JP2002159438A - Image pickup unit for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup unit for an endoscope having durability against sterilization with high pressure and temperature steam, by securely sealing a solid-state image pickup device and a circuit substrate. SOLUTION: The image pickup unit 1 for an endoscope is composed mainly of an objective lens unit 11, an enforcement frame body 13 covering up the solid-state image pickup device 12 or the like, and a signal cable 14. The reinforcement frame body 13 is formed with squashing process of a metal member, and a diametrically larger section 13a is hermetically fixed on the periphery of a device frame 12 by soldering. Sealing 26 is press fittingly arranged around the outside of the signal cable 14 in the inside opening of a diametrically smaller section 13b. The enforcement frame body 13 is made in a sealed condition between the inside and outside. The solid-state image pickup device 12 and an image pickup circuit substrate 23 or the like arranged in the inside space of the diametrically larger section are sealed by a thermoelastic resin 29, which is a styrene polymer and is injected from a clearance formed between the diametrically smaller section 13b and the signal cable 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

[0002]

2. Description of the Related Art Conventionally, an elongated insertion portion is inserted into a body cavity to observe organs in the body cavity, and, when necessary, to perform various treatments using a treatment tool inserted into a treatment tool channel. Medical endoscopes that can be used are widely used. Also, in the industrial field, industrial endoscopes capable of observing and inspecting internal scratches and corrosion of boilers, turbines, engines, chemical plants, and the like are widely used.

[0003] In particular, an endoscope used in the medical field uses an insertion part inserted into a body cavity to observe an organ or the like, or uses a treatment tool inserted into a treatment tool channel of the endoscope. Since various treatments and treatments are performed, if the used endoscope or treatment tool is reused for another patient, it is necessary to prevent patient-to-patient infection through the endoscope or treatment tool. After completion, washing and disinfection had to be performed.

In recent years, autoclave sterilization (high-pressure, high-temperature steam sterilization), which can be used immediately after sterilization without a complicated operation and has a low running cost, is becoming the mainstream of disinfection and sterilization of endoscope devices.

In order to protect the solid-state imaging device and the circuit board from high-pressure and high-temperature steam during the autoclave sterilization, for example, an adhesive is provided around the solid-state imaging device and the circuit board in the solid-state imaging device unit disclosed in JP-A-2000-115594. An arrangement for filling and sealing is shown. In this solid-state imaging device unit, when the adhesive is filled, a method of filling the solid-state imaging device and the circuit board with a large amount of the adhesive, inserting an exterior member, and finally wiping out the overflowing adhesive, and a device frame body Was sealed by a method in which an adhesive was poured from the rear end of the exterior member joined to the sealing member.

[0006]

However, when the solid-state imaging device and the circuit board are sealed by filling with an adhesive or the like by the above-described method, it is difficult to fill the adhesive without unevenness. That is, since air bubbles are mixed in the filled adhesive, there is a problem that a cavity is formed after the adhesive is cured. Then, if a cavity is formed in the cured adhesive, when high-pressure and high-temperature steam sterilization is performed, high-pressure and high-temperature steam may penetrate through the cavity and damage the solid-state imaging device and the circuit board.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an imaging unit for an endoscope having a high-pressure, high-temperature, and high-temperature steam sterilization resistance by securely sealing a solid-state imaging device and a circuit board. I'm

[0008]

An imaging unit for an endoscope according to the present invention comprises: a solid-state imaging device to which an imaging circuit board is connected;
An objective lens unit that forms a subject image on the solid-state imaging device; a holding frame that holds the objective lens unit and the solid-state imaging device; and a frame that forms an internal space in which the imaging circuit board and the solid-state imaging device are arranged. Wherein the frame is formed of a metal member, and a solid-state image sensor and an image pickup circuit board, which are disposed in the internal space of the frame, are ejected at a predetermined pressure. Sealed with a thermoplastic resin.

[0009] The thermoplastic resin is a styrene polymer having temperature resistance during autoclave sterilization.

According to this configuration, by injecting the thermoplastic resin at a predetermined pressure, bubbles are prevented from remaining in the thermoplastic resin, and the periphery of the solid-state imaging device and the imaging circuit board are sealed without unevenness. Further, the styrene-based polymer has temperature resistance at the time of autoclave sterilization, so that thermal problems due to high-pressure and high-temperature steam do not occur.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an imaging unit for an endoscope according to a first embodiment of the present invention.

As shown in FIG. 1, an imaging unit 1 for an endoscope according to the present embodiment includes an objective lens unit 11 disposed on the distal end side, a solid-state imaging device 12 disposed behind the objective lens unit 11, It is mainly composed of a reinforcing frame 13 made of metal such as stainless steel, which is a frame surrounding the solid-state imaging device 12 and the like, and a signal cable 14 extending from the base end of the reinforcing frame 13. I have.

The objective lens unit 11 includes a plurality of optical lenses 15 arranged on a lens frame 16 made of metal such as stainless steel. Here, the optical lens 15 located on the distal end side is air-tightly fixed to the lens frame 16 by metal bonding such as soldering. on the other hand,
The base end of the lens frame 16 is inserted and disposed in a metal element frame 17 made of, for example, stainless steel, and the end of the lens frame 16 at the element frame front end side of the engagement portion with the element frame 17 is hermetically sealed by laser welding. Is fixed.

One surface of a package glass 18 is adhered and fixed to the imaging surface side of the solid-state imaging device 12. A cover glass 19 is adhesively fixed to the other surface of the package glass 18. And this cover glass 19
It is inserted into the element frame 12 and is adhesively fixed at a predetermined position. This allows the objective lens unit 1
An optical image passing through one of the plurality of optical lenses 15 is formed on the imaging surface of the solid-state imaging device 12.

On the other hand, a terminal 21 is provided below the solid-state imaging device 12. For example, an imaging circuit board 23 on one side of which an electronic component 22 such as a capacitor or a transistor is mounted is electrically and mechanically connected to the terminal 21.

In the signal cable 14, for example, a plurality of coaxial cables 24 are inserted. One end of the core wire 24 a and one end of the inner shield 24 b of each coaxial cable 24 are electrically connected to predetermined positions of the electronic component 22 and the imaging circuit board 23.

The core wire 24a and the inner shield 2
The other end of 4b is connected to a video processor including an image processing circuit for generating an electric signal transmitted from the solid-state imaging device into a video signal via an endoscope connector (not shown). Reference numeral 24c is a general shield, and reference numeral 2c.
Reference numeral 5 denotes an outer insulating resin tube that forms the signal cable 14.

The reinforcing frame 13 is formed by forming a pipe-shaped large diameter portion 13a and a small diameter portion 13b by drawing a metal member having a predetermined thickness. The large diameter part 1
Reference numeral 3a is fitted and arranged on the outer periphery of the element frame 12, and the front end is hermetically fixed by soldering. On the other hand, the signal cable 14 is provided in the inner hole of the small diameter portion 13b.
A seal ring 26 made of, for example, synthetic rubber such as fluorine rubber is press-fitted. Thus, the inside and the outside of the reinforcing frame 13 are sealed. At the time of assembling, a more reliable sealing state can be obtained by crushing (caulking) the small diameter portion 13b.

The solid-state imaging device 12 and the imaging circuit board 23 disposed in the large-diameter portion inner space of the reinforcing frame 13 are sealed with a thermoplastic resin 29. The thermoplastic resin 29 is a material having temperature resistance during high-pressure high-temperature steam sterilization, for example, a styrene-based polymer or the like. Before disposing the seal ring 26 at a predetermined position of the small-diameter portion 13b, And the signal cable 14
A predetermined pressure is applied from the gap formed by
3 is injected and injected.

As described above, since the frame is made of a metal reinforcing frame, it is possible to reliably prevent high-pressure and high-temperature steam from passing through the frame that covers the solid-state imaging device and the like. The mechanical strength of the endoscope imaging unit can be greatly improved.

Further, since the reinforcing frame and the element frame are hermetically fixed by metal bonding, the thermoplastic resin can be injected and injected into the frame by applying pressure. Can be uniformly filled to prevent the occurrence of nests, and the high-pressure, high-temperature steam can be reliably prevented from entering the frame through the gap between the reinforcing frame and the element frame.

Further, since the joining position between the reinforcing frame and the element frame is set at a position away from the solid-state image pickup device, it is possible to prevent the heat at the time of metal joining from being conducted to the solid-state image pickup device and cause a thermal problem. Can be prevented.

Further, the thermoplastic resin is made of a styrene-based polymer having temperature resistance during high-pressure high-temperature steam sterilization, thereby preventing the thermoplastic resin from being thermally degraded so as to prevent a solid-state image sensor, an image pickup circuit board, etc. Can be protected more stably.

In this embodiment, the reinforcing frame 13 has a circular pipe shape, but may have a square pipe shape.

FIG. 2 is a view for explaining an imaging unit for an endoscope according to a second embodiment of the present invention.

FIG. 2A is a longitudinal sectional view showing the structure of the imaging unit for an endoscope, and FIG. 2B is a sectional view of FIG.
FIG. 2 is a sectional view taken along line AA shown in FIG. Hereinafter, the same members are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 2B, in the imaging unit 1A for an endoscope according to the present embodiment, the reinforcing frame is formed by drawing in the above-described embodiment. For example, the reinforcing frame main body 31 may have a substantially octagonal cross-sectional shape, and a plate-shaped cover member 32 may be disposed in the opening 31a of the reinforcing frame main body 31. The reinforcing frame 30 is formed by integrally fixing the lever member 32 in an airtight manner.

As shown in FIGS. 2A and 2B, one end of the reinforcing frame main body 31 is fitted over the element frame 17 and fixed by, for example, an adhesive. On the other hand, the other end of the reinforcing frame main body 31 is externally fitted to a cable frame 33 having a front end formed in the same cross-sectional shape as the element frame 17 and fixed by, for example, an adhesive.

A pipe portion 33a is provided at the rear end of the cable frame 33, and the outer periphery of the pipe portion 33a is covered with a heat-shrinkable tube 34.
A through hole 33b is formed at a side portion of the pipe portion 33a to communicate the inner hole with the outside and serve as an injection hole.

The thermoplastic resin 29 filled in the reinforcing frame 30 is connected to the heat-shrinkable tube 34 by a pipe 33a.
Before mounting at a predetermined position, injection is performed by applying a predetermined pressure from the through hole 33b. Thus, the same operation and effect as those of the above-described embodiment can be obtained.

Since the reinforcing frame main body 31 is formed by press working, it is possible to accurately process a free sectional shape. Accordingly, as shown in FIG. 2B, the cross-sectional shape can be formed according to the package shape of the solid-state imaging device 12 and the imaging circuit board 23. Thus, the outer shape of the endoscope imaging unit 1A can be formed to a required size. That is, the size of the endoscope imaging unit can be reduced.

The diameter of the inner peripheral surface of the pipe portion 33a is determined by the size of the thermoplastic resin 2 injected and injected between the inner peripheral surface and the outer periphery of the signal cable 14 through a through hole 33b.
The gap 9 is formed so as to allow the air in the reinforcing frame 30 to be discharged to the outside without flowing out of the reinforcing frame 30 to the outside. Further, the reinforcing frame may be configured by joining a plurality of metal members in an airtight manner by welding or the like.

FIG. 3 is a view for explaining an imaging unit for an endoscope according to a third embodiment of the present invention.

As shown in the figure, in the imaging unit 1B for an endoscope of the present embodiment, the thermoplastic resin 29 is formed in advance so as to fit in the internal space of the large diameter portion 13a of the reinforcing frame 13, for example.

That is, the molding of the thermoplastic resin 29 is performed before the reinforcing frame 13 is attached, and a built-in component such as the solid-state imaging device 12 and the imaging circuit board 23 and a molding die (not shown) in which the element frame 17 is disposed. The thermoplastic resin 29 is injected into the internal space to integrally mold the internal components.

Thereafter, the distal end side of the reinforcing frame 13 is externally fitted to the element frame 12 in which the built-in component and the thermoplastic resin 29 are integrated,
The front end side of the reinforcing frame is hermetically fixed by laser welding.

In the present embodiment, the reinforcing frame 13
In the small diameter portion 13b on the base end side of the
An integrated shield 24c folded back to the fifth side is arranged, and this integrated shield 24c is hermetically fixed to the inner peripheral surface of the small diameter portion 13b by soldering.

As described above, the thermoplastic resin is injected in a state where the built-in element frame, the solid-state image sensor, and the like in the assembled state are arranged at the predetermined positions of the molding die, and the predetermined shape sealed in the thermoplastic resin is injected. By forming a built-in part integrally formed by integrating the built-in parts such as the solid-state imaging device 12 and the imaging circuit board 23, the thermoplastic resin is injected at a higher pressure during injection molding to eliminate air bubbles. It can be nestless.

In addition, since the overall shield and the reinforcing frame are electrically fixed to each other by hermetic bonding such as soldering, it is possible to more reliably prevent high-pressure, high-temperature steam from entering the inside of the reinforcing frame, and to further enhance the strength of the reinforcing frame. The body is electrically conducted by the overall shield, and can have a shielding effect against electromagnetic waves and the like.

Other functions and effects are the same as those of the above-described embodiment.

It should be noted that the present invention is not limited to only the above-described embodiments, and various modifications can be made without departing from the gist of the invention.

[Appendix] According to the embodiment of the present invention described in detail above, the following configuration can be obtained.

(1) A solid-state imaging device to which an imaging circuit board is connected, an objective lens unit for forming a subject image on the solid-state imaging device, a holding frame for holding the objective lens unit and the solid-state imaging device, In an imaging unit for an endoscope, comprising: an imaging circuit board; and a frame forming an internal space in which the solid-state imaging device is disposed, wherein the frame is formed of a metal member, and a solid disposed in the frame internal space. An imaging unit for an endoscope in which a built-in component such as an imaging element and an imaging circuit board is sealed with a thermoplastic resin injected at a predetermined pressure.

(2) The imaging unit for an endoscope according to Appendix 1, wherein the thermoplastic resin is a styrene-based polymer having temperature resistance during autoclave sterilization.

(3) The imaging unit for an endoscope according to appendix 1, wherein the frame is formed by drawing.

(4) The imaging unit for an endoscope according to appendix 1, wherein the frame is formed by air-tightly joining a plurality of members.

(5) The imaging unit for an endoscope according to appendix 1, wherein the thermoplastic resin is injected into the frame at a predetermined pressure to seal internal components such as a solid-state imaging device and an imaging circuit board.

(6) The imaging for an endoscope according to appendix 1, wherein the thermoplastic resin is injected into a predetermined molding die in which the solid-state image pickup device and the built-in object such as the imaging circuit board are arranged, and the built-in object is integrally molded in advance. unit.

[0049]

As described above, according to the present invention, it is possible to provide an imaging unit for an endoscope having a high-temperature and high-temperature steam sterilization resistance by securely sealing a solid-state imaging device and a circuit board.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an imaging unit for an endoscope according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an imaging unit for an endoscope according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating an imaging unit for an endoscope according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope imaging unit 11 ... Objective lens unit 12 ... Solid-state imaging device 13 ... Reinforcement frame 14 ... Signal cable 16 ... Lens frame 23 ... Imaging circuit board 29 ... Thermoplastic resin

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Yousuke Yoshimoto 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Hidetoshi Saito 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Kogyo Co., Ltd. (72) Inventor Yasuyuki Futaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. 2 Olympus Optical Co., Ltd. (72) Inventor Hiroyuki Nagami 2-43 Hatagaya, Shibuya-ku, Tokyo No. 2 Inside Olympus Optical Co., Ltd. (72) Inventor Seiichi Higuma 2-43-2 Hatagaya, Shibuya-ku, Tokyo F-term inside Olympus Optical Co., Ltd. 2H040 BA24 CA21 DA12 GA03 4C061 CC06 FF35 JJ03 JJ06 JJ13 LL01

Claims (2)

[Claims] A solid-state imaging device to which an imaging circuit board is connected; an objective lens unit for forming a subject image on the solid-state imaging device; a holding frame for holding the objective lens unit and the solid-state imaging device; An imaging unit for an endoscope, comprising: an imaging circuit board; and a frame forming an internal space in which the solid-state imaging device is arranged. The solid-state imaging device, wherein the frame is formed of a metal member and is disposed in the frame internal space. An imaging unit for an endoscope, wherein a built-in element such as an element and an imaging circuit board is sealed with a thermoplastic resin injected at a predetermined pressure. 2. The imaging unit for an endoscope according to claim 1, wherein the thermoplastic resin is a styrene-based polymer having temperature resistance during autoclave sterilization.