JPH0545534U - Infrared detector - Google Patents

Abstract

(57) [Abstract] [Purpose] An infrared detector with excellent reliability is obtained by preventing electrolytic corrosion of the compressor and by preventing damage to the connecting pipe attachment portion due to rocking vibration. [Composition] The compressor 5 is placed in a recess of a compressor mounting plate 7 having a radiation fin for an infrared detector.
Is attached and positioned in the chassis 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an infrared detection device for generating a thermal image, for example, by capturing infrared rays emitted from an object with an infrared detection element cooled to an extremely low temperature.

[0002]

[Prior Art]

 3 is a perspective view showing a conventional infrared detecting device, FIG. 4 is a side sectional view of FIG. 3, and FIG. 5 is a view showing a deformation of a compressor mounting plate due to rocking vibration. In FIG. 4, 1 is a lens unit, 2 is a cylindrical dewar that is arranged on the same axis as the lens unit 1 and has an infrared detecting element 3 inside, and 4 is the front surface of the mating surface with the lens unit 1. A chassis having a partition for mounting the dewar 2 on its bottom surface, 5 is a compressor for cooling the dewar 2, 6 is a connecting pipe for supplying the refrigerant from the compressor 5 to the dewar 2, and 7 is a chassis for attaching the compressor 5 to the chassis. 4 is a compressor mounting plate arranged so as to be fixed to the rear surface of the cold plate 4, 8 is a cold finger arranged on the opposite surface of the infrared detecting element 3 of the dewar 2, and 9 is one of which is fitted to the cylindrical surface of the cold finger 8. The other side is a heat conduction block that engages with the bottom surface of the chassis 4, 10 is a fan for cooling the compressor 5, 11 is a fan 10 and A cover arranged so as to enclose the presser mounting plate 7, 12 is cooling air, 15 is the first heat conducting grease applied to the mating portion of the cold fingers 8 and the heat conducting block 9, and 16 is the heat conducting block 9 and the chassis 4. 2 shows the second heat conductive grease applied to the engaging portion of FIG. The cylindrical surface of the cold finger 8 and the mating part of the heat conduction block 9 have a clearance of about 0.3 mm, and even if the chassis 4 and the cold finger 8 behave differently when vibration is applied, they interfere with each other. Consideration is given to avoid conflict. The interior of the lens unit 1 and the chassis 4 is a closed room as a measure against condensation and dust.

Next, the operation will be described. The compressor 5 and the cold finger 8 are connected by a connecting pipe 6, and a high-pressure gas such as helium or argon is enclosed in the inside of the connecting pipe 6. When the piston moves inside the compressor 5 and high-pressure gas is repeatedly compressed, the high-pressure gas moves through the connecting pipe 6, and the pressure fluctuation moves the displacer in the cold finger 8 to move the tip of the cold finger 8 to the adiabatic expansion of the displacer. It cools to an extremely low temperature by the endothermic action. The infrared detecting element 3 mounted inside the dewar 2 having a vacuum inside is also cooled to an extremely low temperature. At this time, the infrared rays that have passed through the lens unit 1 form an image on the infrared detection element 3 and an image signal is sent. Further, the heat of the cold finger 8 portion is transmitted from the first heat conducting grease 15 through the heat conducting block 9 and the second heat conducting grease 16 to the chassis 4 without impairing the cooling performance of the device. It is like this.

[0004]

[Problems to be solved by the device]

 The conventional infrared detection device is configured as described above and has the following problems. First, the cooling air 12 of the fan 10 arranged in the cover 11 was directly blown to the compressor 5 exposed to the outside air to release the heat generation of the compressor 5. Therefore, there is a problem that the compressor 5, which uses dissimilar metals for its respective components, is exposed to the cooling air 12 containing a lot of humidity and salt, and there is a high possibility that electrolytic corrosion will occur at its joint. Further, since the compressor 5 has a large mass, it is fixed to the flat plate-shaped compressor mounting plate 7 only on one surface, so that when the vibration 13 in the vertical direction is applied, the rocking vibration 14 is generated due to the deformation of the plate 7. However, there is a problem that a large stress is generated in the connecting pipe 6 and the connecting pipe 6 is damaged. Further, since the clearance between the heat conduction block 9 and the cold finger 8 provided for absorbing the vibration is large, the heat dissipation efficiency is poor, which is also a subject to be improved.

The present invention has been made in order to solve the above-mentioned problems, and by preventing electrolytic corrosion of the compressor and improving vibration resistance of the connecting pipe portion, it is possible to detect infrared rays with excellent reliability. The purpose is to get the device.

[0006]

[Means for Solving the Problems]

 The infrared detector according to the present invention is such that the compressor is mounted in the chassis which is sealed from the outside, and the compressor mounting plate having high rigidity is mounted on its two surfaces.

[0007]

[Action]

 The infrared detector according to the present invention is located in the chassis in which the compressor is sealed and does not come into contact with the cooling air containing a lot of moisture and salty water, so that the occurrence of electrolytic corrosion can be prevented. In addition, the compressor mounting plate has high rigidity due to the heat dissipating fins provided on itself, and the rigidity after mounting the compressor is dramatically improved by mounting the compressor on two sides in the recess. To do. Therefore, rocking vibration does not occur at the compressor mounting portion, the stress generated in the connecting pipe becomes small, and the vibration resistance of the connecting pipe can be improved.

[0008]

【Example】

 Example 1. FIG. 1 is a sectional view showing an embodiment of an infrared detecting device according to the present invention, in which 1 to 6, 8 and 10 to 16 are exactly the same as the conventional device. In FIG. 1, reference numeral 7 denotes a compressor mounting plate which has a concave portion for mounting the compressor 5 on one surface thereof and a heat radiation fin on the other surface thereof and is arranged so as to be fixed to the rear surface of the chassis 4. Two sides of the compressor 5 are fixed in the recesses of the compressor mounting plate 7. Further, since the compressor 5 is mounted in the recess of the compressor mounting plate, it is positioned inside the chassis 4 by being sealed from the outside. Reference numeral 9 is a heat transfer block, which has a slight clearance so that it can slide in the axial direction to the cold finger 8 and is engaged through a heat transfer grease 15. The other end of the heat conduction block 9 is pressed against the compressor mounting plate 7 by a washer-shaped leaf spring 17 via a heat conduction grease 16.

In the infrared detection device configured as described above, the compressor 5 is located inside the closed chassis 4 and does not come into contact with the cooling air 12 containing a lot of moisture and salty water, so that electrolytic corrosion is generated. Can be prevented. In addition, the compressor mounting plate 7 has high rigidity due to the heat radiation fins provided on itself, and the rigidity after mounting the compressor is dramatically improved by mounting the compressor 5 on two sides in the recess. As a result, the rocking vibration 14 is not generated in the compressor 5 mounting portion, the stress generated in the connecting pipe 6 becomes small, and the vibration resistance of the connecting pipe 6 can be improved. Moreover, since the washer-shaped plate spring 17 also has a function of absorbing vibration, the conventional clearance between the cold finger 8 and the heat conduction block 9 is almost unnecessary, and the heat generated by the cold finger 8 is radiated. The heat dissipation efficiency can be improved by letting it escape to the compressor mounting plate 7, which has good properties.

[0010]

[Effect of the device]

 As described above, according to the infrared detector of the present invention, the infrared detecting device of the present invention can prevent the damage of the connecting pipe mounting portion due to the rocking vibration and prevent the electrolytic corrosion of the compressor due to the cooling air containing a lot of humidity and salty water. There is. Further, the reliability of the device is improved due to the improved heat dissipation efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view showing an infrared detection device according to an embodiment of the present invention.

FIG. 2 is a view showing a washer-shaped leaf spring according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a conventional infrared detection device.

FIG. 4 is a side sectional view of FIG.

FIG. 5 is a diagram showing deformation of a plate due to rocking vibration.

[Explanation of symbols]

 1 Lens Unit 2 Dewar 3 Infrared Detector 4 Chassis 5 Compressor 6 Connecting Pipe 7 Compressor Mounting Plate 8 Cold Finger 9 Heat Conduction Block 10 Fan 11 Cover 12 Cooling Air 13 Vertical Vibration 14 Rocking Vibration 15 First Heat Conductive Grease 16 Second thermal conductive grease 17 Washer-shaped leaf spring

Claims (1)

[Scope of utility model registration request] 1. A lens unit, a cylindrical dewar arranged on the same axis as the lens unit and having an infrared detecting element therein, and a mating surface for the lens unit on the front surface thereof. A chassis having a partition for mounting the dewar on the bottom surface, a compressor for cooling the dewar, a connecting pipe for supplying the refrigerant from the compressor to the dewar, and a recess for mounting the compressor on one surface thereof, The other side has a radiator fin, the compressor mounting plate arranged to be fixed to the rear side of the chassis, the cold finger arranged on the opposite side of the dewar infrared detection element, and one of them is the cold side. A heat transfer block that engages the cylindrical surface of the fingers and joins the other to the compressor mounting plate. A washer-shaped leaf spring disposed between the cold finger and the heat conduction block, a first heat conduction grease applied to a mating portion of the cold finger and the heat conduction block, and the heat conduction. A second heat conductive grease applied to the joint between the block and the compressor mounting plate, a fan for cooling the compressor, and a cover arranged so as to enclose the fan and the heat radiation fins of the compressor mounting plate. Infrared detector characterized by.