JPH0664248B2 - Endoscope tip adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is an endoscope tip mounted on the tip of an endoscope to change the direction and range of the observation optical system on the endoscope body side. Regarding the improvement of the adapter.

[Problems to be Solved by Conventional Techniques and Inventions] In recent years, by inserting an elongated insertion portion into a body cavity, an organ in the body cavity or the like can be observed, and forceps inserted through a forceps channel as necessary. 2. Description of the Related Art A medical endoscope that can be used to collect a tissue in a living body and make a detailed diagnosis of an affected area is widely used. In the industrial field, boilers,
Industrial endoscopes that can observe and inspect the inside of turbines, engines, chemical plants, etc. are widely used.

In particular, by inserting the insertion portion of the medical endoscope into the body cavity,
When observing a diseased part or the like, it is easy to use a direct-viewing endoscope if there is a diseased part in the axial front direction with respect to the distal end side of the insertion part. On the other hand, when observing the inner wall surface of the body cavity on the side orthogonal to the insertion direction, it is easy to observe by using a side-viewing endoscope.
As described above, it is desirable to use an endoscope suitable for the observation site. However, since the endoscope is expensive, when it is necessary to change the viewing angle and the viewing direction, JP-A-56-8532 is used.
No. 4 and Japanese Patent Laid-Open No. 58-12638, a tip adapter equipped with an optical system capable of changing a viewing angle and a viewing direction is attached to the tip of the insertion portion.

However, by attaching the tip adapter to the tip of the endoscope, the objective optical system on the tip adapter side forms the objective optical system of the observation site together with the objective optical system on the endoscope side. If the position on the axis is off,
The focal length was not constant, a clear observation image could not be obtained, and the depth of field sometimes changed.

In other words, in the tip adapter type endoscope, there are variations in the optical system in the scope body (the focusing range is deviated to the near point side or the far point side) and variations in the focus of the optical system in the adapter. There was a problem that the focus range was too biased to the near point side with a combination of the scope and a certain adapter, and was too biased to the far point side with another combination.

On the other hand, the focus adjustment was made unnecessary by increasing the dimensional accuracy of the mechanical parts and optical parts, but the increase in the dimensional accuracy causes an increase in the number of processing steps and assembly workability, etc. There was a defect such as rising.

[Object of the Invention] The object of the present invention is to adjust the focus within the tip adapter in order to ensure that the tip is always in a certain range (for example, 10 to 100 mm) regardless of which endoscope is attached to which tip adapter. (EN) An endoscope tip adapter adapted to perform (adjustment of a focusing range).

[Means and Actions for Solving Problems] Focus adjustment can be performed by providing a moving means capable of moving part or all of the objective optical system of the tip optical adapter for changing the viewing angle and the viewing direction in the optical axis direction. It was made possible.

EXAMPLES The present invention will be specifically described below with reference to the drawings.

1 and 2 show an embodiment of the present invention, FIG. 1 is a cross-sectional view of a distal end portion of an endoscope, and FIG. 2 is an explanatory view showing the entire endoscope.

As shown in FIG. 2, the endoscope 1 includes an elongated insertion portion 2 and
A large-diameter operation portion 3 connected to the rear end side of the insertion portion 2
And a light guide and signal cable 5 extending from the side of the operation unit 3.

A hard tip portion 7 to which a tip adapter 6 is attached is provided on the tip end side of the insertion portion 2, and a bending portion 8 adjacent to the tip end portion 7 and capable of bending is provided on the rear side. Also,
By rotating the bending operation knob 9 provided on the operation portion 3, the bending portion 8 can be bent in the vertical / horizontal directions.

A flexible soft portion (flexible portion) is provided on the rear side of the bending portion 8.
15 are arranged in series.

The tip adapter 6 has a substantially cylindrical shape, and an observation through hole 11 and an illumination light through hole 12 are formed in the front end surface in parallel with the longitudinal direction of the insertion portion 2.

A lens system 10 for changing the angle of view is provided at the front end of the observation through hole 11.
The first lens 13 constituting the above is fitted, and it is fitted in the rear of the lens frame 14 having the male screw portion 18 screwed to the female screw portion 17 provided on the inner periphery of the observation through hole 11.
The second lens 16 constituting the angle-of-view changing lens system 10 is provided and adhered so as to be movable in the longitudinal direction.
The rear end surface of the lens frame 14 has a plurality of radial grooves 2
0, 20 ... Are provided so as to serve as an engaging portion when the lens frame 14 is rotated by, for example, a jig.

A light distribution lens system 19 is fitted and fixed in the illumination through hole 12.

The rear end surface of the tip adapter 6 is provided with a circular recess 21 into which the substantially cylindrical tip component member 22 of the endoscope 1 can be inserted, so that the center lines of the tip adapter 6 and the insertion portion 2 coincide with each other. There is.

A screw portion 23 is threaded on the rear end of the inner peripheral surface of the recess 21, and a groove portion 26 in which an annular watertight member 24 such as an O-ring is inserted on the inner peripheral surface in front of the screw portion 23. Is provided.

The tip forming member 22 inserted into the recess 21 has an observation through hole 27 and an illumination through hole 28 which are parallel to the longitudinal direction of the insertion section 2.
And are provided.

A first lens frame 31 in which an optical rod 29 and an infrared filter 30 are superposed and fitted in the observation through hole 27.
Then, a second lens frame 33 having an objective lens system 32 fitted therein is fitted and positioned behind the first lens frame 31.

The solid-state image sensor 48 is sensitive to the near infrared region, and when infrared light enters the solid-state image sensor 48, it becomes a pseudo signal and deteriorates the image. In order to prevent this image deterioration, an infrared cut filter 30 is provided at the endoscope front end portion 7. Although the position of the infrared cut filter 30 is not limited to only the tip portion 7, it is possible to reduce the cost of the tip adapter 6 alone as compared to the case where it is provided for each tip adapter 6 separately, and the tip end 6 is provided. Adapter 6
This is effective because it is possible to eliminate the variation due to the infrared cut filter 30 for each.

A cover glass 34 is fitted in the front end of the illumination through hole 28, and an end face of a light guide fiber 36 inserted through the insertion portion 2 is in contact with and fixed to a rear end face of the cover glass 34. Has been done.

A step portion 37 and a step portion 38 are formed on the rear portion of the outer periphery of the tip forming member 22 so as to have a smaller diameter toward the rear end portion, and a cylindrical prism frame 39 contacts the front end surface with the step portion 37. contact,
The outer diameter is fitted to match the outer diameter of the tip forming member 22, and is fitted,
It is fixed to the tip forming member 22 by a plurality of screws 41.

At the rear end of the prism frame 39, an optical low-pass filter 42 in the form of a quadrangular prism, a first prism 43 and a second prism 44 as light guide means are held in order from the front end side.

The optical low-pass filter 42 is arranged such that the front end face and the rear end face thereof are perpendicular to the optical axis of the monster lens system 32, and the optical low-pass filter 42 has a rear end face of the first prism 43. The front end face is fixed. A gradient is formed on the rear end side of the first prism 43. On the other hand, the second prism 44 is formed in a wedge shape, and the front end face of the second prism 44 has the first end so that the thin portion is on the tip side.
Is fixed to the sloped surface 46 of the prism 43. The rear end surface 47 of the second prism 44 is inclined with respect to the longitudinal direction of the insertion portion 2, and the imaging surface side of the solid-state image sensor 48 abuts on the rear end surface 47, so that the length of the insertion portion 2 increases. It is arranged to be oblique to the direction.

A substrate 51 is attached to the non-imaging surface side of the solid-state image sensor 48, and the solid-state image sensor 48, the substrate 51, or both the solid-state image sensor 48 and the substrate 51 are fixed to the prism frame 39 by adhesion or the like. ing.

On the rear end side of the substrate, a core wire connecting portion 52 is extended so that the mounting surface side of the solid-state imaging device 48 faces rearward. The core wire connecting portion 52 extends on the front end side of the substrate 51 and the rear surface of the substrate 51. An electronic component 53 is mounted on.

A step portion 54 is provided on the outer peripheral surface of the rear portion of the prism frame 39, and a small diameter portion 56 is formed. The thin portion 56
A cover member 57 having a substantially cylindrical shape and capable of accommodating the substrate 51 is fixed by abutting the front end surface thereof on the step portion 54. The front portion of the outer peripheral surface of the cover member 57 is formed with a small diameter portion 59 which is narrowed forward by a step portion 58, and the rear portion is formed with a small diameter portion 62 which is narrowed backward by a step portion 61.

A connection ring 63 having an outer diameter equivalent to the outer diameter of the tip adapter 6 is inserted into the outer peripheral surface of the front small diameter portion 59 so as to be rotatable on the outer peripheral surface of the small diameter portion 59. ing. A threaded portion 64 having a plurality of slits 65, 65 in the longitudinal direction is provided on the outer peripheral surface of the front portion of the connecting ring 63 by screwing, and is provided on the inner peripheral surface of the rear end of the tip adapter 6. The screw portion 23 can be screwed together. Further, on the inner peripheral surface of the front portion of the connection ring 63, the convex portion 66
Is provided so that it can be engaged with a recess 67 provided on the outer peripheral surface of the front portion of the cover member.

The small diameter portion 62 at the rear portion of the cover member 57 is further formed with a small diameter portion 69 which is narrowed backward by the step 68.

The core wire connecting portion 52 is provided on the inner diameter of the rear portion of the cover member 57.
A cylindrical ring stopper 74 having a core wire through hole 72 and a light guide through hole 73 through which the plurality of core wires 71, 71 ... Connected to is inserted and fixed so as to expose a part of the outer peripheral surface. .

In the exposed portion of the ring stopper 74, the curved portion 8
The frontmost joint piece 76 of a large number of substantially annular joint pieces 76, which are rotatably connected in the insertion portion 2 in the longitudinal direction, is externally fitted and fixed to the ring stopper 74 by a screw 77. ing.

The joint piece 76 is covered with a flexible tube member 78, and a front end portion of the tube member 78 is fitted with a small diameter portion 69 so as to come into contact with the step portion 68. Further, the outer periphery of the tube member 78 is covered with a protective jacket 79 made of a mesh tube or the like in which fine wires of metal or the like are braided in a mesh shape.

The front end portion of the protective jacket 79 is externally fitted to a small diameter portion 85 formed by a step portion 82 on the rear portion of a cylindrical fixing member 81 having an outer diameter equal to or less than the outer diameter of the cover member 57. The front end portion of the protective jacket 79 is the stepped portion 82.
It comes into contact with.

A cylindrical stopper 83 having an outer diameter equivalent to the outer diameter of the fixing member 81 is externally fitted to the outer periphery of the front end portion of the protective jacket 79 fitted to the fixing member 81 by fixing means such as solder. The fixing member 81 and the protective jacket 79 are fixed to each other.

A plurality of screws 84 as locking pieces are radially inserted into the front portion of the fixing member 81 so as to penetrate the inner peripheral surface of the fixing member 81 and are recessed in the small diameter portion 62 of the cover member 57. The tip portion of the screw 84 comes into contact with 86 and is pressed to connect the protective jacket 79 and the tip portion 7.

The outer periphery of the cover member 57 and the screw 84 of the fixing member 81
A cylindrical drop-off preventing member 87 is loosely fitted to the outer periphery including the arrow mark to prevent the screw 84 from falling off. The outer diameter of the fall prevention member 87 is equal to the outer diameter of the tip adapter 6, and a step portion 88 is provided at the front portion of the inner peripheral surface and abuts the step portion 58 provided on the cover member 7. It is like this.

An enlarged diameter portion 92 is formed by a stepped portion 91 at the rear portion of the core wire through hole 73, and the enlarged diameter portion 92 has a cylindrical shape having the same inner diameter as the core wire through hole 73 and a rear portion having a small diameter. The wire stopper 93 is fitted and solidified.

A shielded wire 94 covering the outer circumference of the core wire 71 is expanded and externally fitted to the small-diameter portion of the wire stopper 93, and is fixed by being soldered or electrically conductive with an adhesive or the like so as to maintain electrical continuity.

The core wire 71 is inserted through the wire stopper 93 and connected to the core wire connecting portion 52, and the core wire connecting portion 52 and its vicinity are covered and fixed by a reinforcing member 96 such as an adhesive. The core wire 71 is fixed to the wire stopper 93 by a fixing member 97 such as an insulating adhesive.

By the way, the lens frame 14 provided in the tip adapter 6
Engages the groove portion 20 with, for example, a jig and rotates the lens frame 14 back and forth to rotate the second lens 1
6 can be positioned at a predetermined position. The positioning method is, for example, using a dedicated inspection tool, or a basic endoscope is prepared, and focus adjustment is performed so that the endoscope and a predetermined range are in focus. May be.

The optical system at the tip of the endoscope is focused on an object point at infinity. Furthermore, by placing an afocal (afocal lens) system between the endoscope tip optical system and the tip adapter optical system, it is possible to prevent variations in the distance between the tip optical system and the tip adapter optical system. It becomes easy to absorb, and variation in aberration (particularly spherical aberration) can be suppressed. However, the shape of the optical system is not limited to the above-mentioned one, and may be a substantially afocal system or any other shape. FIG. 3 shows a second embodiment and is a sectional view of the tip adapter.

The tip adapter 101 has a substantially columnar shape, and an observation through hole 102 and an illumination through hole 103 are formed in the front end surface in parallel with the longitudinal direction of the insertion portion 2.

The front portion of the observation through hole 102 is enlarged in diameter by a step portion 104, and a first lens 106 which is in contact with the step portion 104 and constitutes a view angle changing lens system 105 is fitted. .

Further, at the rear of the observation through-hole 102, there is a cylindrical convex portion on the inner peripheral surface at the front end, and the angle of view is changed together with the first lens 106 so as to come into contact with the inner end surface of the convex portion. A lens frame 108 to which a second lens 107 forming the lens system 105 is internally fixed is loosely fitted.

The inner peripheral surface of the observation through hole 102 in which the lens frame 108 is loosely fitted is provided with a hole 109 penetrating the outer peripheral surface of the tip adapter 6 and arranged in the longitudinal direction, and a screw hole 111 in which a screw portion is screwed. ing.

The hole 109 is sealed with a sealing material 113 such as an adhesive, and the screw hole 111 has a tip end abutting against the outer peripheral surface of the lens frame 108 to press and fix the lens frame 108. The screw 112 is screwed in, and the head of the screw 112 is further sealed with a sealing material 113 to prevent the head from falling off.

By the way, for focus adjustment, the distal end adapter 101 is attached to, for example, a basic endoscope, a jig or the like is inserted into the hole 109 from the outside while observing an image, and the lens frame 108 is moved back and forth. The outer peripheral surface of the lens frame 108 is pressed for positioning.

In this embodiment, the positioning is performed by the screw, but other fixing means may be used as long as it can be positioned from the outer peripheral surface of the tip adapter.

According to the present embodiment, the focus adjustment can be performed while observing the image, so that the work efficiency of the focus adjustment can be enhanced as compared with the first embodiment.

Other configurations and operations are similar to those of the first embodiment.

4 to 6 relate to the third embodiment, FIG. 4 is a sectional view of a side-viewing tip adapter, FIG. 5 is a sectional view taken along the line AA ′ in FIG. 4, and FIG. It is a BB 'direction sectional drawing of a figure.

In FIG. 4, the tip adapter 116 has the same outer diameter and is composed of a cylindrical front part constituting member 117 and a columnar part constituting member 118.

A substantially flat surface is formed on a part of the outer peripheral surface of the front component member 117, and two first illumination through holes 119, 119 arranged in the circumferential direction are provided on the front side of the substantially flat surface. However, the first observation through-hole 121 is provided on the rear side so that the optical axis is oriented in a direction perpendicular to the longitudinal direction of the insertion section 2. Further, a recess 126 is provided on the rear end surface of the front component member 117 so that the first illumination through holes 119 and 119 and the first observation through hole 121 pass therethrough.

Light distribution lenses 122 and 122 are fitted and fixed in the first illumination through holes 119 and 119, respectively, and a field angle changing lens system 123 is formed in the first observation through hole 121. The first lens 124 is positioned and fixed by the step.

In the front part of the rear component member 118, a small diameter portion 128 is formed by a step 127, and the front component member 11 is formed.
7, the rear end face of the front part constituting member 117 abuts against the step part 127, and is fixed to the front part forming member 117 by screws 129 and 129 as shown in FIG.

Light guides 132, 132 whose optical axes are bent substantially at right angles are inserted into the front end surface of the rear component member 118.
A plurality of second illumination through holes 131, 131 are provided in the insertion portion 2 in the longitudinal direction, and the front component member 117 is provided.
The optical axes of the light distributing lenses 122 and 122 directed toward the optical axis are aligned with each other to form a light distributing lens system 133 together.

Further, in the front end face of the rear component member 118 adjacent to the second illumination through-holes 131, 131, the rear portion is enlarged in diameter by the step portion 134, and the female screw portion 136 is screwed on the front portion. The through hole 137 is provided in the longitudinal direction with respect to the insertion portion.

The female threaded portion 136 has a cylindrical shape and has a male threaded portion 1 on the outer peripheral surface.
38 is threaded, and a lens frame 141 in which a second lens 139 that constitutes the angle-of-view changing lens system 123 together with the first lens 124 is internally fitted and fixed is screwed, and the length of the insertion portion 2 is increased. It can be moved in any direction.

A right-angle prism 130 is provided on the optical axis in front of the second lens 139 so that the optical axis direction coincides with the optical axis of the first lens 124.

The rear end surface of the lens frame 141 has a plurality of groove portions 1 in the radial direction.
42 is provided so as to serve as an engaging portion when the lens frame 141 is rotated by, for example, a jig.

By the way, in order to adjust the focus of the side-view tip adapter 116, the second lens 139 is fixed in addition to the method of moving the lens frame 141 in which the second lens 139 is fitted back and forth as in the first embodiment. However, the first lens 124 may be moved in the system direction to adjust the focus, and then the first lens 124 may be fixed.

Other configurations and operations are similar to those of the first embodiment.

Although the above embodiment describes the case where the present invention is applied to an electronic scope, it may be applied to a fiberscope, a rigid endoscope, or the like.

[Advantages of the Invention] As described above, at least part of the objective optical system is moved in the optical axis direction at the time of assembling the adapter so that the focusing range in the tip adapter falls within a certain range in any adapter. Since the focus adjustment is performed by using any of the scope bodies, the focusing range can be kept within a certain range.

Therefore, as compared with the means for increasing the dimensional accuracy of the mechanical parts and the optical parts and eliminating the need for focus adjustment, problems such as an increase in the number of processing steps, deterioration of assemblability, and an increase in production cost do not occur.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a cross-sectional view of a distal end portion of an endoscope, FIG. 2 is an explanatory view showing the whole endoscope, and FIG. 3 is a second embodiment. An example is shown, a sectional view of a tip adapter, FIGS. 4 to 6 relate to a third embodiment, FIG. 4 is a sectional view of a tip adapter for side view, and FIG. 5 is A- of FIG.
FIG. 6 is a sectional view taken along the line A ', and FIG. 6 is a sectional view taken along the line BB' of FIG. DESCRIPTION OF SYMBOLS 1 ... Endoscope 2 ... Insertion part 6 ... Tip adapter 7 ... Tip part 14 ... Lens frame 17 ... Female screw part 18 ... Male screw part

Claims (1)

[Claims] 1. A tip adapter that is detachably attached to a tip portion of an endoscope, is connected to an optical system of the endoscope, and converts a viewing angle and a viewing direction. At least a part of an objective optical system is arranged in an optical axis direction. A distal end adapter for an endoscope, characterized in that a moving means capable of moving back and forth is provided, and the optical system is fixed to the distal end adapter after adjustment by forward and backward movement.