JPH03145616A - Hard endoscope - Google Patents

Abstract

PURPOSE:To fix an optical tube to a main body part without applying any forcible force to the optical tube by moving a fixation member forward in the axial direction of a relay optical system and pressing the tapered surface of a pressure ring and the tapered surface of a clamping ring against each other. CONSTITUTION:When a washer 31 is pressed against a tip end side with a clamping ring 30, the taper 30a and the taper 29a of the pressure ring 29 are joined together, the pressure ring 29 is pressed against the step 3e of the main body part 3, and the clamping ring 30 is reduced in diameter in its internal- diameter direction by receiving a force for contraction in the internal-diameter direction to clamp the outer peripheral part of a lens tube pressure cylinder 27. The pressure ring 29, clamping ring 30, and washer 31, on the other hand, are pressed by the step 3e and a clamping screw 32 and fixed to the main body part 3, so the lens tube pressure cylinder 27 is fixed to the main body part 3. Consequently, relay optical system components can be fixed to the main body part 3 without applying any forcible force to the relay optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a rigid endoscope that uses a relay optical system as a means for transmitting an image from an objective section to an eyepiece section.

[Prior Art] As shown in, for example, Japanese Unexamined Patent Publication No. 57-129407, a rigid endoscope consists of a push-in part and a main body part connected to the proximal end of the push-in part. It is made of hard double tubes. A light guide fiber is inserted between the inner tube and the outer tube of the double tube, and an optical tube into which a relay optical system consisting of a relay lens is inserted is inserted into the inner tube. The proximal end of the outer tube is fixed to the narrow diameter part of the main body with a bottom metal, and the optical tube protrudes to the hollow part of the main body, and a fixing frame is fitted to the proximal end of the optical tube. are combined. Further, an adjustment frame is fitted into the fixed frame, and a frame for attaching the eyepiece lens is housed in the adjustment frame.

That is, the proximal end of the optical tube protrudes into the hollow part of the main body, and a fixed frame and an adjustment frame for supporting the lens mounting frame and the eyepiece are attached to the end of the proximal end. Therefore, with only the optical tube consisting of a thin-walled pipe into which the relay optical system is inserted, the fixed frame, adjustment frame, eyepiece lens attached to this frame, and lens mounting support the frame, reducing the weight of the eyepiece optical system, etc. It is directly connected to the optical tube.

As mentioned above, if the structure is such that the fixed frame, adjustment frame, and eyepiece optical system are supported only by an optical tube consisting of a thin-walled pipe with a relay optical system inserted therein, vibrations that may be applied during use or transportation of the rigid endoscope may occur. etc., a bending force is applied to the optical tube, and a bending force is also applied to the relay optical system inserted inside the optical tube.

Therefore, damage such as bending or chipping may occur in the relay optical system.

In order to solve the above-mentioned problems, it is sufficient to fix the fixing frame to the eyepiece connection part of the main body part, but generally, the fixation frame is fixed to the eyepiece connection part of the main body part and the outer tube of the insertion part. The diameter portion has eccentricity due to tolerances during processing, the outer diameter and inner diameter of the outer tube of the insertion portion also have eccentricity due to uneven pipe thickness during drawing processing, and the optical tube similarly has eccentricity.

When these eccentricities are integrated, the amount of eccentricity between the eyepiece connecting portion of the main body and the optical tube may become so large that it cannot be ignored.

In addition, if the fixing frame of the optical tube is fixed to the eyepiece connection part of the main body while eliminating the eccentricity between the eyepiece connection part of the main body and the optical tube, it is possible to connect the eyepiece connection part of the main body and the optical A bending force is applied to the optical tube to correct the eccentricity of the tube, and this result in damage to the relay optical system.

Focusing on this situation, the above-mentioned Japanese Patent Application Laid-Open No. 62-1.2
No. 9407 discloses that an optical system holding member having a tapered holding piece with a slit formed in the rear end and having texture in the radial direction is provided inside the main body, and the optical system holding member is By screwing the base end into the inner circumferential surface of the eyepiece connection part, pressing the inner surface of the holding piece at the distal end against the outer circumferential surface of the adjusting frame, and deforming the holding piece in accordance with the amount of eccentricity of the adjusting frame. The holding piece is further fixed to the adjustment frame with adhesive, brazing material, or the like.

[Problems to be Solved by the Invention] As mentioned above, when the adjustment frame is held by the optical system holding member, no external force such as bending is applied to the optical tube, and damage to the relay optical system can be prevented. Since the optical system holding member is provided with a tapered holding piece,
When the eyepiece and lens are attached to the optical tube during use or transportation, the weight of the frame etc. causes the holding piece to deform and bending force is applied to the optical tube. However, if the elasticity of the holding piece is increased, a forced force may be applied to the optical tube instead.

Furthermore, as mentioned above, if the inner periphery of the holding piece and the outer periphery of the adjustment frame are fixed by gluing or brazing, the optical tube can be inserted into the insertion section in order to repair or replace the relay optical system, etc. When pulling out the tube from the inner tube, it is necessary to remove the bonded and waxed portions, but this work is time-consuming and may not be repairable in some cases.

This invention was made in view of the above-mentioned circumstances, and its purpose is to attach the optical tube to the main body without applying any forced force such as bending force to the optical tube into which the relay optical system is inserted. The present invention aims to provide a rigid endoscope that can be securely fixed and that can be easily attached and detached for repairs and the like.

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides an optical tube that is fitted into an optical tube housing a relay optical system inside the main body and has a tapered outer circumferential surface. A radially extensible clamp is fitted to a ring, which is also fitted to the optical tube, and the clamp includes a retaining ring having an inner circumferential surface with a taper corresponding to the taper of the ring, and a retaining ring attached to the main body of the relay optical tube. and a fixed member that is movable forward and backward in the optical axis direction of the system.

The fixing member is moved forward along the axial direction of the relay optical system, and the tapered surface of the holding ring is brought into pressure contact with the tapered surface of the ring. The optical tube is fixed to the main body by gripping the optical tube. When the fixing member is moved back along the axial direction of the relay optical system, the tightening force of the ring becomes weaker, and the optical tube can be removed from the main body.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 3, reference numeral 1 denotes a rigid endoscope, and this rigid endoscope 1 is provided with an elongated insertion section 2. As shown in FIG. An objective section 2a and an illumination section 2b are provided on the distal end side of the insertion section 2. A main body part 3 is fixed to the proximal end side of the insertion part 2, an eyepiece part 4 is connected to the main body part 3 on the proximal side, and an eyepiece 5 is provided on the proximal side of the eyepiece part 4. It is being Further, a light guide connector 6 is provided on the main body 3 so as to protrude laterally.

The insertion section 2 is formed of a hard double tube, as shown in FIG. The base end of the double outer tube 2C is inserted and fixed into a through hole 3b having a step 3a provided in the main body 3, and the base end of the inner tube 2d reaches the inside of the main body 2. It is being extended. A light guide fiber 7 is inserted between the outer tube 2C and the inner tube 2d,
This negative end is located at the illumination section 2b, and the other end is located at the light guide connector 6. Furthermore, an optical tube 9 in which a relay optical system 8 consisting of a relay lens such as a rod lens or a gradient index lens is pressed inside is contained in the inner tube 2b. Further, the outer periphery of the proximal end of the outer tube 2C is held by a fixing nut 10 screwed from inside the main body 3, and is sandwiched between washers I and 11, and is inserted into the through hole 3b. Watertightness within the insertion portion 2 is ensured by an O-ring 12 which is prevented from deformation by tightening between the step 3a and the fixing nut 10.

On the other hand, the light guide connector 6 includes a light guide holder 14 screwed into a screw hole 13 drilled in the side wall of the main body 3, and covers the outer periphery of the light guide holder 14.
A cylindrical adapter 15 that is removably screwed onto a threaded portion provided on the outer periphery, and a cylindrical adapter 6 that covers the outer periphery of this adapter 15 and is removably screwed onto the light guide holding portion 14. These adapters5.
By attaching and detaching the cable 16, various light guide cables (not shown) can be selectively connected.

Furthermore, light guide holes 1 and 4 a that communicate with the through hole 3 b of the main body part 3 are provided in the light guide holding part 14 so as to extend through the light guide fiber guided from the main body part 3 . The end surface 7a of the slide guide 7 and the end surface 14b of the ride guide holding portion 14 are inserted and bonded so that they become the same.

Further, a groove 1.4c for housing the rubber ring 17 is provided in the proximal side wall of the light guide holding portion 14, and a screw hole 14d is further provided that communicates with the light guide hole 14a from the bottom of the groove 14c. . This screw hole 14d is used when inspecting the watertightness inside the insertion section 2 after the insertion section 2 is assembled, and is closed by screwing the closure screw 18 after the inspection. Note that since the end surface 14b of the light guide holder 14 is formed in a tapered shape, when polishing the end surface 7a of the light guide fiber 7, the light guide holder 1
The end face 14b of No. 4 has the advantage of not being cut much.

Further, as shown in FIG. 2, a cylindrical eyepiece connection part 3c is provided on the proximal side of the main body part 3. A notch 19 having a wedge-shaped cross section is formed at the open end of the eyepiece connecting portion 3c, and one side of a trapezoidal gasket 20 is engaged with the notch 19. A threaded portion 3d is provided on the outer peripheral surface of the eyepiece connection portion 3c.
is formed, and a cylindrical eyepiece tube 21 is screwed into this threaded portion 3d. On the main body 3 side of the eyepiece tube 21, there is an inclined surface 2]a that comes into pressure contact with the gasket 20, and on the proximal side there is a flange portion 21. to which a cover glass 22 is adhered. b is integrally provided, and the eyepiece tube 21 is watertightly connected to the main body portion 3 by a gasket 20. In addition, the above-mentioned Patsukin 20
Since it is trapezoidal, the radial thickness of the eyepiece tube 21 can be made thinner, the outer diameter of the eyepiece part 4 can be made thinner, and it can be strongly crimped, so it has the advantage of being able to maintain sufficient airtightness even against high-pressure steam. be.

Further, a step 3e is formed near the center of the inner peripheral surface of the eyepiece connecting portion 3c, and a female threaded portion 3f is formed on the proximal side.
is formed. Further, at the end of the optical tube 9 surrounded by the eyepiece connecting portion 3c, a cylindrical fixed frame 23 having an inner peripheral portion 23a having a larger diameter than the outer diameter of the optical tube 9 is provided.
is fitted. Then, the inner peripheral part 2 of this fixed frame 23
3a, the final relay lens 8 of the relay optical system 8
This final relay lens 8a is fixed by a lens fixing tube 24 that is screwed into the inner peripheral part 23a of the fixing frame 23. That is, a lens holding tube 25 is fitted to the proximal end of the relay optical system 8 and the outer periphery of the final relay lens 8a so as to be slidable in the axial direction. A flange portion 25a is provided on the tip side of the lens holding tube 25,
A step 25b that comes into contact with the outer peripheral edge of the final relay lens 8a is provided on the inner peripheral surface on the proximal side. A coil spring 26 is fitted on the outside of the lens holding tube 25, one end of which is connected to the flange portion 25a, and the other end is connected to the lens fixing tube 24.
is in contact with the tip of the Therefore, the relay optical system 8 and the final relay lens 8a are always pressed against each other by the coil spring 26, and it is possible to prevent mutual displacement and loosening of the lenses, and to prevent deterioration of resolution and the like. Further, since the final relay lens 8a is not directly tightened with a nut or the like, there is no fear of chipping or the like.

On the outer periphery of the fixed frame 23, there is a lens back presser cylinder 27 and!
They are screwed together so that a stop nut 28 comes into contact with them, and the amount of protrusion of the lens back presser cylinder 27 from the lens fixing cylinder 24 toward the user's hand can be adjusted and fixed by the lock nut 28. Two presser rings are provided on the outer periphery of the lens back presser tube 27, the tip surfaces of which are in contact with the vertical surface of the step 3e of the eyepiece connecting portion 3c. A taper 29a is provided on the inner peripheral surface on the proximal side of this presser ring 29, and a taper 30a formed on the distal end side of the clamp ring 30 provided on the proximal side of the two presser rings is joined to this taper 29a. For this tightening, the ring 30 is formed into a C-shape with a slot 30b in a part of the circumference, and is expandable and retractable in the radial direction. 31 is in contact with the lens back presser tube 2.
It is fitted so as to be slidable in the axis 2 direction of 7. In addition, the outer diameter of the two retaining rings, the tightening ring 30, and the washer 31 is the same as that of the eyepiece connection part 3.
A gap is provided, which is smaller than the inner diameter of C, so that the optical tube 9 does not come into contact even if it is eccentric.

Lens back presser tube 2 located on the proximal side of the washer 31
A tightening screw 32 as a fixing member is provided on the outer periphery of the eyepiece connecting portion 3C, and the tightening screw 32 can press the ring 30 against the holding ring 29 through the washer 31. . That is, when the tightening screw 32 is tightened, the tightening is performed by the taper 30a of the ring 30 and the taper 2 of the holding ring 29.
9a, and the ring 30 is tightened because the slot 30b of the ring 30 is narrowed and the diameter is reduced.
It can be gripped and fixed. Note that this tightening screw 3
2 and the lens back presser cylinder 27 is the washer 3.
1 and the eyepiece connecting portion 3c.

Furthermore, the proximal side of the lens back presser tube 27 protrudes beyond the lens fixing tube 24, and a cylindrical spring presser tube 33 is screwed into this protrusion. An inner flange 33a is provided on the proximal side of the spring holding cylinder 33, and an eyepiece frame 34 is provided passing through the opening of the inner flange 33a. The tip side of the eyepiece frame 34 is inserted into the spring holding tube 33, and the flange portion 34a provided at the tip thereof is connected to the lens back holding tube 27.
It is in contact with the end surface on the hand side. The outer diameter of the flange portion 34a is sufficiently smaller than the inner diameter of the eyepiece frame 34, so that the eyepiece frame 34 can slide in the radial direction of the spring holding cylinder 33. Further, a washer 35 is fitted to approximately the middle portion of the ocular lens frame 34 in the longitudinal direction, and a coil spring 36 is interposed between the washer 35 and the flange portion 34a. The flange portion 34a of the eyepiece frame 34 is elastically urged against the proximal end surface of the lens back presser tube 27 by the coil spring 36.

A field mask 37 that narrows the field of view to the position of the imaging plane of the final relay lens 8a is attached to the end face of the eyepiece frame 34 on the distal end side. Further, an eyepiece 38 is glued to the proximal side of the eyepiece 4 frame 34.
It faces a cover glass 22 provided on the eyepiece 5. Therefore, the eyepiece frame 34 can be slid in the radial direction (perpendicular to the optical axis) while the eyepiece frame 34 is in contact with the lens back presser cylinder 27. Further, a cover glass 2 is provided on the outer periphery of the eyepiece tube 21.
A cover glass holding tube 40 having a flange portion 40a capable of holding down the flange portion 22a of the cover glass holding tube 40 is screwed together, and the eyepiece 5 is screwed into a threaded portion 41 provided on the outer periphery of this cover glass holding tube 40. . In addition, the threaded part 4
1 can be connected to adapters for various photographic devices.

Next, the operation of the rigid endoscope configured as described above will be explained.

The distance between the cover glass 22 and the relay optical system 8 can be reduced by moving the fixed frame 23 and the lens back presser tube 27 placed on the optical tube 9 into which the relay optical system 8 is inserted in the axial direction with respect to the optical tube 9. Adjust to the optimal position. After making this adjustment, the tightening screw 32 is screwed into the eyepiece connection portion 3C of the main body 3 in the distal direction, and the washer 3 is in contact with the distal end surface of the tightening screw 32.
Press 1 to the tip side. Tighten washer 31 with ring 30
When the taper 30a and the taper 29a of the presser ring 29 are pressed against the tip side by the
While being pressed against the step 3e, it also receives a force that tries to expand in the outer radial direction. At this time, during tightening, the ring 30 receives a force that tends to contract in the inner diameter direction due to sliding between the tapers 29a and 30a. This tightening is done with a slot 30b in the ring 30.
, the diameter is reduced by the force that tends to shrink in the inner circumferential direction, thereby gripping the outer circumferential portion of the lens back presser cylinder 27. On the other hand, there are two presser rings, and the tightening ring is 30. Since the washer 31 is crimped by the step 3e and the tightening screw 32 and fixed to the main body 3, the lens back presser cylinder 27 is finally fixed to the main body 3. Also,
The outer diameters of the retaining ring 29, the tightening ring 30, and the washer 31 are smaller than the inner diameter of the eyepiece connection part 3C of the main body 3, so there is a gap, and similarly the inner diameter of the tightening screw 32 is Since it is formed larger than the outer diameter of the back presser cylinder 27, a gap is created. Therefore, even if there is eccentricity between the inner peripheral part of the eyepiece connection part 3c of the main body part 3a and the optical tube 9, the eccentricity is absorbed by the gap, and no unreasonable force such as bending force is applied to the optical tube 9. The lens back presser tube 27 can be reliably fixed to the eyepiece connection portion 3c of the main body portion 3.

In addition, by screwing the tightening screw 32 into the eyepiece connection part 3c of the main body part 3 on the proximal side, the contact surfaces of the presser ring 29, the tightening ring 30, and the washer 31 are loosened, and the back of the lens is loosened. The fixation of the presser tube 27 to the eyepiece connecting portion 3c can be easily released. Therefore, the optical tube 9 is connected to the relay optical system 8.
can be easily extracted from.

In the above embodiment, the tightening ring 3° was formed into a C-shape by providing a slot 30b in a part of the annular body, but the present invention is not limited to the above embodiment. As shown in the figure, a tapered portion 43a is formed at one end of the annular body 43, and slits I-43b are formed at multiple locations in the circumferential direction of the tapered portion 43a.
* may be provided in the axial direction of the annular body 43 to provide elasticity in the radial direction, or the annular body 43 may be formed of rubber or synthetic resin material without providing the slit 43b to provide elasticity in the radial direction. It may also be deformed.

[Effects of the Invention] As explained above, according to the present invention, the relay optical system components can be securely fixed to the main body without applying forced force such as bending force to the relay optical system, and It can be easily attached to and detached from the main body. Therefore, it is possible to prevent damage to the relay optical system, and it is also possible to perform repair and replacement work easily.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical side view of the main body of a rigid endoscope, FIG. 3 is a perspective view of the entire rigid endoscope, and FIG. 4 is a perspective view of a tightening ring showing another embodiment of the present invention. 8 2... Push-in part, 3... Main body part, 8... Relay optical system, 9... Optical tube, 29... Holding ring, 30... Tightening C ring, 29a, 30a. ...Taper, 32...Tightly fixing member).

Claims (1)

[Claims] It consists of an insertion section and a main body connected to the proximal end of the insertion section, and an optical image of the object formed by an objective optical system disposed at the distal end of the insertion section is transferred to the object using a relay optical system. In a rigid endoscope configured to transmit information to a main body and to enable observation from an eyepiece optical system built into the proximal side of the main body, the relay optical system is fitted into an optical tube housing the relay optical system inside the main body. a radially extensible clamping ring having a taper on its outer circumferential surface; a presser ring that is also fitted into the optical tube and having a taper on its inner circumferential surface corresponding to the taper of the tightening ring; The relay optical system is provided in the main body so as to be movable forward and backward in the optical axis direction of the relay optical system, and the clamping ring and the holding ring are crimped onto the main body, and by pressing both tapered surfaces, the diameter of the clamping ring is reduced and the clamping ring is moved back and forth in the optical axis direction of the relay optical system. A rigid endoscope comprising a fixing member that grips a tube.