JPH07191267A - Stereoscopic endoscope - Google Patents

Abstract

PURPOSE:To always obtain good stereoscopic visual images without generating misalignment in images to be observed even if a force, such as an impact, is applied to the insertion part of an endoscope by fixing lenses as an observation optical system to the prescribed position within a lens tube. CONSTITUTION:The lens tube 4a is provided with adhesive holes 15 respectively corresponding to the positions of the relay lens 10 and the objective lenses 12 and 14. All the lenses are fixed in the lens tube 4a by injecting an adhesive 9 from these holes 15. After metal is deposited by evaporation on the circumference of the respective lenses, the vapor deposited metal surfaces of the lenses and the lens tube 4a may be fixed by soldering as the method for fixing the lenses. As a result, the lenses do not tilt and the positional relations between the lenses are held without changing even if an external force (for example, an impact) is applied to the insertion part of the endoscope and shrinkage in an optical axis direction is momentarily generated in a spacer 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic endoscope capable of observing a stereoscopic image.

[0002]

2. Description of the Related Art Conventionally, an endoscope has been widely used, which is capable of observing an inspected site which cannot be directly observed by inserting an elongated insertion portion into a body cavity or the like. Generally, in such an endoscopic device, it is difficult to observe details such as minute irregularities on the surface of the body cavity because the site to be examined can only be captured as a plane image without perspective. However, there was a problem that diagnosis and various kinds of processing could not be performed easily.

Therefore, as shown in FIG. 12, a plurality of observation optical systems are arranged in a line, and the observation optical systems are arranged so that parallax occurs by setting the convergence angle formed by the optical axes of these optical systems. Conventionally, a stereoscopic endoscope capable of stereoscopically viewing an observation site has been proposed. In FIG. 12, the stereoscopic endoscope 1 is composed of an insertion portion 2 and a main body portion 3, and further, from the inside of the insertion portion 2 to the inside of the main body portion 3, a right lens tube 4a and a left lens tube 4b as an observation optical system. And a light guide 5 as an illumination optical system. The right lens tube 4a and the left lens tube 4b are optically connected to the right eyepiece section 6a and the left eyepiece section 6b, respectively, through prisms, mirrors, relay lenses, etc. (not shown) inside the main body 3. ing. Furthermore, after the eyepieces 6a, 6b (right side of the figure)
Is configured to display an image on a monitor via a camera head and a display control device (not shown).

FIG. 15A is a view showing an observation image 17a captured by the right lens tube 4a and an observation image 17b captured by the left lens tube 4b displayed on the monitor 16. As shown in FIG. These images are switched and displayed by a control device (not shown) every 1/120 second, and can be seen with the naked eye only as two left and right images as shown in the figure. However, by using eyeglasses of a liquid crystal shutter system synchronized with this switching speed, the left and right images are fused and can be observed as a stereoscopic image.

FIG. 13 is a sectional view of the right lens tube 4a of the stereoscopic endoscope 1. As shown in the figure, on the inner rear end side (right side in the figure) of the right lens tube 4a, a lens stopper 7 made of a metal pipe and a prism 8 are inserted and positioned, and then fixed with an adhesive 9. Also, the right lens tube 4a
From the tip side (lower left side in the figure) of the relay lens 10 for image transmission in the form of abutting against the lens stopper 7, the spacer 11 made of a metal pipe for ensuring the lens interval, and the objective optics for forming an image. Objective lens 12 constituting the system
Etc., and finally, the objective lens 14 provided with the objective lens 13 is pushed in and the adhesive 9 is injected from the adhesive hole 15 in a state where there is no play in the optical axis direction, and the objective lens 14 is placed inside the right lens tube 4a. It is fixed. As described above, only the lens stopper 7, the prism 8 and the objective lens 14 are directly fixed to the inside of the right lens tube 4a, and other lenses and spacers are not directly fixed to the right lens tube 4a. However, there is no backlash in the direction of the optical axis due to the fixing of the above-mentioned members, so that the structure is fixed.

Since the light guide 5 is provided on the outer peripheral portion of the right lens tube 4a, an adhesive that does not transmit light is used as the adhesive injected into the adhesive hole 15. The configuration of the left lens tube 4b is the same as the configuration of the right lens tube 4b, and thus the description thereof will be omitted.

[0007]

However, in the above-described conventional stereoscopic endoscope 1, even if a slight force (for example, an impact of being repelled by a finger) is applied to the insertion portion 2, the spacer 11 is formed. Instantaneously deforms, resulting in backlash in the optical axis direction and tilting of the lens and the like not fixed to the right lens tube 4a. After that, when the contraction of the spacer 11 returns to its original state due to the elastic force of the insertion portion 2, the spacer 10, etc., the relay lens 10 and the objective lens 1
2 will be fixed in a position and orientation different from the state before the force was applied (see FIG. 14). As described above, when the position and orientation of each lens are changed, the monitor image as shown in FIG. 15A is vertically displaced as shown in FIG. There was a problem of being lost.

Further, a conventional stereoscopic endoscope 1 as shown in FIG.
In order to attach the camera head to the right eyepiece 6a, it is necessary to form the right eyepiece 6a and the left eyepiece 6b at a constant distance. Therefore, inside the main body part 3, a certain distance is maintained between the right lens tube 4a and the left lens tube 4b. Therefore, there is also a problem that the outer shape of the main body portion 3 becomes large and the weight of the endoscope itself increases and it is difficult to hold the endoscope.

In view of the above-mentioned problems of the prior art, the present invention, therefore, shifts the observed image displayed on the monitor even if a force such as a shock is applied to the insertion portion of the endoscope. An object of the present invention is to provide a stereoscopic endoscope that is always light and can be easily held without any problem, and that a good stereoscopic image is always obtained.

[0010]

In order to achieve the above object, a stereoscopic endoscope according to the present invention is an endoscope having a lens tube having a lens as an observation optical system inserted therein, It is characterized in that the lens tube and the lens as the observation optical system are fixed at predetermined positions. Further, the stereoscopic endoscope of the present invention is also characterized in that a lightening hole is provided in an unnecessary portion existing between the observation optical systems passing through the inside of the main body, which does not interfere with the observation optical system. There is.

[0011]

Therefore, in the stereoscopic endoscope according to the present invention, all the lenses constituting the observation optical system inside the insertion portion are fixed at predetermined positions of the supporting member, so that the distance between the lenses is increased. Since the positional relationship of is always unchanged, the observation image displayed on the monitor does not shift even when a force such as a shock is applied to the endoscope insertion portion, and a good stereoscopic image can be always observed. . Further, by providing a lightening hole in an unnecessary portion of the endoscope main body portion that does not interfere with the observation optical system, the weight of the main body portion can be reduced and it can be easily held.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the illustrated embodiments by assigning the same reference numerals to the same members as in the above-mentioned conventional example. First Embodiment FIG. 1 is a sectional view of a right lens tube of a stereoscopic endoscope according to this embodiment. As shown in the figure, in the stereoscopic endoscope of the present embodiment, all the lenses constituting the observation optical system inserted inside the right lens tube 4a are fixed at predetermined positions inside the right lens tube 4a. This is a feature that is significantly different from the conventional device. That is, the right lens tube 4a has a relay lens 10 and an objective lens 12 inserted therein.
A corresponding number of adhesive holes 15 are provided at appropriate positions at positions 13 and 13, respectively, and by pouring the adhesive 9 through these holes, all the lenses are fixed inside the right lens tube 4a. . The configuration of the left lens tube 4b is the same as the configuration of the right lens tube 4a, so the illustration and description of the left lens tube 4b are omitted (the same applies hereinafter). Further, the stereoscopic endoscope in the present embodiment is the same as the conventional device except for the configuration of the left and right lens tubes described above.

The method of fixing the lens is not limited to the method of using the adhesive, and for example, after the metal is vapor-deposited around each of the lenses, the metal vapor deposition surface of the lens and the right lens tube 4a are fixed by soldering. Alternatively, a plurality of adhesive holes 15 may be provided for one lens to fix the lens.

Therefore, in the stereoscopic endoscope according to this embodiment, an external force (for example, a shock) is applied to the endoscope insertion portion 1, and the spacer 1
Even if there is a momentary contraction in the direction of the optical axis at 1, since all the lenses are fixed to the right lens tube 4a, the lenses do not tilt and the positional relationship between the lenses does not change. Good stereoscopic observation is possible.

Second Embodiment FIG. 2 is a sectional view showing the structure of a stereoscopic endoscope according to this embodiment. As shown in the figure, a right inner tube 18a, a left inner tube 18b, and a light guide 5 are fixedly provided inside the insertion portion 2. A right lens tube 4a and a left lens tube 4b are inserted inside the right inner tube 18a and the left inner tube 18b, respectively. Furthermore, in the main body part 3,
A lightening hole 19 for reducing the weight is provided in an unnecessary portion such as a lens tube that does not affect the observation optical system. As described above, the stereoscopic endoscope according to the present embodiment has the right lens tube 4
Conventionally, a right inner tube 18a and a left inner tube 18b are provided on the outer circumferences of a and the left lens tube 4b, respectively, and the body portion 3 is provided with a lightening hole 19 for reducing the weight. This is a characteristic difference from the one described above.

Further, lens tubes 4a and 4b described below
This configuration is also a feature of the stereoscopic endoscope according to the present embodiment. FIG. 3 is an external view of the right lens tube of the stereoscopic endoscope according to the present embodiment. As shown in the drawing, on the outer peripheral surface of the right lens tube 4a, the adhesive hole row 20a, the adhesive hole row 20b, and the adhesive hole row 2 are formed.
0c is provided, and the adhesive holes 15 forming each adhesive hole row are spaced apart by A, B, and C in the optical axis direction so as to correspond to the position of each lens inserted in the right lens tube 4a. have. Further, these adhesive hole rows are adhesive holes 20.
With reference to b, the adhesive hole array 20a is provided at the front end side (left side in the drawing) of the lens tube by a distance x, and the adhesive hole array 20c is provided at the rear end side (right side in the drawing) by a distance x.
This distance x has a length substantially equal to an error that occurs when the lenses and spacers in the lens tube are arranged in the optical axis direction.

Then, the same lenses and spacers (not shown) as those shown in the first embodiment are inserted into the right lens tube 4a, and the adhesive 9 is injected through the adhesive hole 15 to fix the lens. A lens that cannot be fixed at the position of the reference adhesive hole row 20b due to an error generated in the axial direction is adhesively fixed at the position of the adhesive hole 15 of the adhesive hole row 20a or the adhesive hole row 20c. Note that the adhesive used in this embodiment may be one that transmits light because the light of the light guide 5 is blocked by the right inner tube 18a. Further, the number of rows of bonding holes provided on the outer peripheral surface of the right lens tube 4a is not limited to three as described above, and may be two or four or more.

Therefore, the stereoscopic endoscope of the present embodiment has, in addition to the function and effect of the endoscope shown in the first embodiment, after fixing the inner tube and the light guide inside the insertion portion,
Since the lens tube can be freely inserted into and removed from the insertion portion, the lens tube can be easily adjusted. Further, since the error generated in the optical axis direction of the lens and the spacer can be absorbed, the adhesive does not flow into the lens surface. Further, since the inner tubes are provided on the outer peripheral portions of the left and right lens tubes, an adhesive agent that transmits light can be used. Further, since the main body portion is provided with the lightening hole, the main body portion is lightweight and easy to hold.

Third Embodiment FIG. 4 is an external view of the right lens tube of the stereoscopic endoscope according to this embodiment. As shown in the figure, the right lens tube 4a is provided with an elongated adhesive hole 15 extending in the optical axis direction, which is a characteristic difference from those shown in each of the above-mentioned embodiments. Into the right lens tube 4a, lenses and spacers (not shown) similar to those shown in the first embodiment are inserted, and the adhesive material 9 is inserted through the elongated adhesive hole 15.
And the lens is adhesively fixed. Therefore,
If the lens fixing method in this embodiment is used, in addition to the effects of the endoscopes of the first and second embodiments, it is not necessary to provide a large number of adhesive holes on the outer peripheral surface of the lens tube. Can be easily processed, and the cost can be reduced in the manufacturing process.

Fourth Embodiment FIG. 5 is an external view (partially cut away) of the right lens tube of the stereoscopic endoscope according to the present embodiment. In this embodiment,
A feature is that a protrusion 21 is provided on the inner surface of the right lens tube 4a toward the inner diameter direction of the lens tube by press working or the like. Then, in the right lens tube 4a,
The same spacers and relay lenses 10 (not shown) as those shown in the first embodiment are inserted. At this time, since the lens is pushed into the right lens tube 4a against the projection 21, the lens is fixed inside the right lens tube 4a by the elastic force generated between the projection 21 and the lens. Therefore, the lens fixing method of the present embodiment does not require an adhesive agent for fixing the lens, as compared with the methods shown in the above-mentioned respective embodiments, so that the manufacturing process can be shortened and the cost can be further reduced.

Fifth Embodiment FIG. 6 is an external view (partially cut away) of the right lens tube of the stereoscopic endoscope according to the present embodiment. In this embodiment,
A long protrusion 2 extending in the optical axis direction on the inner surface of the right lens tube 4a.
2 is provided, and this point is different in configuration from the right lens tube shown in each of the above embodiments. When a spacer (not shown) and the relay lens 10 similar to those shown in the first embodiment are inserted into the right lens tube 4a, the lens is pushed against the long protrusion 22 and the long protrusion is formed. The lens is fixed inside the right lens tube 4a by the elastic force generated between the portion 22 and the lens. Therefore, also by the lens fixing method of this embodiment, it is possible to obtain the same effects as those of the fourth embodiment.

Sixth Embodiment FIG. 7 is an external view (partially cut away) of the right lens tube of the stereoscopic endoscope according to this embodiment. In this embodiment,
A metal is vapor-deposited on the outer peripheral surfaces of the relay lens 10 and the objective lens 14 which are inserted into the right lens tube 4a.
And a solder layer 24 is further provided on the vapor deposition surface 23. At this time, the metal deposited on the outer peripheral surface of each lens may be chromium, nickel, or the like. And
After inserting each lens provided with the solder layer 24 and the spacer (not shown) shown in the first embodiment into the right lens tube 4a, heat is applied from the outer peripheral surface of the right lens tube 4a to melt the solder layer 24. After that, when the solder layer 24 is cured, the vapor deposition surface 23 and the inner surface of the right lens tube 4a can be bonded, and each lens can be fixed to the inner surface of the right lens tube 4a. It is also possible to provide a concave portion on the outer peripheral surface of each lens and set the vapor deposition surface 23 there.

Therefore, in the lens fixing method of this embodiment, it is not necessary to provide an adhesive hole in the right lens tube 4a as compared with the method shown in the first and second embodiments, and the number of parts required for that is reduced. can do. Also,
Since each lens can be fixed to the inner surface thereof only by heating the outer peripheral surface of the right lens tube 4a, the manufacturing process can be simplified and the cost can be reduced.

Seventh Embodiment FIG. 8 is an external view of a relay lens used in this embodiment. As shown in the figure, the relay lens 10 is provided with a concave portion 25 on the entire outer peripheral surface thereof, and further, a solder portion 26 is provided in the concave portion 25. Then, as shown in FIG. 9, the relay lens 10 is inserted into the right lens tube 4a together with the spacer 11 and further heated from the outer peripheral surface of the right lens tube 4a in a standing state. Melts, spreads downward in the figure, and then hardens to the right lens tube 4
It is fixed to the inner surface of a. After the solder portion 26 is hardened, there is no clearance between the recess 25 and the solder portion 26, so that the relay lens 10 is fixed to the right lens tube 4a in the vertical direction in the figure. Although only the configuration of the relay lens is shown in the present embodiment, it goes without saying that the objective lens is also configured in the same manner. Therefore, according to the lens fixing method of the present embodiment,
Compared with the method shown in the sixth embodiment, the step of depositing metal on the outer circumference of the relay lens can be omitted, so that the cost can be further reduced.

Eighth Embodiment FIG. 10 is an external view (partially notched) of the right lens tube of the stereoscopic endoscope according to the present embodiment in a heated state.
FIG. 11 is an external view (partially cut away) of the right lens tube shown in FIG. 10 at room temperature. The inner diameter of the right lens tube 4a of this embodiment is smaller than the outer diameter of the relay lens 10, the objective lens 14 and the like inserted therein, and when the right lens tube 4a is heated, the inner diameter is expanded due to its expansion. Spread, and a gap 27 is formed as shown in FIG. With this gap 27,
When the respective lenses and the like are inserted into the right lens tube 4a and then the right lens tube 4a is cooled, the inner diameter of the right lens tube 4a returns to the original state and the inserted lenses are replaced with each other, as shown in FIG. Tighten and fix. Therefore, according to the lens fixing method of the present embodiment, as compared with the method shown in the seventh embodiment, it is not necessary to provide a concave portion on the outer peripheral surface of each lens, so that the cost can be further reduced.

As described above, each of the lenses inserted in the left and right lens tubes can be fixed inside the lens tube without difficulty even if the method shown in any of the above embodiments is used, and the endoscope insertion part is protected from impact or the like. Even if an external force is applied, the fixed position of the lens is not displaced. Incidentally, the stereoscopic endoscope according to the present invention is not limited to the method shown in each of the above-mentioned embodiments, and as long as the inner surface of the lens tube and the lens inserted therein can be fixed at a predetermined position, The effects shown in each example can be obtained.

[0027]

As described above, in the stereoscopic endoscope according to the present invention, the positional relationship between the lens systems inserted in the left and right lens tubes in the endoscope insertion portion depends on external force such as impact. Since it is not affected and is always invariable, the image displayed on the monitor does not shift, and good stereoscopic observation is always possible. By providing the above, it has a practical advantage that it is lightweight and easy to hold.

[Brief description of drawings]

FIG. 1 is a sectional view of a right lens tube of a stereoscopic endoscope according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the configuration of a stereoscopic endoscope according to a second embodiment of the present invention.

FIG. 3 is an external view of a right lens tube of the stereoscopic endoscope according to the second embodiment of the present invention.

FIG. 4 is an external view of the right lens tube of the stereoscopic endoscope according to the third embodiment of the present invention.

FIG. 5 is an external view of a right lens tube of the stereoscopic endoscope according to the fourth embodiment of the present invention.

FIG. 6 is an external view of a right lens tube of a stereoscopic endoscope according to a fifth embodiment of the present invention.

FIG. 7 is an external view of the right lens tube of the stereoscopic endoscope according to the sixth embodiment of the present invention.

FIG. 8 is an external view of a relay lens used in a stereoscopic endoscope according to a seventh embodiment of the present invention.

FIG. 9 is a sectional view showing the configuration of the right lens tube of the stereoscopic endoscope according to the seventh embodiment of the present invention.

FIG. 10 is an external view of the right lens tube of the stereoscopic endoscope according to the eighth embodiment of the present invention in a heated state.

11 is an external view of the right lens tube shown in FIG. 10 at room temperature.

FIG. 12 is a cross-sectional view showing a configuration of a conventional stereoscopic endoscope.

FIG. 13 is a cross-sectional view showing the configuration of the right lens tube of the conventional stereoscopic endoscope.

FIG. 14 is an explanatory diagram when the lens inside the right lens tube shown in FIG. 13 is in a tilted state.

FIG. 15 is an explanatory diagram of an observation image of a stereoscopic endoscope displayed on a monitor, (a) showing a normal state,
(B) is a figure showing a state where stereoscopic vision is impossible.

[Explanation of symbols]

 1 Stereoscopic endoscope 2 Endoscope insertion part 3 Endoscope body part 4a Right lens tube 4b Left lens tube 5 Light guide 6a Right eyepiece part 6b Left eyepiece part 7 Lens stopper 8 Prism 9 Adhesive 10 Relay lens 11 Spacer 12, 13, 14 Objective lens 15 Adhesion hole 16 Monitor 17a, 17b Observation image 18a Right inner tube 18b Left inner tube 19 Lightening hole 20a, 20b, 20c Adhesion hole row 21 Protrusion 22 Long protrusion 23 Deposition surface 24 Solder layer 25 concave portion 26 solder portion 27 gap

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 28, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

Claims (1)

[Claims] 1. A stereoscopic endoscope having a lens tube in which a lens as an observation optical system is inserted inside an insertion portion, wherein the lens as the observation optical system is fixed at a predetermined position inside the lens tube. A stereoscopic endoscope characterized in that