JPH02278219A - Cooling device of video endoscope - Google Patents

Abstract

PURPOSE:To eliminate a dark current of a solid-state image pickup element and to make an S/N satisfactory by providing a pump for feeding out a fluid for cooling the solid-state image pickup element in an endoscope. CONSTITUTION:A bimorph piezoelectric pump 22 for feeding out a cooling fluid to a solid-state image pickup element 16 provided in a tip part 11 of an inserting part is provided in the inserting part. the bimorph piezoelectric pump 22 can be formed in a very small size, and accordingly, can be provided in a free space in the tip part 11 of the inserting part, and can be used under a high temperature environment in a state that the tip part 11 of the inserting part is cooled, without forming the diameter of the tip part 11 of the inserting part to a large diameter. In such a way, a dark current of the solid-state image pickup element 16 is eliminated and an S/N can be made satisfactory.

Description

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

[Prior Art and Problems to be Solved by the Invention] Conventionally, industrial endoscopes have been widely 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 rearward to the proximal side using an optical fiber inside the insertion section, and is transmitted over several meters or tens of meters.
A fiber-optic system is used in which the vA is detected at a rear eyepiece that is far away.

By the way, in recent years, instead of fiber endoscopes, COD is installed at the imaging position of the objective optical system (image carrying 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 is susceptible to heat generation at 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. fever and become quite feverish. 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 single-temperature phenomenon 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 a method in Japanese Patent Application Laid-Open No. 60-72528. A cooling method using a Peltier element as described in JP-A No. 60-73612, a method in which a cold N1 vibe is placed in a zigzag pattern on the back of a solid-state image sensor chip, or a method described in JP-A No. 6072526. As shown, the tip of the air supply tube extending from the hand control unit side into the insertion section is exposed around the solid-state Ill element in the tip, and an air pump is used to circulate cooling air to the solid-state image sensor to cool it. I am proposing things etc.

By the way, as mentioned above, most industrial endoscopes have long insertion sections of several millimeters or tens of meters, so as in the prior art example, a pump for delivering fluid to cool the solid-state image element is required. If the pump is provided outside the endoscope, there are disadvantages in that the pump becomes larger and requires a connecting tube to the pump, making it more complicated.

The present invention has been made in view of these circumstances, and includes providing a pump within an endoscope for delivering fluid for cooling a solid-state image sensor, making the pump smaller and having a simpler configuration.
It can be used in high-temperature environments with the tip of the insertion tube cooled without increasing the diameter of the insertion tube, and as a result, the dark current of the solid-state image sensor can be eliminated and the S/N ratio can be improved. The purpose of this invention is to provide a cooling device for a video endoscope.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, the present invention provides a bimorph piezoelectric pump within the insertion section that delivers a cooling fluid to the solid image carrier disposed within the distal end of the insertion section. .

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

1 to 4 relate to a cooling device for a video endoscope of the present invention, in which FIG. 1 is an explanatory diagram showing the overall configuration and an enlarged sectional view of main parts, FIG. 2 is a schematic explanatory diagram, and FIG. 3 is a bimorph FIG. 4 is an explanatory diagram of another example of a bimorph piezoelectric pump.

As shown in FIG. 1, an endoscope device 1 includes a video endoscope 2.
, a control device 3 that has a light source unit that supplies illumination light to the video endoscope 2, integrally or separately, and processes image signals sent from the video endoscope 2; and this control device 3. The monitor includes a television monitor 4 that displays the video signal output from the monitor on the screen.

The video endoscope 2 includes an elongated and flexible insertion section 5, and a large-diameter operation section 6 is connected to the rear end of the insertion section 5. A universal cord 7 extends from the side of the operating section 6, and a light source and signal connector 8 connected to the control device 3 is provided at the tip of the universal cord 7.

The insertion section 5 includes a long flexible tube section 9, a bending section 10 connected to the distal end of the flexible tube section 9 and capable of bending in the vertical/left direction, and a bending section 10 at the distal end of the bending section 10. Continuous tip portion 11
It is equipped with

The bending section 10 can be bent vertically/horizontally by rotating a bending operation knob 12 provided on the operation section 6.

The distal end portion 11 is provided with an observation window 13 and an illumination window 14. An objective lens system 15 is provided inside the observation window 13, and at the imaging position of this objective lens system 15,
A solid-state image sensor 16 such as a COD is provided. The output signal of the solid-state image sensor 16 is processed by the control device 3, and the video signal output from the control device 3 is input to the monitor television 4, so that the subject image is displayed on the monitor 4. It has become. Further, the lighting window 1
A light distribution lens 17 is provided inside the lens 4 . A light guide 18 is connected to the rear end of the light distribution lens 17. The light guide 18 is inserted through the insertion section 5, the operating section 6, and the Uniper cable 7, and is connected to the control device 3 via the connector 8.

The video endoscope 1t2 has a built-in function for forcibly cooling the inside of the insertion portion distal end portion 11 in which the solid-state image sensor 16 is disposed. That is, a cooling air supply tube 19 is extended from the control device 3 through the universal cord 7 and the operating section 6 into the insertion section 5, and the tube 19 inside the insertion section 5 is further inserted into the distal end section 11. The discharge port 20 is extended to face the back side of the solid-state image sensor 16, and the diameter of the tube near the discharge port 20 is expanded, and a bimorph piezoelectric pump 22 is disposed in the enlarged diameter portion 21. Bimorph piezoelectric pump 22
By the operation of , cooling air is sucked in from the outside and blown through the tube 19 to the vicinity 16 of the solid image carrier to cool the solid image carrier 16 or the inside of the insertion portion distal end 11. The cooling exhaust air that is discharged into the distal end portion 11 of the insertion portion via the insertion portion 19 and cools the inside of the distal end portion 11 is sent to the operating portion 6 through the gap formed within the insertion portion 5. The air is discharged to the outside from an air exhaust port (not shown), or an air exhaust tube is inserted into the insertion portion 5 and the air is exhausted to the outside through this duplex.

As shown in FIG. 3, the bimorph piezoelectric pump 22 used for blowing the cooling air includes a pair of bimorph piezoelectric element plates 2.
3 is supported and fixed to the support member 24, and the other end is used as a free end to increase the vibration amplitude by applying a current to form a blower pump (fan).As shown in FIG. Current can be supplied from the drive power source 26 via the supply line 23. This bimorph piezoelectric pump 22 is also constructed as shown in FIG. In the modification shown in FIG. 4, the free end sides of a pair of bimorph piezoelectric element plates 23 are shortened, and a diaphragm 25 made of resin or the like and lightweight and having a large vibration amplitude is connected to the short free end side. . According to this, the amplitude can be made larger than that of the piezoelectric pump 22 shown in FIG.

The bimorph piezoelectric pump 22 can be formed into a very small size, and therefore can be disposed in a free space within the insertion section distal end 11, and the diameter of the insertion section distal end 11 can be increased. do not have.

Note that this bimorph piezoelectric pump 22 may be arranged in the rear exchangeable tube section 9 instead of the tip section 11, and this piezoelectric pump 22 may be arranged not only in one piece but also in plural pieces in parallel or in series. It may also be attached.

5 and 6 relate to a second embodiment of the present invention, FIG. 5 is a schematic explanatory diagram showing the whole, and FIG. 6 is an explanatory diagram of the main part.

In this embodiment, a diaphragm pump is used as the bimorph piezoelectric pump 28 instead of the fan type in the first embodiment. This bimorph piezoelectric pump 28 is interposed in one tube in a free space within the insertion section 5. This pump 28 has tubes 19 connected to the inflow side and discharge side of the pump main body 29, and a check valve 3.
0 and 31, and a diaphragm 32 made of a bimorph piezoelectric element that performs a pumping action by alternately expanding and contracting the volume inside the pump body 29. In this embodiment, other configurations and effects are the same as in the first embodiment.

FIG. 7 is a sectional view of a main part according to a third embodiment of the present invention.

This embodiment has an orifice 33 on the discharge side of the tube 19.
When the cooling air passes through the orifice 33 near the ejection part, it is thermally engraved and cooled, and this cooled cooling air is blown onto the solid-state image sensor 16. ing. The discharge vibrator 33
A bimorph piezoelectric pump 22 or 28 is interposed at the front stage.

Other configurations and effects are the same as in the first embodiment.

8 and 9 relate to a fourth embodiment of the present invention, FIG. 8 is a schematic explanatory diagram showing the whole, and FIG. 9 is an explanatory diagram of the main part.

The above 1. Second. The third embodiment is a system in which cooling air is supplied into the tip of the insertion section to cool the inside of the tip, but in this embodiment, cooling fluid is circulated to remove heat from the solid image carrier 16 and cool it. This is what we are trying to do. That is, the circulation vibrator 34 moves from the control wJ device m3 to the insertion section 5 and its distal end 11.
A solid ME element 16 is disposed within the tip 11.
The piping is arranged in a meandering manner on the back side of the
The diaphragm type bimorph piezoelectric pump 28 shown in the embodiment is interposed, and a heat exchanger 3 is also installed in the control device 3.
5 is set. The heat exchanger 35 also includes a thermoelectric element for electronic cooling, such as a Bertier element 36 and a radiation fin 3.
7 is provided.

In this configuration, the cooling fluid circulates within the circulation pipe 34 by driving the bimorph piezoelectric pump 28, so that the solid-state image sensor 16 can be effectively cooled.

[Effects of the Invention] As explained above, according to the present invention, a pump for delivering fluid for cooling a solid-state image sensor is provided in an endoscope, and the pump is made small and has a simple configuration, and the insertion portion can be easily removed. It can be used in a high temperature environment with the tip of the insertion tube cooled without increasing the diameter, and as a result, the dark Wl
This has the effect of eliminating the flow and improving the S/N ratio.

[Brief explanation of drawings]

1 to 4 relate to a cooling device for a video endoscope of the present invention, in which FIG. 1 is an explanatory diagram showing the overall configuration and an enlarged sectional view of main parts, FIG. 2 is a schematic explanatory diagram, and FIG. 3 is a bimorph An explanatory diagram of a piezoelectric pump, FIG. 4 is an explanatory diagram of another example of a bimorph piezoelectric pump, FIGS. 5 and 6 relate to a second embodiment of the present invention, and FIG. 5 is a schematic explanatory diagram showing the whole, 6 is an explanatory diagram of the main part, FIG. 7 is a sectional view of the main part according to the third embodiment of the present invention, and FIG.
9 and 9 relate to a fourth embodiment of the present invention, FIG. 8 is a schematic explanatory diagram showing the whole, and FIG. 9 is an explanatory diagram of the main part.

Claims (1)

[Claims] 1. A cooling device for a video endoscope, characterized in that a bimorph piezoelectric pump is provided in the insertion section to send cooling fluid to a solid-state image sensor disposed in the distal end of the insertion section.