to the circuit board, the signal line behind the shield can be arranged straight and the exposed portion of the signal line can be made extremely short.

As a result, an adhesive is applied to reinforce the exposed portion of the signal line, and the length of the portion which becomes the hard tip portion is shortened, the insertability is improved and the pain to the patient is reduced, and the object is The sniper performance for the part is improved.

Further, since only the core wire can be bent when the circuit board is bent, the force applied to the soldering portion of the wiring due to the twisting of the wiring when the circuit board is bent is very small, and the soldering There is no force to peel off.

Since the shields are put together and soldered, the soldering work can be performed very easily.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view of a tip portion of an electronic endoscope according to an embodiment.

FIG. 2 is a development view of a circuit board to which the signal cable of the embodiment is connected.

FIG. 3 is a processing step diagram for connecting the signal cable of the embodiment.

FIG. 4 is a process drawing for connecting the signal cable of the embodiment.

FIG. 5 is a front cross-sectional view after bending the circuit board of the embodiment.

FIG. 6 is a development view of a circuit board to which a signal cable of a conventional example is connected.

FIG. 7 is a front cross-sectional view of a conventional circuit board after bending.

FIG. 8 is a side sectional view of a circuit board to which a signal cable of a conventional example is connected.

[Explanation of symbols]

 11 tip body 31 solid-state image sensor 40 circuit board 50 signal cable 51 signal line 52 jacket tube 53 core wire 54 shield

Claims (1)

[Claims] 1. A signal in which a circuit board, in which an electronic circuit connected to a solid-state image sensor is wired, is arranged in the tip of an insertion portion of an endoscope, and a plurality of signal lines formed by surrounding a core wire with a shield are bundled. A cable is inserted into the insertion portion, and at the tip of the electronic endoscope in which the signal line is connected to the circuit board, the shield is pulled out from the respective tip portions of the plurality of signal lines, and the bundle of core wires A distal end portion of an electronic endoscope, characterized in that a drawn-out portion of the shield is annularly wound around an outer periphery, and the annular portion is soldered to the circuit board.