JP2005204830A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope capable of coping with autoclave sterilization, for which a glass lens provided on an insertion part tip and exposed to the outside of the endoscope can be easily positioned to a lens frame and joined to the lens frame by using a molten metal material in the state of being positioned. <P>SOLUTION: The endoscope comprises: the lens frame arranged at the insertion part tip; the 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, between the lens frame and the glass lens, a mechanical positioning and fitting part for both positioned at the back part of the lens frame is provided, and an annular clearance part where the molten metal material is to be made to flow in is provided on the front part of the positioning and fitting part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an endoscope objective lens.

  A plurality of lens holes are usually formed at the distal end of the insertion portion of the endoscope, and a substantially cylindrical lens frame is fitted and fixed in these lens holes, and an observation optical system and illumination optics are placed in the lens frame. An optical system such as a 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 located 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 formed between the glass lens outer periphery and the lens frame inner periphery. A molten metal material is poured into the clearance, and a glass lens is bonded to the lens frame with the molten metal material (for example, Patent Document 1).

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

  In order for the glass lens to exhibit desired lens performance, it is necessary to fix the glass lens at a predetermined position in the lens frame. However, before the glass lens and the lens frame are joined using the molten metal material, an annular clearance exists between the two, so that the glass lens can move in the radial direction within the lens frame. Therefore, it is difficult to join the glass lens to the lens frame using a molten metal material in a state where the glass lens is positioned at a predetermined position in the lens frame.

  As another example of an endoscope that can handle autoclave sterilization, the outer diameters of all the lenses constituting the optical system are the same as those of the lens frame. There is also a case in which a cover glass (glass window) located in front is fitted in a watertight state. With such a configuration, each lens is positioned in the radial direction with respect to the lens frame, so that the desired lens performance can be exhibited, and further, the space between the cover glass and the lens frame is watertight. High-temperature and high-pressure gas in the autoclave does not enter the endoscope from the endoscope tip.

  However, when the cover glass is arranged in front of the lens positioned at the tip in this way, for example, when the optical system is an observation optical system, the viewing angle becomes narrow, and in the case of an illumination optical system, the light emitted from the cover glass is reduced. There arises a problem that the emission angle becomes narrow.

  It is an object of the present invention to easily position a glass lens exposed to the outside of an endoscope provided at the distal end of an insertion portion with respect to a lens frame, and use a molten metal material in the positioned state. An object of the present invention is to provide an endoscope capable of being sterilized by autoclave that can be joined to a frame.

  The endoscope of the present invention includes a lens frame disposed at the distal end of the insertion portion; a glass lens fitted to the distal end portion of the lens frame; and a clearance between the inner periphery of the lens frame and the outer periphery of the glass lens. In the endoscope having the molten metal material, a mechanical positioning fitting portion of both of them located in the back of the lens frame is provided between the lens frame and the glass lens, and the positioning fitting is performed. An annular clearance portion for allowing the molten metal material to flow in is provided in front of the joint portion.

  When the metallization process is performed on the entire cylindrical outer peripheral surface of the glass lens, the bonding force by the molten metal material is improved.

The positioning fitting portion and the annular clearance portion can be configured as follows, for example.
As a first example, the lens frame has a small-diameter hole portion having a stopper flange with which the glass lens can abut on the back, and a large diameter larger than the small-diameter hole portion provided in front of the small-diameter hole portion. A diameter hole portion, and the glass lens has a constant diameter that is the same diameter as the small diameter hole portion, and the positioning fitting portion is configured by the small diameter hole portion and the glass lens outer periphery, and the large diameter hole portion And the said annular clearance part is comprised by the said glass lens outer periphery.

  As a second example, a constant-diameter fitting hole portion having a fixed diameter and a stopper flange with which the glass lens abuts at the back is formed in the lens frame, and the glass lens is formed in the constant-diameter fitting hole portion. It has a large diameter portion having the same diameter as the constant diameter fitting hole portion to be fitted, and a small diameter portion smaller in diameter than the large diameter portion provided in front of the large diameter portion. The positioning fitting portion is constituted by the large diameter portion, and the annular clearance portion is constituted by the constant diameter fitting hole portion and the small diameter portion.

  As a third example, the lens frame has a constant diameter fitting hole portion having a fixed diameter and a stopper flange with which the glass lens is in contact with the back portion, and the stopper flange around the back portion of the constant diameter fitting hole portion. An annular taper portion formed across the glass tape is formed, and the glass lens has an annular taper portion corresponding to the annular taper portion and a constant diameter portion having a smaller diameter than the constant diameter fitting hole portion. The positioning fitting portion is constituted by the annular tapered portion of the lens frame and the glass lens, and the annular clearance portion is constituted by the constant diameter fitting hole portion and the constant diameter portion.

  As a fourth example, the lens frame includes a frame main body having a caulking portion for caulking the rear portion of the glass lens, and a decorative frame body coupled to the frame main body so as to surround the caulking portion and the outer periphery of the glass lens. The positioning fitting portion is constituted by the caulking portion and the rear portion of the glass lens, and the annular clearance portion is constituted by the decorative frame body and the outer periphery of the glass lens.

  According to the present invention, the glass lens exposed to the outside of the endoscope provided at the distal end of the insertion portion can be easily positioned with respect to the lens frame, and the lens frame is formed using the molten metal material in the positioned state. Can be joined.

Hereinafter, a first embodiment in which the present invention is applied to an electronic endoscope 10 will be described with reference to FIGS.
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 material constituting the distal end of the insertion portion 12 is provided with 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 optical 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 12c is formed on the distal end surface of the distal end member 12b, and the small diameter lens hole and the lens frame 17 include: A light distribution lens 20 positioned immediately before the light distribution lens 18 is fitted and fixed in a watertight state by a molten metal material M1 such as solder, and the light distribution lenses 18 and 20 constitute an illumination optical system.

  As shown in FIGS. 2 and 4, the tip member 12b is formed with a large-diameter lens hole (lens hole) 21 having a circular cross section that penetrates the tip member 12b in the longitudinal direction. A substantially cylindrical lens frame 22 made of a heat-resistant material such as metal is fitted and fixed in the large-diameter lens hole 21 in a watertight state, and an illumination optical system LG and a CCD 37 are provided in the lens frame 22. .

  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 and CCD 37 provided therein will be described in detail.
A large-diameter hole 23 having a circular shape when viewed from the front is formed on the inner periphery of the lens frame 22, and a small diameter having a smaller diameter than the large-diameter hole 23 and a circular shape when viewed from the front is formed immediately after the large-diameter hole 23. A hole 24 is formed, and immediately after the small-diameter hole 24, a stopper flange 25 having an annular shape in front view and an inner diameter smaller than that of the small-diameter hole 24 is formed. A lens group holding hole 26 having a diameter larger than the inner diameter of the stopper flange 25 is formed immediately after the stopper flange 25. The lens group holding hole 26 has a diameter larger than that of the lens group holding hole 26 and circular when viewed from the front. The screw hole 27 is formed. Further, immediately after the screw hole 27, a CCD holding hole 28 having a diameter larger than that of the screw hole 27 and circular in front view is formed, and all the holes 23, 24, 26, 27, 28 and the stopper flange 25 are concentric with each other. I am doing.

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 large-diameter hole portion 23 is provided) is placed on a horizontal surface such as a work table, and the front end surface of the lens frame 22 faces upward. Then, a glass lens L1 having a circular shape in front view and the same outer diameter as that of the small-diameter hole 24 is dropped into the small-diameter hole 24 from the front opening 22a of the lens frame 22 and brought into contact with the stopper flange 25. When the glass lens L1 is thus fitted into the small diameter hole 24, the optical axis of the glass lens 39 automatically coincides with the central axis of the lens frame 22 (positioning is performed).
In this state, the molten metal material M2 made of gold and tin is poured into the entire annular clearance formed between the large-diameter hole 23 and the outer periphery of the glass lens L1, and the molten metal material M2 is cooled, so that the glass lens L1 is cooled. And the large-diameter hole 23 are joined. Since the metal lens is applied to the portion of the outer periphery of the glass lens L1 facing the large-diameter hole 23, the glass lens L1 is firmly bonded to the large-diameter hole 23, and the glass lens L1 and the large-diameter hole 23 are The space becomes watertight.
A positioning fitting portion is constituted by the small diameter hole portion 24 and the outer periphery of the glass lens L1, and an annular clearance portion is constituted by the large diameter hole portion 23 and the outer periphery of the glass lens L1.

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. It fits into the hole 26, the front surface of the leading lens 29 is brought into contact with the stopper flange 25, 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 CCD cable 36 extending into the electronic endoscope 10 from the insertion protrusion 14 b to the insertion portion 12 is pulled out from the tip of the large diameter lens hole 21 to the outside of the electronic endoscope 10, and the tip of the CCD cable 36 is drawn. The electrical substrate 37a connected to the electrical substrate 37 and the 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 positioned immediately after the color correction filter 34. . 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.

  When the integration of the lens frame 22 and the CCD 37 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 surface of the lens frame 22 and the front end surface of the front end member 12b are made continuous. . Further, as shown in FIG. 2, the rear end portion of the lens frame 22 and the CCD cable 36 are bonded to the inner peripheral surface of the insertion portion 12 with an adhesive S2.

Thus, according to this embodiment, if the glass lens L1 exposed to the outside of the electronic endoscope 10 is fitted into the small diameter hole 24, the glass lens L1 is positioned with respect to the lens frame 22, The glass lens L1 can be joined to the lens frame 22 by the molten metal material M2 in a state where the optical axis of the glass lens L1 is aligned with the center axis of the lens frame 22 (large diameter lens hole 21).
In addition, since the glass lens L1, which is the tip lens of the observation optical system LG, is exposed to the outside of the electronic endoscope 10, there is no problem that the viewing angle of the observation optical system LG becomes narrow.
Further, solder or the like can be used as the molten metal material M2, but if the molten metal material M2 made of gold and tin is used as in the present embodiment, durability against autoclave sterilization is improved.

Next, a second embodiment of the present invention will be described with reference to FIG.
In this embodiment, the shape of the lens frame 40 and the glass lens L2 is different from that of the first embodiment, but the other members are the same as those of the first embodiment. Detailed description thereof is omitted.

As in the first embodiment, a stopper flange 25, a lens group holding hole 26, a screw hole 27, and a CCD holding hole 28 are formed on the inner periphery of the lens frame 40. A constant-diameter fitting hole 41 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 40.
The glass lens L2 has a circular shape when viewed from the front, and its rear end portion is a cylindrical large-diameter portion L2a having the same diameter as the constant-diameter fitting hole 41, and the front portion of the large-diameter portion L2a is a constant-diameter fitting hole. The small-diameter portion L2b is smaller in diameter than the portion 41 and is metallized on the outer periphery of the small-diameter portion L2b.
The fixed diameter fitting hole 41 and the large diameter portion L2a constitute a positioning fitting portion, and the constant diameter fitting hole 41 and the small diameter portion L2b constitute an annular clearance portion.
The observation optical system LG is configured by the glass lens L2 and the lenses 29, 30, and 31.

As in the first embodiment, the glass lens L2 is attached to the lens frame 40 before the lenses 29, 30, 31, spacers 32, 33, color correction filter 34, set screw 35, and CCD 37 are attached to the lens frame 40. Installed.
Specifically, the rear end surface of the lens frame 40 is placed on a horizontal surface such as a work table, the front end surface of the lens frame 40 faces upward, and the glass lens L2 is fitted with a constant diameter from the front opening 40a of the lens frame 40. The large-diameter portion L2a is fitted into the constant-diameter fitting hole 41, and its rear surface is brought into contact with the stopper flange 25. Then, since the entire outer periphery of the glass lens L2 comes into contact with the constant diameter fitting hole 41, the glass lens L2 is positioned with respect to the lens frame 40, and the optical axis of the glass lens L2 coincides with the central axis of the lens frame 40. To do.

  Next, the molten metal material M2 is poured into an annular clearance formed between the lens frame 40 and the small diameter portion L2b of the glass lens L2, and the lens frame 40 and the glass lens L2 are joined.

  Thereafter, the lens frame 40 is turned upside down, and the lenses 29, 30, 31, spacers 32, 33, the color correction filter 34, the holding screw 35, and the CCD 37 are attached to the lens frame 40 in the same manner as in the first embodiment. The lens frame 40 is attached to the large-diameter lens hole 21 of the tip member 12b.

In this embodiment, as in the first embodiment, if the large-diameter portion L2a of the glass lens L2 exposed to the outside of the electronic endoscope 10 is fitted into the constant-diameter fitting hole 41, the glass Since the lens L2 is positioned with respect to the lens frame 40, the glass lens L2 is made of the molten metal material M2 in a state where the optical axis of the glass lens L2 is aligned with the central axis of the lens frame 40 (large diameter lens hole 21). Can be bonded to the lens frame 40.
Furthermore, the lens frame 40 of the present embodiment has a fixed-diameter fitting hole portion 41 as a whole that forms a positioning fitting portion. Therefore, the small-diameter hole portion 24 that is a positioning fitting portion has a large-diameter hole portion 23. It is easier to fit the glass lens L2 than the lens frame 22 of the first embodiment located on the back side.

Next, a third embodiment of the present invention will be described with reference to FIG.
In this embodiment, the shape of the lens frame 50 and the glass lens L3 is different from that of the first embodiment, but the other members are the same as those of the first embodiment. Detailed description thereof is omitted.

As in the first embodiment, a stopper flange 25, a lens group holding hole 26, a screw hole 27, and a CCD holding hole 28 are formed on the inner periphery of the lens frame 50. The front end of the inner periphery of the lens frame 50 extends over a constant diameter fitting hole 51 having a constant diameter at all positions in a circular shape in the front view and in the axial direction, and the constant diameter fitting hole 51 and the stopper flange 25. An annular taper portion 52 is formed.
The glass lens L3 having a circular shape in front view has a constant diameter portion L3a whose diameter is smaller than that of the constant diameter fitting hole portion 51 and a constant diameter, and an annular tapered portion having a shape corresponding to the annular tapered portion 52 formed on the outer periphery of the rear end. L3b is provided, and the entire outer periphery of the constant diameter portion L3a is subjected to metallization processing.
The annular taper portions 52 and L3b constitute a positioning fitting portion, and the constant diameter fitting hole portion 51 and the constant diameter portion L3a constitute an annular clearance portion.
Further, the observation optical system LG is configured by the glass lens L3 and the lenses 29, 30, and 31.

As in the first embodiment, the glass lens L3 is attached to the lens frame 50 before the lenses 29, 30, 31, spacers 32, 33, color correction filter 34, set screw 35, and CCD 37 are attached to the lens frame 50. Installed.
Specifically, the rear end surface of the lens frame 50 is placed on a horizontal surface such as a work table, the front end surface of the lens frame 50 faces upward, and the glass lens L3 is fitted with a constant diameter from the front opening 50a of the lens frame 50. The annular taper portion L3b is fitted into the annular taper portion 52, and the rear surface thereof is brought into contact with the stopper flange 25. Then, the glass lens L3 is positioned with respect to the lens frame 50, and the optical axis of the glass lens L3 coincides with the central axis of the lens frame 50.

  Next, the molten metal material M2 is poured into an annular clearance formed between the constant diameter fitting hole 51 and the constant diameter portion L3a, and the lens frame 50 and the glass lens L3 are joined.

  Thereafter, the lens frame 50 is turned upside down, and the lenses 29, 30, 31, spacers 32, 33, the color correction filter 34, the holding screw 35, and the CCD 37 are mounted on the lens frame 50, and the lens frame 50 is attached to the tip member 12b. The large-diameter lens hole 21 is mounted.

Also in this embodiment, as in the first embodiment, if the annular tapered portion L3b of the glass lens L3 exposed to the outside of the electronic endoscope 10 is fitted to the annular tapered portion 52, the glass lens L3 is formed. Since the glass lens L3 is positioned with respect to the lens frame 50, the glass lens L3 is moved to the lens frame by the molten metal material M2 in a state where the optical axis of the glass lens L3 is aligned with the central axis of the lens frame 50 (large diameter lens hole 21). 50.
Furthermore, since the diameter of the constant diameter fitting hole 51 of the lens frame 50 of this embodiment is larger than the diameter of the glass lens L3, it is easy to fit the glass lens L3 into the constant diameter fitting hole 51. There is an advantage that the glass lens L3 can be easily positioned as compared with the first and second embodiments.

Finally, a fourth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, the shapes of the lens frame 60 and the glass lens L4 are different from those of the first embodiment, but the other members are the same as those of the first embodiment. Detailed description thereof is omitted.

The lens frame 60 of the present embodiment includes a frame body 61 and a decorative frame body 62 that are separate from each other.
Similar to the lens frame 22 of the first embodiment, a stopper flange 25, a lens group holding hole 26, a screw hole 27, and a CCD holding hole 28 are formed on the inner periphery of the frame body 61. A front end portion of the inner periphery of the frame main body 61 includes a caulking portion 63 that is concentric with the frame main body 61 and has a circular cylindrical shape when viewed from the front, and an annular step portion 64 that is positioned on the outer peripheral side of the caulking portion 63. .
The rear part of the annular decorative frame 62 is a thin part 62a whose inner diameter is larger than the outer diameter of the caulking part 63, and the front part is a thick part 62b whose inner diameter is smaller than that of the thin part 62a. .

The front portion of the glass lens L4 that is circular in front view is a cylindrical small diameter portion L4a that has a diameter smaller than the inner diameter of the caulking portion 63 and the decorative frame body 62, and a rear portion of the caulking portion 63. The large-diameter portion L4b has a substantially cylindrical shape with the same diameter as the inner diameter, and the entire outer periphery of the small-diameter portion L4a is metalized.
A positioning fitting portion is constituted by the caulking portion 63 and the large diameter portion L4b, and an annular clearance portion is constituted by the small diameter portion L4a and the decorative frame body 62.
Further, an observation optical system LG is constituted by the glass lens L4 and the lenses 29, 30, and 31.

As in the first embodiment, the glass lens L4 is attached to the frame body 61 before the lenses 29, 30, 31, spacers 32, 33, color correction filter 34, set screw 35, and CCD 37 are attached to the frame body 61. Installed.
Specifically, the rear end surface of the frame main body 61 is placed on a horizontal surface such as a work table, the front end surface of the frame main body 61 is directed upward, and the glass lens L4 is inside the caulking portion 63 from the front opening 61a of the frame main body 61. The rear surface of the glass lens L4 is brought into contact with the stopper flange 25. Then, since the entire outer peripheral surface of the large-diameter portion L4b contacts the inner peripheral surface of the caulking portion 63, the glass lens L4 is positioned with respect to the frame main body 61, and the optical axis of the glass lens L4 is the central axis of the frame main body 61. Matches. In this state, when the caulking portion 63 is caulked so as to cover the large diameter portion L4b as illustrated, the glass lens L4 is fixed to the frame body 61.

  Next, the decorative frame body 62 is positioned outside the caulking portion 63, and the decorative frame body 62 is placed on the annular stepped portion 64. Then, since an annular clearance is formed between the inner peripheral surface of the decorative frame body 62 and the caulking portion 63 and the small diameter portion L4a, the molten metal material M2 is poured into this clearance, and the decorative frame body 62, the glass lens L4, And the frame main body 61 is joined to each other.

  Thereafter, the frame main body 61 is turned upside down, and the lenses 29, 30, 31, spacers 32, 33, the color correction filter 34, the holding screw 35, and the CCD 37 are mounted on the frame main body 61, and the frame main body 61 and the decorative frame body are attached. 62 is attached to the large-diameter lens hole 21 of the tip member 12b.

  Also in this embodiment, similarly to the first embodiment, if the glass lens L4 exposed to the outside of the electronic endoscope 10 is fitted in the caulking portion 63, the glass lens L4 is attached to the frame body 61. Therefore, the glass lens L4 is made of the molten metal material M2 so that the optical axis of the glass lens L4 coincides with the central axis of the frame body 61 (large diameter lens hole 21). 62 can be joined.

  Further, after the glass lens L4 is positioned with respect to the frame main body 61, the caulking portion 63 is caulked to fix the glass lens L4, so that the optical axis of the glass lens L4 coincides with the central axis of the frame main body 61. Can be securely held. Therefore, when the glass lens L4 is joined to the frame body 61 and the decorative frame body 62 by the molten metal material M2, the optical axis of the glass lens L4 does not deviate from the center axis of the frame body 61.

  In the present embodiment, the present invention is applied to the observation optical system LG, but it is of course possible to apply it to the illumination optical system (light distribution lens) side.

1 is an overall view showing an electronic endoscope and a processor according to a first 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 an expanded sectional view similar to FIG. 3 of the 2nd Embodiment of this invention. It is an expanded sectional view similar to FIG. 3 of the 3rd Embodiment of this invention. It is an expanded sectional view similar to FIG. 3 of the 4th Embodiment of this invention.

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 (lens hole)
22 Lens frame 22a Front opening 22b Rear opening 23 Large diameter hole (annular clearance)
24 Small-diameter hole (positioning fitting part)
25 Stopper flange 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 38 CCD cable 40 Lens frame 40a Front side opening 41 Constant diameter fitting hole (positioning fitting part) (annular clearance part)
50 Lens frame 51 Constant diameter fitting hole (annular clearance)
52 Annular taper (positioning fitting)
60 Lens frame 61 Frame body 62 Decorative frame (annular clearance)
62a Thin part 62b Thick part 63 Caulking part (positioning fitting part)
64 annular step L1 glass lens (positioning fitting part) (annular clearance part)
L2 Glass lens L2a Large diameter part (positioning fitting part)
L2b Small diameter part (annular clearance part)
L3 Glass lens L3a Constant diameter part (annular clearance part)
L3b Annular taper (positioning fitting)
L4 glass lens (positioning fitting part) (annular clearance part)
L4a Small diameter portion L4b Large diameter portion LG Observation optical system M1 M2 Molten metal material S1 S2 Adhesive

Claims (6)

A lens frame disposed at the distal end of the insertion section;
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
Between the lens frame and the glass lens, there is provided a mechanical positioning fitting portion located at the back of the lens frame, and an annular shape for allowing the molten metal material to flow in front of the positioning fitting portion. An endoscope having a clearance portion. The endoscope according to claim 1, wherein
The glass lens is an endoscope in which a metallization process is applied to a cylindrical outer peripheral surface. The endoscope according to claim 1 or 2,
The lens frame includes a small-diameter hole portion having a stopper flange with which the glass lens can abut on the back, and a large-diameter hole portion provided in front of the small-diameter hole portion and having a larger diameter than the small-diameter hole portion. The glass lens has a constant diameter that is the same diameter as the small-diameter hole portion, and the positioning fitting portion is constituted by the small-diameter hole portion and the outer periphery of the glass lens. The large-diameter hole portion and the glass lens An endoscope in which the annular clearance portion is formed by an outer periphery. The endoscope according to claim 1 or 2,
The lens frame is formed with a constant diameter fitting hole having a fixed diameter and a stopper flange with which the glass lens abuts at the back, and the glass lens is fitted into the constant diameter fitting hole. A large diameter portion having the same diameter as the constant diameter fitting hole portion, and a small diameter portion having a smaller diameter than the large diameter portion provided in front of the large diameter portion, and the constant diameter fitting hole portion and the large diameter An endoscope in which the positioning fitting portion is formed by a portion, and the annular clearance portion is formed by the constant diameter fitting hole portion and the small diameter portion. The endoscope according to claim 1 or 2,
The lens frame has a constant-diameter fitting hole portion having a fixed diameter and a stopper flange with which the glass lens is in contact with the back portion, and the stopper flange around the back portion of the constant-diameter fitting hole portion. The glass lens has an annular tapered portion corresponding to the annular tapered portion and a constant diameter portion having a smaller diameter than the constant diameter fitting hole portion, and the lens frame and the glass. An endoscope in which the positioning fitting portion is formed by the annular tapered portion of the lens, and the annular clearance portion is formed by the constant diameter fitting hole portion and the constant diameter portion. The endoscope according to claim 1 or 2,
The lens frame includes a frame main body having a caulking portion for caulking a rear portion of the glass lens, and a decorative frame body coupled to the frame main body so as to surround the caulking portion and the outer periphery of the glass lens. An endoscope in which the positioning fitting portion is formed by the rear portion of the glass lens and the annular clearance portion is formed by the outer periphery of the decorative frame body and the glass lens.

Images