JPH05261064A - Front end of electron endoscope - Google Patents

Abstract

PURPOSE:To provide the front end of an electron endoscope which prohibits the peeling of the joint of an objective optical system, etc., even if a signal cable is pushed and pulled. CONSTITUTION:A circuit board 42 is connected to a solid-state image pickup element 31 in the state of having flexibility with this element in the front end of the electron endoscope constituted by fixing an objective optical system 13 provided at the front end in the insertion part of the endoscope and the solid-state image pickup element 31, and by coupling and connecting the circuit board 42 connected with the signal cable 43 and the solid-state image pickup element 31 in the front end of the insertion part.

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 conventional electronic endoscope, a solid-state image pickup device and a circuit board are integrally connected and connected to each other in the distal end of an insertion portion and fixed by an adhesive so that they do not move with each other. In addition to being bonded to the objective optical system, a signal cable was connected to the circuit board by soldering or the like, and these were configured as one unit.

[0003]

Since the signal cable is inserted into the insertion portion of the endoscope over its entire length, the signal cable will not be signaled if the insertion portion is looped or the bending portion formed in the insertion portion is fully bent. The cable is pushed and pulled hard.

Then, the force reaches the objective optical system via the circuit board and the solid-state image pickup device, and the joint between the solid-state image pickup device and the objective optical system is peeled off, or the joint between the optical parts in the objective optical system is peeled off. I had to do it. In particular, when it is placed in a sterilization device or the like and is in a high temperature state, it tends to peel off.

Therefore, an object of the present invention is to provide a distal end portion of an electronic endoscope in which a joint of an objective optical system or the like does not peel off even when a signal cable is pushed and pulled.

[0006]

In order to achieve the above object, the distal end portion of the electronic endoscope of the present invention fixes the objective optical system provided at the distal end of the insertion portion of the endoscope and the solid-state image pickup device. At the same time, the circuit board is flexible with respect to the solid-state image sensor at the tip of the electronic endoscope in which the circuit board to which the signal cable is connected and the solid-state image sensor are connected and connected in the tip of the insertion section. It is characterized by being connected in a state having.

The circuit board may be fixed to the distal end of the insertion portion of the endoscope, and elastic filling is provided around the connection portion between the circuit board and the solid-state image sensor in the distal end of the insertion portion. The agent may be filled.

[0008]

Embodiments will be described with reference to the drawings. 2 is a front view of the tip of the electronic endoscope, and FIG. 1 is a sectional view taken along the line I-I.

In FIG. 1, reference numeral 1 is 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. The outer periphery thereof is covered with a mesh tube 4 made of thin metal wires and a jacket tube 5 made of rubber.

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 most advanced wire guide 8 by silver brazing. Reference numeral 9 denotes a stopper pipe that is fixed to the end of the most advanced wire guide 8 by silver brazing or the like to prevent the stopper from coming off.

Reference numeral 11 denotes a tip body connected to the tip of the bending portion 1 via a connecting tube 12, and is 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 therein. The objective optical system 13 includes an objective lens group 13a including a plurality of lenses, a color correction filter 13b, a low-pass filter 13c, and a right-angle prism 1.
3d and.

The axial direction of the objective lens group 13a 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 are lens frames to which an objective lens group 13a including a cemented lens is fitted and adhered. 17 is an aperture stop. Reference numeral 18 is an O-ring for sealing. Reference numeral 20 shown in FIG. 2 denotes an illumination window, from which the illumination light transmitted through the illumination light guide fiber bundle is radiated outward to illuminate a subject in front of the tip end main body 11.
21 and 22 are air supply / water supply nozzles. 23 is the outlet of the forceps channel.

As shown in FIG. 1, a solid-state image pickup device 31 is arranged in the body portion 11b of the tip end 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 shape or a rectangular shape, and is arranged parallel to the optical axis of the objective lens group 13a.

The optical axis of the objective optical system 13 is perpendicular to the center of the image receiving surface 31a of the solid-state image pickup device 31 by the right-angle prism 13d arranged between the objective lens group 13a and the solid-state image pickup device 31. Is reflected in the right angle direction.

Right angle prism 13d and objective lens group 13a
Between the connection tube 19 and the connection tube 19 connected to the rear half of the lens frame 16.
The light-shielding mask 25, the color correction filter 13b, and the low-pass filter 13c are bonded and inserted in the inside, and the right-angle prism 13d and the low-pass filter 13c are also bonded to each other.

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. 42 is a solid-state image sensor 31
It is a flexible circuit board 42 to which an electronic component (not shown) for performing the signal processing is attached, and is fixedly connected to the tip portion of the signal cable 43 by soldering. The solid-state image sensor 31 is fixed to the tip side thereof, and the image-receiving surface 31a side of the solid-state image sensor 31 is joined to the right-angle prism 13d.

As shown in FIG. 4, the circuit board 42 is bent in a U-shape and the periphery thereof is covered with a shield tape 44 and an insulating tape 45, and an epoxy adhesive 60 is provided in the internal space. It is filled and hardened to prevent deformation.

In this way, the objective optical system 13, the solid-state image pickup device 31, the circuit board 42 and the signal cable 43 are integrally formed as one unit as a whole, and the connecting cylinder 12 is provided with a pair of upper and lower pressing plates 46. Through the fixing screw 5
It is fixed by 2.

The circuit board 42 constituting this unit is
As described above, the portion hardened with the epoxy adhesive 60 is made rigid, but as shown in FIG. 5, between the hardened portion and the portion to which the solid-state image sensor 31 is fixed. The portion (neck portion) 42a of the circuit board 42 has a narrow width and can be easily bent in a direction perpendicular to the surface.

Therefore, even if the signal cable 43 is strongly pushed and pulled by strongly looping the insertion portion of the endoscope or bending the bending portion 1 to the full extent, it is fixed to the connecting cylinder 12 by the fixing screw 52. The circuit board 42 does not move back and forth or left and right, and a twisting or tilting force applied to the circuit board 42 from the signal cable 43 is absorbed by the flexible neck portion 42a, and the solid-state image sensor 31 and the objective optical system. It does not reach 13.

FIG. 6 shows a second embodiment of the present invention, in which a silicone adhesive having elasticity is provided in the space formed around the solid-state image pickup device 31 and the circuit board 42 in the tip of the insertion portion. 70 etc. are filled.

In this way, the elastic adhesive 70
Since the solid-state imaging device 31 and the objective optical system 13 are hard to move and the neck portion 42a of the circuit board 42 remains flexible, the circuit board 42 is slightly moved by the force applied to the signal cable 43. However, the solid-state image sensor 31
It is hard to convey power to.

[0026]

According to the tip of the electronic endoscope of the present invention,
Since the circuit board is connected to the solid-state image sensor in a flexible state, even if the signal cable connected to the circuit board is strongly pushed and pulled, the force is not transmitted to the solid-state image sensor part, and Also, peeling does not occur at a joint between the objective optical system and a joint inside the objective optical system.

[Brief description of drawings]

FIG. 1 is a side sectional view (II sectional view) of a first embodiment.

FIG. 2 is a front view of the first embodiment.

FIG. 3 is a front sectional view (III-III sectional view) of the first embodiment.
Is.

FIG. 4 is a front sectional view (IV-IV sectional view) of the first embodiment.

FIG. 5 is a partial plan view of the first embodiment.

FIG. 6 is a side sectional view of a second embodiment.

[Explanation of symbols]

 Reference Signs List 11 Tip Main Body 12 Connection Cylinder 13 Objective Optical System 31 Solid-State Image Sensor 42 Circuit Board 42a Neck 43 Signal Cable

Claims (3)

[Claims] 1. An objective optical system provided at the tip of an insertion part of an endoscope and a solid-state image sensor are fixed to each other, and a circuit board to which a signal cable is connected and the solid-state image sensor are provided in the tip of the insertion part. A distal end portion of the electronic endoscope, wherein the circuit board is connected to the solid-state imaging device in a flexible state at a distal end portion of the electronic endoscope connected and connected. 2. A distal end portion of an electronic endoscope according to claim 1, wherein the circuit board is fixed to a distal end portion of an insertion portion of the endoscope. 3. The distal end portion of the electronic endoscope according to claim 1, wherein an elastic filler is filled around a connection portion between the circuit board and the solid-state image sensor in the distal end of the insertion portion.