JPH04317622A - Tip part of endoscope - Google Patents

Abstract

PURPOSE:To prevent the circuit board from being deformed due to force applied from a signal cable, and to obtain the excellent durability without causing damage on the circuit board and an electric fault even if it is used repeatedly by integrating a flexible circuit base material with an objective optical system and a solid-state image pickup element by a reinforcing member. CONSTITUTION:Objective optical systems 13, 35, 36 and 33, a solid-state image pickup element 31 and a circuit board 40 are foxed and connected generally as one unit, and by joining a reinforcing member 48 to them, the whole becomes an integral firm unit. Especially, the rear part side of the reinforcing member 48 is formed along the circuit board 40, and also, joined, therefore, the circuit board 40 is not deformed easily by force transmitted from a signal cable 43, etc. Also, the reinforcing member 48 utilizes a recessed part between a rectangular prism 33 and the circuit board 40, and is placed mainly in its inside. Moreover, it is pressed and fixed to a drum part 11b of the tip part main body 11 with a small screw 49.

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 endoscope having a solid-state image sensor provided within the distal end of an insertion portion.

0002

2. Description of the Related Art When a solid-state imaging device is provided at the tip of an insertion section, a circuit board on which a driving circuit and the like are wired must be placed near it.

Recently, such a circuit board is made by bending a flexible plate and placing it parallel to the axial direction of the tip body so as not to block the cross section of the insertion section of the endoscope. Ru. Then, the signal cable is passed through the insertion portion from the circuit board to the rear.

0004

SUMMARY OF THE INVENTION When such an endoscope is used for inspection inside a human body cavity, the entire insertion portion is bent. In particular, the curved portion formed on the distal end side and bent by remote control is frequently bent with a small radius of curvature.

[0005] Then, each time the signal cable is pulled,
As pushing, twisting, and other forces are applied, repeated use can lead to damage to the circuit board or electrical failure.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tip end portion of an endoscope that has excellent durability and does not cause damage to the circuit board or electrical failure in the circuit board.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the distal end of the endoscope of the present invention has an objective optical system built in the distal end main body provided at the distal end of the insertion section, and an objective optical system built in the distal end main body provided at the distal end of the insertion section. A solid-state image sensor fixed to the rear end of the system, a flexible circuit board to which the solid-state image sensor is attached and arranged approximately parallel to the axial direction of the tip body, and a tip attached to the circuit board. a signal cable fixedly attached and routed rearward; and a reinforcing member fixedly fixed to the objective optical system and the solid-state image pickup device on the front side, and fixed to the circuit board along the longitudinal direction on the rear side. It is characterized by having the following.

[0008]

[Embodiment] An embodiment will be described with reference to the drawings.

FIG. 1 shows the tip of the insertion section of the endoscope. In the figure, reference numeral 1 indicates a curved portion formed at the tip of an elongated flexible tube forming the insertion portion, and a plurality of nodal rings 2 are rotatably connected by rivets 3. Its outer periphery is covered with a mesh tube 4 made of thin metal wire and an outer skin tube 5 made of rubber.

[0010] A bending operation wire 7 that is remotely towed and operated
is inserted into a wire guide 8 protruding inwardly from each node ring 2 so as to be able to move forward and backward. The tip of each bending operation wire 7 is fixed to the wire guide 8 by silver brazing or the like. 9 is a stopper pipe 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 main body connected to the tip of the curved portion 1 via a connecting tube 12, and includes a metal body 11b.
and a head portion 11a made of electrically insulating plastic joined to the tip portion thereof.

The tip main body 11 has a circular cross-sectional shape when viewed from the tip side (left side in FIG. 1), and has an objective lens group 13 built into the head 11a.

The objective lens group 13 is composed of a plurality of lenses, the axial direction of which coincides with the axial direction of the tip body 11, and the object in front (left side in FIG. 1) is the subject. The observation window 14 is formed by the most advanced lens of the antirostral lens group 13.

Reference numerals 15 and 16 denote lens frames into which the lenses of the objective lens group 13 are fitted and bonded, and the outer lens frame 15
is joined to the head portion 11a of the tip body. 17 is the brightness aperture. 18 is an O-ring for sealing.

A connecting tube 34 connected to 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 fixed inside the interior, and a right-angle prism 33 is joined to the rear end surface of the low-pass filter 36. An optical system is formed.

A solid-state image sensor 31 is bonded to the exit surface side of a right-angle prism 33 located at the rear end of the objective optical system, with the centering adjusted relative to the objective optical system. As the solid-state image sensor 31, for example, a CCD (charge coupled device)
is used.

In this way, the optical axis of the objective lens group 13 is bent laterally at a right angle by the right angle prism 33, and an observed image is formed on the image receiving surface 31a of the solid-state image sensor 31.

Light guide fiber bundle 21 for illumination
The output end 21a is fixed to the head 11a of the tip main body with its axis parallel to the objective lens group 13. A light distribution lens (concave lens) 22 is disposed on the end face to widen the distribution angle of the emitted illumination light.

In this way, the light distribution lens 22 is connected to the illumination window 2.
3, and the object in front of the tip main body 11 is illuminated by the illumination light transmitted through the illumination light guide fiber bundle 21.

FIG. 2 is a front view of the head 11a of the tip body. As shown here, the illumination windows 23 are provided at two locations, and the light guide fiber bundles 21 are disposed inside each of the illumination windows 23. Reference numeral 24 denotes a treatment instrument outlet for protruding the probing forceps and other treatment instruments. 25 and 26 are air supply nozzles and water supply nozzles.

Furthermore, as shown in FIG. 3, the connecting tube 34
And the optical elements inside thereof are formed into a substantially square shape by cutting out unnecessary and wasteful parts. 27 and 28
are air pipelines and water pipelines. 29 is a treatment instrument insertion conduit (
forceps channel).

Returning to FIG. 1, the circuit board 40 to which the solid-state image sensor 31 is attached is made of a single flexible electrically insulating plastic plate.

The circuit board 40 is arranged parallel to the axial direction of the tip main body 11, and by taking advantage of its flexibility, it is folded into three along the axial direction as shown in FIG. Filled with electrically insulating adhesive. 41 is an electronic component that is attached to the circuit board 40 and constitutes a drive circuit and the like.

[0024] The tip of a lead wire 44 of a signal cable 43 that is routed backward is fixed to the rear end portion of the circuit board 40 by soldering. The signal cable 43 is inserted over the entire length of the elongated insertion portion,
Signals are transmitted between the solid-state image sensor 31 and an externally provided video processor (not shown).

Reference numeral 48 denotes a reinforcing member for improving the durability of the circuit board 40, and is made of a metal with good adhesive properties, such as brass. The front side of the reinforcing member 48 is bonded and fixed to the back surface of the reflective surface of the right-angle prism 33 and the periphery of the image receiving surface 31a of the solid-state image sensor 31, and the rear side is formed long along the longitudinal direction of the circuit board 40. It is bonded and fixed to the outer surface of the circuit board 40 over a relatively wide area.

In this embodiment, if this reinforcing member 4
Even if 8 is not present, objective optical systems 13, 35, 36, 3
3, the solid-state image sensor 31, and the circuit board 40 are fixedly connected as one unit.

However, by joining these reinforcing members 48 together, the whole becomes an integral and strong unit. In particular, since the rear side of the reinforcing member 48 is formed along and joined to the circuit board 40, the circuit board 4 may be damaged by the force transmitted from the signal cable 43 or the like.
0 is not easily deformed.

Further, the reinforcing member 48 is mainly disposed inside the rectangular prism 33 and the circuit board 40 by utilizing the recess between the rectangular prism 33 and the circuit board 40 so as not to narrow the effective space of the tip main body 11. There is. This reinforcing member 48 is
As shown in FIGS. 1 and 5, it is press-fixed to the body portion 11b of the tip body 11 with machine screws 49.

[0029]

According to the distal end portion of the endoscope of the present invention, the flexible circuit board is integrated with the objective optical system and the solid-state image pickup device by the reinforcing member, so that the force applied from the signal cable The circuit board does not easily deform, and even after repeated use, the circuit board has excellent durability without being damaged or electrically malfunctioning.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of an embodiment.

FIG. 2 is a front view of the embodiment.

FIG. 3 is a sectional view taken along III-III of the embodiment.

FIG. 4 is a sectional view taken along line IV-IV of the embodiment.

FIG. 5 is a V-V sectional view of the embodiment.

[Explanation of symbols]

11 Tip body 13 Objective lens group 31 Solid-state image sensor 33 Right angle prism 40 Circuit board 43 Signal cable 48 Reinforcement member

Claims (1)

[Claims] Claims: 1. An objective optical system built into a distal end body provided at the distal end of an insertion section; a solid-state image sensor fixed to the rear end of the objective optical system; and a solid-state image sensor attached to the distal end body. A flexible circuit board arranged substantially parallel to the axial direction of the main body, a signal cable whose tip is fixed to the circuit board and led through to the rear, and the objective optical system and the above on the front side. A distal end portion of an endoscope, characterized in that a reinforcing member is fixed to a solid-state image sensor and fixed to the circuit board along the longitudinal direction of the circuit board on the rear side.