JP2005204908A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope in which a high frequency current generated from a high frequency treating implement is prevented from reaching the inside of the endoscope even when the high frequency treating implement is used at the time of treatment in the endoscope for which a lens is fixed to an insertion part tip by using a lens frame composed of a conductive material and a molten metal material. <P>SOLUTION: The endoscope comprises: the lens frame composed of the conductive material and arranged at the insertion part tip; a glass lens fitted to the tip part of the lens frame; and the molten metal material made to flow into a clearance between the inner periphery of the lens frame and the outer periphery of the glass lens. In the endoscope, a back annular part where a metallization processing is executed positioned at the back part of the lens frame and a front annular part where it is not executed are formed in two divisions in an axial direction on the outer peripheral surface of the glass lens, the molten metal material is made to flow into the clearance between the back annular part and the lens frame, the front annular part is fitted to the housing hole part of a cover material composed of an insulating material, and the lens frame and the molten metal material are prevented from being exposed to the outside of the endoscope by the cover material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a structure around an objective lens of an endoscope.

  A plurality of lens holes are usually formed at the distal end of the insertion portion of the endoscope, and a substantially cylindrical metal lens frame is fitted and fixed in these lens holes, and an observation optical system or An optical system such as an illumination optical system (light distribution lens) is fitted. Furthermore, in recent years, it has become common to sterilize after the use of an endoscope, and autoclave sterilization that can be completed in several tens of minutes is more convenient than EOG sterilization, which requires several hours for sterilization. It is desired to be able to cope with autoclave sterilization. For this reason, the lens that is positioned at the tip of the optical system of the endoscope and is exposed to the outside of the endoscope is a glass lens having excellent heat resistance, and an annular shape formed between the outer periphery of the glass lens and the inner periphery of the lens frame. A molten metal material is poured into the clearance, and a glass lens is joined to the lens frame with the molten metal material (for example, Patent Document 1 and Patent Document 2).

The glass lens is not melted or deformed by the high-temperature and high-pressure gas in the autoclave, and the high-temperature and high-pressure gas enters the endoscope from between the outer periphery of the glass lens and the inner periphery of the lens frame by the molten metal material. Therefore, the endoscope having such a configuration can cope with autoclave sterilization.
JP 2000-60793 A JP 2000-70214 A

  However, in the above prior art, the metal lens frame and the molten metal material are exposed at the distal end surface of the insertion portion. Therefore, if a high-frequency treatment instrument is used during treatment with an endoscope, a high-frequency current generated from the high-frequency treatment instrument is used. However, there is a possibility of affecting the electrical component (for example, CCD) that is built into the endoscope through the lens frame and the molten metal material and is built in the endoscope.

  An object of the present invention is an endoscope in which a lens frame made of a conductive material or a molten metal material is used to fix a lens to the distal end of an insertion portion. An object of the present invention is to provide an endoscope in which high-frequency current does not reach the inside of the endoscope.

  The endoscope of the present invention includes a lens frame made of a conductive material disposed at the distal end of the insertion portion; a glass lens fitted to the distal end portion of the lens frame; and between the inner periphery of the lens frame and the outer periphery of the glass lens. In an endoscope having a molten metal material that has flowed into the clearance of the glass lens, the outer peripheral surface of the glass lens is bifurcated in the axial direction and is subjected to a metallization process located in the inner part of the lens frame. A cover material made of an insulating material, and a molten metal material flowing into the clearance between the inner annular portion and the lens frame. The lens frame and the molten metal material are not exposed to the outside of the endoscope by the cover material.

  A fitting recess having a diameter larger than that of the glass lens and capable of fitting the glass lens is formed at the tip of the lens frame, an annular taper portion is formed in an inner peripheral back portion of the fitting recess, and It is preferable to form an annular tapered portion having a shape corresponding to the annular tapered portion on the outer periphery of the rear end of the inner annular portion. In this way, the glass lens can be easily positioned with respect to the lens frame by fitting the annular tapered portion of the inner annular portion with the annular tapered portion of the fitting recess.

  In order to improve the durability of the molten metal material, the molten metal material may be composed of gold and tin.

  According to the present invention, even when a high-frequency treatment instrument is used during treatment, a high-frequency current generated from the high-frequency treatment instrument is prevented from reaching the inside of the endoscope.

Hereinafter, an embodiment in which the present invention is applied to an electronic endoscope 10 will be described with reference to the accompanying drawings.
An electronic endoscope 10 illustrated in FIG. 1 includes an operation unit 11 and an insertion unit 12, and a bending unit 12 a of the insertion unit 12 is vertically and horizontally depending on the operation of a bending operation device 13 provided in the operation unit 11. To curve.
A universal tube 14 extends from the operation portion 11, and a connector portion 14 a is connected to the free end of the universal tube 14. The connector 14a is provided with an insertion protrusion 14b. The insertion protrusion 14b is inserted into an insertion port 15b provided in a case 15a of a processor 15 incorporating a light source device (not shown). It can be inserted and removed.

A light guide fiber 16 is disposed inside the insertion protrusion 14 b, the connector part 14 a, the universal tube 14, the operation part 11, and the insertion part 12.
As shown in FIG. 2, the distal end member 12b made of a hard insulating material constituting the distal end of the insertion portion 12 has a light guide fiber insertion hole 12c extending in the longitudinal direction from the rear end to immediately after the front end. A substantially cylindrical lens frame 17 is fitted and fixed to the tip of the light guide fiber insertion hole 12c. The distal end portion of the light guide fiber 16 is inserted into the light guide fiber insertion hole 12 c and the lens frame 17, and the emission end surface formed at the distal end of the light guide fiber 16 is the light distribution lens 18 supported by the lens frame 17. It is connected to the. Further, as shown in FIGS. 2 and 4, a small-diameter lens hole 19 communicating with the light guide fiber insertion hole 12 c is formed on the distal end surface of the distal end member 12 b, and the small-diameter lens hole 19 and the lens frame 17 are formed in the small-diameter lens hole 19 and the lens frame 17. The rear part of the light distribution lens 20 located immediately before the light distribution lens 18 is fitted. The rear outer peripheral surface of the light distribution lens 20 is metallized, and this portion is joined to the lens frame 17 in a watertight state by a molten metal material M1, and the illumination optical system is formed by both the light distribution lenses 18 and 20. Composed.

  As shown in FIGS. 2 and 4, the tip member 12b has a large-diameter lens hole 21 having a circular cross section that penetrates the tip member 12b in the longitudinal direction. A large cylindrical lens frame 22 made of metal is fitted and fixed in the large-diameter lens hole 21, and an observation optical system LG and a CCD 37 are provided in the lens frame 22. Further, a cover material C made of plastic having insulating properties and heat resistance against the autoclave, which is positioned immediately before the lens frame 22, is fitted into the large-diameter lens hole 21 so as to surround the outer periphery of the glass lens L1.

  When the insertion projection 14b of the electronic endoscope 10 having such a configuration is connected to the insertion port 15b of the processor 15 and the light source device built in the processor 15 is turned on, the light generated by the light source device is guided. The light is irradiated from the light distribution lenses 18 and 20 to the outside of the electronic endoscope 10 through the fiber 16. Then, an image obtained via the observation optical system LG is displayed on a television monitor (not shown) connected to the processor 15.

Next, the lens frame 22 and the observation optical system LG, the CCD 37, and the cover material C provided therein will be described in detail.
A constant-diameter fitting hole (fitting concave portion) 23 having a constant diameter at all positions in a circular shape when viewed from the front and in the axial direction is formed at the tip of the inner periphery of the lens frame 22. Immediately after the portion 23, a stopper flange 24 having an annular shape in front view and an inner diameter smaller than that of the constant-diameter fitting hole portion 23 is formed. And between the fixed diameter fitting hole part 23 and the stopper flange 24, the cyclic | annular taper part 25 of the circular front view straddling both is formed. A lens group holding hole 26 having a diameter larger than the inner diameter of the stopper flange 24 is formed immediately after the stopper flange 24, and immediately after the lens group holding hole 26, the lens group holding hole 26 has a diameter larger than that of the lens group holding hole 26. The screw hole 27 is formed. Further, immediately after the screw hole 27, a CCD holding hole 28 having a larger diameter than the screw hole 27 and circular in front view is formed, and all the holes 23, 26, 27, 28, the stopper flange 24 and the annular taper portion 25 are formed. Are concentric with each other. Further, an annular recess 22 c is formed on the outer periphery of the front end of the lens frame 22.

  A front-view circular glass lens L1, which is a front end lens of the observation optical system LG, has a constant diameter front annular portion L1a and a larger diameter and a constant diameter than the front annular portion L1a located behind the front annular portion L1a. A rear annular portion L1b having a constant diameter smaller than the fitting hole portion 23, and an annular tapered portion L1c having a shape corresponding to the annular tapered portion 25 formed on the outer periphery of the rear end of the inner annular portion L1b. As shown in FIG. 5, the entire outer periphery of the back annular portion L1b is subjected to metallization processing (the hatched portion).

  The rear part of the cover material C is a cylindrical fitting part C1 that can be fitted into the annular recess 22c in a watertight state, and the front part can be fitted into the outer periphery of the front annular part L1a of the glass lens L1 in a watertight state. A storage hole C2 is formed.

The observation optical system LG and the CCD 37 are attached to the lens frame 22 before being fitted and fixed in the large-diameter lens hole 21 by the following procedure.
First, the rear end surface of the lens frame 22 (the end surface opposite to the side on which the constant-diameter fitting hole 23 is provided) is placed on a horizontal surface such as a workbench, and the front end surface of the lens frame 22 faces upward. Turn. Then, the glass lens L1 is dropped from the front opening 22a of the lens frame 22 into the constant diameter fitting hole 23, the annular tapered portion L1c is fitted into the annular tapered portion 25, and the rear surface thereof is brought into contact with the stopper flange 24. . Then, the glass lens L1 is positioned with respect to the lens frame 22, and the optical axis of the glass lens L1 coincides with the central axis of the lens frame 22.

  In this state, the molten metal material M2 made of gold and tin is poured into the entire annular clearance formed between the constant diameter fitting hole 23 and the outer periphery of the inner annular portion L1b of the glass lens L1, and the molten metal material M2 The glass lens L1 and the constant diameter fitting hole 23 are joined. Since the portion facing the constant diameter fitting hole 23 on the outer periphery of the glass lens L1 is subjected to metallization, the glass lens L1 is firmly joined to the constant diameter fitting hole 23, and the glass lens L1 and the constant diameter are fixed. The space between the fitting holes 23 is in a watertight state.

Next, the lens frame 22 is turned upside down, the front end face thereof is placed on the horizontal plane, and the rear end face is directed upward.
In this state, the three lenses 29, 30, 31, the annular spacers 32, 33, and the color correction filter 34 are dropped into the lens frame 22 from the rear opening 22b of the lens frame 22, and these members are held in the lens group. The front lens 29 is fitted into the hole 26, the front surface of the lens 29 is brought into contact with the stopper flange 24, and adjacent members are brought into contact with each other. All of these members 29, 30, 31, 32, 33, and 34 have the same outer diameter as the lens group holding hole 26 and are circular in front view, so that the entire outer peripheral surface contacts the lens group holding hole 26. The optical axes of the lenses 29, 30, and 31 coincide with the optical axis of the glass lens L1 (coincides with the central axis of the lens frame 22).

  Next, an annular holding screw 35 is dropped into the lens frame 22 from the rear opening 22b, and a screw portion 35a formed on the outer periphery of the holding screw 35 is screwed into the screw hole 27 so that the front surface of the holding screw 35 is a color correction filter. 34 is brought into contact with the rear surface. Thus, the observation optical system LG is constituted by the glass lens L1 supported by the lens frame 22 and the lenses 29, 30, and 31.

Next, the distal end portion of the CCD cable 36 extending into the electronic endoscope 10 from the insertion protrusion 14b to the insertion portion 12 is pulled out from the distal end of the large-diameter lens hole 21 to the outside of the electronic endoscope 10, and then the CCD cable. An electrical substrate 37a connected to the tip of 36 and a CCD (imaging device) 37 connected to the electrical substrate 37a are fitted and fixed to the CCD holding hole 28 from the rear opening 22b, and the CCD 37 is immediately after the color correction filter 34. To be located. And as shown in FIG. 2, the front-end | tip part of CCD cable 36 is joined to the lens frame 22 with the adhesive agent S1.
Finally, the fitting part C1 of the cover material C is fitted into the annular recess 22c in a watertight state, and the storage hole C2 is fitted into the outer periphery of the front annular part L1a of the glass lens L1 in a watertight state.

When the integration of the lens frame 22 and the cover material C is completed in this way, the lens frame 22 is fitted into the large-diameter lens hole 21 from the rear end side, and the front end surface of the cover material C is set to the front end surface of the front end member 12b. And continue. Then, the space between the cover material C and the large-diameter lens hole 21 is in a watertight state, and the molten metal material M2 and the lens frame 22 are not exposed to the outside of the electronic endoscope 10.
Further, as shown in FIG. 2, the rear end portion of the lens frame 22 and the CCD cable 36 are joined to the inner peripheral surface of the insertion portion 12 with an adhesive S2.

  Thus, in this embodiment, the cover material C made of an insulating material is fitted into the large-diameter lens hole 21, and the molten metal material M 2 and the metal lens frame 22 are connected to the electronic endoscope 10 by the cover material C. Since it is not exposed to the outside, even if a high-frequency treatment instrument is used during the treatment of the electronic endoscope 10, the high-frequency current generated from the high-frequency treatment instrument is electronically viewed through the molten metal material M2 and the lens frame 22. There is no transmission inside the mirror 10. Therefore, there is no possibility that electrical components such as the CCD 37 disposed in the electronic endoscope 10 are affected by the high frequency current.

  Although solder or the like can be used as the molten metal material M2, if the molten metal material M2 made of gold and tin is used as in the present embodiment, durability against autoclave sterilization is improved.

In the present embodiment, the present invention is applied to the observation optical system LG, but it is of course possible to apply the present invention to the illumination optical system (light distribution lens) side.
Further, the cover material C may be formed integrally with the tip member 12b.

1 is an overall view showing an electronic endoscope and a processor according to an embodiment of the present invention. It is the expanded sectional view which follows the II-II line of FIG. Similarly, it is an enlarged sectional view showing a state in which the lens frame, the observation optical system and its peripheral members are taken out from the electronic endoscope. It is a front view of the front end surface of an insertion part similarly. It is the expansion perspective view which looked at the glass lens from back.

Explanation of symbols

10 Electronic endoscope (endoscope)
DESCRIPTION OF SYMBOLS 11 Operation part 12 Insertion part 12a Bending part 12b Tip member 12c Light guide fiber insertion hole 13 Bending operation apparatus 14 Universal tube 14a Connector part 14b Insertion protrusion 15 Processor 15a Case 15b Insertion port 16 Light guide fiber 17 Lens frame 18 Light distribution lens (illumination optical system)
19 Small-diameter lens hole 20 Light distribution lens (illumination optical system)
21 Large-diameter lens hole 22 Lens frame 22a Front side opening 22b Rear side opening 22c Annular recess 23 Constant diameter fitting hole (recess for fitting)
24 Stopper flange 25 Annular taper portion 26 Lens group holding hole 27 Screw hole 28 CCD holding hole 29 30 31 Lens (observation optical system)
32 33 Annular spacer 34 Color correction filter 35 Holding screw 35a Screw part 36 CCD cable 37 CCD (imaging device)
37a Electric board C Cover material C1 Fitting part C2 Storage hole part L1 Glass lens L1a Front annular part L1b Back annular part L1c Annular taper part LG Observation optical system M1 M2 Molten metal material S1 S2 Adhesive

Claims (3)

A lens frame made of a conductive material disposed at the distal end of the insertion portion;
A glass lens fitted to the tip of the lens frame; and a molten metal material introduced into the clearance between the inner periphery of the lens frame and the outer periphery of the glass lens;
In an endoscope having
The outer peripheral surface of the glass lens is divided into two in the axial direction, and a rear annular portion that has been subjected to metallization processing and a front annular portion that is not applied, which are located in the inner portion of the lens frame,
Allowing the molten metal material to flow into the clearance between the inner annular portion and the lens frame;
The front annular portion is fitted into a housing hole of a cover material made of an insulating material so that the lens frame and the molten metal material are not exposed to the outside of the endoscope by the cover material. Endoscope. The endoscope according to claim 1, wherein a fitting recess having a diameter larger than that of the glass lens and capable of fitting the glass lens is formed at a distal end portion of the lens frame, and an inner peripheral back portion of the fitting recess. An endoscope in which an annular taper portion is formed and an annular taper portion having a shape corresponding to the annular taper portion is formed on the outer periphery of the rear end of the inner annular portion. The endoscope according to claim 1 or 2, wherein the molten metal material is made of gold and tin.

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