JPH02250017A - Cooling attachment device for video endoscope - Google Patents

Abstract

PURPOSE:To use the cooling attachment device in high temperature environment while the tip part of an insertion part is cooled and to eliminate the dark current of a solid-state image pickup element and improve the S/N ratio by forming an insertion hole wherein the tip part side of the insertion part is inserted, providing a cooling part which cools the tip side of the insertion part on the outer peripheral side of the insertion hole, and then providing a heat insulation part which cuts off heat from the use environment on the outer peripheral side of the cooling part. CONSTITUTION:An electron endoscope 2 is equipped with the thin and long flexible insertion part 3 and a large diameter operation part 4 is coupled successively with the rear end part of the insertion part 3; and a universal code 6 is extended from the side part of this operation part 4 and a light source and a signal connector 7 which are connected to a controller 9 are provided atop the cord. In this case, the cooling attachment device 15 which covers the tip part 13 of the insertion part of the video endoscope 2 is fitted detachably to the tip part 13. Consequently, while the insertion part tip part is cooled, the device can be used in high temperature environment, the dark current of the solid-state image pickup element is eliminated, and the S/N ratio is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a cooling attachment device for a video endoscope that enables observation in a high temperature environment.

[Prior Art and Problems to be Solved by the Invention] Conventionally, the industrial internal IC method has been used to observe the inside of equipment such as the inside of a jet engine, the inside of a boiler, and the inside of a nuclear reactor. Most of these endoscopes are equipped with an objective optical system at the distal end of the elongated insertion section, and the formed optical image is transmitted to the rear and proximal side using an optical fiber inside the insertion section, and is transmitted several meters or tens of meters away. A fiber-optic system is used in which observation is performed through the rear eyepiece.

By the way, in recent years, instead of fiber endoscopes, COD has been installed at the imaging position of the objective optical system (layer image optical system) at the distal end of the insertion section.
A solid-state imaging device such as the above is installed, and the formed optical image is photoelectrically converted into an imaging signal, transmitted inside the insertion tube to the rear proximal side, and sent from the rear proximal operation unit to a monitor via a separate video processor for display. Video endoscopes are being used in a wide range of fields.

However, the solid-state image sensor placed at the tip of this video endoscope generates heat from the end of the illumination light guide located at the tip, heat from the surrounding environment, and even heat from the solid-state image sensor itself. You'll have a fever, and you'll have a lot of fever. When this video endoscope is used in a high-temperature environment such as inside a jet engine, the output signal of the solid-state image sensor is Another problem is that the dark current becomes considerably large and the S/N ratio deteriorates.

Therefore, in order to prevent the phenomenon of temperature rise of the solid-state image sensor in the distal end even when the video endoscope is used in a high-temperature environment as described above, the present applicant has proposed the method described in Japanese Patent Laid-Open No. 60-72528. A cooling device using a Vertier element as described in JP-A-60-73612, a cooling vibrator installed in a zigzag pattern on the back side of a solid-state image element chip, or a method described in JP-A-6072526. As shown in the figure, the tip of the air supply tube extending from the hand control unit side into the insertion section is exposed around the solid-state image sensor inside the tip, and an air pump is used to circulate cooling air around the solid-state image sensor to cool it. etc. are proposed.

However, in all of the above-mentioned prior art examples, a Vertier element is provided at the distal end of the video endoscope, or a coolant circulation path is provided from the operating section to the distal end of the insertion section, so that the insertion section or the distal end is Another problem arises that the diameter is large and complicated.

The present invention has been made in view of these circumstances, and does not require adding a configuration to the video endoscope itself for cooling the inside of the distal end in which the solid-state image pickup device is incorporated, and therefore does not make the configuration complicated. , it is possible to use the tip of the insertion tube in a cooled state in a high-temperature environment without increasing the diameter of the insertion tube or the tip, and as a result, the dark current of the solid-state image is eliminated and the S/N ratio is improved. Video that made it possible to do well
The object of the present invention is to provide a cooling attachment device for an endoscope.

[Means for Solving the Problems and Their Effects] In order to achieve the above-mentioned object, the present invention provides a video endoscope with a video endoscope having a video endoscope having a video endoscope having a video endoscope, which is capable of being attached to and detached from the distal end of the insertion section so as to surround the distal end of the insertion section in which the solid-state imaging device is disposed. It has an insertion hole into which the distal end of the insertion section is inserted, and a cooling section for cooling the distal end of the insertion section is provided on the outer periphery of the insertion hole, and the cooling section is used on the outer periphery of the cooling section. A heat insulating section is provided to block heat from the environment.

With this configuration, the attachment device can be attached to the distal end of the insertion tube of the video endoscope as needed, and when it is attached, the heat of the operating environment such as a boiler is blocked by the heat insulating section, and the attachment device is not attached to the distal end of the insertion tube. In addition, the distal end of the insertion portion is cooled by the cooling section.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 5 relate to the first embodiment of the device of the present invention,
Fig. 1 is an explanatory view showing the overall configuration, Fig. 2 is a perspective view showing the distal end of the insertion section of the video endoscope shown in Fig. 1 inserted into the cooling attachment device, and Fig. 3 is an explanatory view. 2 is an enlarged longitudinal sectional view of FIG. 2, FIG. 4 is a sectional view taken along the line IV-mV of FIG. 3, and FIG. 5 is an explanatory view showing injection of cryogen immediately before use of the cooling attachment device.

As shown in FIG. 1, the endoscope device 1 includes a video
, a control device 9 that includes a built-in light source unit that supplies illumination light to the video endoscope 2 and processes image signals sent from the video endoscope 2; It is equipped with a monitor television 10 that displays the signal on the screen.

The electronic endoscope 2 includes an elongated and flexible insertion section 3,
A large-diameter operating section 4 is connected to the rear end of the insertion section 3 . A universal cord 6 is inserted from the side of this operation unit 4.
A light source and a signal connector 7 connected to the control device 9 are provided at the tip of the universal cord 6 .

The insertion section 3 includes a long flexible tube section 11 and the flexible tube section 1.
A curved portion 12 that can be bent in the vertical/horizontal direction is provided at the tip of the curved portion 1, and a tip portion 1 is connected to the tip of the curved portion 12.
3.

The bending section 12 can be bent in the vertical/horizontal direction by rotating a bending operation knob 14 provided on the operation section 4.

The distal end portion 13 is provided with an observation window and an illumination window. An objective lens system is provided inside the observation window,
A solid-state imaging device such as a COD is disposed at the imaging position of this objective lens system. The output signal of this solid-state image sensor is
The signal is processed by the control device 9, and the control device 9
A video signal output from the camera is input to a monitor television 10, and a subject image is displayed on this monitor 10. Further, a light distribution lens is provided inside the illumination window. A light guide is connected to the rear end of this light distribution lens. This light guide is inserted into the insertion section 3.
It is inserted through the operation part 4 and the universal cord 6,
It is connected to the control device 9 via a connector 7.

The video endoscope 2 does not have a built-in function to forcibly cool the distal end portion 13 of the insertion portion in which the solid-state imaging device is disposed, and is normally used in a normal temperature environment. A cooling attachment device 15 is detachably attached to the insertion section distal end 13 of the video endoscope 2 so as to wrap around and surround the distal end 13. The cooling attachment device 15 includes a cylindrical exterior casing 17 made of a material that does not corrode, such as metal or synthetic resin, and has an endoscope tip exposure hole 16 at the center of the front end with an open rear end, and an exterior casing 19. and a heat conduction layer 18 disposed on the entire inner surface of the outer casing 17, and a heat conduction layer 18 disposed axially backward from the endoscope tip exposure hole 16 of the outer casing 17 and in contact with the insertion portion distal end 13 inserted therein. A heat exchange sleeve 19 as an insertion hole formed of ceramics, metal, etc. with good properties, and a cryogen 21 as a coolant filled in a space 20 formed between the heat insulation W118 and the heat exchange sleeve 19; A rear lid body 2 having a heat insulating layer 22 on an inner surface that is fixed to the rear end opening 17a of the exterior casing 17 by a fixing means such as a screwing means and closed.
It is composed of 3.

The plugging material 21 is a coolant that achieves a low temperature by mixing two or more substances, and its composition (weight percentage) and lowest temperature reached are illustrated in Tables 1 and 2.

(Leaves below) Table 1 With this configuration, there is a heat insulating layer 18 on the outer layer side of the cooling attachment device 15, which blocks heat transmitted through the exterior casing 17 from the surrounding environment, and this heat insulating layer 1
The inner space 20 of 8 is filled with a cryogen 21, and this cryogen 21 absorbs surrounding heat due to its endothermic action due to chemical reactions or the like. The inner surface of the space 20 filled with the cryogen 21 is a heat exchange sleeve 19 made of a material with good thermal conductivity. The heat at the end and the heat of the solid-state imaging device itself are conducted to the cold agent 21, and the insertion portion distal end 13
It is for cooling. Also, although there is a heat insulating layer 18 on the exterior side, complete heat insulation cannot be expected, so the above-mentioned cryogen 2
1, it also absorbs some of the heat transferred from the surrounding environment. In this manner, the temperatures inside the cooling attachment device 15 and the tip end portion 13 of the insertion portion are balanced to a point where the dark current of the signal output of the solid-state Illll elementary image can be ignored.

In the first embodiment, a cryogen 21 is used as the cooling section. Since this cryogen 21 undergoes a slow reaction and maintains its endothermic effect, it is convenient for cooling video endoscopes used in high-temperature environments. However, after the chemical reaction is completed, the endothermic effect disappears and it cannot be regenerated to cause a chemical reaction, so it can only be used once. For this reason, in the first embodiment, as shown in FIG. 5, the outer casing 17 and the rear container body 23 are separable, so that the cryogen 21 can be refilled.

That is, just before using the video endoscopy vL2 in a high temperature environment, the cryogen 2 is injected into the attachment device 15 by the syringe 24.
Inject 1 and see in the video? It is used by inserting the tip 13 of the insertion part of the mirror 2, and after use, the cryogen 21 that has completed the endothermic reaction can be discarded, so it can be used as many times as you like by refilling the cryogen 21. can do.

FIG. 6 is a sectional view showing a second embodiment of the present invention.

In this embodiment, the outer casing 17, the heat insulating layer 18, and the rear lid 23 are the same as those in the first embodiment, but the endoscope tip insertion hole is formed by spirally winding a vibrator 25 instead of a sleeve. Then, insert the tip end 1 of the insertion part in contact with this inner periphery of the spiral.
3 is inserted and installed. The helical vibrator 25 is eccentrically arranged in the casing 17 in the axial direction. - side, partition plate 2 inside the casing 17 on the anti-eccentric side.
A coolant tank 27 filled with liquid nitrogen, for example, is disposed through the tank 6, and the base side of the vibrator 25 is connected to the tank 2.
It is detachably connected to the spout 27a of No.7. Further, a vaporizer 28 is connected to the tip side of the spiral vibe 25,
The heat insulating layer 18 and the outer casing 17 of this carburetor 28 part
Vaporization holes 29 are formed in the.

In such a configuration, by opening the valve, liquid nitrogen is filled from the tank 27 into the spiral vibrator 25, and this liquid nitrogen is vaporized by the vaporizer 29 and discharged to the outside through the vaporization hole 29. The spiral vibrator 25 forming the insertion hole is rapidly cooled by the heat of vaporization, and accordingly, the distal end portion 13 of the video endoscope 2 inserted and attached in contact with the inner periphery is also cooled. The vaporizer 29 may be formed of a filter with fine meshes laminated in multiple layers, or may be of a mechanical valve type. Furthermore, tank 27
When the liquid nitrogen in the tank is used up, replace the entire tank or refill the tank with liquid nitrogen.
Can be used as many times as you like.

In each of the above embodiments of the present invention, a heat insulating material or a vacuum layer may be used as the heat insulating layer. Further, in the first embodiment, a chemical reaction-based refrigerant was used as the refrigerant, but any refrigerant may be used as long as it has an endothermic action.

[Effects of the Invention] As explained above, according to the present invention, there is no need to add a configuration to the video 1A mirror itself for cooling the inside of the tip portion in which the solid-state image pickup device is incorporated, and therefore the configuration is complicated. It is possible to use the tip of the insertion tube in a cooled state in a high-temperature environment without increasing the diameter of the insertion tube or the tip, and as a result, the dark current of the solid-state R pixel element is eliminated and the S
This has the effect of improving the /N ratio.

[Brief explanation of drawings]

1 to 5 relate to the first embodiment of the device of the present invention,
Figure 1 is a clear view showing the overall configuration, Figure 2 is a perspective view showing the distal end of the insertion section of the video endoscope shown in Figure 1 inserted into the cooling attachment device, and Figure 3 is the 4 is a sectional view taken along the rV-rV line in FIG. 3, FIG. 5 is an explanatory diagram showing the injection of cryogen immediately before using the cooling attachment device, and FIG. 6 is a diagram showing the second embodiment. FIG. 1... Endoscope @ 13... Insertion section tip 1
5... Cooling attachment device 17... Exterior casing 18... Heat insulation layer 19.
・・Heat exchange sleeve 21・Cryogen 25・Spiral pipe procedure manual (spontaneous)

Claims (1)

[Claims] It can be detachably attached to the insertion portion distal end portion of the video endoscope so as to surround the insertion portion distal end portion in which the solid-state imaging device is disposed, and has an insertion hole into which the insertion portion distal end side is inserted;
A cooling unit for a video endoscope is provided on the outer periphery of the insertion hole for cooling the distal end of the insertion section, and a heat insulating section for blocking heat from the usage environment is provided on the outer periphery of the cooling unit. Attachment device.