JPH0771550B2 - Electronic endoscope - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic endoscope having a solid-state image sensor provided at a distal end portion of an insertion portion.

[Conventional technology]

Recently, instead of an optical endoscope for observing an in-vivo image using a fiber, an electronic endoscope has been developed in which a solid-state imaging device such as a CCD is arranged at the tip of an insertion portion. In such an endoscope, it is desired to reduce the diameter of the endoscope in order to ease the pain of the patient at the time of insertion. Therefore, for example, in JP-A-60-241011, in an electronic endoscope, the optical axis of the objective optical system is bent at a substantially right angle by an optical element, and the solid-state image pickup element is arranged substantially parallel to the insertion axis of the endoscope. ,
It has been proposed to reduce the diameter of the tip.

[Problems to be solved by the invention]

On the other hand, not only the solid-state image sensor chip but also a clock generation integrated circuit for driving the solid-state image sensor, an amplifier circuit for amplifying the video output from the solid-state image sensor, etc. need to be incorporated at the tip of the endoscope. There is. At that time, since the solid-state image sensor chip is once packaged and connected to the board on which other electronic components are mounted, the space for the solid-state image sensor package and the packaged solid-state image sensor are mounted on other electronic components. It is necessary to provide a space for connecting to the substrate, and the distal end portion of the endoscope becomes thicker and the length of the hard tip portion becomes longer.

The present invention has been made in view of the above circumstances, and it is possible to reduce the diameter of the distal end portion and the length of the distal end hard portion, and further to provide an electronic endoscope in which the distal end circuit substrate is not easily broken. The purpose is to provide.

[Means and Actions for Solving Problems]

The present invention is an electronic endoscope in which the optical axis of an objective optical system at the tip of an insertion portion is bent at a substantially right angle by an optical element, and an optical image is guided to a solid-state image pickup element arranged substantially parallel to the axis of the insertion portion. In the above, the solid-state imaging device is provided on one surface side of the support member disposed in the distal end portion, the circuit board for the distal end circuit is provided on the same surface side, and the solid-state imaging device and the substrate are connected by a bonding wire. It is possible to reduce the diameter and shorten the length of the hard portion at the tip, and further it is difficult to break the substrate for the tip circuit.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 relate to the first embodiment of the present invention.
FIG. 1 is a sectional view of the tip of the insertion portion of the electronic endoscope, and FIG. 2 is an external view showing the entire electronic endoscope.

As shown in FIG. 2, the electronic endoscope 31 has a slender and flexible insertion portion 32, for example, and a large-diameter operation portion 33 connected to the rear end of the insertion portion 32. A flexible cable 34 extends laterally from the rear end of the operation portion 33, and a connector 35 is provided at the tip of the cable 34.
Is provided. The electronic endoscope 31 is the connector.
Through 35, it is connected to a control device 36 in which a light source device and a video signal processing circuit are incorporated. further,
A color CRT monitor 37 as a display means is connected to the control device 36.

On the distal end side of the insertion portion 32, a rigid distal end portion 39 and a curving portion 40 adjacent to the distal end portion 39 and capable of curving toward the rear side are sequentially provided. Further, by rotating the bending operation knob 41 provided on the operation portion 33, the bending portion 40 can be bent in the left / right / up / down directions. Also,
The operation section 33 is provided with an insertion port 42 that communicates with a forceps channel provided in the insertion section 32.

The tip 39 is constructed as shown in FIG.

That is, the tip portion 39 includes the substantially columnar tip forming portion 2 made of a hard material such as metal. This tip component 2
A through hole 3 for illumination, a through hole 4 for observation, a through hole for a forceps channel (not shown), and a through hole for an air / water feeding channel are formed in the through hole in the longitudinal direction of the insertion portion. In the through hole 3 for illumination,
The illumination lens is fitted from the tip side of the light guide 6, and then the tip of the light guide 6 is fitted and fixed to the through hole 3 with a screw 7 from a direction perpendicular to the optical axis of the illumination lens. This light guide 6 has a metal pipe 6a on the tip side.
The coating member 6b is used to cover the portion covered by the method up to the middle of the tip 39. An objective lens frame 8 is fitted in the observation through hole 4 and is fixed together with the objective lens frame 8 and the supporting member 16 by screws 9 from a direction perpendicular to the optical axis of the objective lens as will be described later. It has become so. After being screwed with the screw 9, the hole for the screw is filled with the filler 10. An objective lens system 11 is positioned and attached to the objective lens frame 8. A packing 12 is arranged in the space between the inner wall surface of the observation through hole 4 and the groove portion 8a formed on the outer wall surface of the lens frame 8. A parallel flat glass plate 13 is fitted and fixed to the rear end side of the lens frame 8. A reflection prism 14 is fixed to the rear end surface of the parallel flat glass plate 13. In this prism 14, the entrance surface 14a is perpendicular to the optical axis of the objective lens system 11, and the exit surface 14b is the objective lens system 11
Are arranged so as to be parallel to the optical axis of. A solid-state image sensor 15 such as a CCD or SIT is fixed to the exit surface 14b of the prism 14. Although not shown, a color filter is provided in a so-called chip-on type on the light incident surface side of the solid-state imaging device 15. The solid-state image sensor 15 is fixed on a plate-shaped support member 16. The support member 16 is made of, for example, a metal plate, and is a solid-state image sensor when the temperature changes.
It is desirable that the thermal expansion coefficient is low so that peeling does not occur between 15 and 15. For example, 12 chrome stainless steel, 18 chrome stainless steel, molybdenum steel or the like plated with nickel or gold is used. It should be noted that a ceramic such as alumina or glass provided with a conductive pattern may be used. The support member 16 extends to the lower portion of the cylindrical lens frame 8, and the plate-shaped support member 16 and the cylindrical lens frame 8 are fixed to each other in a state where they are in close contact with a connecting member 17 made of metal. . Therefore, the connecting member 17 is formed so that the side fixed to the support member 16 is flat and the side fixed to the lens frame 8 is cylindrical. The rear end surface of the connecting member 17, the front end surface of the solid-state imaging device 15, and the prism 14
The space formed between the incident surfaces 14a is filled with the sealing resin 21. Further, on the supporting member 16, a ceramic substrate 22 is fixed to the rear side of the solid-state image sensor 15. On this ceramic substrate 22, a peripheral IC (integrated circuit) chip 18 is arranged on the side closer to the solid-state image pickup device 15 side, and electronic components 19 such as a chip capacitor and a chip resistor are provided at the rear part thereof.
Is provided. Then, some of the external electrodes of the solid-state imaging device 15 are connected to the substrate 22 and some of them are connected to the peripheral IC chip 18 by bonding wires 20. This peripheral IC
The chip 18 and the wire bonding portion are resin-sealed with a sealing resin 21. The cable 23 extending from the operation portion side of the endoscope bundles the shielded wires and further covers the shielded wires. The outer conductor of each shield wire and the outermost shield wire 24 are soldered on the rear surface side of the support member 16, and the core wire 25 is connected to the electronic component 19 and the substrate 22. The sealing resin 21, the electronic component 19, the shield wire 24, the core wire 25, and the substrate 22 are covered with the filler 26 from above. As the filler 26, for example, a silicone adhesive having elasticity is used. In addition, in the above-mentioned structure, the supporting member 16, the connecting member 17, and the lens frame 8 are in a conductive state. In addition, the peripheral IC chip 18, the substrate 22, and the support member 16 are also electrically connected. Also,
The objective lens frame 8, the solid-state image pickup device 15, the support member 16, the substrate 22, and the cable 23 are integrally configured so that they can be attached and detached from the distal end constituent portion 2 by removing screws 9. Further, the rear end portion of the tip forming portion 2 is fitted and fixed at the position of the tip portion of the hard cylindrical tip outer cylinder 27 so as to surround the built-in components such as the light guide 6 and the support member 16. Has been done. The tip outer cylinder 27 has a length that extends to a position that extends further than the rear end of the support member 16. On the other hand, a large number of substantially annular joint pieces 28 are rotatably connected in the longitudinal direction in the bending portion 40 adjacent to the tip portion 39, and the joint piece 28 at the foremost end is the tip outer cylinder 27. It is connected to a curved tube 30 fitted and fixed to the rear end of the. And these joint pieces
28 is a curved rubber that serves as an outer skin fixed to the rear end of the curved tube 30.
It is covered by 29. In addition, according to the present embodiment, it is possible to reduce the diameter of the tip portion, and since the solid-state imaging device is not disposed on the tip circuit substrate, the tip circuit substrate can be shortened and mechanically destroyed. A difficult substrate can be obtained.

FIG. 3 is a sectional view of the tip of an endoscope showing another embodiment of the present invention. The same functional parts as those shown in FIG. 1 are designated by the same reference numerals.
In this embodiment, the connecting member 17 in FIG. 1 is formed integrally with the supporting member 16. Further, the support member 16 has a step portion 16a having a step formed behind the position where the solid-state imaging device 15 is provided. In this embodiment, the lower end surface of the step portion 16a is formed so as to be located above the lower end surface of the portion where the solid-state imaging device 15 is provided. That is, the notch 24a is formed by scraping off the back surface side of the step portion 16a. In this cutout portion 24a, the shield wire is provided on the back surface side of the step portion 16a.
24 is soldered. By connecting in this way, the portion of the supporting member 16 extending rearward from the substrate 22 is reduced and the length L of the distal end hard portion is shortened. That is, the connecting portion of the cable 18 with the supporting member 16 is overlapped with the substrate 22 in the insertion axis direction. It should be noted that the stepped portion 13a is formed to such an extent that the fitting portion at the rear end portion of the tip outer cylinder 27 of the bending tube 30 is avoided even if it is not ground to this extent.
The support member 16 and the bending tube 30 can be overlapped in the axial direction even if the back surface of the support member 16 is shaved, so that the length L of the hard end portion can be shortened. In addition, in this embodiment, the lower end surface of the step portion 16a of the support member 16 is located above the upper end surface of the solid-state imaging device 15, but this is not always necessary. However, by overlapping the solid-state imaging device 15 and the substrate 22 in the insertion axis direction, the length L of the hard tip portion can be shortened. Further, the end surface 22a on the front end side of the substrate 22 is formed obliquely and the bonding wire 20
The bonding pad space is secured and the interference with the bonding wire 20 is prevented.

Since the peripheral IC chip 18 and the electronic component 19 are mounted on the board 22 and are resin-sealed with the sealing resin 51, the board 22 may be taken out to a dirty environment outside the clean room. Further, a sealing resin 21 is provided between the solid-state image sensor 15 and the substrate 22.
Is resin-sealed. The filler 26 covers the upper portion of the substrate 22, the core wire 25 of the cable 23, and the like.

Further, the prism 14, the solid-state image sensor 15, the substrate 22, the electronic component 19
Both side surfaces and the upper surface may be shielded by a shield member.

With the above-described configuration, the force applied to the cable 23 during bending is received by the lens frame 1 via the support member 16,
Peeling is unlikely to occur between the solid-state imaging device 15 and the prism 14 and between the parallel flat glass plate 26 and the prism 14. According to the present embodiment, the length L of the hard tip portion can be shortened,
Similar to the first embodiment, the tip circuit board is less likely to be broken.

〔The invention's effect〕

As described above, according to the present invention, there is no need for a space for packaging a solid-state image sensor and a space for connecting the packaged solid-state image sensor to a board on which other electronic components are mounted. It is possible to shorten the length of the tip hard portion. Further, since the solid-state image pickup device is not arranged on the substrate, the circuit board for the tip circuit can be shortened and is not easily mechanically broken.

[Brief description of drawings]

FIG. 1 is a sectional view of a tip portion of an embodiment of the present invention,
FIG. 3 is an external view of the endoscope of the same embodiment, and FIG. 3 is a sectional view of the tip of another embodiment of the present invention. 11 …… Objective lens system, 14 …… Prism (optical element), 15…
… Solid-state image sensor, 16 …… Supporting member, 20 …… Bonding wire, 22 …… Tip circuit board, 39 …… End portion of endoscope.

Claims (1)

[Claims] 1. An electronic endoscope in which an optical axis of an objective optical system at the tip of an insertion portion is bent at a substantially right angle by an optical element, and the optical axis is guided to a solid-state image pickup element arranged substantially parallel to the axis of the insertion portion. In the mirror, the solid-state image pickup device is provided on one surface side of the support member disposed in the tip portion, and the tip circuit substrate is provided on the same surface side of the support member, and the solid-state image pickup device and the substrate are connected. An electronic endoscope characterized by.